text: /*
   * Copyright © 2010-2011 Intel Corporation
   * Copyright © 2008-2011 Kristian Høgsberg
   * Copyright © 2012-2015 Collabora, Ltd.
   *
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sublicense, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * The above copyright notice and this permission notice (including the
   * next paragraph) shall be included in all copies or substantial
   * portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
   * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
   * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  #include "config.h"
  
  #include <fcntl.h>
  #include <stdio.h>
  #include <string.h>
  #include <stdlib.h>
  #include <stdint.h>
  #include <limits.h>
  #include <stdarg.h>
  #include <assert.h>
  #include <sys/ioctl.h>
  #include <sys/mman.h>
  #include <sys/wait.h>
  #include <sys/socket.h>
  #include <sys/utsname.h>
  #include <sys/stat.h>
  #include <unistd.h>
  #include <math.h>
  #include <linux/input.h>
  #include <dlfcn.h>
  #include <signal.h>
  #include <setjmp.h>
  #include <sys/time.h>
  #include <time.h>
  #include <errno.h>
  
  #include "timeline.h"
  
  #include "compositor.h"
  #include "scaler-server-protocol.h"
  #include "presentation-time-server-protocol.h"
  #include "shared/helpers.h"
  #include "shared/os-compatibility.h"
  #include "shared/timespec-util.h"
  #include "git-version.h"
  #include "version.h"
  
  #define DEFAULT_REPAINT_WINDOW 7 /* milliseconds */
  
  static void
  weston_output_transform_scale_init(struct weston_output *output,
  				   uint32_t transform, uint32_t scale);
  
  static void
  weston_compositor_build_view_list(struct weston_compositor *compositor);
  
  static void weston_mode_switch_finish(struct weston_output *output,
  				      int mode_changed,
  				      int scale_changed)
  {
  	struct weston_seat *seat;
  	struct wl_resource *resource;
  	pixman_region32_t old_output_region;
  	int version;
  
  	pixman_region32_init(&old_output_region);
  	pixman_region32_copy(&old_output_region, &output->region);
  
  	/* Update output region and transformation matrix */
  	weston_output_transform_scale_init(output, output->transform, output->current_scale);
  
  	pixman_region32_init(&output->previous_damage);
  	pixman_region32_init_rect(&output->region, output->x, output->y,
  				  output->width, output->height);
  
  	weston_output_update_matrix(output);
  
  	/* If a pointer falls outside the outputs new geometry, move it to its
  	 * lower-right corner */
  	wl_list_for_each(seat, &output->compositor->seat_list, link) {
  		struct weston_pointer *pointer = weston_seat_get_pointer(seat);
  		int32_t x, y;
  
  		if (!pointer)
  			continue;
  
  		x = wl_fixed_to_int(pointer->x);
  		y = wl_fixed_to_int(pointer->y);
  
  		if (!pixman_region32_contains_point(&old_output_region,
  						    x, y, NULL) ||
  		    pixman_region32_contains_point(&output->region,
  						   x, y, NULL))
  			continue;
  
  		if (x >= output->x + output->width)
  			x = output->x + output->width - 1;
  		if (y >= output->y + output->height)
  			y = output->y + output->height - 1;
  
  		pointer->x = wl_fixed_from_int(x);
  		pointer->y = wl_fixed_from_int(y);
  	}
  
  	pixman_region32_fini(&old_output_region);
  
  	if (!mode_changed && !scale_changed)
  		return;
  
  	/* notify clients of the changes */
  	wl_resource_for_each(resource, &output->resource_list) {
  		if (mode_changed) {
  			wl_output_send_mode(resource,
  					    output->current_mode->flags,
  					    output->current_mode->width,
  					    output->current_mode->height,
  					    output->current_mode->refresh);
  		}
  
  		version = wl_resource_get_version(resource);
  		if (version >= WL_OUTPUT_SCALE_SINCE_VERSION && scale_changed)
  			wl_output_send_scale(resource, output->current_scale);
  
  		if (version >= WL_OUTPUT_DONE_SINCE_VERSION)
  			wl_output_send_done(resource);
  	}
  }
  
  WL_EXPORT int
  weston_output_mode_set_native(struct weston_output *output,
  			      struct weston_mode *mode,
  			      int32_t scale)
  {
  	int ret;
  	int mode_changed = 0, scale_changed = 0;
  
  	if (!output->switch_mode)
  		return -1;
  
  	if (!output->original_mode) {
  		mode_changed = 1;
  		ret = output->switch_mode(output, mode);
  		if (ret < 0)
  			return ret;
  		if (output->current_scale != scale) {
  			scale_changed = 1;
  			output->current_scale = scale;
  		}
  	}
  
  	output->native_mode = mode;
  	output->native_scale = scale;
  
  	weston_mode_switch_finish(output, mode_changed, scale_changed);
  
  	return 0;
  }
  
  WL_EXPORT int
  weston_output_mode_switch_to_native(struct weston_output *output)
  {
  	int ret;
  	int mode_changed = 0, scale_changed = 0;
  
  	if (!output->switch_mode)
  		return -1;
  
  	if (!output->original_mode) {
  		weston_log("already in the native mode\n");
  		return -1;
  	}
  	/* the non fullscreen clients haven't seen a mode set since we
  	 * switched into a temporary, so we need to notify them if the
  	 * mode at that time is different from the native mode now.
  	 */
  	mode_changed = (output->original_mode != output->native_mode);
  	scale_changed = (output->original_scale != output->native_scale);
  
  	ret = output->switch_mode(output, output->native_mode);
  	if (ret < 0)
  		return ret;
  
  	output->current_scale = output->native_scale;
  
  	output->original_mode = NULL;
  	output->original_scale = 0;
  
  	weston_mode_switch_finish(output, mode_changed, scale_changed);
  
  	return 0;
  }
  
  WL_EXPORT int
  weston_output_mode_switch_to_temporary(struct weston_output *output,
  				       struct weston_mode *mode,
  				       int32_t scale)
  {
  	int ret;
  
  	if (!output->switch_mode)
  		return -1;
  
  	/* original_mode is the last mode non full screen clients have seen,
  	 * so we shouldn't change it if we already have one set.
  	 */
  	if (!output->original_mode) {
  		output->original_mode = output->native_mode;
  		output->original_scale = output->native_scale;
  	}
  	ret = output->switch_mode(output, mode);
  	if (ret < 0)
  		return ret;
  
  	output->current_scale = scale;
  
  	weston_mode_switch_finish(output, 0, 0);
  
  	return 0;
  }
  
  static void
  child_client_exec(int sockfd, const char *path)
  {
  	int clientfd;
  	char s[32];
  	sigset_t allsigs;
  
  	/* do not give our signal mask to the new process */
  	sigfillset(&allsigs);
  	sigprocmask(SIG_UNBLOCK, &allsigs, NULL);
  
  	/* Launch clients as the user. Do not lauch clients with wrong euid.*/
  	if (seteuid(getuid()) == -1) {
  		weston_log("compositor: failed seteuid\n");
  		return;
  	}
  
  	/* SOCK_CLOEXEC closes both ends, so we dup the fd to get a
  	 * non-CLOEXEC fd to pass through exec. */
  	clientfd = dup(sockfd);
  	if (clientfd == -1) {
  		weston_log("compositor: dup failed: %m\n");
  		return;
  	}
  
  	snprintf(s, sizeof s, "%d", clientfd);
  	setenv("WAYLAND_SOCKET", s, 1);
  
  	if (execl(path, path, NULL) < 0)
  		weston_log("compositor: executing '%s' failed: %m\n",
  			path);
  }
  
  WL_EXPORT struct wl_client *
  weston_client_launch(struct weston_compositor *compositor,
  		     struct weston_process *proc,
  		     const char *path,
  		     weston_process_cleanup_func_t cleanup)
  {
  	int sv[2];
  	pid_t pid;
  	struct wl_client *client;
  
  	weston_log("launching '%s'\n", path);
  
  	if (os_socketpair_cloexec(AF_UNIX, SOCK_STREAM, 0, sv) < 0) {
  		weston_log("weston_client_launch: "
  			"socketpair failed while launching '%s': %m\n",
  			path);
  		return NULL;
  	}
  
  	pid = fork();
  	if (pid == -1) {
  		close(sv[0]);
  		close(sv[1]);
  		weston_log("weston_client_launch: "
  			"fork failed while launching '%s': %m\n", path);
  		return NULL;
  	}
  
  	if (pid == 0) {
  		child_client_exec(sv[1], path);
  		_exit(-1);
  	}
  
  	close(sv[1]);
  
  	client = wl_client_create(compositor->wl_display, sv[0]);
  	if (!client) {
  		close(sv[0]);
  		weston_log("weston_client_launch: "
  			"wl_client_create failed while launching '%s'.\n",
  			path);
  		return NULL;
  	}
  
  	proc->pid = pid;
  	proc->cleanup = cleanup;
  	weston_watch_process(proc);
  
  	return client;
  }
  
  struct process_info {
  	struct weston_process proc;
  	char *path;
  };
  
  static void
  process_handle_sigchld(struct weston_process *process, int status)
  {
  	struct process_info *pinfo =
  		container_of(process, struct process_info, proc);
  
  	/*
  	 * There are no guarantees whether this runs before or after
  	 * the wl_client destructor.
  	 */
  
  	if (WIFEXITED(status)) {
  		weston_log("%s exited with status %d\n", pinfo->path,
  			   WEXITSTATUS(status));
  	} else if (WIFSIGNALED(status)) {
  		weston_log("%s died on signal %d\n", pinfo->path,
  			   WTERMSIG(status));
  	} else {
  		weston_log("%s disappeared\n", pinfo->path);
  	}
  
  	free(pinfo->path);
  	free(pinfo);
  }
  
  WL_EXPORT struct wl_client *
  weston_client_start(struct weston_compositor *compositor, const char *path)
  {
  	struct process_info *pinfo;
  	struct wl_client *client;
  
  	pinfo = zalloc(sizeof *pinfo);
  	if (!pinfo)
  		return NULL;
  
  	pinfo->path = strdup(path);
  	if (!pinfo->path)
  		goto out_free;
  
  	client = weston_client_launch(compositor, &pinfo->proc, path,
  				      process_handle_sigchld);
  	if (!client)
  		goto out_str;
  
  	return client;
  
  out_str:
  	free(pinfo->path);
  
  out_free:
  	free(pinfo);
  
  	return NULL;
  }
  
  static void
  region_init_infinite(pixman_region32_t *region)
  {
  	pixman_region32_init_rect(region, INT32_MIN, INT32_MIN,
  				  UINT32_MAX, UINT32_MAX);
  }
  
  static struct weston_subsurface *
  weston_surface_to_subsurface(struct weston_surface *surface);
  
  WL_EXPORT struct weston_view *
  weston_view_create(struct weston_surface *surface)
  {
  	struct weston_view *view;
  
  	view = zalloc(sizeof *view);
  	if (view == NULL)
  		return NULL;
  
  	view->surface = surface;
  
  	/* Assign to surface */
  	wl_list_insert(&surface->views, &view->surface_link);
  
  	wl_signal_init(&view->destroy_signal);
  	wl_list_init(&view->link);
  	wl_list_init(&view->layer_link.link);
  
  	pixman_region32_init(&view->clip);
  
  	view->alpha = 1.0;
  	pixman_region32_init(&view->transform.opaque);
  
  	wl_list_init(&view->geometry.transformation_list);
  	wl_list_insert(&view->geometry.transformation_list,
  		       &view->transform.position.link);
  	weston_matrix_init(&view->transform.position.matrix);
  	wl_list_init(&view->geometry.child_list);
  	pixman_region32_init(&view->geometry.scissor);
  	pixman_region32_init(&view->transform.boundingbox);
  	view->transform.dirty = 1;
  
  	return view;
  }
  
  struct weston_frame_callback {
  	struct wl_resource *resource;
  	struct wl_list link;
  };
  
  struct weston_presentation_feedback {
  	struct wl_resource *resource;
  
  	/* XXX: could use just wl_resource_get_link() instead */
  	struct wl_list link;
  
  	/* The per-surface feedback flags */
  	uint32_t psf_flags;
  };
  
  static void
  weston_presentation_feedback_discard(
  		struct weston_presentation_feedback *feedback)
  {
  	wp_presentation_feedback_send_discarded(feedback->resource);
  	wl_resource_destroy(feedback->resource);
  }
  
  static void
  weston_presentation_feedback_discard_list(struct wl_list *list)
  {
  	struct weston_presentation_feedback *feedback, *tmp;
  
  	wl_list_for_each_safe(feedback, tmp, list, link)
  		weston_presentation_feedback_discard(feedback);
  }
  
  static void
  weston_presentation_feedback_present(
  		struct weston_presentation_feedback *feedback,
  		struct weston_output *output,
  		uint32_t refresh_nsec,
  		const struct timespec *ts,
  		uint64_t seq,
  		uint32_t flags)
  {
  	struct wl_client *client = wl_resource_get_client(feedback->resource);
  	struct wl_resource *o;
  	uint64_t secs;
  
  	wl_resource_for_each(o, &output->resource_list) {
  		if (wl_resource_get_client(o) != client)
  			continue;
  
  		wp_presentation_feedback_send_sync_output(feedback->resource, o);
  	}
  
  	secs = ts->tv_sec;
  	wp_presentation_feedback_send_presented(feedback->resource,
  						secs >> 32, secs & 0xffffffff,
  						ts->tv_nsec,
  						refresh_nsec,
  						seq >> 32, seq & 0xffffffff,
  						flags | feedback->psf_flags);
  	wl_resource_destroy(feedback->resource);
  }
  
  static void
  weston_presentation_feedback_present_list(struct wl_list *list,
  					  struct weston_output *output,
  					  uint32_t refresh_nsec,
  					  const struct timespec *ts,
  					  uint64_t seq,
  					  uint32_t flags)
  {
  	struct weston_presentation_feedback *feedback, *tmp;
  
  	assert(!(flags & WP_PRESENTATION_FEEDBACK_INVALID) ||
  	       wl_list_empty(list));
  
  	wl_list_for_each_safe(feedback, tmp, list, link)
  		weston_presentation_feedback_present(feedback, output,
  						     refresh_nsec, ts, seq,
  						     flags);
  }
  
  static void
  surface_state_handle_buffer_destroy(struct wl_listener *listener, void *data)
  {
  	struct weston_surface_state *state =
  		container_of(listener, struct weston_surface_state,
  			     buffer_destroy_listener);
  
  	state->buffer = NULL;
  }
  
  static void
  weston_surface_state_init(struct weston_surface_state *state)
  {
  	state->newly_attached = 0;
  	state->buffer = NULL;
  	state->buffer_destroy_listener.notify =
  		surface_state_handle_buffer_destroy;
  	state->sx = 0;
  	state->sy = 0;
  
  	pixman_region32_init(&state->damage_surface);
  	pixman_region32_init(&state->damage_buffer);
  	pixman_region32_init(&state->opaque);
  	region_init_infinite(&state->input);
  
  	wl_list_init(&state->frame_callback_list);
  	wl_list_init(&state->feedback_list);
  
  	state->buffer_viewport.buffer.transform = WL_OUTPUT_TRANSFORM_NORMAL;
  	state->buffer_viewport.buffer.scale = 1;
  	state->buffer_viewport.buffer.src_width = wl_fixed_from_int(-1);
  	state->buffer_viewport.surface.width = -1;
  	state->buffer_viewport.changed = 0;
  }
  
  static void
  weston_surface_state_fini(struct weston_surface_state *state)
  {
  	struct weston_frame_callback *cb, *next;
  
  	wl_list_for_each_safe(cb, next,
  			      &state->frame_callback_list, link)
  		wl_resource_destroy(cb->resource);
  
  	weston_presentation_feedback_discard_list(&state->feedback_list);
  
  	pixman_region32_fini(&state->input);
  	pixman_region32_fini(&state->opaque);
  	pixman_region32_fini(&state->damage_surface);
  	pixman_region32_fini(&state->damage_buffer);
  
  	if (state->buffer)
  		wl_list_remove(&state->buffer_destroy_listener.link);
  	state->buffer = NULL;
  }
  
  static void
  weston_surface_state_set_buffer(struct weston_surface_state *state,
  				struct weston_buffer *buffer)
  {
  	if (state->buffer == buffer)
  		return;
  
  	if (state->buffer)
  		wl_list_remove(&state->buffer_destroy_listener.link);
  	state->buffer = buffer;
  	if (state->buffer)
  		wl_signal_add(&state->buffer->destroy_signal,
  			      &state->buffer_destroy_listener);
  }
  
  WL_EXPORT struct weston_surface *
  weston_surface_create(struct weston_compositor *compositor)
  {
  	struct weston_surface *surface;
  
  	surface = zalloc(sizeof *surface);
  	if (surface == NULL)
  		return NULL;
  
  	wl_signal_init(&surface->destroy_signal);
  
  	surface->compositor = compositor;
  	surface->ref_count = 1;
  
  	surface->buffer_viewport.buffer.transform = WL_OUTPUT_TRANSFORM_NORMAL;
  	surface->buffer_viewport.buffer.scale = 1;
  	surface->buffer_viewport.buffer.src_width = wl_fixed_from_int(-1);
  	surface->buffer_viewport.surface.width = -1;
  
  	weston_surface_state_init(&surface->pending);
  
  	pixman_region32_init(&surface->damage);
  	pixman_region32_init(&surface->opaque);
  	region_init_infinite(&surface->input);
  
  	wl_list_init(&surface->views);
  
  	wl_list_init(&surface->frame_callback_list);
  	wl_list_init(&surface->feedback_list);
  
  	wl_list_init(&surface->subsurface_list);
  	wl_list_init(&surface->subsurface_list_pending);
  
  	weston_matrix_init(&surface->buffer_to_surface_matrix);
  	weston_matrix_init(&surface->surface_to_buffer_matrix);
  
  	return surface;
  }
  
  WL_EXPORT void
  weston_surface_set_color(struct weston_surface *surface,
  		 float red, float green, float blue, float alpha)
  {
  	surface->compositor->renderer->surface_set_color(surface, red, green, blue, alpha);
  }
  
  WL_EXPORT void
  weston_view_to_global_float(struct weston_view *view,
  			    float sx, float sy, float *x, float *y)
  {
  	if (view->transform.enabled) {
  		struct weston_vector v = { { sx, sy, 0.0f, 1.0f } };
  
  		weston_matrix_transform(&view->transform.matrix, &v);
  
  		if (fabsf(v.f[3]) < 1e-6) {
  			weston_log("warning: numerical instability in "
  				"%s(), divisor = %g\n", __func__,
  				v.f[3]);
  			*x = 0;
  			*y = 0;
  			return;
  		}
  
  		*x = v.f[0] / v.f[3];
  		*y = v.f[1] / v.f[3];
  	} else {
  		*x = sx + view->geometry.x;
  		*y = sy + view->geometry.y;
  	}
  }
  
  WL_EXPORT void
  weston_transformed_coord(int width, int height,
  			 enum wl_output_transform transform,
  			 int32_t scale,
  			 float sx, float sy, float *bx, float *by)
  {
  	switch (transform) {
  	case WL_OUTPUT_TRANSFORM_NORMAL:
  	default:
  		*bx = sx;
  		*by = sy;
  		break;
  	case WL_OUTPUT_TRANSFORM_FLIPPED:
  		*bx = width - sx;
  		*by = sy;
  		break;
  	case WL_OUTPUT_TRANSFORM_90:
  		*bx = height - sy;
  		*by = sx;
  		break;
  	case WL_OUTPUT_TRANSFORM_FLIPPED_90:
  		*bx = height - sy;
  		*by = width - sx;
  		break;
  	case WL_OUTPUT_TRANSFORM_180:
  		*bx = width - sx;
  		*by = height - sy;
  		break;
  	case WL_OUTPUT_TRANSFORM_FLIPPED_180:
  		*bx = sx;
  		*by = height - sy;
  		break;
  	case WL_OUTPUT_TRANSFORM_270:
  		*bx = sy;
  		*by = width - sx;
  		break;
  	case WL_OUTPUT_TRANSFORM_FLIPPED_270:
  		*bx = sy;
  		*by = sx;
  		break;
  	}
  
