text: /**************************************************************************
   *
   * Copyright © 2010 Jakob Bornecrantz
   *
   * 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.
   *
   **************************************************************************/
  
  
  #define USE_TRACE 0
  #define WIDTH 300
  #define HEIGHT 300
  #define NEAR 30
  #define FAR 1000
  #define FLIP 0
  
  /* pipe_*_state structs */
  #include "pipe/p_state.h"
  /* pipe_context */
  #include "pipe/p_context.h"
  /* pipe_screen */
  #include "pipe/p_screen.h"
  /* PIPE_* */
  #include "pipe/p_defines.h"
  /* TGSI_SEMANTIC_{POSITION|GENERIC} */
  #include "pipe/p_shader_tokens.h"
  /* pipe_buffer_* helpers */
  #include "util/u_inlines.h"
  
  /* constant state object helper */
  #include "cso_cache/cso_context.h"
  
  /* debug_dump_surface_bmp */
  #include "util/u_debug.h"
  /* util_draw_vertex_buffer helper */
  #include "util/u_draw_quad.h"
  /* FREE & CALLOC_STRUCT */
  #include "util/u_memory.h"
  /* util_make_[fragment|vertex]_passthrough_shader */
  #include "util/u_simple_shaders.h"
  
  /* sw_screen_create: to get a software pipe driver */
  #include "target-helpers/inline_sw_helper.h"
  /* debug_screen_wrap: to wrap with debug pipe drivers */
  #include "target-helpers/inline_debug_helper.h"
  /* null software winsys */
  #include "sw/null/null_sw_winsys.h"
  
  struct program
  {
  	struct pipe_screen *screen;
  	struct pipe_context *pipe;
  	struct cso_context *cso;
  
  	struct pipe_blend_state blend;
  	struct pipe_depth_stencil_alpha_state depthstencil;
  	struct pipe_rasterizer_state rasterizer;
  	struct pipe_viewport_state viewport;
  	struct pipe_framebuffer_state framebuffer;
  	struct pipe_vertex_element velem[2];
  
  	void *vs;
  	void *fs;
  
  	float clear_color[4];
  
  	struct pipe_resource *vbuf;
  	struct pipe_resource *target;
  };
  
  static void init_prog(struct program *p)
  {
  	/* create the software rasterizer */
  	p->screen = sw_screen_create(null_sw_create());
  	/* wrap the screen with any debugger */
  	p->screen = debug_screen_wrap(p->screen);
  
  	/* create the pipe driver context and cso context */
  	p->pipe = p->screen->context_create(p->screen, NULL);
  	p->cso = cso_create_context(p->pipe);
  
  	/* set clear color */
  	p->clear_color[0] = 0.3;
  	p->clear_color[1] = 0.1;
  	p->clear_color[2] = 0.3;
  	p->clear_color[3] = 1.0;
  
  	/* vertex buffer */
  	{
  		float vertices[4][2][4] = {
  			{
  				{ 0.0f, -0.9f, 0.0f, 1.0f },
  				{ 1.0f, 0.0f, 0.0f, 1.0f }
  			},
  			{
  				{ -0.9f, 0.9f, 0.0f, 1.0f },
  				{ 0.0f, 1.0f, 0.0f, 1.0f }
  			},
  			{
  				{ 0.9f, 0.9f, 0.0f, 1.0f },
  				{ 0.0f, 0.0f, 1.0f, 1.0f }
  			}
  		};
  
  		p->vbuf = pipe_buffer_create(p->screen, PIPE_BIND_VERTEX_BUFFER, sizeof(vertices));
  		pipe_buffer_write(p->pipe, p->vbuf, 0, sizeof(vertices), vertices);
  	}
  
  	/* render target texture */
  	{
  		struct pipe_resource tmplt;
  		memset(&tmplt, 0, sizeof(tmplt));
  		tmplt.target = PIPE_TEXTURE_2D;
  		tmplt.format = PIPE_FORMAT_B8G8R8A8_UNORM; /* All drivers support this */
  		tmplt.width0 = WIDTH;
  		tmplt.height0 = HEIGHT;
  		tmplt.depth0 = 1;
  		tmplt.last_level = 0;
  		tmplt.bind = PIPE_BIND_RENDER_TARGET;
  
  		p->target = p->screen->resource_create(p->screen, &tmplt);
  	}
  
  	/* disabled blending/masking */
  	memset(&p->blend, 0, sizeof(p->blend));
  	p->blend.rt[0].colormask = PIPE_MASK_RGBA;
  
  	/* no-op depth/stencil/alpha */
  	memset(&p->depthstencil, 0, sizeof(p->depthstencil));
  
  	/* rasterizer */
  	memset(&p->rasterizer, 0, sizeof(p->rasterizer));
  	p->rasterizer.cull_face = PIPE_FACE_NONE;
  	p->rasterizer.gl_rasterization_rules = 1;
  
