text: /*
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version 2
   * of the License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   *
   * The Original Code is Copyright (C) 2008 Blender Foundation.
   * All rights reserved.
   */
  
  /** \file
   * \ingroup wm
   *
   * Gestures (cursor motions) creating, evaluating and drawing, shared between operators.
   */
  
  #include "DNA_screen_types.h"
  #include "DNA_vec_types.h"
  #include "DNA_userdef_types.h"
  #include "DNA_windowmanager_types.h"
  
  #include "MEM_guardedalloc.h"
  
  #include "BLI_bitmap_draw_2d.h"
  #include "BLI_blenlib.h"
  #include "BLI_math.h"
  #include "BLI_utildefines.h"
  #include "BLI_lasso_2d.h"
  
  #include "BKE_context.h"
  
  #include "WM_api.h"
  #include "WM_types.h"
  
  #include "wm.h"
  #include "wm_draw.h"
  
  #include "GPU_immediate.h"
  #include "GPU_immediate_util.h"
  #include "GPU_state.h"
  
  #include "BIF_glutil.h"
  
  /* context checked on having screen, window and area */
  wmGesture *WM_gesture_new(bContext *C, const wmEvent *event, int type)
  {
    wmGesture *gesture = MEM_callocN(sizeof(wmGesture), "new gesture");
    wmWindow *window = CTX_wm_window(C);
    ARegion *ar = CTX_wm_region(C);
  
    BLI_addtail(&window->gesture, gesture);
  
    gesture->type = type;
    gesture->event_type = event->type;
    gesture->winrct = ar->winrct;
    gesture->user_data.use_free = true; /* Free if userdata is set. */
    gesture->modal_state = GESTURE_MODAL_NOP;
  
    if (ELEM(type,
             WM_GESTURE_RECT,
             WM_GESTURE_CROSS_RECT,
             WM_GESTURE_TWEAK,
             WM_GESTURE_CIRCLE,
             WM_GESTURE_STRAIGHTLINE)) {
      rcti *rect = MEM_callocN(sizeof(rcti), "gesture rect new");
  
      gesture->customdata = rect;
      rect->xmin = event->x - gesture->winrct.xmin;
      rect->ymin = event->y - gesture->winrct.ymin;
      if (type == WM_GESTURE_CIRCLE) {
        /* caller is responsible for initializing 'xmax' to radius. */
      }
      else {
        rect->xmax = event->x - gesture->winrct.xmin;
        rect->ymax = event->y - gesture->winrct.ymin;
      }
    }
    else if (ELEM(type, WM_GESTURE_LINES, WM_GESTURE_LASSO)) {
      short *lasso;
      gesture->points_alloc = 1024;
      gesture->customdata = lasso = MEM_mallocN(sizeof(short[2]) * gesture->points_alloc,
                                                "lasso points");
      lasso[0] = event->x - gesture->winrct.xmin;
      lasso[1] = event->y - gesture->winrct.ymin;
      gesture->points = 1;
    }
  
    return gesture;
  }
  
  void WM_gesture_end(bContext *C, wmGesture *gesture)
  {
    wmWindow *win = CTX_wm_window(C);
  
    if (win->tweak == gesture) {
      win->tweak = NULL;
    }
    BLI_remlink(&win->gesture, gesture);
    MEM_freeN(gesture->customdata);
    WM_generic_user_data_free(&gesture->user_data);
    MEM_freeN(gesture);
  }
  
  void WM_gestures_remove(bContext *C)
  {
    wmWindow *win = CTX_wm_window(C);
  
    while (win->gesture.first) {
      WM_gesture_end(C, win->gesture.first);
    }
  }
  
  bool WM_gesture_is_modal_first(const wmGesture *gesture)
  {
    if (gesture == NULL) {
      return true;
    }
    return (gesture->is_active_prev == false);
  }
  
  /* tweak and line gestures */
  int wm_gesture_evaluate(wmGesture *gesture, const wmEvent *event)
  {
    if (gesture->type == WM_GESTURE_TWEAK) {
      rcti *rect = gesture->customdata;
      const int delta[2] = {
          BLI_rcti_size_x(rect),
          BLI_rcti_size_y(rect),
      };
  
      if (WM_event_drag_test_with_delta(event, delta)) {
        int theta = round_fl_to_int(4.0f * atan2f((float)delta[1], (float)delta[0]) / (float)M_PI);
        int val = EVT_GESTURE_W;
  
        if (theta == 0) {
          val = EVT_GESTURE_E;
        }
        else if (theta == 1) {
          val = EVT_GESTURE_NE;
        }
        else if (theta == 2) {
          val = EVT_GESTURE_N;
        }
        else if (theta == 3) {
          val = EVT_GESTURE_NW;
        }
        else if (theta == -1) {
          val = EVT_GESTURE_SE;
        }
        else if (theta == -2) {
          val = EVT_GESTURE_S;
        }
        else if (theta == -3) {
          val = EVT_GESTURE_SW;
        }
  