  	*bx *= scale;
  	*by *= scale;
  }
  
  WL_EXPORT pixman_box32_t
  weston_transformed_rect(int width, int height,
  			enum wl_output_transform transform,
  			int32_t scale,
  			pixman_box32_t rect)
  {
  	float x1, x2, y1, y2;
  
  	pixman_box32_t ret;
  
  	weston_transformed_coord(width, height, transform, scale,
  				 rect.x1, rect.y1, &x1, &y1);
  	weston_transformed_coord(width, height, transform, scale,
  				 rect.x2, rect.y2, &x2, &y2);
  
  	if (x1 <= x2) {
  		ret.x1 = x1;
  		ret.x2 = x2;
  	} else {
  		ret.x1 = x2;
  		ret.x2 = x1;
  	}
  
  	if (y1 <= y2) {
  		ret.y1 = y1;
  		ret.y2 = y2;
  	} else {
  		ret.y1 = y2;
  		ret.y2 = y1;
  	}
  
  	return ret;
  }
  
  /** Transform a region by a matrix, restricted to axis-aligned transformations
   *
   * Warning: This function does not work for projective, affine, or matrices
   * that encode arbitrary rotations. Only 90-degree step rotations are
   * supported.
   */
  WL_EXPORT void
  weston_matrix_transform_region(pixman_region32_t *dest,
  			       struct weston_matrix *matrix,
  			       pixman_region32_t *src)
  {
  	pixman_box32_t *src_rects, *dest_rects;
  	int nrects, i;
  
  	src_rects = pixman_region32_rectangles(src, &nrects);
  	dest_rects = malloc(nrects * sizeof(*dest_rects));
  	if (!dest_rects)
  		return;
  
  	for (i = 0; i < nrects; i++) {
  		struct weston_vector vec1 = {{
  			src_rects[i].x1, src_rects[i].y1, 0, 1
  		}};
  		weston_matrix_transform(matrix, &vec1);
  		vec1.f[0] /= vec1.f[3];
  		vec1.f[1] /= vec1.f[3];
  
  		struct weston_vector vec2 = {{
  			src_rects[i].x2, src_rects[i].y2, 0, 1
  		}};
  		weston_matrix_transform(matrix, &vec2);
  		vec2.f[0] /= vec2.f[3];
  		vec2.f[1] /= vec2.f[3];
  
  		if (vec1.f[0] < vec2.f[0]) {
  			dest_rects[i].x1 = floor(vec1.f[0]);
  			dest_rects[i].x2 = ceil(vec2.f[0]);
  		} else {
  			dest_rects[i].x1 = floor(vec2.f[0]);
  			dest_rects[i].x2 = ceil(vec1.f[0]);
  		}
  
  		if (vec1.f[1] < vec2.f[1]) {
  			dest_rects[i].y1 = floor(vec1.f[1]);
  			dest_rects[i].y2 = ceil(vec2.f[1]);
  		} else {
  			dest_rects[i].y1 = floor(vec2.f[1]);
  			dest_rects[i].y2 = ceil(vec1.f[1]);
  		}
  	}
  
  	pixman_region32_clear(dest);
  	pixman_region32_init_rects(dest, dest_rects, nrects);
  	free(dest_rects);
  }
  
  WL_EXPORT void
  weston_transformed_region(int width, int height,
  			  enum wl_output_transform transform,
  			  int32_t scale,
  			  pixman_region32_t *src, pixman_region32_t *dest)
  {
  	pixman_box32_t *src_rects, *dest_rects;
  	int nrects, i;
  
  	if (transform == WL_OUTPUT_TRANSFORM_NORMAL && scale == 1) {
  		if (src != dest)
  			pixman_region32_copy(dest, src);
  		return;
  	}
  
  	src_rects = pixman_region32_rectangles(src, &nrects);
  	dest_rects = malloc(nrects * sizeof(*dest_rects));
  	if (!dest_rects)
  		return;
  
  	if (transform == WL_OUTPUT_TRANSFORM_NORMAL) {
  		memcpy(dest_rects, src_rects, nrects * sizeof(*dest_rects));
  	} else {
  		for (i = 0; i < nrects; i++) {
  			switch (transform) {
  			default:
  			case WL_OUTPUT_TRANSFORM_NORMAL:
  				dest_rects[i].x1 = src_rects[i].x1;
  				dest_rects[i].y1 = src_rects[i].y1;
  				dest_rects[i].x2 = src_rects[i].x2;
  				dest_rects[i].y2 = src_rects[i].y2;
  				break;
  			case WL_OUTPUT_TRANSFORM_90:
  				dest_rects[i].x1 = height - src_rects[i].y2;
  				dest_rects[i].y1 = src_rects[i].x1;
  				dest_rects[i].x2 = height - src_rects[i].y1;
  				dest_rects[i].y2 = src_rects[i].x2;
  				break;
  			case WL_OUTPUT_TRANSFORM_180:
  				dest_rects[i].x1 = width - src_rects[i].x2;
  				dest_rects[i].y1 = height - src_rects[i].y2;
  				dest_rects[i].x2 = width - src_rects[i].x1;
  				dest_rects[i].y2 = height - src_rects[i].y1;
  				break;
  			case WL_OUTPUT_TRANSFORM_270:
  				dest_rects[i].x1 = src_rects[i].y1;
  				dest_rects[i].y1 = width - src_rects[i].x2;
  				dest_rects[i].x2 = src_rects[i].y2;
  				dest_rects[i].y2 = width - src_rects[i].x1;
  				break;
  			case WL_OUTPUT_TRANSFORM_FLIPPED:
  				dest_rects[i].x1 = width - src_rects[i].x2;
  				dest_rects[i].y1 = src_rects[i].y1;
  				dest_rects[i].x2 = width - src_rects[i].x1;
  				dest_rects[i].y2 = src_rects[i].y2;
  				break;
  			case WL_OUTPUT_TRANSFORM_FLIPPED_90:
  				dest_rects[i].x1 = height - src_rects[i].y2;
  				dest_rects[i].y1 = width - src_rects[i].x2;
  				dest_rects[i].x2 = height - src_rects[i].y1;
  				dest_rects[i].y2 = width - src_rects[i].x1;
  				break;
  			case WL_OUTPUT_TRANSFORM_FLIPPED_180:
  				dest_rects[i].x1 = src_rects[i].x1;
  				dest_rects[i].y1 = height - src_rects[i].y2;
  				dest_rects[i].x2 = src_rects[i].x2;
  				dest_rects[i].y2 = height - src_rects[i].y1;
  				break;
  			case WL_OUTPUT_TRANSFORM_FLIPPED_270:
  				dest_rects[i].x1 = src_rects[i].y1;
  				dest_rects[i].y1 = src_rects[i].x1;
  				dest_rects[i].x2 = src_rects[i].y2;
  				dest_rects[i].y2 = src_rects[i].x2;
  				break;
  			}
  		}
  	}
  
  	if (scale != 1) {
  		for (i = 0; i < nrects; i++) {
  			dest_rects[i].x1 *= scale;
  			dest_rects[i].x2 *= scale;
  			dest_rects[i].y1 *= scale;
  			dest_rects[i].y2 *= scale;
  		}
  	}
  
  	pixman_region32_clear(dest);
  	pixman_region32_init_rects(dest, dest_rects, nrects);
  	free(dest_rects);
  }
  
  static void
  scaler_surface_to_buffer(struct weston_surface *surface,
  			 float sx, float sy, float *bx, float *by)
  {
  	struct weston_buffer_viewport *vp = &surface->buffer_viewport;
  	double src_width, src_height;
  	double src_x, src_y;
  
  	if (vp->buffer.src_width == wl_fixed_from_int(-1)) {
  		if (vp->surface.width == -1) {
  			*bx = sx;
  			*by = sy;
  			return;
  		}
  
  		src_x = 0.0;
  		src_y = 0.0;
  		src_width = surface->width_from_buffer;
  		src_height = surface->height_from_buffer;
  	} else {
  		src_x = wl_fixed_to_double(vp->buffer.src_x);
  		src_y = wl_fixed_to_double(vp->buffer.src_y);
  		src_width = wl_fixed_to_double(vp->buffer.src_width);
  		src_height = wl_fixed_to_double(vp->buffer.src_height);
  	}
  
  	*bx = sx * src_width / surface->width + src_x;
  	*by = sy * src_height / surface->height + src_y;
  }
  
  WL_EXPORT void
  weston_surface_to_buffer_float(struct weston_surface *surface,
  			       float sx, float sy, float *bx, float *by)
  {
  	struct weston_buffer_viewport *vp = &surface->buffer_viewport;
  
  	/* first transform coordinates if the scaler is set */
  	scaler_surface_to_buffer(surface, sx, sy, bx, by);
  
  	weston_transformed_coord(surface->width_from_buffer,
  				 surface->height_from_buffer,
  				 vp->buffer.transform, vp->buffer.scale,
  				 *bx, *by, bx, by);
  }
  
  /** Transform a rectangle from surface coordinates to buffer coordinates
   *
   * \param surface The surface to fetch wl_viewport and buffer transformation
   * from.
   * \param rect The rectangle to transform.
   * \return The transformed rectangle.
   *
   * Viewport and buffer transformations can only do translation, scaling,
   * and rotations in 90-degree steps. Therefore the only loss in the
   * conversion is coordinate rounding.
   *
   * However, some coordinate rounding takes place as an intermediate
   * step before the buffer scale factor is applied, so the rectangle
   * boundary may not be exactly as expected.
   *
   * This is OK for damage tracking since a little extra coverage is
   * not a problem.
   */
  WL_EXPORT pixman_box32_t
  weston_surface_to_buffer_rect(struct weston_surface *surface,
  			      pixman_box32_t rect)
  {
  	struct weston_buffer_viewport *vp = &surface->buffer_viewport;
  	float xf, yf;
  
  	/* first transform box coordinates if the scaler is set */
  	scaler_surface_to_buffer(surface, rect.x1, rect.y1, &xf, &yf);
  	rect.x1 = floorf(xf);
  	rect.y1 = floorf(yf);
  
  	scaler_surface_to_buffer(surface, rect.x2, rect.y2, &xf, &yf);
  	rect.x2 = ceilf(xf);
  	rect.y2 = ceilf(yf);
  
  	return weston_transformed_rect(surface->width_from_buffer,
  				       surface->height_from_buffer,
  				       vp->buffer.transform, vp->buffer.scale,
  				       rect);
  }
  
  /** Transform a region from surface coordinates to buffer coordinates
   *
   * \param surface The surface to fetch wl_viewport and buffer transformation
   * from.
   * \param surface_region[in] The region in surface coordinates.
   * \param buffer_region[out] The region converted to buffer coordinates.
   *
   * Buffer_region must be init'd, but will be completely overwritten.
   *
   * Viewport and buffer transformations can only do translation, scaling,
   * and rotations in 90-degree steps. Therefore the only loss in the
   * conversion is from the coordinate rounding that takes place in
   * \ref weston_surface_to_buffer_rect.
   */
  WL_EXPORT void
  weston_surface_to_buffer_region(struct weston_surface *surface,
  				pixman_region32_t *surface_region,
  				pixman_region32_t *buffer_region)
  {
  	pixman_box32_t *src_rects, *dest_rects;
  	int nrects, i;
  
  	src_rects = pixman_region32_rectangles(surface_region, &nrects);
  	dest_rects = malloc(nrects * sizeof(*dest_rects));
  	if (!dest_rects)
  		return;
  
  	for (i = 0; i < nrects; i++) {
  		dest_rects[i] = weston_surface_to_buffer_rect(surface,
  							      src_rects[i]);
  	}
  
  	pixman_region32_fini(buffer_region);
  	pixman_region32_init_rects(buffer_region, dest_rects, nrects);
  	free(dest_rects);
  }
  
  WL_EXPORT void
  weston_view_move_to_plane(struct weston_view *view,
  			     struct weston_plane *plane)
  {
  	if (view->plane == plane)
  		return;
  
  	weston_view_damage_below(view);
  	view->plane = plane;
  	weston_surface_damage(view->surface);
  }
  
  /** Inflict damage on the plane where the view is visible.
   *
   * \param view The view that causes the damage.
   *
   * If the view is currently on a plane (including the primary plane),
   * take the view's boundingbox, subtract all the opaque views that cover it,
   * and add the remaining region as damage to the plane. This corresponds
   * to the damage inflicted to the plane if this view disappeared.
   *
   * A repaint is scheduled for this view.
   *
   * The region of all opaque views covering this view is stored in
   * weston_view::clip and updated by view_accumulate_damage() during
   * weston_output_repaint(). Specifically, that region matches the
   * scenegraph as it was last painted.
   */
  WL_EXPORT void
  weston_view_damage_below(struct weston_view *view)
  {
  	pixman_region32_t damage;
  
  	pixman_region32_init(&damage);
  	pixman_region32_subtract(&damage, &view->transform.boundingbox,
  				 &view->clip);
  	if (view->plane)
  		pixman_region32_union(&view->plane->damage,
  				      &view->plane->damage, &damage);
  	pixman_region32_fini(&damage);
  	weston_view_schedule_repaint(view);
  }
  
  /**
   * \param es    The surface
   * \param mask  The new set of outputs for the surface
   *
   * Sets the surface's set of outputs to the ones specified by
   * the new output mask provided.  Identifies the outputs that
   * have changed, the posts enter and leave events for these
   * outputs as appropriate.
   */
  static void
  weston_surface_update_output_mask(struct weston_surface *es, uint32_t mask)
  {
  	uint32_t different = es->output_mask ^ mask;
  	uint32_t entered = mask & different;
  	uint32_t left = es->output_mask & different;
  	struct weston_output *output;
  	struct wl_resource *resource = NULL;
  	struct wl_client *client;
  
  	es->output_mask = mask;
  	if (es->resource == NULL)
  		return;
  	if (different == 0)
  		return;
  
  	client = wl_resource_get_client(es->resource);
  
  	wl_list_for_each(output, &es->compositor->output_list, link) {
  		if (1u << output->id & different)
  			resource =
  				wl_resource_find_for_client(&output->resource_list,
  							 client);
  		if (resource == NULL)
  			continue;
  		if (1u << output->id & entered)
  			wl_surface_send_enter(es->resource, resource);
  		if (1u << output->id & left)
  			wl_surface_send_leave(es->resource, resource);
  	}
  }
  
  /** Recalculate which output(s) the surface has views displayed on
   *
   * \param es  The surface to remap to outputs
   *
   * Finds the output that is showing the largest amount of one
   * of the surface's various views.  This output becomes the
   * surface's primary output for vsync and frame callback purposes.
   *
   * Also notes all outputs of all of the surface's views
   * in the output_mask for the surface.
   */
  static void
  weston_surface_assign_output(struct weston_surface *es)
  {
  	struct weston_output *new_output;
  	struct weston_view *view;
  	pixman_region32_t region;
  	uint32_t max, area, mask;
  	pixman_box32_t *e;
  
  	new_output = NULL;
  	max = 0;
  	mask = 0;
  	pixman_region32_init(&region);
  	wl_list_for_each(view, &es->views, surface_link) {
  		if (!view->output)
  			continue;
  
  		pixman_region32_intersect(&region, &view->transform.boundingbox,
  					  &view->output->region);
  
  		e = pixman_region32_extents(&region);
  		area = (e->x2 - e->x1) * (e->y2 - e->y1);
  
  		mask |= view->output_mask;
  
  		if (area >= max) {
  			new_output = view->output;
  			max = area;
  		}
  	}
  	pixman_region32_fini(&region);
  
  	es->output = new_output;
  	weston_surface_update_output_mask(es, mask);
  }
  
  /** Recalculate which output(s) the view is displayed on
   *
   * \param ev  The view to remap to outputs
   *
   * Identifies the set of outputs that the view is visible on,
   * noting them into the output_mask.  The output that the view
   * is most visible on is set as the view's primary output.
   *
   * Also does the same for the view's surface.  See
   * weston_surface_assign_output().
   */
  static void
  weston_view_assign_output(struct weston_view *ev)
  {
  	struct weston_compositor *ec = ev->surface->compositor;
  	struct weston_output *output, *new_output;
  	pixman_region32_t region;
  	uint32_t max, area, mask;
  	pixman_box32_t *e;
  
  	new_output = NULL;
  	max = 0;
  	mask = 0;
  	pixman_region32_init(&region);
  	wl_list_for_each(output, &ec->output_list, link) {
  		if (output->destroying)
  			continue;
  
  		pixman_region32_intersect(&region, &ev->transform.boundingbox,
  					  &output->region);
  
  		e = pixman_region32_extents(&region);
  		area = (e->x2 - e->x1) * (e->y2 - e->y1);
  
  		if (area > 0)
  			mask |= 1u << output->id;
  
  		if (area >= max) {
  			new_output = output;
  			max = area;
  		}
  	}
  	pixman_region32_fini(&region);
  
  	ev->output = new_output;
  	ev->output_mask = mask;
  
  	weston_surface_assign_output(ev->surface);
  }
  
  static void
  weston_view_to_view_map(struct weston_view *from, struct weston_view *to,
  			int from_x, int from_y, int *to_x, int *to_y)
  {
  	float x, y;
  
  	weston_view_to_global_float(from, from_x, from_y, &x, &y);
  	weston_view_from_global_float(to, x, y, &x, &y);
  
  	*to_x = round(x);
  	*to_y = round(y);
  }
  
  static void
  weston_view_transfer_scissor(struct weston_view *from, struct weston_view *to)
  {
  	pixman_box32_t *a;
  	pixman_box32_t b;
  
  	a = pixman_region32_extents(&from->geometry.scissor);
  
  	weston_view_to_view_map(from, to, a->x1, a->y1, &b.x1, &b.y1);
  	weston_view_to_view_map(from, to, a->x2, a->y2, &b.x2, &b.y2);
  
  	pixman_region32_fini(&to->geometry.scissor);
  	pixman_region32_init_with_extents(&to->geometry.scissor, &b);
  }
  
  static void
  view_compute_bbox(struct weston_view *view, const pixman_box32_t *inbox,
  		  pixman_region32_t *bbox)
  {
  	float min_x = HUGE_VALF,  min_y = HUGE_VALF;
  	float max_x = -HUGE_VALF, max_y = -HUGE_VALF;
  	int32_t s[4][2] = {
  		{ inbox->x1, inbox->y1 },
  		{ inbox->x1, inbox->y2 },
  		{ inbox->x2, inbox->y1 },
  		{ inbox->x2, inbox->y2 },
  	};
  	float int_x, int_y;
  	int i;
  
  	if (inbox->x1 == inbox->x2 || inbox->y1 == inbox->y2) {
  		/* avoid rounding empty bbox to 1x1 */
  		pixman_region32_init(bbox);
  		return;
  	}
  
  	for (i = 0; i < 4; ++i) {
  		float x, y;
  		weston_view_to_global_float(view, s[i][0], s[i][1], &x, &y);
  		if (x < min_x)
  			min_x = x;
  		if (x > max_x)
  			max_x = x;
  		if (y < min_y)
  			min_y = y;
  		if (y > max_y)
  			max_y = y;
  	}
  
  	int_x = floorf(min_x);
  	int_y = floorf(min_y);
  	pixman_region32_init_rect(bbox, int_x, int_y,
  				  ceilf(max_x) - int_x, ceilf(max_y) - int_y);
  }
  
  static void
  weston_view_update_transform_disable(struct weston_view *view)
  {
  	view->transform.enabled = 0;
  
  	/* round off fractions when not transformed */
  	view->geometry.x = roundf(view->geometry.x);
  	view->geometry.y = roundf(view->geometry.y);
  
