text: /* Display a cleared blue window.  This demo has no dependencies on
   * any utility code, just the graw interface and gallium.
   */
  
  #include "graw_util.h"
  
  static const int WIDTH = 300;
  static const int HEIGHT = 300;
  
  static struct graw_info info;
  
  
  static struct pipe_resource *texture = NULL;
  static struct pipe_sampler_view *sv = NULL;
  static void *sampler = NULL;
  
  struct vertex {
     float position[4];
     float color[4];
  };
  
  static struct vertex vertices[] =
  {
     { { 0.9, -0.9, 0.0, 1.0 },
       { 1, 0, 0, 1 } },
  
     { { 0.9,  0.9, 0.0, 1.0 },
       { 1, 1, 0, 1 } },
  
     { {-0.9,  0.9, 0.0, 1.0 },
       { 0, 1, 0, 1 } },
  
     { {-0.9,  -0.9, 0.0, 1.0 },
       { 0, 0, 0, 1 } },
  };
  
  
  
  
  static void set_vertices( void )
  {
     struct pipe_vertex_element ve[2];
     struct pipe_vertex_buffer vbuf;
     void *handle;
  
     memset(ve, 0, sizeof ve);
  
     ve[0].src_offset = Offset(struct vertex, position);
     ve[0].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
     ve[1].src_offset = Offset(struct vertex, color);
     ve[1].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
  
     handle = info.ctx->create_vertex_elements_state(info.ctx, 2, ve);
     info.ctx->bind_vertex_elements_state(info.ctx, handle);
  
     memset(&vbuf, 0, sizeof vbuf);
  
     vbuf.stride = sizeof( struct vertex );
     vbuf.buffer_offset = 0;
     vbuf.buffer.resource = pipe_buffer_create_with_data(info.ctx,
                                                PIPE_BIND_VERTEX_BUFFER,
                                                PIPE_USAGE_DEFAULT,
                                                sizeof(vertices),
                                                vertices);
  
     info.ctx->set_vertex_buffers(info.ctx, 0, 1, &vbuf);
  }
  
  static void set_vertex_shader( void )
  {
     void *handle;
     const char *text =
        "VERT\n"
        "DCL IN[0]\n"
        "DCL IN[1]\n"
        "DCL OUT[0], POSITION\n"
        "DCL OUT[1], GENERIC[0]\n"
        "  0: MOV OUT[1], IN[1]\n"
        "  1: MOV OUT[0], IN[0]\n"
        "  2: END\n";
  
     handle = graw_parse_vertex_shader(info.ctx, text);
     info.ctx->bind_vs_state(info.ctx, handle);
  }
  
  static void set_fragment_shader( void )
  {
     void *handle;
     const char *text =
        "FRAG\n"
        "DCL IN[0], GENERIC[0], PERSPECTIVE\n"
        "DCL OUT[0], COLOR\n"
        "DCL TEMP[0]\n"
        "DCL SAMP[0]\n"
        "DCL SVIEW[0], 2D, FLOAT\n"
        "  0: TXP TEMP[0], IN[0], SAMP[0], 2D\n"
        "  1: MOV OUT[0], TEMP[0]\n"
        "  2: END\n";
  
     handle = graw_parse_fragment_shader(info.ctx, text);
     info.ctx->bind_fs_state(info.ctx, handle);
  }
  
  
  static void draw( void )
  {
     union pipe_color_union clear_color = { {.5,.5,.5,1} };
  
     info.ctx->clear(info.ctx, PIPE_CLEAR_COLOR, &clear_color, 0, 0);
     util_draw_arrays(info.ctx, PIPE_PRIM_QUADS, 0, 4);
     info.ctx->flush(info.ctx, NULL, 0);
  
     graw_save_surface_to_file(info.ctx, info.color_surf[0], NULL);
  
     graw_util_flush_front(&info);
  }
  
  
  #define SIZE 16
  
  static void init_tex( void )
  { 
     ubyte tex2d[SIZE][SIZE][4];
     int s, t;
  
  #if (SIZE != 2)
     for (s = 0; s < SIZE; s++) {
        for (t = 0; t < SIZE; t++) {
           if (0) {
              int x = (s ^ t) & 1;
  	    tex2d[t][s][0] = (x) ? 0 : 63;
  	    tex2d[t][s][1] = (x) ? 0 : 128;
  	    tex2d[t][s][2] = 0;
  	    tex2d[t][s][3] = 0xff;
           }
           else {
              int x = ((s ^ t) >> 2) & 1;
  	    tex2d[t][s][0] = s*255/(SIZE-1);
  	    tex2d[t][s][1] = t*255/(SIZE-1);
  	    tex2d[t][s][2] = (x) ? 0 : 128;
  	    tex2d[t][s][3] = 0xff;
           }
        }
     }
  #else
     tex2d[0][0][0] = 0;
     tex2d[0][0][1] = 255;
     tex2d[0][0][2] = 255;
     tex2d[0][0][3] = 0;
  
     tex2d[0][1][0] = 0;
     tex2d[0][1][1] = 0;
     tex2d[0][1][2] = 255;
     tex2d[0][1][3] = 255;
  
     tex2d[1][0][0] = 255;
     tex2d[1][0][1] = 255;
     tex2d[1][0][2] = 0;
     tex2d[1][0][3] = 255;
  
     tex2d[1][1][0] = 255;
     tex2d[1][1][1] = 0;
     tex2d[1][1][2] = 0;
     tex2d[1][1][3] = 255;
  #endif
  
     texture = graw_util_create_tex2d(&info, SIZE, SIZE, 
                                      PIPE_FORMAT_B8G8R8A8_UNORM, tex2d);
  
     sv = graw_util_create_simple_sampler_view(&info, texture);
     info.ctx->set_sampler_views(info.ctx, PIPE_SHADER_FRAGMENT, 0, 1, &sv);
  
     sampler = graw_util_create_simple_sampler(&info, 
                                               PIPE_TEX_WRAP_REPEAT,
                                               PIPE_TEX_FILTER_NEAREST);
     info.ctx->bind_sampler_states(info.ctx, PIPE_SHADER_FRAGMENT,
                                   0, 1, &sampler);
  }
  
  
  static void init( void )
  {
     if (!graw_util_create_window(&info, WIDTH, HEIGHT, 1, FALSE))
        exit(1);
  
     graw_util_default_state(&info, FALSE);
  
     {
        struct pipe_rasterizer_state rasterizer;
        void *handle;
        memset(&rasterizer, 0, sizeof rasterizer);
        rasterizer.cull_face = PIPE_FACE_NONE;
        rasterizer.half_pixel_center = 1;
        rasterizer.bottom_edge_rule = 1;
        rasterizer.depth_clip_near = 1;
        rasterizer.depth_clip_far = 1;
        handle = info.ctx->create_rasterizer_state(info.ctx, &rasterizer);
        info.ctx->bind_rasterizer_state(info.ctx, handle);
     }
  
     graw_util_viewport(&info, 0, 0, WIDTH, HEIGHT, 30, 1000);
  
     init_tex();
  
     set_vertices();
     set_vertex_shader();
     set_fragment_shader();
  }
  
  
  static void args(int argc, char *argv[])
  {
     int i;
  
     for (i = 1; i < argc;) {
        if (graw_parse_args(&i, argc, argv)) {
           continue;
        }
        exit(1);
     }
  }
  
  int main( int argc, char *argv[] )
  {
     args(argc, argv);
     init();
  
     graw_set_display_func( draw );
     graw_main_loop();
     return 0;
  }
  