  #if 0
        /* debug */
        if (val == 1) {
          printf("tweak north\n");
        }
        if (val == 2) {
          printf("tweak north-east\n");
        }
        if (val == 3) {
          printf("tweak east\n");
        }
        if (val == 4) {
          printf("tweak south-east\n");
        }
        if (val == 5) {
          printf("tweak south\n");
        }
        if (val == 6) {
          printf("tweak south-west\n");
        }
        if (val == 7) {
          printf("tweak west\n");
        }
        if (val == 8) {
          printf("tweak north-west\n");
        }
  #endif
        return val;
      }
    }
    return 0;
  }
  
  /* ******************* gesture draw ******************* */
  
  static void wm_gesture_draw_line(wmGesture *gt)
  {
    rcti *rect = (rcti *)gt->customdata;
  
    uint shdr_pos = GPU_vertformat_attr_add(
        immVertexFormat(), "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
  
    immBindBuiltinProgram(GPU_SHADER_2D_LINE_DASHED_UNIFORM_COLOR);
  
    float viewport_size[4];
    glGetFloatv(GL_VIEWPORT, viewport_size);
    immUniform2f("viewport_size", viewport_size[2], viewport_size[3]);
  
    immUniform1i("colors_len", 2); /* "advanced" mode */
    immUniformArray4fv(
        "colors", (float *)(float[][4]){{0.4f, 0.4f, 0.4f, 1.0f}, {1.0f, 1.0f, 1.0f, 1.0f}}, 2);
    immUniform1f("dash_width", 8.0f);
    immUniform1f("dash_factor", 0.5f);
  
    float xmin = (float)rect->xmin;
    float ymin = (float)rect->ymin;
  
    immBegin(GPU_PRIM_LINES, 2);
    immVertex2f(shdr_pos, xmin, ymin);
    immVertex2f(shdr_pos, (float)rect->xmax, (float)rect->ymax);
    immEnd();
  
    immUnbindProgram();
  }
  
  static void wm_gesture_draw_rect(wmGesture *gt)
  {
    rcti *rect = (rcti *)gt->customdata;
  
    uint shdr_pos = GPU_vertformat_attr_add(
        immVertexFormat(), "pos", GPU_COMP_I32, 2, GPU_FETCH_INT_TO_FLOAT);
  
    GPU_blend(true);
  
    immBindBuiltinProgram(GPU_SHADER_2D_UNIFORM_COLOR);
    immUniformColor4f(1.0f, 1.0f, 1.0f, 0.05f);
  
    immRecti(shdr_pos, rect->xmin, rect->ymin, rect->xmax, rect->ymax);
  
    immUnbindProgram();
  
    GPU_blend(false);
  
    shdr_pos = GPU_vertformat_attr_add(immVertexFormat(), "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
  
    immBindBuiltinProgram(GPU_SHADER_2D_LINE_DASHED_UNIFORM_COLOR);
  
    float viewport_size[4];
    glGetFloatv(GL_VIEWPORT, viewport_size);
    immUniform2f("viewport_size", viewport_size[2], viewport_size[3]);
  
    immUniform1i("colors_len", 2); /* "advanced" mode */
    immUniformArray4fv(
        "colors", (float *)(float[][4]){{0.4f, 0.4f, 0.4f, 1.0f}, {1.0f, 1.0f, 1.0f, 1.0f}}, 2);
    immUniform1f("dash_width", 8.0f);
    immUniform1f("dash_factor", 0.5f);
  
    imm_draw_box_wire_2d(
        shdr_pos, (float)rect->xmin, (float)rect->ymin, (float)rect->xmax, (float)rect->ymax);
  
    immUnbindProgram();
  
    /* draws a diagonal line in the lined box to test wm_gesture_draw_line */
    // wm_gesture_draw_line(gt);
  }
  
  static void wm_gesture_draw_circle(wmGesture *gt)
  {
    rcti *rect = (rcti *)gt->customdata;
  
    GPU_blend(true);
  
    const uint shdr_pos = GPU_vertformat_attr_add(
        immVertexFormat(), "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
  
    immBindBuiltinProgram(GPU_SHADER_2D_UNIFORM_COLOR);
  
    immUniformColor4f(1.0f, 1.0f, 1.0f, 0.05f);
    imm_draw_circle_fill_2d(shdr_pos, (float)rect->xmin, (float)rect->ymin, (float)rect->xmax, 40);
  
    immUnbindProgram();
  