  	/* Otherwise identity matrix, but with x and y translation. */
  	view->transform.position.matrix.type = WESTON_MATRIX_TRANSFORM_TRANSLATE;
  	view->transform.position.matrix.d[12] = view->geometry.x;
  	view->transform.position.matrix.d[13] = view->geometry.y;
  
  	view->transform.matrix = view->transform.position.matrix;
  
  	view->transform.inverse = view->transform.position.matrix;
  	view->transform.inverse.d[12] = -view->geometry.x;
  	view->transform.inverse.d[13] = -view->geometry.y;
  
  	pixman_region32_init_rect(&view->transform.boundingbox,
  				  0, 0,
  				  view->surface->width,
  				  view->surface->height);
  	if (view->geometry.scissor_enabled)
  		pixman_region32_intersect(&view->transform.boundingbox,
  					  &view->transform.boundingbox,
  					  &view->geometry.scissor);
  
  	pixman_region32_translate(&view->transform.boundingbox,
  				  view->geometry.x, view->geometry.y);
  
  	if (view->alpha == 1.0) {
  		pixman_region32_copy(&view->transform.opaque,
  				     &view->surface->opaque);
  		pixman_region32_translate(&view->transform.opaque,
  					  view->geometry.x,
  					  view->geometry.y);
  	}
  }
  
  static int
  weston_view_update_transform_enable(struct weston_view *view)
  {
  	struct weston_view *parent = view->geometry.parent;
  	struct weston_matrix *matrix = &view->transform.matrix;
  	struct weston_matrix *inverse = &view->transform.inverse;
  	struct weston_transform *tform;
  	pixman_region32_t surfregion;
  	const pixman_box32_t *surfbox;
  
  	view->transform.enabled = 1;
  
  	/* Otherwise identity matrix, but with x and y translation. */
  	view->transform.position.matrix.type = WESTON_MATRIX_TRANSFORM_TRANSLATE;
  	view->transform.position.matrix.d[12] = view->geometry.x;
  	view->transform.position.matrix.d[13] = view->geometry.y;
  
  	weston_matrix_init(matrix);
  	wl_list_for_each(tform, &view->geometry.transformation_list, link)
  		weston_matrix_multiply(matrix, &tform->matrix);
  
  	if (parent)
  		weston_matrix_multiply(matrix, &parent->transform.matrix);
  
  	if (weston_matrix_invert(inverse, matrix) < 0) {
  		/* Oops, bad total transformation, not invertible */
  		weston_log("error: weston_view %p"
  			" transformation not invertible.\n", view);
  		return -1;
  	}
  
  	if (view->alpha == 1.0 &&
  	    matrix->type == WESTON_MATRIX_TRANSFORM_TRANSLATE) {
  		pixman_region32_copy(&view->transform.opaque,
  				     &view->surface->opaque);
  		pixman_region32_translate(&view->transform.opaque,
  					  matrix->d[12],
  					  matrix->d[13]);
  	}
  	pixman_region32_init_rect(&surfregion, 0, 0,
  				  view->surface->width, view->surface->height);
  	if (view->geometry.scissor_enabled)
  		pixman_region32_intersect(&surfregion, &surfregion,
  					  &view->geometry.scissor);
  	surfbox = pixman_region32_extents(&surfregion);
  
  	view_compute_bbox(view, surfbox, &view->transform.boundingbox);
  	pixman_region32_fini(&surfregion);
  
  	return 0;
  }
  
  static struct weston_layer *
  get_view_layer(struct weston_view *view)
  {
  	if (view->parent_view)
  		return get_view_layer(view->parent_view);
  	return view->layer_link.layer;
  }
  
  WL_EXPORT void
  weston_view_update_transform(struct weston_view *view)
  {
  	struct weston_view *parent = view->geometry.parent;
  	struct weston_layer *layer;
  	pixman_region32_t mask;
  
  	if (!view->transform.dirty)
  		return;
  
  	if (parent)
  		weston_view_update_transform(parent);
  
  	view->transform.dirty = 0;
  
  	weston_view_damage_below(view);
  
  	pixman_region32_fini(&view->transform.boundingbox);
  	pixman_region32_fini(&view->transform.opaque);
  	pixman_region32_init(&view->transform.opaque);
  
  	/* transform.position is always in transformation_list */
  	if (view->geometry.transformation_list.next ==
  	    &view->transform.position.link &&
  	    view->geometry.transformation_list.prev ==
  	    &view->transform.position.link &&
  	    !parent) {
  		weston_view_update_transform_disable(view);
  	} else {
  		if (weston_view_update_transform_enable(view) < 0)
  			weston_view_update_transform_disable(view);
  	}
  
  	layer = get_view_layer(view);
  	if (layer) {
  		pixman_region32_init_with_extents(&mask, &layer->mask);
  		pixman_region32_intersect(&view->transform.boundingbox,
  					  &view->transform.boundingbox, &mask);
  		pixman_region32_intersect(&view->transform.opaque,
  					  &view->transform.opaque, &mask);
  		pixman_region32_fini(&mask);
  	}
  
  	if (parent) {
  		if (parent->geometry.scissor_enabled) {
  			view->geometry.scissor_enabled = true;
  			weston_view_transfer_scissor(parent, view);
  		} else {
  			view->geometry.scissor_enabled = false;
  		}
  	}
  
  	weston_view_damage_below(view);
  
  	weston_view_assign_output(view);
  
  	wl_signal_emit(&view->surface->compositor->transform_signal,
  		       view->surface);
  }
  
  WL_EXPORT void
  weston_view_geometry_dirty(struct weston_view *view)
  {
  	struct weston_view *child;
  
  	/*
  	 * The invariant: if view->geometry.dirty, then all views
  	 * in view->geometry.child_list have geometry.dirty too.
  	 * Corollary: if not parent->geometry.dirty, then all ancestors
  	 * are not dirty.
  	 */
  
  	if (view->transform.dirty)
  		return;
  
  	view->transform.dirty = 1;
  
  	wl_list_for_each(child, &view->geometry.child_list,
  			 geometry.parent_link)
  		weston_view_geometry_dirty(child);
  }
  
  WL_EXPORT void
  weston_view_to_global_fixed(struct weston_view *view,
  			    wl_fixed_t vx, wl_fixed_t vy,
  			    wl_fixed_t *x, wl_fixed_t *y)
  {
  	float xf, yf;
  
  	weston_view_to_global_float(view,
  				    wl_fixed_to_double(vx),
  				    wl_fixed_to_double(vy),
  				    &xf, &yf);
  	*x = wl_fixed_from_double(xf);
  	*y = wl_fixed_from_double(yf);
  }
  
  WL_EXPORT void
  weston_view_from_global_float(struct weston_view *view,
  			      float x, float y, float *vx, float *vy)
  {
  	if (view->transform.enabled) {
  		struct weston_vector v = { { x, y, 0.0f, 1.0f } };
  
  		weston_matrix_transform(&view->transform.inverse, &v);
  
  		if (fabsf(v.f[3]) < 1e-6) {
  			weston_log("warning: numerical instability in "
  				"weston_view_from_global(), divisor = %g\n",
  				v.f[3]);
  			*vx = 0;
  			*vy = 0;
  			return;
  		}
  
  		*vx = v.f[0] / v.f[3];
  		*vy = v.f[1] / v.f[3];
  	} else {
  		*vx = x - view->geometry.x;
  		*vy = y - view->geometry.y;
  	}
  }
  
  WL_EXPORT void
  weston_view_from_global_fixed(struct weston_view *view,
  			      wl_fixed_t x, wl_fixed_t y,
  			      wl_fixed_t *vx, wl_fixed_t *vy)
  {
  	float vxf, vyf;
  
  	weston_view_from_global_float(view,
  				      wl_fixed_to_double(x),
  				      wl_fixed_to_double(y),
  				      &vxf, &vyf);
  	*vx = wl_fixed_from_double(vxf);
  	*vy = wl_fixed_from_double(vyf);
  }
  
  WL_EXPORT void
  weston_view_from_global(struct weston_view *view,
  			int32_t x, int32_t y, int32_t *vx, int32_t *vy)
  {
  	float vxf, vyf;
  
  	weston_view_from_global_float(view, x, y, &vxf, &vyf);
  	*vx = floorf(vxf);
  	*vy = floorf(vyf);
  }
  
  /**
   * \param surface  The surface to be repainted
   *
   * Marks the output(s) that the surface is shown on as needing to be
   * repainted.  See weston_output_schedule_repaint().
   */
  WL_EXPORT void
  weston_surface_schedule_repaint(struct weston_surface *surface)
  {
  	struct weston_output *output;
  
  	wl_list_for_each(output, &surface->compositor->output_list, link)
  		if (surface->output_mask & (1u << output->id))
  			weston_output_schedule_repaint(output);
  }
  
  /**
   * \param view  The view to be repainted
   *
   * Marks the output(s) that the view is shown on as needing to be
   * repainted.  See weston_output_schedule_repaint().
   */
  WL_EXPORT void
  weston_view_schedule_repaint(struct weston_view *view)
  {
  	struct weston_output *output;
  
  	wl_list_for_each(output, &view->surface->compositor->output_list, link)
  		if (view->output_mask & (1u << output->id))
  			weston_output_schedule_repaint(output);
  }
  
  /**
   * XXX: This function does it the wrong way.
   * surface->damage is the damage from the client, and causes
   * surface_flush_damage() to copy pixels. No window management action can
   * cause damage to the client-provided content, warranting re-upload!
   *
   * Instead of surface->damage, this function should record the damage
   * with all the views for this surface to avoid extraneous texture
   * uploads.
   */
  WL_EXPORT void
  weston_surface_damage(struct weston_surface *surface)
  {
  	pixman_region32_union_rect(&surface->damage, &surface->damage,
  				   0, 0, surface->width,
  				   surface->height);
  
  	weston_surface_schedule_repaint(surface);
  }
  
  WL_EXPORT void
  weston_view_set_position(struct weston_view *view, float x, float y)
  {
  	if (view->geometry.x == x && view->geometry.y == y)
  		return;
  
  	view->geometry.x = x;
  	view->geometry.y = y;
  	weston_view_geometry_dirty(view);
  }
  
  static void
  transform_parent_handle_parent_destroy(struct wl_listener *listener,
  				       void *data)
  {
  	struct weston_view *view =
  		container_of(listener, struct weston_view,
  			     geometry.parent_destroy_listener);
  
  	weston_view_set_transform_parent(view, NULL);
  }
  
  WL_EXPORT void
  weston_view_set_transform_parent(struct weston_view *view,
  				 struct weston_view *parent)
  {
  	if (view->geometry.parent) {
  		wl_list_remove(&view->geometry.parent_destroy_listener.link);
  		wl_list_remove(&view->geometry.parent_link);
  
  		if (!parent)
  			view->geometry.scissor_enabled = false;
  	}
  
  	view->geometry.parent = parent;
  
  	view->geometry.parent_destroy_listener.notify =
  		transform_parent_handle_parent_destroy;
  	if (parent) {
  		wl_signal_add(&parent->destroy_signal,
  			      &view->geometry.parent_destroy_listener);
  		wl_list_insert(&parent->geometry.child_list,
  			       &view->geometry.parent_link);
  	}
  
  	weston_view_geometry_dirty(view);
  }
  
  /** Set a clip mask rectangle on a view
   *
   * \param view The view to set the clip mask on.
   * \param x Top-left corner X coordinate of the clip rectangle.
   * \param y Top-left corner Y coordinate of the clip rectangle.
   * \param width Width of the clip rectangle, non-negative.
   * \param height Height of the clip rectangle, non-negative.
   *
   * A shell may set a clip mask rectangle on a view. Everything outside
   * the rectangle is cut away for input and output purposes: it is
   * not drawn and cannot be hit by hit-test based input like pointer
   * motion or touch-downs. Everything inside the rectangle will behave
   * normally. Clients are unaware of clipping.
   *
   * The rectangle is set in surface-local coordinates. Setting a clip
   * mask rectangle does not affect the view position, the view is positioned
   * as it would be without a clip. The clip also does not change
   * weston_surface::width,height.
   *
   * The clip mask rectangle is part of transformation inheritance
   * (weston_view_set_transform_parent()). A clip set in the root of the
   * transformation inheritance tree will affect all views in the tree.
   * A clip can be set only on the root view. Attempting to set a clip
   * on view that has a transformation parent will fail. Assigning a parent
   * to a view that has a clip set will cause the clip to be forgotten.
   *
   * Because the clip mask is an axis-aligned rectangle, it poses restrictions
   * on the additional transformations in the child views. These transformations
   * may not rotate the coordinate axes, i.e., only translation and scaling
   * are allowed. Violating this restriction causes the clipping to malfunction.
   * Furthermore, using scaling may cause rounding errors in child clipping.
   *
   * The clip mask rectangle is not automatically adjusted based on
   * wl_surface.attach dx and dy arguments.
   *
   * A clip mask rectangle can be set only if the compositor capability
   * WESTON_CAP_VIEW_CLIP_MASK is present.
   *
   * This function sets the clip mask rectangle and schedules a repaint for
   * the view.
   */
  WL_EXPORT void
  weston_view_set_mask(struct weston_view *view,
  		     int x, int y, int width, int height)
  {
  	struct weston_compositor *compositor = view->surface->compositor;
  
  	if (!(compositor->capabilities & WESTON_CAP_VIEW_CLIP_MASK)) {
  		weston_log("%s not allowed without capability!\n", __func__);
  		return;
  	}
  
  	if (view->geometry.parent) {
  		weston_log("view %p has a parent, clip forbidden!\n", view);
  		return;
  	}
  
  	if (width < 0 || height < 0) {
  		weston_log("%s: illegal args %d, %d, %d, %d\n", __func__,
  			   x, y, width, height);
  		return;
  	}
  
  	pixman_region32_fini(&view->geometry.scissor);
  	pixman_region32_init_rect(&view->geometry.scissor, x, y, width, height);
  	view->geometry.scissor_enabled = true;
  	weston_view_geometry_dirty(view);
  	weston_view_schedule_repaint(view);
  }
  
  /** Remove the clip mask from a view
   *
   * \param view The view to remove the clip mask from.
   *
   * Removed the clip mask rectangle and schedules a repaint.
   *
   * \sa weston_view_set_mask
   */
  WL_EXPORT void
  weston_view_set_mask_infinite(struct weston_view *view)
  {
  	view->geometry.scissor_enabled = false;
  	weston_view_geometry_dirty(view);
  	weston_view_schedule_repaint(view);
  }
  
  WL_EXPORT bool
  weston_view_is_mapped(struct weston_view *view)
  {
  	if (view->output)
  		return true;
  	else
  		return false;
  }
  
  WL_EXPORT bool
  weston_surface_is_mapped(struct weston_surface *surface)
  {
  	if (surface->output)
  		return true;
  	else
  		return false;
  }
  
  static void
  surface_set_size(struct weston_surface *surface, int32_t width, int32_t height)
  {
  	struct weston_view *view;
  
  	if (surface->width == width && surface->height == height)
  		return;
  
  	surface->width = width;
  	surface->height = height;
  
  	wl_list_for_each(view, &surface->views, surface_link)
  		weston_view_geometry_dirty(view);
  }
  
  WL_EXPORT void
  weston_surface_set_size(struct weston_surface *surface,
  			int32_t width, int32_t height)
  {
  	assert(!surface->resource);
  	surface_set_size(surface, width, height);
  }
  
  static int
  fixed_round_up_to_int(wl_fixed_t f)
  {
  	return wl_fixed_to_int(wl_fixed_from_int(1) - 1 + f);
  }
  
  static void
  convert_size_by_transform_scale(int32_t *width_out, int32_t *height_out,
  				int32_t width, int32_t height,
  				uint32_t transform,
  				int32_t scale)
  {
  	assert(scale > 0);
  
  	switch (transform) {
  	case WL_OUTPUT_TRANSFORM_NORMAL:
  	case WL_OUTPUT_TRANSFORM_180:
  	case WL_OUTPUT_TRANSFORM_FLIPPED:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_180:
  		*width_out = width / scale;
  		*height_out = height / scale;
  		break;
  	case WL_OUTPUT_TRANSFORM_90:
  	case WL_OUTPUT_TRANSFORM_270:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_90:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_270:
  		*width_out = height / scale;
  		*height_out = width / scale;
  		break;
  	default:
  		assert(0 && "invalid transform");
  	}
  }
  
  static void
  weston_surface_calculate_size_from_buffer(struct weston_surface *surface)
  {
  	struct weston_buffer_viewport *vp = &surface->buffer_viewport;
  
  	if (!surface->buffer_ref.buffer) {
  		surface->width_from_buffer = 0;
  		surface->height_from_buffer = 0;
  		return;
  	}
  
  	convert_size_by_transform_scale(&surface->width_from_buffer,
  					&surface->height_from_buffer,
  					surface->buffer_ref.buffer->width,
  					surface->buffer_ref.buffer->height,
  					vp->buffer.transform,
  					vp->buffer.scale);
  }
  
  static void
  weston_surface_update_size(struct weston_surface *surface)
  {
  	struct weston_buffer_viewport *vp = &surface->buffer_viewport;
  	int32_t width, height;
  
  	width = surface->width_from_buffer;
  	height = surface->height_from_buffer;
  
  	if (width != 0 && vp->surface.width != -1) {
  		surface_set_size(surface,
  				 vp->surface.width, vp->surface.height);
  		return;
  	}
  
  	if (width != 0 && vp->buffer.src_width != wl_fixed_from_int(-1)) {
  		int32_t w = fixed_round_up_to_int(vp->buffer.src_width);
  		int32_t h = fixed_round_up_to_int(vp->buffer.src_height);
  
  		surface_set_size(surface, w ?: 1, h ?: 1);
  		return;
  	}
  
  	surface_set_size(surface, width, height);
  }
  
  WL_EXPORT uint32_t
  weston_compositor_get_time(void)
  {
         struct timeval tv;
  
         gettimeofday(&tv, NULL);
  
         return tv.tv_sec * 1000 + tv.tv_usec / 1000;
  }
  
  WL_EXPORT struct weston_view *
  weston_compositor_pick_view(struct weston_compositor *compositor,
  			    wl_fixed_t x, wl_fixed_t y,
  			    wl_fixed_t *vx, wl_fixed_t *vy)
  {
  	struct weston_view *view;
  	wl_fixed_t view_x, view_y;
  	int view_ix, view_iy;
  	int ix = wl_fixed_to_int(x);
  	int iy = wl_fixed_to_int(y);
  
  	wl_list_for_each(view, &compositor->view_list, link) {
  		if (!pixman_region32_contains_point(
  				&view->transform.boundingbox, ix, iy, NULL))
  			continue;
  
  		weston_view_from_global_fixed(view, x, y, &view_x, &view_y);
  		view_ix = wl_fixed_to_int(view_x);
  		view_iy = wl_fixed_to_int(view_y);
  
  		if (!pixman_region32_contains_point(&view->surface->input,
  						    view_ix, view_iy, NULL))
  			continue;
  
  		if (view->geometry.scissor_enabled &&
  		    !pixman_region32_contains_point(&view->geometry.scissor,
  						    view_ix, view_iy, NULL))
  			continue;
  
  		*vx = view_x;
  		*vy = view_y;
  		return view;
  	}
  
  	*vx = wl_fixed_from_int(-1000000);
  	*vy = wl_fixed_from_int(-1000000);
  	return NULL;
  }
  
  static void
  weston_compositor_repick(struct weston_compositor *compositor)
  {
  	struct weston_seat *seat;
  
  	if (!compositor->session_active)
  		return;
  
  	wl_list_for_each(seat, &compositor->seat_list, link)
  		weston_seat_repick(seat);
  }
  