  	/* drawing destination */
  	memset(&p->framebuffer, 0, sizeof(p->framebuffer));
  	p->framebuffer.width = WIDTH;
  	p->framebuffer.height = HEIGHT;
  	p->framebuffer.nr_cbufs = 1;
  	p->framebuffer.cbufs[0] = p->screen->get_tex_surface(p->screen, p->target, 0, 0, 0, PIPE_BIND_RENDER_TARGET);
  
  	/* viewport, depth isn't really needed */
  	{
  		float x = 0;
  		float y = 0;
  		float z = FAR;
  		float half_width = (float)WIDTH / 2.0f;
  		float half_height = (float)HEIGHT / 2.0f;
  		float half_depth = ((float)FAR - (float)NEAR) / 2.0f;
  		float scale, bias;
  
  		if (FLIP) {
  			scale = -1.0f;
  			bias = (float)HEIGHT;
  		} else {
  			scale = 1.0f;
  			bias = 0.0f;
  		}
  
  		p->viewport.scale[0] = half_width;
  		p->viewport.scale[1] = half_height * scale;
  		p->viewport.scale[2] = half_depth;
  		p->viewport.scale[3] = 1.0f;
  
  		p->viewport.translate[0] = half_width + x;
  		p->viewport.translate[1] = (half_height + y) * scale + bias;
  		p->viewport.translate[2] = half_depth + z;
  		p->viewport.translate[3] = 0.0f;
  	}
  
  	/* vertex elements state */
  	memset(p->velem, 0, sizeof(p->velem));
  	p->velem[0].src_offset = 0 * 4 * sizeof(float); /* offset 0, first element */
  	p->velem[0].instance_divisor = 0;
  	p->velem[0].vertex_buffer_index = 0;
  	p->velem[0].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
  
  	p->velem[1].src_offset = 1 * 4 * sizeof(float); /* offset 16, second element */
  	p->velem[1].instance_divisor = 0;
  	p->velem[1].vertex_buffer_index = 0;
  	p->velem[1].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
  
  	/* vertex shader */
  	{
  			const uint semantic_names[] = { TGSI_SEMANTIC_POSITION,
  							TGSI_SEMANTIC_COLOR };
  			const uint semantic_indexes[] = { 0, 0 };
  			p->vs = util_make_vertex_passthrough_shader(p->pipe, 2, semantic_names, semantic_indexes);
  	}
  
  	/* fragment shader */
  	p->fs = util_make_fragment_passthrough_shader(p->pipe);
  }
  
  static void close_prog(struct program *p)
  {
  	/* unset all state */
  	cso_release_all(p->cso);
  
  	p->pipe->delete_vs_state(p->pipe, p->vs);
  	p->pipe->delete_fs_state(p->pipe, p->fs);
  
  	pipe_surface_reference(&p->framebuffer.cbufs[0], NULL);
  	pipe_resource_reference(&p->target, NULL);
  	pipe_resource_reference(&p->vbuf, NULL);
  
  	cso_destroy_context(p->cso);
  	p->pipe->destroy(p->pipe);
  	p->screen->destroy(p->screen);
  
  	FREE(p);
  }
  
  static void draw(struct program *p)
  {
  	/* set the render target */
  	cso_set_framebuffer(p->cso, &p->framebuffer);
  
  	/* clear the render target */
  	p->pipe->clear(p->pipe, PIPE_CLEAR_COLOR, p->clear_color, 0, 0);
  
  	/* set misc state we care about */
  	cso_set_blend(p->cso, &p->blend);
  	cso_set_depth_stencil_alpha(p->cso, &p->depthstencil);
  	cso_set_rasterizer(p->cso, &p->rasterizer);
  	cso_set_viewport(p->cso, &p->viewport);
  
  	/* shaders */
  	cso_set_fragment_shader_handle(p->cso, p->fs);
  	cso_set_vertex_shader_handle(p->cso, p->vs);
  
  	/* vertex element data */
  	cso_set_vertex_elements(p->cso, 2, p->velem);
  
  	util_draw_vertex_buffer(p->pipe,
  	                        p->vbuf, 0,
  	                        PIPE_PRIM_TRIANGLES,
  	                        3,  /* verts */
  	                        2); /* attribs/vert */
  
  	p->pipe->flush(p->pipe, PIPE_FLUSH_RENDER_CACHE, NULL);
  
  	debug_dump_surface_bmp(p->pipe, "result.bmp", p->framebuffer.cbufs[0]);
  }
  
  int main(int argc, char** argv)
  {
  	struct program *p = CALLOC_STRUCT(program);
  
  	init_prog(p);
  	draw(p);
  	close_prog(p);
  
  	return 0;
  }
  