    GPU_blend(false);
  
    immBindBuiltinProgram(GPU_SHADER_2D_LINE_DASHED_UNIFORM_COLOR);
  
    float viewport_size[4];
    glGetFloatv(GL_VIEWPORT, viewport_size);
    immUniform2f("viewport_size", viewport_size[2], viewport_size[3]);
  
    immUniform1i("colors_len", 2); /* "advanced" mode */
    immUniformArray4fv(
        "colors", (float *)(float[][4]){{0.4f, 0.4f, 0.4f, 1.0f}, {1.0f, 1.0f, 1.0f, 1.0f}}, 2);
    immUniform1f("dash_width", 4.0f);
    immUniform1f("dash_factor", 0.5f);
  
    imm_draw_circle_wire_2d(shdr_pos, (float)rect->xmin, (float)rect->ymin, (float)rect->xmax, 40);
  
    immUnbindProgram();
  }
  
  struct LassoFillData {
    unsigned char *px;
    int width;
  };
  
  static void draw_filled_lasso_px_cb(int x, int x_end, int y, void *user_data)
  {
    struct LassoFillData *data = user_data;
    unsigned char *col = &(data->px[(y * data->width) + x]);
    memset(col, 0x10, x_end - x);
  }
  
  static void draw_filled_lasso(wmGesture *gt)
  {
    const short *lasso = (short *)gt->customdata;
    const int tot = gt->points;
    int(*moves)[2] = MEM_mallocN(sizeof(*moves) * (tot + 1), __func__);
    int i;
    rcti rect;
    float red[4] = {1.0f, 0.0f, 0.0f, 0.0f};
  
    for (i = 0; i < tot; i++, lasso += 2) {
      moves[i][0] = lasso[0];
      moves[i][1] = lasso[1];
    }
  
    BLI_lasso_boundbox(&rect, (const int(*)[2])moves, tot);
  
    BLI_rcti_translate(&rect, gt->winrct.xmin, gt->winrct.ymin);
    BLI_rcti_isect(&gt->winrct, &rect, &rect);
    BLI_rcti_translate(&rect, -gt->winrct.xmin, -gt->winrct.ymin);
  
    /* highly unlikely this will fail, but could crash if (tot == 0) */
    if (BLI_rcti_is_empty(&rect) == false) {
      const int w = BLI_rcti_size_x(&rect);
      const int h = BLI_rcti_size_y(&rect);
      unsigned char *pixel_buf = MEM_callocN(sizeof(*pixel_buf) * w * h, __func__);
      struct LassoFillData lasso_fill_data = {pixel_buf, w};
  
      BLI_bitmap_draw_2d_poly_v2i_n(rect.xmin,
                                    rect.ymin,
                                    rect.xmax,
                                    rect.ymax,
                                    (const int(*)[2])moves,
                                    tot,
                                    draw_filled_lasso_px_cb,
                                    &lasso_fill_data);
  
      /* Additive Blending */
      GPU_blend(true);
      glBlendFunc(GL_ONE, GL_ONE);
  
      GLint unpack_alignment;
      glGetIntegerv(GL_UNPACK_ALIGNMENT, &unpack_alignment);
  
      glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  
      IMMDrawPixelsTexState state = immDrawPixelsTexSetup(GPU_SHADER_2D_IMAGE_SHUFFLE_COLOR);
      GPU_shader_bind(state.shader);
      GPU_shader_uniform_vector(
          state.shader, GPU_shader_get_uniform_ensure(state.shader, "shuffle"), 4, 1, red);
  
      immDrawPixelsTex(&state,
                       rect.xmin,
                       rect.ymin,
                       w,
                       h,
                       GL_RED,
                       GL_UNSIGNED_BYTE,
                       GL_NEAREST,
                       pixel_buf,
                       1.0f,
                       1.0f,
                       NULL);
  
      GPU_shader_unbind();
  
      glPixelStorei(GL_UNPACK_ALIGNMENT, unpack_alignment);
  
      MEM_freeN(pixel_buf);
  
      GPU_blend(false);
      glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    }
  
    MEM_freeN(moves);
  }
  
  static void wm_gesture_draw_lasso(wmGesture *gt, bool filled)
  {
    const short *lasso = (short *)gt->customdata;
    int i;
  
    if (filled) {
      draw_filled_lasso(gt);
    }
  
    const int numverts = gt->points;
  