  WL_EXPORT void
  weston_view_unmap(struct weston_view *view)
  {
  	struct weston_seat *seat;
  
  	if (!weston_view_is_mapped(view))
  		return;
  
  	weston_view_damage_below(view);
  	view->output = NULL;
  	view->plane = NULL;
  	weston_layer_entry_remove(&view->layer_link);
  	wl_list_remove(&view->link);
  	wl_list_init(&view->link);
  	view->output_mask = 0;
  	weston_surface_assign_output(view->surface);
  
  	if (weston_surface_is_mapped(view->surface))
  		return;
  
  	wl_list_for_each(seat, &view->surface->compositor->seat_list, link) {
  		struct weston_touch *touch = weston_seat_get_touch(seat);
  		struct weston_pointer *pointer = weston_seat_get_pointer(seat);
  		struct weston_keyboard *keyboard =
  			weston_seat_get_keyboard(seat);
  
  		if (keyboard && keyboard->focus == view->surface)
  			weston_keyboard_set_focus(keyboard, NULL);
  		if (pointer && pointer->focus == view)
  			weston_pointer_clear_focus(pointer);
  		if (touch && touch->focus == view)
  			weston_touch_set_focus(touch, NULL);
  	}
  }
  
  WL_EXPORT void
  weston_surface_unmap(struct weston_surface *surface)
  {
  	struct weston_view *view;
  
  	wl_list_for_each(view, &surface->views, surface_link)
  		weston_view_unmap(view);
  	surface->output = NULL;
  }
  
  static void
  weston_surface_reset_pending_buffer(struct weston_surface *surface)
  {
  	weston_surface_state_set_buffer(&surface->pending, NULL);
  	surface->pending.sx = 0;
  	surface->pending.sy = 0;
  	surface->pending.newly_attached = 0;
  	surface->pending.buffer_viewport.changed = 0;
  }
  
  WL_EXPORT void
  weston_view_destroy(struct weston_view *view)
  {
  	wl_signal_emit(&view->destroy_signal, view);
  
  	assert(wl_list_empty(&view->geometry.child_list));
  
  	if (weston_view_is_mapped(view)) {
  		weston_view_unmap(view);
  		weston_compositor_build_view_list(view->surface->compositor);
  	}
  
  	wl_list_remove(&view->link);
  	weston_layer_entry_remove(&view->layer_link);
  
  	pixman_region32_fini(&view->clip);
  	pixman_region32_fini(&view->geometry.scissor);
  	pixman_region32_fini(&view->transform.boundingbox);
  	pixman_region32_fini(&view->transform.opaque);
  
  	weston_view_set_transform_parent(view, NULL);
  
  	wl_list_remove(&view->surface_link);
  
  	free(view);
  }
  
  WL_EXPORT void
  weston_surface_destroy(struct weston_surface *surface)
  {
  	struct weston_frame_callback *cb, *next;
  	struct weston_view *ev, *nv;
  
  	if (--surface->ref_count > 0)
  		return;
  
  	assert(surface->resource == NULL);
  
  	wl_signal_emit(&surface->destroy_signal, surface);
  
  	assert(wl_list_empty(&surface->subsurface_list_pending));
  	assert(wl_list_empty(&surface->subsurface_list));
  
  	wl_list_for_each_safe(ev, nv, &surface->views, surface_link)
  		weston_view_destroy(ev);
  
  	weston_surface_state_fini(&surface->pending);
  
  	weston_buffer_reference(&surface->buffer_ref, NULL);
  
  	pixman_region32_fini(&surface->damage);
  	pixman_region32_fini(&surface->opaque);
  	pixman_region32_fini(&surface->input);
  
  	wl_list_for_each_safe(cb, next, &surface->frame_callback_list, link)
  		wl_resource_destroy(cb->resource);
  
  	weston_presentation_feedback_discard_list(&surface->feedback_list);
  
  	free(surface);
  }
  
  static void
  destroy_surface(struct wl_resource *resource)
  {
  	struct weston_surface *surface = wl_resource_get_user_data(resource);
  
  	assert(surface);
  
  	/* Set the resource to NULL, since we don't want to leave a
  	 * dangling pointer if the surface was refcounted and survives
  	 * the weston_surface_destroy() call. */
  	surface->resource = NULL;
  	weston_surface_destroy(surface);
  }
  
  static void
  weston_buffer_destroy_handler(struct wl_listener *listener, void *data)
  {
  	struct weston_buffer *buffer =
  		container_of(listener, struct weston_buffer, destroy_listener);
  
  	wl_signal_emit(&buffer->destroy_signal, buffer);
  	free(buffer);
  }
  
  WL_EXPORT struct weston_buffer *
  weston_buffer_from_resource(struct wl_resource *resource)
  {
  	struct weston_buffer *buffer;
  	struct wl_listener *listener;
  
  	listener = wl_resource_get_destroy_listener(resource,
  						    weston_buffer_destroy_handler);
  
  	if (listener)
  		return container_of(listener, struct weston_buffer,
  				    destroy_listener);
  
  	buffer = zalloc(sizeof *buffer);
  	if (buffer == NULL)
  		return NULL;
  
  	buffer->resource = resource;
  	wl_signal_init(&buffer->destroy_signal);
  	buffer->destroy_listener.notify = weston_buffer_destroy_handler;
  	buffer->y_inverted = 1;
  	wl_resource_add_destroy_listener(resource, &buffer->destroy_listener);
  
  	return buffer;
  }
  
  static void
  weston_buffer_reference_handle_destroy(struct wl_listener *listener,
  				       void *data)
  {
  	struct weston_buffer_reference *ref =
  		container_of(listener, struct weston_buffer_reference,
  			     destroy_listener);
  
  	assert((struct weston_buffer *)data == ref->buffer);
  	ref->buffer = NULL;
  }
  
  WL_EXPORT void
  weston_buffer_reference(struct weston_buffer_reference *ref,
  			struct weston_buffer *buffer)
  {
  	if (ref->buffer && buffer != ref->buffer) {
  		ref->buffer->busy_count--;
  		if (ref->buffer->busy_count == 0) {
  			assert(wl_resource_get_client(ref->buffer->resource));
  			wl_resource_queue_event(ref->buffer->resource,
  						WL_BUFFER_RELEASE);
  		}
  		wl_list_remove(&ref->destroy_listener.link);
  	}
  
  	if (buffer && buffer != ref->buffer) {
  		buffer->busy_count++;
  		wl_signal_add(&buffer->destroy_signal,
  			      &ref->destroy_listener);
  	}
  
  	ref->buffer = buffer;
  	ref->destroy_listener.notify = weston_buffer_reference_handle_destroy;
  }
  
  static void
  weston_surface_attach(struct weston_surface *surface,
  		      struct weston_buffer *buffer)
  {
  	weston_buffer_reference(&surface->buffer_ref, buffer);
  
  	if (!buffer) {
  		if (weston_surface_is_mapped(surface))
  			weston_surface_unmap(surface);
  	}
  
  	surface->compositor->renderer->attach(surface, buffer);
  
  	weston_surface_calculate_size_from_buffer(surface);
  	weston_presentation_feedback_discard_list(&surface->feedback_list);
  }
  
  WL_EXPORT void
  weston_compositor_damage_all(struct weston_compositor *compositor)
  {
  	struct weston_output *output;
  
  	wl_list_for_each(output, &compositor->output_list, link)
  		weston_output_damage(output);
  }
  
  WL_EXPORT void
  weston_output_damage(struct weston_output *output)
  {
  	struct weston_compositor *compositor = output->compositor;
  
  	pixman_region32_union(&compositor->primary_plane.damage,
  			      &compositor->primary_plane.damage,
  			      &output->region);
  	weston_output_schedule_repaint(output);
  }
  
  static void
  surface_flush_damage(struct weston_surface *surface)
  {
  	if (surface->buffer_ref.buffer &&
  	    wl_shm_buffer_get(surface->buffer_ref.buffer->resource))
  		surface->compositor->renderer->flush_damage(surface);
  
  	if (weston_timeline_enabled_ &&
  	    pixman_region32_not_empty(&surface->damage))
  		TL_POINT("core_flush_damage", TLP_SURFACE(surface),
  			 TLP_OUTPUT(surface->output), TLP_END);
  
  	pixman_region32_clear(&surface->damage);
  }
  
  static void
  view_accumulate_damage(struct weston_view *view,
  		       pixman_region32_t *opaque)
  {
  	pixman_region32_t damage;
  
  	pixman_region32_init(&damage);
  	if (view->transform.enabled) {
  		pixman_box32_t *extents;
  
  		extents = pixman_region32_extents(&view->surface->damage);
  		view_compute_bbox(view, extents, &damage);
  	} else {
  		pixman_region32_copy(&damage, &view->surface->damage);
  		pixman_region32_translate(&damage,
  					  view->geometry.x, view->geometry.y);
  	}
  
  	pixman_region32_intersect(&damage, &damage,
  				  &view->transform.boundingbox);
  	pixman_region32_subtract(&damage, &damage, opaque);
  	pixman_region32_union(&view->plane->damage,
  			      &view->plane->damage, &damage);
  	pixman_region32_fini(&damage);
  	pixman_region32_copy(&view->clip, opaque);
  	pixman_region32_union(opaque, opaque, &view->transform.opaque);
  }
  
  static void
  compositor_accumulate_damage(struct weston_compositor *ec)
  {
  	struct weston_plane *plane;
  	struct weston_view *ev;
  	pixman_region32_t opaque, clip;
  
  	pixman_region32_init(&clip);
  
  	wl_list_for_each(plane, &ec->plane_list, link) {
  		pixman_region32_copy(&plane->clip, &clip);
  
  		pixman_region32_init(&opaque);
  
  		wl_list_for_each(ev, &ec->view_list, link) {
  			if (ev->plane != plane)
  				continue;
  
  			view_accumulate_damage(ev, &opaque);
  		}
  
  		pixman_region32_union(&clip, &clip, &opaque);
  		pixman_region32_fini(&opaque);
  	}
  
  	pixman_region32_fini(&clip);
  
  	wl_list_for_each(ev, &ec->view_list, link)
  		ev->surface->touched = false;
  
  	wl_list_for_each(ev, &ec->view_list, link) {
  		if (ev->surface->touched)
  			continue;
  		ev->surface->touched = true;
  
  		surface_flush_damage(ev->surface);
  
  		/* Both the renderer and the backend have seen the buffer
  		 * by now. If renderer needs the buffer, it has its own
  		 * reference set. If the backend wants to keep the buffer
  		 * around for migrating the surface into a non-primary plane
  		 * later, keep_buffer is true. Otherwise, drop the core
  		 * reference now, and allow early buffer release. This enables
  		 * clients to use single-buffering.
  		 */
  		if (!ev->surface->keep_buffer)
  			weston_buffer_reference(&ev->surface->buffer_ref, NULL);
  	}
  }
  
  static void
  surface_stash_subsurface_views(struct weston_surface *surface)
  {
  	struct weston_subsurface *sub;
  
  	wl_list_for_each(sub, &surface->subsurface_list, parent_link) {
  		if (sub->surface == surface)
  			continue;
  
  		wl_list_insert_list(&sub->unused_views, &sub->surface->views);
  		wl_list_init(&sub->surface->views);
  
  		surface_stash_subsurface_views(sub->surface);
  	}
  }
  
  static void
  surface_free_unused_subsurface_views(struct weston_surface *surface)
  {
  	struct weston_subsurface *sub;
  	struct weston_view *view, *nv;
  
  	wl_list_for_each(sub, &surface->subsurface_list, parent_link) {
  		if (sub->surface == surface)
  			continue;
  
  		wl_list_for_each_safe(view, nv, &sub->unused_views, surface_link) {
  			weston_view_unmap (view);
  			weston_view_destroy(view);
  		}
  
  		surface_free_unused_subsurface_views(sub->surface);
  	}
  }
  
  static void
  view_list_add_subsurface_view(struct weston_compositor *compositor,
  			      struct weston_subsurface *sub,
  			      struct weston_view *parent)
  {
  	struct weston_subsurface *child;
  	struct weston_view *view = NULL, *iv;
  
  	if (!weston_surface_is_mapped(sub->surface))
  		return;
  
  	wl_list_for_each(iv, &sub->unused_views, surface_link) {
  		if (iv->geometry.parent == parent) {
  			view = iv;
  			break;
  		}
  	}
  
  	if (view) {
  		/* Put it back in the surface's list of views */
  		wl_list_remove(&view->surface_link);
  		wl_list_insert(&sub->surface->views, &view->surface_link);
  	} else {
  		view = weston_view_create(sub->surface);
  		weston_view_set_position(view,
  					 sub->position.x,
  					 sub->position.y);
  		weston_view_set_transform_parent(view, parent);
  	}
  
  	view->parent_view = parent;
  	weston_view_update_transform(view);
  
  	if (wl_list_empty(&sub->surface->subsurface_list)) {
  		wl_list_insert(compositor->view_list.prev, &view->link);
  		return;
  	}
  
  	wl_list_for_each(child, &sub->surface->subsurface_list, parent_link) {
  		if (child->surface == sub->surface)
  			wl_list_insert(compositor->view_list.prev, &view->link);
  		else
  			view_list_add_subsurface_view(compositor, child, view);
  	}
  }
  
  static void
  view_list_add(struct weston_compositor *compositor,
  	      struct weston_view *view)
  {
  	struct weston_subsurface *sub;
  
  	weston_view_update_transform(view);
  
  	if (wl_list_empty(&view->surface->subsurface_list)) {
  		wl_list_insert(compositor->view_list.prev, &view->link);
  		return;
  	}
  
  	wl_list_for_each(sub, &view->surface->subsurface_list, parent_link) {
  		if (sub->surface == view->surface)
  			wl_list_insert(compositor->view_list.prev, &view->link);
  		else
  			view_list_add_subsurface_view(compositor, sub, view);
  	}
  }
  
  static void
  weston_compositor_build_view_list(struct weston_compositor *compositor)
  {
  	struct weston_view *view;
  	struct weston_layer *layer;
  
  	wl_list_for_each(layer, &compositor->layer_list, link)
  		wl_list_for_each(view, &layer->view_list.link, layer_link.link)
  			surface_stash_subsurface_views(view->surface);
  
  	wl_list_init(&compositor->view_list);
  	wl_list_for_each(layer, &compositor->layer_list, link) {
  		wl_list_for_each(view, &layer->view_list.link, layer_link.link) {
  			view_list_add(compositor, view);
  		}
  	}
  
  	wl_list_for_each(layer, &compositor->layer_list, link)
  		wl_list_for_each(view, &layer->view_list.link, layer_link.link)
  			surface_free_unused_subsurface_views(view->surface);
  }
  
  static void
  weston_output_take_feedback_list(struct weston_output *output,
  				 struct weston_surface *surface)
  {
  	struct weston_view *view;
  	struct weston_presentation_feedback *feedback;
  	uint32_t flags = 0xffffffff;
  
  	if (wl_list_empty(&surface->feedback_list))
  		return;
  
  	/* All views must have the flag for the flag to survive. */
  	wl_list_for_each(view, &surface->views, surface_link) {
  		/* ignore views that are not on this output at all */
  		if (view->output_mask & (1u << output->id))
  			flags &= view->psf_flags;
  	}
  
  	wl_list_for_each(feedback, &surface->feedback_list, link)
  		feedback->psf_flags = flags;
  
  	wl_list_insert_list(&output->feedback_list, &surface->feedback_list);
  	wl_list_init(&surface->feedback_list);
  }
  
  static int
  weston_output_repaint(struct weston_output *output)
  {
  	struct weston_compositor *ec = output->compositor;
  	struct weston_view *ev;
  	struct weston_animation *animation, *next;
  	struct weston_frame_callback *cb, *cnext;
  	struct wl_list frame_callback_list;
  	pixman_region32_t output_damage;
  	int r;
  
  	if (output->destroying)
  		return 0;
  
  	TL_POINT("core_repaint_begin", TLP_OUTPUT(output), TLP_END);
  
  	/* Rebuild the surface list and update surface transforms up front. */
  	weston_compositor_build_view_list(ec);
  
  	if (output->assign_planes && !output->disable_planes) {
  		output->assign_planes(output);
  	} else {
  		wl_list_for_each(ev, &ec->view_list, link) {
  			weston_view_move_to_plane(ev, &ec->primary_plane);
  			ev->psf_flags = 0;
  		}
  	}
  
  	wl_list_init(&frame_callback_list);
  	wl_list_for_each(ev, &ec->view_list, link) {
  		/* Note: This operation is safe to do multiple times on the
  		 * same surface.
  		 */
  		if (ev->surface->output == output) {
  			wl_list_insert_list(&frame_callback_list,
  					    &ev->surface->frame_callback_list);
  			wl_list_init(&ev->surface->frame_callback_list);
  
  			weston_output_take_feedback_list(output, ev->surface);
  		}
  	}
  
  	compositor_accumulate_damage(ec);
  
  	pixman_region32_init(&output_damage);
  	pixman_region32_intersect(&output_damage,
  				  &ec->primary_plane.damage, &output->region);
  	pixman_region32_subtract(&output_damage,
  				 &output_damage, &ec->primary_plane.clip);
  
  	if (output->dirty)
  		weston_output_update_matrix(output);
  
  	r = output->repaint(output, &output_damage);
  
  	pixman_region32_fini(&output_damage);
  
  	output->repaint_needed = 0;
  
  	weston_compositor_repick(ec);
  
  	wl_list_for_each_safe(cb, cnext, &frame_callback_list, link) {
  		wl_callback_send_done(cb->resource, output->frame_time);
  		wl_resource_destroy(cb->resource);
  	}
  
  	wl_list_for_each_safe(animation, next, &output->animation_list, link) {
  		animation->frame_counter++;
  		animation->frame(animation, output, output->frame_time);
  	}
  
  	TL_POINT("core_repaint_posted", TLP_OUTPUT(output), TLP_END);
  
  	return r;
  }
  
  static void
  weston_output_schedule_repaint_reset(struct weston_output *output)
  {
  	output->repaint_scheduled = 0;
  	TL_POINT("core_repaint_exit_loop", TLP_OUTPUT(output), TLP_END);
  }
  
  static int
  output_repaint_timer_handler(void *data)
  {
  	struct weston_output *output = data;
  	struct weston_compositor *compositor = output->compositor;
  
  	if (output->repaint_needed &&
  	    compositor->state != WESTON_COMPOSITOR_SLEEPING &&
  	    compositor->state != WESTON_COMPOSITOR_OFFSCREEN &&
  	    weston_output_repaint(output) == 0)
  		return 0;
  
  	weston_output_schedule_repaint_reset(output);
  
  	return 0;
  }
  
  WL_EXPORT void
  weston_output_finish_frame(struct weston_output *output,
  			   const struct timespec *stamp,
  			   uint32_t presented_flags)
  {
  	struct weston_compositor *compositor = output->compositor;
  	int32_t refresh_nsec;
  	struct timespec now;
  	struct timespec gone;
  	int msec;
  
  	TL_POINT("core_repaint_finished", TLP_OUTPUT(output),
  		 TLP_VBLANK(stamp), TLP_END);
  
  	refresh_nsec = millihz_to_nsec(output->current_mode->refresh);
  	weston_presentation_feedback_present_list(&output->feedback_list,
  						  output, refresh_nsec, stamp,
  						  output->msc,
  						  presented_flags);
  
  	output->frame_time = stamp->tv_sec * 1000 + stamp->tv_nsec / 1000000;
  
  	weston_compositor_read_presentation_clock(compositor, &now);
  	timespec_sub(&gone, &now, stamp);
  	msec = (refresh_nsec - timespec_to_nsec(&gone)) / 1000000; /* floor */
  	msec -= compositor->repaint_msec;
  
  	if (msec < -1000 || msec > 1000) {
  		static bool warned;
  
  		if (!warned)
  			weston_log("Warning: computed repaint delay is "
  				   "insane: %d msec\n", msec);
  		warned = true;
  
  		msec = 0;
  	}
  
  	/* Called from restart_repaint_loop and restart happens already after
  	 * the deadline given by repaint_msec? In that case we delay until
  	 * the deadline of the next frame, to give clients a more predictable
  	 * timing of the repaint cycle to lock on. */
  	if (presented_flags == WP_PRESENTATION_FEEDBACK_INVALID && msec < 0)
  		msec += refresh_nsec / 1000000;
  
  	if (msec < 1)
  		output_repaint_timer_handler(output);
  	else
  		wl_event_source_timer_update(output->repaint_timer, msec);
  }
  
  static void
  idle_repaint(void *data)
  {
  	struct weston_output *output = data;
  
  	output->start_repaint_loop(output);
  }
  
  WL_EXPORT void
  weston_layer_entry_insert(struct weston_layer_entry *list,
  			  struct weston_layer_entry *entry)
  {
  	wl_list_insert(&list->link, &entry->link);
  	entry->layer = list->layer;
  }
  
  WL_EXPORT void
  weston_layer_entry_remove(struct weston_layer_entry *entry)
  {
  	wl_list_remove(&entry->link);
  	wl_list_init(&entry->link);
  	entry->layer = NULL;
  }
  
  WL_EXPORT void
  weston_layer_init(struct weston_layer *layer, struct wl_list *below)
  {
  	wl_list_init(&layer->view_list.link);
  	layer->view_list.layer = layer;
  	weston_layer_set_mask_infinite(layer);
  	if (below != NULL)
  		wl_list_insert(below, &layer->link);
  }
  
  WL_EXPORT void
  weston_layer_set_mask(struct weston_layer *layer,
  		      int x, int y, int width, int height)
  {
  	struct weston_view *view;
  
  	layer->mask.x1 = x;
  	layer->mask.x2 = x + width;
  	layer->mask.y1 = y;
  	layer->mask.y2 = y + height;
  
  	wl_list_for_each(view, &layer->view_list.link, layer_link.link) {
  		weston_view_geometry_dirty(view);
  	}
  }
  
  WL_EXPORT void
  weston_layer_set_mask_infinite(struct weston_layer *layer)
  {
  	weston_layer_set_mask(layer, INT32_MIN, INT32_MIN,
  				     UINT32_MAX, UINT32_MAX);
  }
  
  WL_EXPORT void
  weston_output_schedule_repaint(struct weston_output *output)
  {
  	struct weston_compositor *compositor = output->compositor;
  	struct wl_event_loop *loop;
  
  	if (compositor->state == WESTON_COMPOSITOR_SLEEPING ||
  	    compositor->state == WESTON_COMPOSITOR_OFFSCREEN)
  		return;
  
  	if (!output->repaint_needed)
  		TL_POINT("core_repaint_req", TLP_OUTPUT(output), TLP_END);
  
  	loop = wl_display_get_event_loop(compositor->wl_display);
  	output->repaint_needed = 1;
  	if (output->repaint_scheduled)
  		return;
  
  	wl_event_loop_add_idle(loop, idle_repaint, output);
  	output->repaint_scheduled = 1;
  	TL_POINT("core_repaint_enter_loop", TLP_OUTPUT(output), TLP_END);
  }
  
  WL_EXPORT void
  weston_compositor_schedule_repaint(struct weston_compositor *compositor)
  {
  	struct weston_output *output;
  
  	wl_list_for_each(output, &compositor->output_list, link)
  		weston_output_schedule_repaint(output);
  }
  
  static void
  surface_destroy(struct wl_client *client, struct wl_resource *resource)
  {
  	wl_resource_destroy(resource);
  }
  
  static void
  surface_attach(struct wl_client *client,
  	       struct wl_resource *resource,
  	       struct wl_resource *buffer_resource, int32_t sx, int32_t sy)
  {
  	struct weston_surface *surface = wl_resource_get_user_data(resource);
  	struct weston_buffer *buffer = NULL;
  
  	if (buffer_resource) {
  		buffer = weston_buffer_from_resource(buffer_resource);
  		if (buffer == NULL) {
  			wl_client_post_no_memory(client);
  			return;
  		}
  	}
  
  	/* Attach, attach, without commit in between does not send
  	 * wl_buffer.release. */
  	weston_surface_state_set_buffer(&surface->pending, buffer);
  
  	surface->pending.sx = sx;
  	surface->pending.sy = sy;
  	surface->pending.newly_attached = 1;
  }
  
  static void
  surface_damage(struct wl_client *client,
  	       struct wl_resource *resource,
  	       int32_t x, int32_t y, int32_t width, int32_t height)
  {
  	struct weston_surface *surface = wl_resource_get_user_data(resource);
  
  	if (width <= 0 || height <= 0)
  		return;
  
  	pixman_region32_union_rect(&surface->pending.damage_surface,
  				   &surface->pending.damage_surface,
  				   x, y, width, height);
  }
  
  static void
  surface_damage_buffer(struct wl_client *client,
  		      struct wl_resource *resource,
  		      int32_t x, int32_t y, int32_t width, int32_t height)
  {
  	struct weston_surface *surface = wl_resource_get_user_data(resource);
  
  	if (width <= 0 || height <= 0)
  		return;
  
  	pixman_region32_union_rect(&surface->pending.damage_buffer,
  				   &surface->pending.damage_buffer,
  				   x, y, width, height);
  }
  
  static void
  destroy_frame_callback(struct wl_resource *resource)
  {
  	struct weston_frame_callback *cb = wl_resource_get_user_data(resource);
  
  	wl_list_remove(&cb->link);
  	free(cb);
  }
  
  static void
  surface_frame(struct wl_client *client,
  	      struct wl_resource *resource, uint32_t callback)
  {
  	struct weston_frame_callback *cb;
  	struct weston_surface *surface = wl_resource_get_user_data(resource);
  
  	cb = malloc(sizeof *cb);
  	if (cb == NULL) {
  		wl_resource_post_no_memory(resource);
  		return;
  	}
  
  	cb->resource = wl_resource_create(client, &wl_callback_interface, 1,
  					  callback);
  	if (cb->resource == NULL) {
  		free(cb);
  		wl_resource_post_no_memory(resource);
  		return;
  	}
  
  	wl_resource_set_implementation(cb->resource, NULL, cb,
  				       destroy_frame_callback);
  
  	wl_list_insert(surface->pending.frame_callback_list.prev, &cb->link);
  }
  
  static void
  surface_set_opaque_region(struct wl_client *client,
  			  struct wl_resource *resource,
  			  struct wl_resource *region_resource)
  {
  	struct weston_surface *surface = wl_resource_get_user_data(resource);
  	struct weston_region *region;
  
  	if (region_resource) {
  		region = wl_resource_get_user_data(region_resource);
  		pixman_region32_copy(&surface->pending.opaque,
  				     &region->region);
  	} else {
  		pixman_region32_clear(&surface->pending.opaque);
  	}
  }
  
  static void
  surface_set_input_region(struct wl_client *client,
  			 struct wl_resource *resource,
  			 struct wl_resource *region_resource)
  {
  	struct weston_surface *surface = wl_resource_get_user_data(resource);
  	struct weston_region *region;
  
  	if (region_resource) {
  		region = wl_resource_get_user_data(region_resource);
  		pixman_region32_copy(&surface->pending.input,
  				     &region->region);
  	} else {
  		pixman_region32_fini(&surface->pending.input);
  		region_init_infinite(&surface->pending.input);
  	}
  }
  
  static void
  weston_surface_commit_subsurface_order(struct weston_surface *surface)
  {
  	struct weston_subsurface *sub;
  
  	wl_list_for_each_reverse(sub, &surface->subsurface_list_pending,
  				 parent_link_pending) {
  		wl_list_remove(&sub->parent_link);
  		wl_list_insert(&surface->subsurface_list, &sub->parent_link);
  	}
  }
  
  static void
  weston_surface_build_buffer_matrix(const struct weston_surface *surface,
  				   struct weston_matrix *matrix)
  {
  	const struct weston_buffer_viewport *vp = &surface->buffer_viewport;
  	double src_width, src_height, dest_width, dest_height;
  
  	weston_matrix_init(matrix);
  
  	if (vp->buffer.src_width == wl_fixed_from_int(-1)) {
  		src_width = surface->width_from_buffer;
  		src_height = surface->height_from_buffer;
  	} else {
  		src_width = wl_fixed_to_double(vp->buffer.src_width);
  		src_height = wl_fixed_to_double(vp->buffer.src_height);
  	}
  
  	if (vp->surface.width == -1) {
  		dest_width = src_width;
  		dest_height = src_height;
  	} else {
  		dest_width = vp->surface.width;
  		dest_height = vp->surface.height;
  	}
  
  	if (src_width != dest_width || src_height != dest_height)
  		weston_matrix_scale(matrix,
  				    src_width / dest_width,
  				    src_height / dest_height, 1);
  
  	if (vp->buffer.src_width != wl_fixed_from_int(-1))
  		weston_matrix_translate(matrix,
  					wl_fixed_to_double(vp->buffer.src_x),
  					wl_fixed_to_double(vp->buffer.src_y),
  					0);
  
  	switch (vp->buffer.transform) {
  	case WL_OUTPUT_TRANSFORM_FLIPPED:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_90:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_180:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_270:
  		weston_matrix_scale(matrix, -1, 1, 1);
  		weston_matrix_translate(matrix,
  					surface->width_from_buffer, 0, 0);
  		break;
  	}
  
  	switch (vp->buffer.transform) {
  	default:
  	case WL_OUTPUT_TRANSFORM_NORMAL:
  	case WL_OUTPUT_TRANSFORM_FLIPPED:
  		break;
  	case WL_OUTPUT_TRANSFORM_90:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_90:
  		weston_matrix_rotate_xy(matrix, 0, 1);
  		weston_matrix_translate(matrix,
  					surface->height_from_buffer, 0, 0);
  		break;
  	case WL_OUTPUT_TRANSFORM_180:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_180:
  		weston_matrix_rotate_xy(matrix, -1, 0);
  		weston_matrix_translate(matrix,
  					surface->width_from_buffer,
  					surface->height_from_buffer, 0);
  		break;
  	case WL_OUTPUT_TRANSFORM_270:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_270:
  		weston_matrix_rotate_xy(matrix, 0, -1);
  		weston_matrix_translate(matrix,
  					0, surface->width_from_buffer, 0);
  		break;
  	}
  
  	weston_matrix_scale(matrix, vp->buffer.scale, vp->buffer.scale, 1);
  }
  
  /* Translate pending damage in buffer co-ordinates to surface
   * co-ordinates and union it with a pixman_region32_t.
   * This should only be called after the buffer is attached.
   */
  static void
  apply_damage_buffer(pixman_region32_t *dest,
  		    struct weston_surface *surface,
  		    struct weston_surface_state *state)
  {
  	struct weston_buffer *buffer = surface->buffer_ref.buffer;
  
  	/* wl_surface.damage_buffer needs to be clipped to the buffer,
  	 * translated into surface co-ordinates and unioned with
  	 * any other surface damage.
  	 * None of this makes sense if there is no buffer though.
  	 */
  	if (buffer && pixman_region32_not_empty(&state->damage_buffer)) {
  		pixman_region32_t buffer_damage;
  
  		pixman_region32_intersect_rect(&state->damage_buffer,
  					       &state->damage_buffer,
  					       0, 0, buffer->width,
  					       buffer->height);
  		pixman_region32_init(&buffer_damage);
  		weston_matrix_transform_region(&buffer_damage,
  					       &surface->buffer_to_surface_matrix,
  					       &state->damage_buffer);
  		pixman_region32_union(dest, dest, &buffer_damage);
  		pixman_region32_fini(&buffer_damage);
  	}
  	/* We should clear this on commit even if there was no buffer */
  	pixman_region32_clear(&state->damage_buffer);
  }
  
  static void
  weston_surface_commit_state(struct weston_surface *surface,
  			    struct weston_surface_state *state)
  {
  	struct weston_view *view;
  	pixman_region32_t opaque;
  
  	/* wl_surface.set_buffer_transform */
  	/* wl_surface.set_buffer_scale */
  	/* wl_viewport.set */
  	surface->buffer_viewport = state->buffer_viewport;
  
  	/* wl_surface.attach */
  	if (state->newly_attached)
  		weston_surface_attach(surface, state->buffer);
  	weston_surface_state_set_buffer(state, NULL);
  
  	weston_surface_build_buffer_matrix(surface,
  					   &surface->surface_to_buffer_matrix);
  	weston_matrix_invert(&surface->buffer_to_surface_matrix,
  			     &surface->surface_to_buffer_matrix);
  
  	if (state->newly_attached || state->buffer_viewport.changed) {
  		weston_surface_update_size(surface);
  		if (surface->configure)
  			surface->configure(surface, state->sx, state->sy);
  	}
  
  	state->sx = 0;
  	state->sy = 0;
  	state->newly_attached = 0;
  	state->buffer_viewport.changed = 0;
  
  	/* wl_surface.damage and wl_surface.damage_buffer */
  	if (weston_timeline_enabled_ &&
  	    (pixman_region32_not_empty(&state->damage_surface) ||
  	     pixman_region32_not_empty(&state->damage_buffer)))
  		TL_POINT("core_commit_damage", TLP_SURFACE(surface), TLP_END);
  
  	pixman_region32_union(&surface->damage, &surface->damage,
  			      &state->damage_surface);
  
  	apply_damage_buffer(&surface->damage, surface, state);
  
  	pixman_region32_intersect_rect(&surface->damage, &surface->damage,
  				       0, 0, surface->width, surface->height);
  	pixman_region32_clear(&state->damage_surface);
  
  	/* wl_surface.set_opaque_region */
  	pixman_region32_init(&opaque);
  	pixman_region32_intersect_rect(&opaque, &state->opaque,
  				       0, 0, surface->width, surface->height);
  
  	if (!pixman_region32_equal(&opaque, &surface->opaque)) {
  		pixman_region32_copy(&surface->opaque, &opaque);
  		wl_list_for_each(view, &surface->views, surface_link)
  			weston_view_geometry_dirty(view);
  	}
  
  	pixman_region32_fini(&opaque);
  
  	/* wl_surface.set_input_region */
  	pixman_region32_intersect_rect(&surface->input, &state->input,
  				       0, 0, surface->width, surface->height);
  
  	/* wl_surface.frame */
  	wl_list_insert_list(&surface->frame_callback_list,
  			    &state->frame_callback_list);
  	wl_list_init(&state->frame_callback_list);
  
  	/* XXX:
  	 * What should happen with a feedback request, if there
  	 * is no wl_buffer attached for this commit?
  	 */
  
  	/* presentation.feedback */
  	wl_list_insert_list(&surface->feedback_list,
  			    &state->feedback_list);
  	wl_list_init(&state->feedback_list);
  }
  
  static void
  weston_surface_commit(struct weston_surface *surface)
  {
  	weston_surface_commit_state(surface, &surface->pending);
  
  	weston_surface_commit_subsurface_order(surface);
  
  	weston_surface_schedule_repaint(surface);
  }
  
  static void
  weston_subsurface_commit(struct weston_subsurface *sub);
  
  static void
  weston_subsurface_parent_commit(struct weston_subsurface *sub,
  				int parent_is_synchronized);
  
  static void
  surface_commit(struct wl_client *client, struct wl_resource *resource)
  {
  	struct weston_surface *surface = wl_resource_get_user_data(resource);
  	struct weston_subsurface *sub = weston_surface_to_subsurface(surface);
  
  	if (sub) {
  		weston_subsurface_commit(sub);
  		return;
  	}
  
  	weston_surface_commit(surface);
  
  	wl_list_for_each(sub, &surface->subsurface_list, parent_link) {
  		if (sub->surface != surface)
  			weston_subsurface_parent_commit(sub, 0);
  	}
  }
  
  static void
  surface_set_buffer_transform(struct wl_client *client,
  			     struct wl_resource *resource, int transform)
  {
  	struct weston_surface *surface = wl_resource_get_user_data(resource);
  
  	/* if wl_output.transform grows more members this will need to be updated. */
  	if (transform < 0 ||
  	    transform > WL_OUTPUT_TRANSFORM_FLIPPED_270) {
  		wl_resource_post_error(resource,
  			WL_SURFACE_ERROR_INVALID_TRANSFORM,
  			"buffer transform must be a valid transform "
  			"('%d' specified)", transform);
  		return;
  	}
  
  	surface->pending.buffer_viewport.buffer.transform = transform;
  	surface->pending.buffer_viewport.changed = 1;
  }
  
  static void
  surface_set_buffer_scale(struct wl_client *client,
  			 struct wl_resource *resource,
  			 int32_t scale)
  {
  	struct weston_surface *surface = wl_resource_get_user_data(resource);
  
  	if (scale < 1) {
  		wl_resource_post_error(resource,
  			WL_SURFACE_ERROR_INVALID_SCALE,
  			"buffer scale must be at least one "
  			"('%d' specified)", scale);
  		return;
  	}
  
  	surface->pending.buffer_viewport.buffer.scale = scale;
  	surface->pending.buffer_viewport.changed = 1;
  }
  
  static const struct wl_surface_interface surface_interface = {
  	surface_destroy,
  	surface_attach,
  	surface_damage,
  	surface_frame,
  	surface_set_opaque_region,
  	surface_set_input_region,
  	surface_commit,
  	surface_set_buffer_transform,
  	surface_set_buffer_scale,
  	surface_damage_buffer
  };
  
  static void
  compositor_create_surface(struct wl_client *client,
  			  struct wl_resource *resource, uint32_t id)
  {
  	struct weston_compositor *ec = wl_resource_get_user_data(resource);
  	struct weston_surface *surface;
  
  	surface = weston_surface_create(ec);
  	if (surface == NULL) {
  		wl_resource_post_no_memory(resource);
  		return;
  	}
  
  	surface->resource =
  		wl_resource_create(client, &wl_surface_interface,
  				   wl_resource_get_version(resource), id);
  	if (surface->resource == NULL) {
  		weston_surface_destroy(surface);
  		wl_resource_post_no_memory(resource);
  		return;
  	}
  	wl_resource_set_implementation(surface->resource, &surface_interface,
  				       surface, destroy_surface);
  
  	wl_signal_emit(&ec->create_surface_signal, surface);
  }
  
  static void
  destroy_region(struct wl_resource *resource)
  {
  	struct weston_region *region = wl_resource_get_user_data(resource);
  
  	pixman_region32_fini(&region->region);
  	free(region);
  }
  
  static void
  region_destroy(struct wl_client *client, struct wl_resource *resource)
  {
  	wl_resource_destroy(resource);
  }
  
  static void
  region_add(struct wl_client *client, struct wl_resource *resource,
  	   int32_t x, int32_t y, int32_t width, int32_t height)
  {
  	struct weston_region *region = wl_resource_get_user_data(resource);
  
  	pixman_region32_union_rect(&region->region, &region->region,
  				   x, y, width, height);
  }
  
  static void
  region_subtract(struct wl_client *client, struct wl_resource *resource,
  		int32_t x, int32_t y, int32_t width, int32_t height)
  {
  	struct weston_region *region = wl_resource_get_user_data(resource);
  	pixman_region32_t rect;
  
  	pixman_region32_init_rect(&rect, x, y, width, height);
  	pixman_region32_subtract(&region->region, &region->region, &rect);
  	pixman_region32_fini(&rect);
  }
  
  static const struct wl_region_interface region_interface = {
  	region_destroy,
  	region_add,
  	region_subtract
  };
  
  static void
  compositor_create_region(struct wl_client *client,
  			 struct wl_resource *resource, uint32_t id)
  {
  	struct weston_region *region;
  
  	region = malloc(sizeof *region);
  	if (region == NULL) {
  		wl_resource_post_no_memory(resource);
  		return;
  	}
  
  	pixman_region32_init(&region->region);
  
  	region->resource =
  		wl_resource_create(client, &wl_region_interface, 1, id);
  	if (region->resource == NULL) {
  		free(region);
  		wl_resource_post_no_memory(resource);
  		return;
  	}
  	wl_resource_set_implementation(region->resource, &region_interface,
  				       region, destroy_region);
  }
  
  static const struct wl_compositor_interface compositor_interface = {
  	compositor_create_surface,
  	compositor_create_region
  };
  
  static void
  weston_subsurface_commit_from_cache(struct weston_subsurface *sub)
  {
  	struct weston_surface *surface = sub->surface;
  
  	weston_surface_commit_state(surface, &sub->cached);
  	weston_buffer_reference(&sub->cached_buffer_ref, NULL);
  
  	weston_surface_commit_subsurface_order(surface);
  
  	weston_surface_schedule_repaint(surface);
  
  	sub->has_cached_data = 0;
  }
  
  static void
  weston_subsurface_commit_to_cache(struct weston_subsurface *sub)
  {
  	struct weston_surface *surface = sub->surface;
  