    /* Nothing to draw, do early output. */
    if (numverts < 2) {
      return;
    }
  
    const uint shdr_pos = GPU_vertformat_attr_add(
        immVertexFormat(), "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
  
    immBindBuiltinProgram(GPU_SHADER_2D_LINE_DASHED_UNIFORM_COLOR);
  
    float viewport_size[4];
    glGetFloatv(GL_VIEWPORT, viewport_size);
    immUniform2f("viewport_size", viewport_size[2], viewport_size[3]);
  
    immUniform1i("colors_len", 2); /* "advanced" mode */
    immUniformArray4fv(
        "colors", (float *)(float[][4]){{0.4f, 0.4f, 0.4f, 1.0f}, {1.0f, 1.0f, 1.0f, 1.0f}}, 2);
    immUniform1f("dash_width", 2.0f);
    immUniform1f("dash_factor", 0.5f);
  
    immBegin((gt->type == WM_GESTURE_LASSO) ? GPU_PRIM_LINE_LOOP : GPU_PRIM_LINE_STRIP, numverts);
  
    for (i = 0; i < gt->points; i++, lasso += 2) {
      immVertex2f(shdr_pos, (float)lasso[0], (float)lasso[1]);
    }
  
    immEnd();
  
    immUnbindProgram();
  }
  
  static void wm_gesture_draw_cross(wmWindow *win, wmGesture *gt)
  {
    rcti *rect = (rcti *)gt->customdata;
    const int winsize_x = WM_window_pixels_x(win);
    const int winsize_y = WM_window_pixels_y(win);
  
    float x1, x2, y1, y2;
  
    const uint shdr_pos = GPU_vertformat_attr_add(
        immVertexFormat(), "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
  
    immBindBuiltinProgram(GPU_SHADER_2D_LINE_DASHED_UNIFORM_COLOR);
  
    float viewport_size[4];
    glGetFloatv(GL_VIEWPORT, viewport_size);
    immUniform2f("viewport_size", viewport_size[2], viewport_size[3]);
  
    immUniform1i("colors_len", 2); /* "advanced" mode */
    immUniformArray4fv(
        "colors", (float *)(float[][4]){{0.4f, 0.4f, 0.4f, 1.0f}, {1.0f, 1.0f, 1.0f, 1.0f}}, 2);
    immUniform1f("dash_width", 8.0f);
    immUniform1f("dash_factor", 0.5f);
  
    immBegin(GPU_PRIM_LINES, 4);
  
    x1 = (float)(rect->xmin - winsize_x);
    y1 = (float)rect->ymin;
    x2 = (float)(rect->xmin + winsize_x);
    y2 = y1;
  
    immVertex2f(shdr_pos, x1, y1);
    immVertex2f(shdr_pos, x2, y2);
  
    x1 = (float)rect->xmin;
    y1 = (float)(rect->ymin - winsize_y);
    x2 = x1;
    y2 = (float)(rect->ymin + winsize_y);
  
    immVertex2f(shdr_pos, x1, y1);
    immVertex2f(shdr_pos, x2, y2);
  
    immEnd();
  
    immUnbindProgram();
  }
  
  /* called in wm_draw.c */
  void wm_gesture_draw(wmWindow *win)
  {
    wmGesture *gt = (wmGesture *)win->gesture.first;
  
    GPU_line_width(1.0f);
    for (; gt; gt = gt->next) {
      /* all in subwindow space */
      wmViewport(&gt->winrct);
  
      if (gt->type == WM_GESTURE_RECT) {
        wm_gesture_draw_rect(gt);
      }
  #if 0
      else if (gt->type == WM_GESTURE_TWEAK) {
        wm_gesture_draw_line(gt);
      }
  #endif
      else if (gt->type == WM_GESTURE_CIRCLE) {
        wm_gesture_draw_circle(gt);
      }
      else if (gt->type == WM_GESTURE_CROSS_RECT) {
        if (gt->is_active) {
          wm_gesture_draw_rect(gt);
        }
        else {
          wm_gesture_draw_cross(win, gt);
        }
      }
      else if (gt->type == WM_GESTURE_LINES) {
        wm_gesture_draw_lasso(gt, false);
      }
      else if (gt->type == WM_GESTURE_LASSO) {
        wm_gesture_draw_lasso(gt, true);
      }
      else if (gt->type == WM_GESTURE_STRAIGHTLINE) {
        wm_gesture_draw_line(gt);
      }
    }
  }
  
  void wm_gesture_tag_redraw(bContext *C)
  {
    bScreen *screen = CTX_wm_screen(C);
  
    if (screen) {
      screen->do_draw_gesture = true;
    }
  }
  