  	/*
  	 * If this commit would cause the surface to move by the
  	 * attach(dx, dy) parameters, the old damage region must be
  	 * translated to correspond to the new surface coordinate system
  	 * origin.
  	 */
  	pixman_region32_translate(&sub->cached.damage_surface,
  				  -surface->pending.sx, -surface->pending.sy);
  	pixman_region32_union(&sub->cached.damage_surface,
  			      &sub->cached.damage_surface,
  			      &surface->pending.damage_surface);
  	pixman_region32_clear(&surface->pending.damage_surface);
  
  	if (surface->pending.newly_attached) {
  		sub->cached.newly_attached = 1;
  		weston_surface_state_set_buffer(&sub->cached,
  						surface->pending.buffer);
  		weston_buffer_reference(&sub->cached_buffer_ref,
  					surface->pending.buffer);
  		weston_presentation_feedback_discard_list(
  					&sub->cached.feedback_list);
  	}
  	sub->cached.sx += surface->pending.sx;
  	sub->cached.sy += surface->pending.sy;
  
  	apply_damage_buffer(&sub->cached.damage_surface, surface, &surface->pending);
  
  	sub->cached.buffer_viewport.changed |=
  		surface->pending.buffer_viewport.changed;
  	sub->cached.buffer_viewport.buffer =
  		surface->pending.buffer_viewport.buffer;
  	sub->cached.buffer_viewport.surface =
  		surface->pending.buffer_viewport.surface;
  
  	weston_surface_reset_pending_buffer(surface);
  
  	pixman_region32_copy(&sub->cached.opaque, &surface->pending.opaque);
  
  	pixman_region32_copy(&sub->cached.input, &surface->pending.input);
  
  	wl_list_insert_list(&sub->cached.frame_callback_list,
  			    &surface->pending.frame_callback_list);
  	wl_list_init(&surface->pending.frame_callback_list);
  
  	wl_list_insert_list(&sub->cached.feedback_list,
  			    &surface->pending.feedback_list);
  	wl_list_init(&surface->pending.feedback_list);
  
  	sub->has_cached_data = 1;
  }
  
  static bool
  weston_subsurface_is_synchronized(struct weston_subsurface *sub)
  {
  	while (sub) {
  		if (sub->synchronized)
  			return true;
  
  		if (!sub->parent)
  			return false;
  
  		sub = weston_surface_to_subsurface(sub->parent);
  	}
  
  	return false;
  }
  
  static void
  weston_subsurface_commit(struct weston_subsurface *sub)
  {
  	struct weston_surface *surface = sub->surface;
  	struct weston_subsurface *tmp;
  
  	/* Recursive check for effectively synchronized. */
  	if (weston_subsurface_is_synchronized(sub)) {
  		weston_subsurface_commit_to_cache(sub);
  	} else {
  		if (sub->has_cached_data) {
  			/* flush accumulated state from cache */
  			weston_subsurface_commit_to_cache(sub);
  			weston_subsurface_commit_from_cache(sub);
  		} else {
  			weston_surface_commit(surface);
  		}
  
  		wl_list_for_each(tmp, &surface->subsurface_list, parent_link) {
  			if (tmp->surface != surface)
  				weston_subsurface_parent_commit(tmp, 0);
  		}
  	}
  }
  
  static void
  weston_subsurface_synchronized_commit(struct weston_subsurface *sub)
  {
  	struct weston_surface *surface = sub->surface;
  	struct weston_subsurface *tmp;
  
  	/* From now on, commit_from_cache the whole sub-tree, regardless of
  	 * the synchronized mode of each child. This sub-surface or some
  	 * of its ancestors were synchronized, so we are synchronized
  	 * all the way down.
  	 */
  
  	if (sub->has_cached_data)
  		weston_subsurface_commit_from_cache(sub);
  
  	wl_list_for_each(tmp, &surface->subsurface_list, parent_link) {
  		if (tmp->surface != surface)
  			weston_subsurface_parent_commit(tmp, 1);
  	}
  }
  
  static void
  weston_subsurface_parent_commit(struct weston_subsurface *sub,
  				int parent_is_synchronized)
  {
  	struct weston_view *view;
  	if (sub->position.set) {
  		wl_list_for_each(view, &sub->surface->views, surface_link)
  			weston_view_set_position(view,
  						 sub->position.x,
  						 sub->position.y);
  
  		sub->position.set = 0;
  	}
  
  	if (parent_is_synchronized || sub->synchronized)
  		weston_subsurface_synchronized_commit(sub);
  }
  
  static int
  subsurface_get_label(struct weston_surface *surface, char *buf, size_t len)
  {
  	return snprintf(buf, len, "sub-surface");
  }
  
  static void
  subsurface_configure(struct weston_surface *surface, int32_t dx, int32_t dy)
  {
  	struct weston_compositor *compositor = surface->compositor;
  	struct weston_view *view;
  
  	wl_list_for_each(view, &surface->views, surface_link)
  		weston_view_set_position(view,
  					 view->geometry.x + dx,
  					 view->geometry.y + dy);
  
  	/* No need to check parent mappedness, because if parent is not
  	 * mapped, parent is not in a visible layer, so this sub-surface
  	 * will not be drawn either.
  	 */
  	if (!weston_surface_is_mapped(surface)) {
  		struct weston_output *output;
  
  		/* Cannot call weston_view_update_transform(),
  		 * because that would call it also for the parent surface,
  		 * which might not be mapped yet. That would lead to
  		 * inconsistent state, where the window could never be
  		 * mapped.
  		 *
  		 * Instead just assign any output, to make
  		 * weston_surface_is_mapped() return true, so that when the
  		 * parent surface does get mapped, this one will get
  		 * included, too. See view_list_add().
  		 */
  		assert(!wl_list_empty(&compositor->output_list));
  		output = container_of(compositor->output_list.next,
  				      struct weston_output, link);
  
  		surface->output = output;
  		weston_surface_update_output_mask(surface, 1u << output->id);
  	}
  }
  
  static struct weston_subsurface *
  weston_surface_to_subsurface(struct weston_surface *surface)
  {
  	if (surface->configure == subsurface_configure)
  		return surface->configure_private;
  
  	return NULL;
  }
  
  WL_EXPORT struct weston_surface *
  weston_surface_get_main_surface(struct weston_surface *surface)
  {
  	struct weston_subsurface *sub;
  
  	while (surface && (sub = weston_surface_to_subsurface(surface)))
  		surface = sub->parent;
  
  	return surface;
  }
  
  WL_EXPORT int
  weston_surface_set_role(struct weston_surface *surface,
  			const char *role_name,
  			struct wl_resource *error_resource,
  			uint32_t error_code)
  {
  	assert(role_name);
  
  	if (surface->role_name == NULL ||
  	    surface->role_name == role_name ||
  	    strcmp(surface->role_name, role_name) == 0) {
  		surface->role_name = role_name;
  
  		return 0;
  	}
  
  	wl_resource_post_error(error_resource, error_code,
  			       "Cannot assign role %s to wl_surface@%d,"
  			       " already has role %s\n",
  			       role_name,
  			       wl_resource_get_id(surface->resource),
  			       surface->role_name);
  	return -1;
  }
  
  WL_EXPORT void
  weston_surface_set_label_func(struct weston_surface *surface,
  			      int (*desc)(struct weston_surface *,
  					  char *, size_t))
  {
  	surface->get_label = desc;
  	surface->timeline.force_refresh = 1;
  }
  
  /** Get the size of surface contents
   *
   * \param surface The surface to query.
   * \param width Returns the width of raw contents.
   * \param height Returns the height of raw contents.
   *
   * Retrieves the raw surface content size in pixels for the given surface.
   * This is the whole content size in buffer pixels. If the surface
   * has no content or the renderer does not implement this feature,
   * zeroes are returned.
   *
   * This function is used to determine the buffer size needed for
   * a weston_surface_copy_content() call.
   */
  WL_EXPORT void
  weston_surface_get_content_size(struct weston_surface *surface,
  				int *width, int *height)
  {
  	struct weston_renderer *rer = surface->compositor->renderer;
  
  	if (!rer->surface_get_content_size) {
  		*width = 0;
  		*height = 0;
  		return;
  	}
  
  	rer->surface_get_content_size(surface, width, height);
  }
  
  /** Copy surface contents to system memory.
   *
   * \param surface The surface to copy from.
   * \param target Pointer to the target memory buffer.
   * \param size Size of the target buffer in bytes.
   * \param src_x X location on contents to copy from.
   * \param src_y Y location on contents to copy from.
   * \param width Width in pixels of the area to copy.
   * \param height Height in pixels of the area to copy.
   * \return 0 for success, -1 for failure.
   *
   * Surface contents are maintained by the renderer. They can be in a
   * reserved weston_buffer or as a copy, e.g. a GL texture, or something
   * else.
   *
   * Surface contents are copied into memory pointed to by target,
   * which has size bytes of space available. The target memory
   * may be larger than needed, but being smaller returns an error.
   * The extra bytes in target may or may not be written; their content is
   * unspecified. Size must be large enough to hold the image.
   *
   * The image in the target memory will be arranged in rows from
   * top to bottom, and pixels on a row from left to right. The pixel
   * format is PIXMAN_a8b8g8r8, 4 bytes per pixel, and stride is exactly
   * width * 4.
   *
   * Parameters src_x and src_y define the upper-left corner in buffer
   * coordinates (pixels) to copy from. Parameters width and height
   * define the size of the area to copy in pixels.
   *
   * The rectangle defined by src_x, src_y, width, height must fit in
   * the surface contents. Otherwise an error is returned.
   *
   * Use surface_get_data_size to determine the content size; the
   * needed target buffer size and rectangle limits.
   *
   * CURRENT IMPLEMENTATION RESTRICTIONS:
   * - the machine must be little-endian due to Pixman formats.
   *
   * NOTE: Pixman formats are premultiplied.
   */
  WL_EXPORT int
  weston_surface_copy_content(struct weston_surface *surface,
  			    void *target, size_t size,
  			    int src_x, int src_y,
  			    int width, int height)
  {
  	struct weston_renderer *rer = surface->compositor->renderer;
  	int cw, ch;
  	const size_t bytespp = 4; /* PIXMAN_a8b8g8r8 */
  
  	if (!rer->surface_copy_content)
  		return -1;
  
  	weston_surface_get_content_size(surface, &cw, &ch);
  
  	if (src_x < 0 || src_y < 0)
  		return -1;
  
  	if (width <= 0 || height <= 0)
  		return -1;
  
  	if (src_x + width > cw || src_y + height > ch)
  		return -1;
  
  	if (width * bytespp * height > size)
  		return -1;
  
  	return rer->surface_copy_content(surface, target, size,
  					 src_x, src_y, width, height);
  }
  
  static void
  subsurface_set_position(struct wl_client *client,
  			struct wl_resource *resource, int32_t x, int32_t y)
  {
  	struct weston_subsurface *sub = wl_resource_get_user_data(resource);
  
  	if (!sub)
  		return;
  
  	sub->position.x = x;
  	sub->position.y = y;
  	sub->position.set = 1;
  }
  
  static struct weston_subsurface *
  subsurface_from_surface(struct weston_surface *surface)
  {
  	struct weston_subsurface *sub;
  
  	sub = weston_surface_to_subsurface(surface);
  	if (sub)
  		return sub;
  
  	wl_list_for_each(sub, &surface->subsurface_list, parent_link)
  		if (sub->surface == surface)
  			return sub;
  
  	return NULL;
  }
  
  static struct weston_subsurface *
  subsurface_sibling_check(struct weston_subsurface *sub,
  			 struct weston_surface *surface,
  			 const char *request)
  {
  	struct weston_subsurface *sibling;
  
  	sibling = subsurface_from_surface(surface);
  
  	if (!sibling) {
  		wl_resource_post_error(sub->resource,
  			WL_SUBSURFACE_ERROR_BAD_SURFACE,
  			"%s: wl_surface@%d is not a parent or sibling",
  			request, wl_resource_get_id(surface->resource));
  		return NULL;
  	}
  
  	if (sibling->parent != sub->parent) {
  		wl_resource_post_error(sub->resource,
  			WL_SUBSURFACE_ERROR_BAD_SURFACE,
  			"%s: wl_surface@%d has a different parent",
  			request, wl_resource_get_id(surface->resource));
  		return NULL;
  	}
  
  	return sibling;
  }
  
  static void
  subsurface_place_above(struct wl_client *client,
  		       struct wl_resource *resource,
  		       struct wl_resource *sibling_resource)
  {
  	struct weston_subsurface *sub = wl_resource_get_user_data(resource);
  	struct weston_surface *surface =
  		wl_resource_get_user_data(sibling_resource);
  	struct weston_subsurface *sibling;
  
  	if (!sub)
  		return;
  
  	sibling = subsurface_sibling_check(sub, surface, "place_above");
  	if (!sibling)
  		return;
  
  	wl_list_remove(&sub->parent_link_pending);
  	wl_list_insert(sibling->parent_link_pending.prev,
  		       &sub->parent_link_pending);
  }
  
  static void
  subsurface_place_below(struct wl_client *client,
  		       struct wl_resource *resource,
  		       struct wl_resource *sibling_resource)
  {
  	struct weston_subsurface *sub = wl_resource_get_user_data(resource);
  	struct weston_surface *surface =
  		wl_resource_get_user_data(sibling_resource);
  	struct weston_subsurface *sibling;
  
  	if (!sub)
  		return;
  
  	sibling = subsurface_sibling_check(sub, surface, "place_below");
  	if (!sibling)
  		return;
  
  	wl_list_remove(&sub->parent_link_pending);
  	wl_list_insert(&sibling->parent_link_pending,
  		       &sub->parent_link_pending);
  }
  
  static void
  subsurface_set_sync(struct wl_client *client, struct wl_resource *resource)
  {
  	struct weston_subsurface *sub = wl_resource_get_user_data(resource);
  
  	if (sub)
  		sub->synchronized = 1;
  }
  
  static void
  subsurface_set_desync(struct wl_client *client, struct wl_resource *resource)
  {
  	struct weston_subsurface *sub = wl_resource_get_user_data(resource);
  
  	if (sub && sub->synchronized) {
  		sub->synchronized = 0;
  
  		/* If sub became effectively desynchronized, flush. */
  		if (!weston_subsurface_is_synchronized(sub))
  			weston_subsurface_synchronized_commit(sub);
  	}
  }
  
  static void
  weston_subsurface_unlink_parent(struct weston_subsurface *sub)
  {
  	wl_list_remove(&sub->parent_link);
  	wl_list_remove(&sub->parent_link_pending);
  	wl_list_remove(&sub->parent_destroy_listener.link);
  	sub->parent = NULL;
  }
  
  static void
  weston_subsurface_destroy(struct weston_subsurface *sub);
  
  static void
  subsurface_handle_surface_destroy(struct wl_listener *listener, void *data)
  {
  	struct weston_subsurface *sub =
  		container_of(listener, struct weston_subsurface,
  			     surface_destroy_listener);
  	assert(data == sub->surface);
  
  	/* The protocol object (wl_resource) is left inert. */
  	if (sub->resource)
  		wl_resource_set_user_data(sub->resource, NULL);
  
  	weston_subsurface_destroy(sub);
  }
  
  static void
  subsurface_handle_parent_destroy(struct wl_listener *listener, void *data)
  {
  	struct weston_subsurface *sub =
  		container_of(listener, struct weston_subsurface,
  			     parent_destroy_listener);
  	assert(data == sub->parent);
  	assert(sub->surface != sub->parent);
  
  	if (weston_surface_is_mapped(sub->surface))
  		weston_surface_unmap(sub->surface);
  
  	weston_subsurface_unlink_parent(sub);
  }
  
  static void
  subsurface_resource_destroy(struct wl_resource *resource)
  {
  	struct weston_subsurface *sub = wl_resource_get_user_data(resource);
  
  	if (sub)
  		weston_subsurface_destroy(sub);
  }
  
  static void
  subsurface_destroy(struct wl_client *client, struct wl_resource *resource)
  {
  	wl_resource_destroy(resource);
  }
  
  static void
  weston_subsurface_link_parent(struct weston_subsurface *sub,
  			      struct weston_surface *parent)
  {
  	sub->parent = parent;
  	sub->parent_destroy_listener.notify = subsurface_handle_parent_destroy;
  	wl_signal_add(&parent->destroy_signal,
  		      &sub->parent_destroy_listener);
  
  	wl_list_insert(&parent->subsurface_list, &sub->parent_link);
  	wl_list_insert(&parent->subsurface_list_pending,
  		       &sub->parent_link_pending);
  }
  
  static void
  weston_subsurface_link_surface(struct weston_subsurface *sub,
  			       struct weston_surface *surface)
  {
  	sub->surface = surface;
  	sub->surface_destroy_listener.notify =
  		subsurface_handle_surface_destroy;
  	wl_signal_add(&surface->destroy_signal,
  		      &sub->surface_destroy_listener);
  }
  
  static void
  weston_subsurface_destroy(struct weston_subsurface *sub)
  {
  	struct weston_view *view, *next;
  
  	assert(sub->surface);
  
  	if (sub->resource) {
  		assert(weston_surface_to_subsurface(sub->surface) == sub);
  		assert(sub->parent_destroy_listener.notify ==
  		       subsurface_handle_parent_destroy);
  
  		wl_list_for_each_safe(view, next, &sub->surface->views, surface_link) {
  			weston_view_unmap(view);
  			weston_view_destroy(view);
  		}
  
  		if (sub->parent)
  			weston_subsurface_unlink_parent(sub);
  
  		weston_surface_state_fini(&sub->cached);
  		weston_buffer_reference(&sub->cached_buffer_ref, NULL);
  
  		sub->surface->configure = NULL;
  		sub->surface->configure_private = NULL;
  		weston_surface_set_label_func(sub->surface, NULL);
  	} else {
  		/* the dummy weston_subsurface for the parent itself */
  		assert(sub->parent_destroy_listener.notify == NULL);
  		wl_list_remove(&sub->parent_link);
  		wl_list_remove(&sub->parent_link_pending);
  	}
  
  	wl_list_remove(&sub->surface_destroy_listener.link);
  	free(sub);
  }
  
  static const struct wl_subsurface_interface subsurface_implementation = {
  	subsurface_destroy,
  	subsurface_set_position,
  	subsurface_place_above,
  	subsurface_place_below,
  	subsurface_set_sync,
  	subsurface_set_desync
  };
  
  static struct weston_subsurface *
  weston_subsurface_create(uint32_t id, struct weston_surface *surface,
  			 struct weston_surface *parent)
  {
  	struct weston_subsurface *sub;
  	struct wl_client *client = wl_resource_get_client(surface->resource);
  
  	sub = zalloc(sizeof *sub);
  	if (sub == NULL)
  		return NULL;
  
  	wl_list_init(&sub->unused_views);
  
  	sub->resource =
  		wl_resource_create(client, &wl_subsurface_interface, 1, id);
  	if (!sub->resource) {
  		free(sub);
  		return NULL;
  	}
  
  	wl_resource_set_implementation(sub->resource,
  				       &subsurface_implementation,
  				       sub, subsurface_resource_destroy);
  	weston_subsurface_link_surface(sub, surface);
  	weston_subsurface_link_parent(sub, parent);
  	weston_surface_state_init(&sub->cached);
  	sub->cached_buffer_ref.buffer = NULL;
  	sub->synchronized = 1;
  
  	return sub;
  }
  
  /* Create a dummy subsurface for having the parent itself in its
   * sub-surface lists. Makes stacking order manipulation easy.
   */
  static struct weston_subsurface *
  weston_subsurface_create_for_parent(struct weston_surface *parent)
  {
  	struct weston_subsurface *sub;
  
  	sub = zalloc(sizeof *sub);
  	if (sub == NULL)
  		return NULL;
  
  	weston_subsurface_link_surface(sub, parent);
  	sub->parent = parent;
  	wl_list_insert(&parent->subsurface_list, &sub->parent_link);
  	wl_list_insert(&parent->subsurface_list_pending,
  		       &sub->parent_link_pending);
  
  	return sub;
  }
  
  static void
  subcompositor_get_subsurface(struct wl_client *client,
  			     struct wl_resource *resource,
  			     uint32_t id,
  			     struct wl_resource *surface_resource,
  			     struct wl_resource *parent_resource)
  {
  	struct weston_surface *surface =
  		wl_resource_get_user_data(surface_resource);
  	struct weston_surface *parent =
  		wl_resource_get_user_data(parent_resource);
  	struct weston_subsurface *sub;
  	static const char where[] = "get_subsurface: wl_subsurface@";
  
  	if (surface == parent) {
  		wl_resource_post_error(resource,
  			WL_SUBCOMPOSITOR_ERROR_BAD_SURFACE,
  			"%s%d: wl_surface@%d cannot be its own parent",
  			where, id, wl_resource_get_id(surface_resource));
  		return;
  	}
  
  	if (weston_surface_to_subsurface(surface)) {
  		wl_resource_post_error(resource,
  			WL_SUBCOMPOSITOR_ERROR_BAD_SURFACE,
  			"%s%d: wl_surface@%d is already a sub-surface",
  			where, id, wl_resource_get_id(surface_resource));
  		return;
  	}
  
  	if (weston_surface_set_role(surface, "wl_subsurface", resource,
  				    WL_SUBCOMPOSITOR_ERROR_BAD_SURFACE) < 0)
  		return;
  
  	if (weston_surface_get_main_surface(parent) == surface) {
  		wl_resource_post_error(resource,
  			WL_SUBCOMPOSITOR_ERROR_BAD_SURFACE,
  			"%s%d: wl_surface@%d is an ancestor of parent",
  			where, id, wl_resource_get_id(surface_resource));
  		return;
  	}
  
  	/* make sure the parent is in its own list */
  	if (wl_list_empty(&parent->subsurface_list)) {
  		if (!weston_subsurface_create_for_parent(parent)) {
  			wl_resource_post_no_memory(resource);
  			return;
  		}
  	}
  
  	sub = weston_subsurface_create(id, surface, parent);
  	if (!sub) {
  		wl_resource_post_no_memory(resource);
  		return;
  	}
  
  	surface->configure = subsurface_configure;
  	surface->configure_private = sub;
  	weston_surface_set_label_func(surface, subsurface_get_label);
  }
  
  static void
  subcompositor_destroy(struct wl_client *client, struct wl_resource *resource)
  {
  	wl_resource_destroy(resource);
  }
  
  static const struct wl_subcompositor_interface subcompositor_interface = {
  	subcompositor_destroy,
  	subcompositor_get_subsurface
  };
  
  static void
  bind_subcompositor(struct wl_client *client,
  		   void *data, uint32_t version, uint32_t id)
  {
  	struct weston_compositor *compositor = data;
  	struct wl_resource *resource;
  
  	resource =
  		wl_resource_create(client, &wl_subcompositor_interface, 1, id);
  	if (resource == NULL) {
  		wl_client_post_no_memory(client);
  		return;
  	}
  	wl_resource_set_implementation(resource, &subcompositor_interface,
  				       compositor, NULL);
  }
  
  /** Set a DPMS mode on all of the compositor's outputs
   *
   * \param compositor The compositor instance
   * \param state The DPMS state the outputs will be set to
   */
  static void
  weston_compositor_dpms(struct weston_compositor *compositor,
  		       enum dpms_enum state)
  {
          struct weston_output *output;
  
          wl_list_for_each(output, &compositor->output_list, link)
  		if (output->set_dpms)
  			output->set_dpms(output, state);
  }
  
  /** Restores the compositor to active status
   *
   * \param compositor The compositor instance
   *
   * If the compositor was in a sleeping mode, all outputs are powered
   * back on via DPMS.  Otherwise if the compositor was inactive
   * (idle/locked, offscreen, or sleeping) then the compositor's wake
   * signal will fire.
   *
   * Restarts the idle timer.
   */
  WL_EXPORT void
  weston_compositor_wake(struct weston_compositor *compositor)
  {
  	uint32_t old_state = compositor->state;
  
  	/* The state needs to be changed before emitting the wake
  	 * signal because that may try to schedule a repaint which
  	 * will not work if the compositor is still sleeping */
  	compositor->state = WESTON_COMPOSITOR_ACTIVE;
  
  	switch (old_state) {
  	case WESTON_COMPOSITOR_SLEEPING:
  		weston_compositor_dpms(compositor, WESTON_DPMS_ON);
  		/* fall through */
  	case WESTON_COMPOSITOR_IDLE:
  	case WESTON_COMPOSITOR_OFFSCREEN:
  		wl_signal_emit(&compositor->wake_signal, compositor);
  		/* fall through */
  	default:
  		wl_event_source_timer_update(compositor->idle_source,
  					     compositor->idle_time * 1000);
  	}
  }
  
  /** Turns off rendering and frame events for the compositor.
   *
   * \param compositor The compositor instance
   *
   * This is used for example to prevent further rendering while the
   * compositor is shutting down.
   *
   * \note When offscreen state is entered, outputs will be powered
   * back on if they were sleeping (in DPMS off mode), even though
   * no rendering will be performed.
   *
   * Stops the idle timer.
   */
  WL_EXPORT void
  weston_compositor_offscreen(struct weston_compositor *compositor)
  {
  	switch (compositor->state) {
  	case WESTON_COMPOSITOR_OFFSCREEN:
  		return;
  	case WESTON_COMPOSITOR_SLEEPING:
  		weston_compositor_dpms(compositor, WESTON_DPMS_ON);
  		/* fall through */
  	default:
  		compositor->state = WESTON_COMPOSITOR_OFFSCREEN;
  		wl_event_source_timer_update(compositor->idle_source, 0);
  	}
  }
  
  /** Powers down all attached output devices
   *
   * \param compositor The compositor instance
   *
   * Causes rendering to the outputs to cease, and no frame events to be
   * sent.  Only powers down the outputs if the compositor is not already
   * in sleep mode.
   *
   * Stops the idle timer.
   */
  WL_EXPORT void
  weston_compositor_sleep(struct weston_compositor *compositor)
  {
  	if (compositor->state == WESTON_COMPOSITOR_SLEEPING)
  		return;
  
  	wl_event_source_timer_update(compositor->idle_source, 0);
  	compositor->state = WESTON_COMPOSITOR_SLEEPING;
  	weston_compositor_dpms(compositor, WESTON_DPMS_OFF);
  }
  
  /** Sets compositor to idle mode
   *
   * \param data The compositor instance
   *
   * This is called when the idle timer fires.  Once the compositor is in
   * idle mode it requires a wake action (e.g. via
   * weston_compositor_wake()) to restore it.  The compositor's
   * idle_signal will be triggered when the idle event occurs.
   *
   * Idleness can be inhibited by setting the compositor's idle_inhibit
   * property.
   */
  static int
  idle_handler(void *data)
  {
  	struct weston_compositor *compositor = data;
  
  	if (compositor->idle_inhibit)
  		return 1;
  
  	compositor->state = WESTON_COMPOSITOR_IDLE;
  	wl_signal_emit(&compositor->idle_signal, compositor);
  
  	return 1;
  }
  
  WL_EXPORT void
  weston_plane_init(struct weston_plane *plane,
  			struct weston_compositor *ec,
  			int32_t x, int32_t y)
  {
  	pixman_region32_init(&plane->damage);
  	pixman_region32_init(&plane->clip);
  	plane->x = x;
  	plane->y = y;
  	plane->compositor = ec;
  
  	/* Init the link so that the call to wl_list_remove() when releasing
  	 * the plane without ever stacking doesn't lead to a crash */
  	wl_list_init(&plane->link);
  }
  
  WL_EXPORT void
  weston_plane_release(struct weston_plane *plane)
  {
  	struct weston_view *view;
  
  	pixman_region32_fini(&plane->damage);
  	pixman_region32_fini(&plane->clip);
  
  	wl_list_for_each(view, &plane->compositor->view_list, link) {
  		if (view->plane == plane)
  			view->plane = NULL;
  	}
  
  	wl_list_remove(&plane->link);
  }
  
  WL_EXPORT void
  weston_compositor_stack_plane(struct weston_compositor *ec,
  			      struct weston_plane *plane,
  			      struct weston_plane *above)
  {
  	if (above)
  		wl_list_insert(above->link.prev, &plane->link);
  	else
  		wl_list_insert(&ec->plane_list, &plane->link);
  }
  
  static void unbind_resource(struct wl_resource *resource)
  {
  	wl_list_remove(wl_resource_get_link(resource));
  }
  
  static void
  bind_output(struct wl_client *client,
  	    void *data, uint32_t version, uint32_t id)
  {
  	struct weston_output *output = data;
  	struct weston_mode *mode;
  	struct wl_resource *resource;
  
  	resource = wl_resource_create(client, &wl_output_interface,
  				      version, id);
  	if (resource == NULL) {
  		wl_client_post_no_memory(client);
  		return;
  	}
  
  	wl_list_insert(&output->resource_list, wl_resource_get_link(resource));
  	wl_resource_set_implementation(resource, NULL, data, unbind_resource);
  
  	wl_output_send_geometry(resource,
  				output->x,
  				output->y,
  				output->mm_width,
  				output->mm_height,
  				output->subpixel,
  				output->make, output->model,
  				output->transform);
  	if (version >= WL_OUTPUT_SCALE_SINCE_VERSION)
  		wl_output_send_scale(resource,
  				     output->current_scale);
  
  	wl_list_for_each (mode, &output->mode_list, link) {
  		wl_output_send_mode(resource,
  				    mode->flags,
  				    mode->width,
  				    mode->height,
  				    mode->refresh);
  	}
  
  	if (version >= WL_OUTPUT_DONE_SINCE_VERSION)
  		wl_output_send_done(resource);
  }
  
  /* Move other outputs when one is removed so the space remains contiguos. */
  static void
  weston_compositor_remove_output(struct weston_compositor *compositor,
  				struct weston_output *remove_output)
  {
  	struct weston_output *output;
  	int offset = 0;
  
  	wl_list_for_each(output, &compositor->output_list, link) {
  		if (output == remove_output) {
  			offset = output->width;
  			continue;
  		}
  
  		if (offset > 0) {
  			weston_output_move(output,
  					   output->x - offset, output->y);
  			output->dirty = 1;
  		}
  	}
  }
  
  WL_EXPORT void
  weston_output_destroy(struct weston_output *output)
  {
  	struct wl_resource *resource;
  	struct weston_view *view;
  
  	output->destroying = 1;
  
  	wl_list_for_each(view, &output->compositor->view_list, link) {
  		if (view->output_mask & (1u << output->id))
  			weston_view_assign_output(view);
  	}
  
  	wl_event_source_remove(output->repaint_timer);
  
  	weston_presentation_feedback_discard_list(&output->feedback_list);
  
  	weston_compositor_remove_output(output->compositor, output);
  	wl_list_remove(&output->link);
  
  	wl_signal_emit(&output->compositor->output_destroyed_signal, output);
  	wl_signal_emit(&output->destroy_signal, output);
  
  	free(output->name);
  	pixman_region32_fini(&output->region);
  	pixman_region32_fini(&output->previous_damage);
  	output->compositor->output_id_pool &= ~(1u << output->id);
  
  	wl_resource_for_each(resource, &output->resource_list) {
  		wl_resource_set_destructor(resource, NULL);
  	}
  
  	wl_global_destroy(output->global);
  }
  
  WL_EXPORT void
  weston_output_update_matrix(struct weston_output *output)
  {
  	float magnification;
  
  	weston_matrix_init(&output->matrix);
  	weston_matrix_translate(&output->matrix, -output->x, -output->y, 0);
  
  	if (output->zoom.active) {
  		magnification = 1 / (1 - output->zoom.spring_z.current);
  		weston_output_update_zoom(output);
  		weston_matrix_translate(&output->matrix, -output->zoom.trans_x,
  					-output->zoom.trans_y, 0);
  		weston_matrix_scale(&output->matrix, magnification,
  				    magnification, 1.0);
  	}
  
  	switch (output->transform) {
  	case WL_OUTPUT_TRANSFORM_FLIPPED:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_90:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_180:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_270:
  		weston_matrix_translate(&output->matrix, -output->width, 0, 0);
  		weston_matrix_scale(&output->matrix, -1, 1, 1);
  		break;
  	}
  
  	switch (output->transform) {
  	default:
  	case WL_OUTPUT_TRANSFORM_NORMAL:
  	case WL_OUTPUT_TRANSFORM_FLIPPED:
  		break;
  	case WL_OUTPUT_TRANSFORM_90:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_90:
  		weston_matrix_translate(&output->matrix, 0, -output->height, 0);
  		weston_matrix_rotate_xy(&output->matrix, 0, 1);
  		break;
  	case WL_OUTPUT_TRANSFORM_180:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_180:
  		weston_matrix_translate(&output->matrix,
  					-output->width, -output->height, 0);
  		weston_matrix_rotate_xy(&output->matrix, -1, 0);
  		break;
  	case WL_OUTPUT_TRANSFORM_270:
  	case WL_OUTPUT_TRANSFORM_FLIPPED_270:
  		weston_matrix_translate(&output->matrix, -output->width, 0, 0);
  		weston_matrix_rotate_xy(&output->matrix, 0, -1);
  		break;
  	}
  
  	if (output->current_scale != 1)
  		weston_matrix_scale(&output->matrix,
  				    output->current_scale,
  				    output->current_scale, 1);
  
  	output->dirty = 0;
  
  	weston_matrix_invert(&output->inverse_matrix, &output->matrix);
  }
  
  static void
  weston_output_transform_scale_init(struct weston_output *output, uint32_t transform, uint32_t scale)
  {
  	output->transform = transform;
  	output->native_scale = scale;
  	output->current_scale = scale;
  
  	convert_size_by_transform_scale(&output->width, &output->height,
  					output->current_mode->width,
  					output->current_mode->height,
  					transform, scale);
  }
  
  static void
  weston_output_init_geometry(struct weston_output *output, int x, int y)
  {
  	output->x = x;
  	output->y = y;
  
  	pixman_region32_init(&output->previous_damage);
  	pixman_region32_init_rect(&output->region, x, y,
  				  output->width,
  				  output->height);
  }
  
  WL_EXPORT void
  weston_output_move(struct weston_output *output, int x, int y)
  {
  	struct wl_resource *resource;
  
  	output->move_x = x - output->x;
  	output->move_y = y - output->y;
  
  	if (output->move_x == 0 && output->move_y == 0)
  		return;
  
  	weston_output_init_geometry(output, x, y);
  
  	output->dirty = 1;
  
  	/* Move views on this output. */
  	wl_signal_emit(&output->compositor->output_moved_signal, output);
  
  	/* Notify clients of the change for output position. */
  	wl_resource_for_each(resource, &output->resource_list) {
  		wl_output_send_geometry(resource,
  					output->x,
  					output->y,
  					output->mm_width,
  					output->mm_height,
  					output->subpixel,
  					output->make,
  					output->model,
  					output->transform);
  
  		if (wl_resource_get_version(resource) >= WL_OUTPUT_DONE_SINCE_VERSION)
  			wl_output_send_done(resource);
  	}
  }
  
  /** Initialize a weston_output object's parameters
   *
   * \param output     The weston_output object to initialize
   * \param c          The output's compositor
   * \param x          x coordinate for the output in global coordinate space
   * \param y          y coordinate for the output in global coordinate space
   * \param mm_width   Physical width of the output as reported by the backend
   * \param mm_height  Physical height of the output as reported by the backend
   * \param transform  Rotation of the output
   * \param scale      Native scaling factor for the output
   *
   * Sets up the transformation, zoom, and geometry of the output using
   * the input properties.
   *
   * Establishes a repaint timer for the output with the relevant display
   * object's event loop.  See output_repaint_timer_handler().
   *
   * The output is assigned an ID.  Weston can support up to 32 distinct
   * outputs, with IDs numbered from 0-31; the compositor's output_id_pool
   * is referred to and used to find the first available ID number, and
   * then this ID is marked as used in output_id_pool.
   *
   * The output is also assigned a Wayland global with the wl_output
   * external interface.
   */
  WL_EXPORT void
  weston_output_init(struct weston_output *output, struct weston_compositor *c,
  		   int x, int y, int mm_width, int mm_height, uint32_t transform,
  		   int32_t scale)
  {
  	struct wl_event_loop *loop;
  
  	/* Verify we haven't reached the limit of 32 available output IDs */
  	assert(ffs(~c->output_id_pool) > 0);
  
  	output->compositor = c;
  	output->x = x;
  	output->y = y;
  	output->mm_width = mm_width;
  	output->mm_height = mm_height;
  	output->dirty = 1;
  	output->original_scale = scale;
  
  	weston_output_transform_scale_init(output, transform, scale);
  	weston_output_init_zoom(output);
  
  	weston_output_init_geometry(output, x, y);
  	weston_output_damage(output);
  
  	wl_signal_init(&output->frame_signal);
  	wl_signal_init(&output->destroy_signal);
  	wl_list_init(&output->animation_list);
  	wl_list_init(&output->resource_list);
  	wl_list_init(&output->feedback_list);
  	wl_list_init(&output->link);
  
  	loop = wl_display_get_event_loop(c->wl_display);
  	output->repaint_timer = wl_event_loop_add_timer(loop,
  					output_repaint_timer_handler, output);
  
  	/* Invert the output id pool and look for the lowest numbered
  	 * switch (the least significant bit).  Take that bit's position
  	 * as our ID, and mark it used in the compositor's output_id_pool.
  	 */
  	output->id = ffs(~output->compositor->output_id_pool) - 1;
  	output->compositor->output_id_pool |= 1u << output->id;
  
  	output->global =
  		wl_global_create(c->wl_display, &wl_output_interface, 2,
  				 output, bind_output);
  }
  
  /** Adds an output to the compositor's output list and
   *  send the compositor's output_created signal.
   *
   * \param compositor The compositor instance.
   * \param output The output to be added.
   */
  WL_EXPORT void
  weston_compositor_add_output(struct weston_compositor *compositor,
                               struct weston_output *output)
  {
  	wl_list_insert(compositor->output_list.prev, &output->link);
  	wl_signal_emit(&compositor->output_created_signal, output);
  }
  
  WL_EXPORT void
  weston_output_transform_coordinate(struct weston_output *output,
  				   double device_x, double device_y,
  				   double *x, double *y)
  {
  	struct weston_vector p = { {
  		device_x,
  		device_y,
  		0.0,
  		1.0 } };
  
  	weston_matrix_transform(&output->inverse_matrix, &p);
  
  	*x = p.f[0] / p.f[3];
  	*y = p.f[1] / p.f[3];
  }
  
  static void
  destroy_viewport(struct wl_resource *resource)
  {
  	struct weston_surface *surface =
  		wl_resource_get_user_data(resource);
  
  	surface->viewport_resource = NULL;
  	surface->pending.buffer_viewport.buffer.src_width =
  		wl_fixed_from_int(-1);
  	surface->pending.buffer_viewport.surface.width = -1;
  	surface->pending.buffer_viewport.changed = 1;
  }
  
  static void
  viewport_destroy(struct wl_client *client,
  		 struct wl_resource *resource)
  {
  	wl_resource_destroy(resource);
  }
  
  static void
  viewport_set(struct wl_client *client,
  	     struct wl_resource *resource,
  	     wl_fixed_t src_x,
  	     wl_fixed_t src_y,
  	     wl_fixed_t src_width,
  	     wl_fixed_t src_height,
  	     int32_t dst_width,
  	     int32_t dst_height)
  {
  	struct weston_surface *surface =
  		wl_resource_get_user_data(resource);
  
  	assert(surface->viewport_resource != NULL);
  
  	if (wl_fixed_to_double(src_width) < 0 ||
  	    wl_fixed_to_double(src_height) < 0) {
  		wl_resource_post_error(resource,
  			WL_VIEWPORT_ERROR_BAD_VALUE,
  			"source dimensions must be non-negative (%fx%f)",
  			wl_fixed_to_double(src_width),
  			wl_fixed_to_double(src_height));
  		return;
  	}
  
  	if (dst_width <= 0 || dst_height <= 0) {
  		wl_resource_post_error(resource,
  			WL_VIEWPORT_ERROR_BAD_VALUE,
  			"destination dimensions must be positive (%dx%d)",
  			dst_width, dst_height);
  		return;
  	}
  
  	surface->pending.buffer_viewport.buffer.src_x = src_x;
  	surface->pending.buffer_viewport.buffer.src_y = src_y;
  	surface->pending.buffer_viewport.buffer.src_width = src_width;
  	surface->pending.buffer_viewport.buffer.src_height = src_height;
  	surface->pending.buffer_viewport.surface.width = dst_width;
  	surface->pending.buffer_viewport.surface.height = dst_height;
  	surface->pending.buffer_viewport.changed = 1;
  }
  
  static void
  viewport_set_source(struct wl_client *client,
  		    struct wl_resource *resource,
  		    wl_fixed_t src_x,
  		    wl_fixed_t src_y,
  		    wl_fixed_t src_width,
  		    wl_fixed_t src_height)
  {
  	struct weston_surface *surface =
  		wl_resource_get_user_data(resource);
  
  	assert(surface->viewport_resource != NULL);
  
  	if (src_width == wl_fixed_from_int(-1) &&
  	    src_height == wl_fixed_from_int(-1)) {
  		/* unset source size */
  		surface->pending.buffer_viewport.buffer.src_width =
  			wl_fixed_from_int(-1);
  		surface->pending.buffer_viewport.changed = 1;
  		return;
  	}
  
  	if (src_width <= 0 || src_height <= 0) {
  		wl_resource_post_error(resource,
  			WL_VIEWPORT_ERROR_BAD_VALUE,
  			"source size must be positive (%fx%f)",
  			wl_fixed_to_double(src_width),
  			wl_fixed_to_double(src_height));
  		return;
  	}
  
  	surface->pending.buffer_viewport.buffer.src_x = src_x;
  	surface->pending.buffer_viewport.buffer.src_y = src_y;
  	surface->pending.buffer_viewport.buffer.src_width = src_width;
  	surface->pending.buffer_viewport.buffer.src_height = src_height;
  	surface->pending.buffer_viewport.changed = 1;
  }
  
  static void
  viewport_set_destination(struct wl_client *client,
  			 struct wl_resource *resource,
  			 int32_t dst_width,
  			 int32_t dst_height)
  {
  	struct weston_surface *surface =
  		wl_resource_get_user_data(resource);
  
  	assert(surface->viewport_resource != NULL);
  
  	if (dst_width == -1 && dst_height == -1) {
  		/* unset destination size */
  		surface->pending.buffer_viewport.surface.width = -1;
  		surface->pending.buffer_viewport.changed = 1;
  		return;
  	}
  
  	if (dst_width <= 0 || dst_height <= 0) {
  		wl_resource_post_error(resource,
  			WL_VIEWPORT_ERROR_BAD_VALUE,
  			"destination size must be positive (%dx%d)",
  			dst_width, dst_height);
  		return;
  	}
  
  	surface->pending.buffer_viewport.surface.width = dst_width;
  	surface->pending.buffer_viewport.surface.height = dst_height;
  	surface->pending.buffer_viewport.changed = 1;
  }
  
  static const struct wl_viewport_interface viewport_interface = {
  	viewport_destroy,
  	viewport_set,
  	viewport_set_source,
  	viewport_set_destination
  };
  
  static void
  scaler_destroy(struct wl_client *client,
  	       struct wl_resource *resource)
  {
  	wl_resource_destroy(resource);
  }
  
  static void
  scaler_get_viewport(struct wl_client *client,
  		    struct wl_resource *scaler,
  		    uint32_t id,
  		    struct wl_resource *surface_resource)
  {
  	int version = wl_resource_get_version(scaler);
  	struct weston_surface *surface =
  		wl_resource_get_user_data(surface_resource);
  	struct wl_resource *resource;
  
  	if (surface->viewport_resource) {
  		wl_resource_post_error(scaler,
  			WL_SCALER_ERROR_VIEWPORT_EXISTS,
  			"a viewport for that surface already exists");
  		return;
  	}
  
  	resource = wl_resource_create(client, &wl_viewport_interface,
  				      version, id);
  	if (resource == NULL) {
  		wl_client_post_no_memory(client);
  		return;
  	}
  
  	wl_resource_set_implementation(resource, &viewport_interface,
  				       surface, destroy_viewport);
  
  	surface->viewport_resource = resource;
  }
  
  static const struct wl_scaler_interface scaler_interface = {
  	scaler_destroy,
  	scaler_get_viewport
  };
  
  static void
  bind_scaler(struct wl_client *client,
  	    void *data, uint32_t version, uint32_t id)
  {
  	struct wl_resource *resource;
  
  	resource = wl_resource_create(client, &wl_scaler_interface,
  				      version, id);
  	if (resource == NULL) {
  		wl_client_post_no_memory(client);
  		return;
  	}
  
  	wl_resource_set_implementation(resource, &scaler_interface,
  				       NULL, NULL);
  }
  
  static void
  destroy_presentation_feedback(struct wl_resource *feedback_resource)
  {
  	struct weston_presentation_feedback *feedback;
  
  	feedback = wl_resource_get_user_data(feedback_resource);
  
  	wl_list_remove(&feedback->link);
  	free(feedback);
  }
  
  static void
  presentation_destroy(struct wl_client *client, struct wl_resource *resource)
  {
  	wl_resource_destroy(resource);
  }
  
  static void
  presentation_feedback(struct wl_client *client,
  		      struct wl_resource *presentation_resource,
  		      struct wl_resource *surface_resource,
  		      uint32_t callback)
  {
  	struct weston_surface *surface;
  	struct weston_presentation_feedback *feedback;
  
  	surface = wl_resource_get_user_data(surface_resource);
  
  	feedback = zalloc(sizeof *feedback);
  	if (feedback == NULL)
  		goto err_calloc;
  
  	feedback->resource = wl_resource_create(client,
  					&wp_presentation_feedback_interface,
  					1, callback);
  	if (!feedback->resource)
  		goto err_create;
  
  	wl_resource_set_implementation(feedback->resource, NULL, feedback,
  				       destroy_presentation_feedback);
  
  	wl_list_insert(&surface->pending.feedback_list, &feedback->link);
  
  	return;
  
  err_create:
  	free(feedback);
  
  err_calloc:
  	wl_client_post_no_memory(client);
  }
  
  static const struct wp_presentation_interface presentation_implementation = {
  	presentation_destroy,
  	presentation_feedback
  };
  
  static void
  bind_presentation(struct wl_client *client,
  		  void *data, uint32_t version, uint32_t id)
  {
  	struct weston_compositor *compositor = data;
  	struct wl_resource *resource;
  
  	resource = wl_resource_create(client, &wp_presentation_interface,
  				      version, id);
  	if (resource == NULL) {
  		wl_client_post_no_memory(client);
  		return;
  	}
  
  	wl_resource_set_implementation(resource, &presentation_implementation,
  				       compositor, NULL);
  	wp_presentation_send_clock_id(resource, compositor->presentation_clock);
  }
  
  static void
  compositor_bind(struct wl_client *client,
  		void *data, uint32_t version, uint32_t id)
  {
  	struct weston_compositor *compositor = data;
  	struct wl_resource *resource;
  
  	resource = wl_resource_create(client, &wl_compositor_interface,
  				      version, id);
  	if (resource == NULL) {
  		wl_client_post_no_memory(client);
  		return;
  	}
  
  	wl_resource_set_implementation(resource, &compositor_interface,
  				       compositor, NULL);
  }
  
  WL_EXPORT int
  weston_environment_get_fd(const char *env)
  {
  	char *e, *end;
  	int fd, flags;
  
  	e = getenv(env);
  	if (!e)
  		return -1;
  	fd = strtol(e, &end, 0);
  	if (*end != '\0')
  		return -1;
  
  	flags = fcntl(fd, F_GETFD);
  	if (flags == -1)
  		return -1;
  
  	fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
  	unsetenv(env);
  
  	return fd;
  }
  
  static void
  timeline_key_binding_handler(struct weston_keyboard *keyboard, uint32_t time,
  			     uint32_t key, void *data)
  {
  	struct weston_compositor *compositor = data;
  
  	if (weston_timeline_enabled_)
  		weston_timeline_close();
  	else
  		weston_timeline_open(compositor);
  }
  
  /** Create the compositor.
   *
   * This functions creates and initializes a compositor instance.
   *
   * \param display The Wayland display to be used.
   * \param user_data A pointer to an object that can later be retrieved
   * using the \ref weston_compositor_get_user_data function.
   * \return The compositor instance on success or NULL on failure.
   */
  WL_EXPORT struct weston_compositor *
  weston_compositor_create(struct wl_display *display, void *user_data)
  {
  	struct weston_compositor *ec;
  	struct wl_event_loop *loop;
  
  	ec = zalloc(sizeof *ec);
  	if (!ec)
  		return NULL;
  
  	ec->wl_display = display;
  	ec->user_data = user_data;
  	wl_signal_init(&ec->destroy_signal);
  	wl_signal_init(&ec->create_surface_signal);
  	wl_signal_init(&ec->activate_signal);
  	wl_signal_init(&ec->transform_signal);
  	wl_signal_init(&ec->kill_signal);
  	wl_signal_init(&ec->idle_signal);
  	wl_signal_init(&ec->wake_signal);
  	wl_signal_init(&ec->show_input_panel_signal);
  	wl_signal_init(&ec->hide_input_panel_signal);
  	wl_signal_init(&ec->update_input_panel_signal);
  	wl_signal_init(&ec->seat_created_signal);
  	wl_signal_init(&ec->output_created_signal);
  	wl_signal_init(&ec->output_destroyed_signal);
  	wl_signal_init(&ec->output_moved_signal);
  	wl_signal_init(&ec->session_signal);
  	ec->session_active = 1;
  
  	ec->output_id_pool = 0;
  	ec->repaint_msec = DEFAULT_REPAINT_WINDOW;
  
  	if (!wl_global_create(ec->wl_display, &wl_compositor_interface, 4,
  			      ec, compositor_bind))
  		goto fail;
  
  	if (!wl_global_create(ec->wl_display, &wl_subcompositor_interface, 1,
  			      ec, bind_subcompositor))
  		goto fail;
  
  	if (!wl_global_create(ec->wl_display, &wl_scaler_interface, 2,
  			      ec, bind_scaler))
  		goto fail;
  
  	if (!wl_global_create(ec->wl_display, &wp_presentation_interface, 1,
  			      ec, bind_presentation))
  		goto fail;
  
  	wl_list_init(&ec->view_list);
  	wl_list_init(&ec->plane_list);
  	wl_list_init(&ec->layer_list);
  	wl_list_init(&ec->seat_list);
  	wl_list_init(&ec->output_list);
  	wl_list_init(&ec->key_binding_list);
  	wl_list_init(&ec->modifier_binding_list);
  	wl_list_init(&ec->button_binding_list);
  	wl_list_init(&ec->touch_binding_list);
  	wl_list_init(&ec->axis_binding_list);
  	wl_list_init(&ec->debug_binding_list);
  
  	weston_plane_init(&ec->primary_plane, ec, 0, 0);
  	weston_compositor_stack_plane(ec, &ec->primary_plane, NULL);
  
  	wl_data_device_manager_init(ec->wl_display);
  
  	wl_display_init_shm(ec->wl_display);
  
  	loop = wl_display_get_event_loop(ec->wl_display);
  	ec->idle_source = wl_event_loop_add_timer(loop, idle_handler, ec);
  
  	weston_layer_init(&ec->fade_layer, &ec->layer_list);
  	weston_layer_init(&ec->cursor_layer, &ec->fade_layer.link);
  
  	weston_compositor_add_debug_binding(ec, KEY_T,
  					    timeline_key_binding_handler, ec);
  
  	return ec;
  
  fail:
  	free(ec);
  	return NULL;
  }
  
  WL_EXPORT void
  weston_compositor_shutdown(struct weston_compositor *ec)
  {
  	struct weston_output *output, *next;
  
  	wl_event_source_remove(ec->idle_source);
  
  	/* Destroy all outputs associated with this compositor */
  	wl_list_for_each_safe(output, next, &ec->output_list, link)
  		output->destroy(output);
  
  	if (ec->renderer)
  		ec->renderer->destroy(ec);
  
  	weston_binding_list_destroy_all(&ec->key_binding_list);
  	weston_binding_list_destroy_all(&ec->modifier_binding_list);
  	weston_binding_list_destroy_all(&ec->button_binding_list);
  	weston_binding_list_destroy_all(&ec->touch_binding_list);
  	weston_binding_list_destroy_all(&ec->axis_binding_list);
  	weston_binding_list_destroy_all(&ec->debug_binding_list);
  
  	weston_plane_release(&ec->primary_plane);
  }
  
  WL_EXPORT void
  weston_compositor_exit_with_code(struct weston_compositor *compositor,
  				 int exit_code)
  {
  	if (compositor->exit_code == EXIT_SUCCESS)
  		compositor->exit_code = exit_code;
  
  	weston_compositor_exit(compositor);
  }
  
  WL_EXPORT void
  weston_compositor_set_default_pointer_grab(struct weston_compositor *ec,
  			const struct weston_pointer_grab_interface *interface)
  {
  	struct weston_seat *seat;
  
  	ec->default_pointer_grab = interface;
  	wl_list_for_each(seat, &ec->seat_list, link) {
  		struct weston_pointer *pointer = weston_seat_get_pointer(seat);
  
  		if (pointer)
  			weston_pointer_set_default_grab(pointer, interface);
  	}
  }
  
  WL_EXPORT int
  weston_compositor_set_presentation_clock(struct weston_compositor *compositor,
  					 clockid_t clk_id)
  {
  	struct timespec ts;
  
  	if (clock_gettime(clk_id, &ts) < 0)
  		return -1;
  
  	compositor->presentation_clock = clk_id;
  
  	return 0;
  }
  
  /*
   * For choosing the software clock, when the display hardware or API
   * does not expose a compatible presentation timestamp.
   */
  WL_EXPORT int
  weston_compositor_set_presentation_clock_software(
  					struct weston_compositor *compositor)
  {
  	/* In order of preference */
  	static const clockid_t clocks[] = {
  		CLOCK_MONOTONIC_RAW,	/* no jumps, no crawling */
  		CLOCK_MONOTONIC_COARSE,	/* no jumps, may crawl, fast & coarse */
  		CLOCK_MONOTONIC,	/* no jumps, may crawl */
  		CLOCK_REALTIME_COARSE,	/* may jump and crawl, fast & coarse */
  		CLOCK_REALTIME		/* may jump and crawl */
  	};
  	unsigned i;
  
  	for (i = 0; i < ARRAY_LENGTH(clocks); i++)
  		if (weston_compositor_set_presentation_clock(compositor,
  							     clocks[i]) == 0)
  			return 0;
  
  	weston_log("Error: no suitable presentation clock available.\n");
  
  	return -1;
  }
  
  /** Read the current time from the Presentation clock
   *
   * \param compositor
   * \param ts[out] The current time.
   *
   * \note Reading the current time in user space is always imprecise to some
   * degree.
   *
   * This function is never meant to fail. If reading the clock does fail,
   * an error message is logged and a zero time is returned. Callers are not
   * supposed to detect or react to failures.
   */
  WL_EXPORT void
  weston_compositor_read_presentation_clock(
  			const struct weston_compositor *compositor,
  			struct timespec *ts)
  {
  	static bool warned;
  	int ret;
  
  	ret = clock_gettime(compositor->presentation_clock, ts);
  	if (ret < 0) {
  		ts->tv_sec = 0;
  		ts->tv_nsec = 0;
  
  		if (!warned)
  			weston_log("Error: failure to read "
  				   "the presentation clock %#x: '%m' (%d)\n",
  				   compositor->presentation_clock, errno);
  		warned = true;
  	}
  }
  
  /** Import dmabuf buffer into current renderer
   *
   * \param compositor
   * \param buffer the dmabuf buffer to import
   * \return true on usable buffers, false otherwise
   *
   * This function tests that the linux_dmabuf_buffer is usable
   * for the current renderer. Returns false on unusable buffers. Usually
   * usability is tested by importing the dmabufs for composition.
   *
   * This hook is also used for detecting if the renderer supports
   * dmabufs at all. If the renderer hook is NULL, dmabufs are not
   * supported.
   * */
  WL_EXPORT bool
  weston_compositor_import_dmabuf(struct weston_compositor *compositor,
  				struct linux_dmabuf_buffer *buffer)
  {
  	struct weston_renderer *renderer;
  
  	renderer = compositor->renderer;
  
  	if (renderer->import_dmabuf == NULL)
  		return false;
  
  	return renderer->import_dmabuf(compositor, buffer);
  }
  
  WL_EXPORT void
  weston_version(int *major, int *minor, int *micro)
  {
  	*major = WESTON_VERSION_MAJOR;
  	*minor = WESTON_VERSION_MINOR;
  	*micro = WESTON_VERSION_MICRO;
  }
  
  WL_EXPORT void *
  weston_load_module(const char *name, const char *entrypoint)
  {
  	const char *builddir = getenv("WESTON_BUILD_DIR");
  	char path[PATH_MAX];
  	void *module, *init;
  
  	if (name == NULL)
  		return NULL;
  
  	if (name[0] != '/') {
  		if (builddir)
  			snprintf(path, sizeof path, "%s/.libs/%s", builddir, name);
  		else
  			snprintf(path, sizeof path, "%s/%s", MODULEDIR, name);
  	} else {
  		snprintf(path, sizeof path, "%s", name);
  	}
  
  	module = dlopen(path, RTLD_NOW | RTLD_NOLOAD);
  	if (module) {
  		weston_log("Module '%s' already loaded\n", path);
  		dlclose(module);
  		return NULL;
  	}
  
  	weston_log("Loading module '%s'\n", path);
  	module = dlopen(path, RTLD_NOW);
  	if (!module) {
  		weston_log("Failed to load module: %s\n", dlerror());
  		return NULL;
  	}
  
  	init = dlsym(module, entrypoint);
  	if (!init) {
  		weston_log("Failed to lookup init function: %s\n", dlerror());
  		dlclose(module);
  		return NULL;
  	}
  
  	return init;
  }
  
  
  /** Destroys the compositor.
   *
   * This function cleans up the compositor state and destroys it.
   *
   * \param compositor The compositor to be destroyed.
   */
  WL_EXPORT void
  weston_compositor_destroy(struct weston_compositor *compositor)
  {
  	/* prevent further rendering while shutting down */
  	compositor->state = WESTON_COMPOSITOR_OFFSCREEN;
  
  	wl_signal_emit(&compositor->destroy_signal, compositor);
  
  	weston_compositor_xkb_destroy(compositor);
  
  	if (compositor->backend)
  		compositor->backend->destroy(compositor);
  	free(compositor);
  }
  
  /** Instruct the compositor to exit.
   *
   * This functions does not directly destroy the compositor object, it merely
   * command it to start the tear down process. It is not guaranteed that the
   * tear down will happen immediately.
   *
   * \param compositor The compositor to tear down.
   */
  WL_EXPORT void
  weston_compositor_exit(struct weston_compositor *compositor)
  {
  	compositor->exit(compositor);
  }
  
  /** Return the user data stored in the compositor.
   *
   * This function returns the user data pointer set with user_data parameter
   * to the \ref weston_compositor_create function.
   */
  WL_EXPORT void *
  weston_compositor_get_user_data(struct weston_compositor *compositor)
  {
  	return compositor->user_data;
  }
  