text: /* Display a cleared blue window.  This demo has no dependencies on
   * any utility code, just the graw interface and gallium.
   */
  
  #include "state_tracker/graw.h"
  #include "pipe/p_screen.h"
  #include "pipe/p_context.h"
  #include "pipe/p_shader_tokens.h"
  #include "pipe/p_state.h"
  #include "pipe/p_defines.h"
  #include <stdio.h>              /* for fread(), etc */
  
  #include "util/u_inlines.h"
  #include "util/u_memory.h"      /* Offset() */
  #include "util/u_draw_quad.h"
  #include "util/u_box.h"    
  
  static const char *filename = NULL;
  unsigned show_fps = 0;
  
  
  static void usage(char *name)
  {
     fprintf(stderr, "usage: %s [ options ] shader_filename\n", name);
  #ifndef _WIN32
     fprintf(stderr, "\n" );
     fprintf(stderr, "options:\n");
     fprintf(stderr, "    -fps  show frames per second\n");
  #endif
  }
  
  
  enum pipe_format formats[] = {
     PIPE_FORMAT_RGBA8888_UNORM,
     PIPE_FORMAT_BGRA8888_UNORM,
     PIPE_FORMAT_NONE
  };
  
  static const int WIDTH = 250;
  static const int HEIGHT = 250;
  
  static struct pipe_screen *screen = NULL;
  static struct pipe_context *ctx = NULL;
  static struct pipe_resource *rttex = NULL;
  static struct pipe_surface *surf = NULL;
  static struct pipe_sampler_view *sv = NULL;
  static void *sampler = NULL;
  static void *window = NULL;
  static struct pipe_resource *samptex = NULL;
  
  struct vertex {
     float position[4];
     float color[4];
     float texcoord[4];
  };
  
  /* Vertex data matches progs/fp/fp-tri.c, but flipped in Y dimension
   * so that the final images are the same.
   */
  static struct vertex vertices[] =
  {
     { { 0.9, 0.9, 0.0, 1.0 },
       { 0, 0, 1, 1 },
       { 1, 1, 0, 1 } },
  
     { { 0.9,  -0.9, 0.0, 1.0 },
       { 1, 0, 0, 1 },
       { 1, -1, 0, 1 } },
  
     { {-0.9,  0.0, 0.0, 1.0 },
       { 0, 1, 0, 1 },
       { -1, 0, 0, 1 } },
  };
  
  static float constants1[] = 
  {  0.4, 0, 0,  1,
     1,   1, 1,  1,
     2,   2, 2,  2,
     4,   8, 16, 32,
  
     3,  0, 0, 0,
     0, .5, 0, 0,
     1,  0, 0, 1,
     0,  0, 0, 1,
  
     1, 0, 0, 0.5,
     0, 1, 0, 0.5,
     0, 0, 1, 0,
     0, 0, 0, 1,
  };
  
  
  static float constants2[] = 
  {  1, 0, 0,  1,
     0, 1, 0,  1,
     0, 0, 1,  1,
     0, 0, 0,  0,
  
     1,  1, 0, 1,
     1, .5, 0, 1,
     1,  0, 0, 1,
     0,  0, 0, 1,
  
     1, 0, 0, 0.5,
     0, 1, 0, 0.5,
     0, 0, 1, 0,
     0, 0, 0, 1,
  };
  
  static void init_fs_constbuf( void )
  {
     struct pipe_constant_buffer cb1;
     struct pipe_constant_buffer cb2;
  
     memset(&cb1, 0, sizeof cb1);
     cb1.buffer_size = sizeof constants1;
     cb1.user_buffer = constants1;
  
     ctx->set_constant_buffer(ctx,
                              PIPE_SHADER_FRAGMENT, 0,
                              &cb1);
  
     memset(&cb2, 0, sizeof cb2);
     cb2.buffer_size = sizeof constants2;
     cb2.user_buffer = constants2;
  
     ctx->set_constant_buffer(ctx,
                              PIPE_SHADER_FRAGMENT, 1,
                              &cb2);
  }
  
  
  static void set_viewport( float x, float y,
                            float width, float height,
                            float zNear, float zFar)
  {
     float z = zFar;
     float half_width = (float)width / 2.0f;
     float half_height = (float)height / 2.0f;
     float half_depth = ((float)zFar - (float)zNear) / 2.0f;
     struct pipe_viewport_state vp;
  
     vp.scale[0] = half_width;
     vp.scale[1] = half_height;
     vp.scale[2] = half_depth;
  
     vp.translate[0] = half_width + x;
     vp.translate[1] = half_height + y;
     vp.translate[2] = half_depth + z;
  
     ctx->set_viewport_states( ctx, 0, 1, &vp );
  }
  
  static void set_vertices( void )
  {
     struct pipe_vertex_element ve[3];
     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;
     ve[2].src_offset = Offset(struct vertex, texcoord);
     ve[2].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
  
     handle = ctx->create_vertex_elements_state(ctx, 3, ve);
     ctx->bind_vertex_elements_state(ctx, handle);
  
     memset(&vbuf, 0, sizeof vbuf);
  
     vbuf.stride = sizeof( struct vertex );
     vbuf.buffer_offset = 0;
     vbuf.buffer.resource = pipe_buffer_create_with_data(ctx,
                                                PIPE_BIND_VERTEX_BUFFER,
                                                PIPE_USAGE_DEFAULT,
                                                sizeof(vertices),
                                                vertices);
  
     ctx->set_vertex_buffers(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 IN[2]\n"
        "DCL OUT[0], POSITION\n"
        "DCL OUT[1], COLOR[0]\n"
        "DCL OUT[2], GENERIC[0]\n"
        "  MOV OUT[0], IN[0]\n"
        "  MOV OUT[1], IN[1]\n"
        "  MOV OUT[2], IN[2]\n"
        "  END\n";
  
     handle = graw_parse_vertex_shader(ctx, text);
     ctx->bind_vs_state(ctx, handle);
  }
  
  static void set_fragment_shader( const char *filename )
  {
     FILE *f;
     char buf[50000];
     void *handle;
     int sz;
  
     if ((f = fopen(filename, "r")) == NULL) {
        fprintf(stderr, "Couldn't open %s\n", filename);
        exit(1);
     }
  
     sz = fread(buf, 1, sizeof(buf), f);
     if (!feof(f)) {
        printf("file too long\n");
        exit(1);
     }
     printf("%.*s\n", sz, buf);
     buf[sz] = 0;
  
     handle = graw_parse_fragment_shader(ctx, buf);
     ctx->bind_fs_state(ctx, handle);
     fclose(f);
  }
  
  
  static void draw( void )
  {
     union pipe_color_union clear_color = { {.1,.3,.5,0} };
  
     ctx->clear(ctx, PIPE_CLEAR_COLOR, &clear_color, 0, 0);
     util_draw_arrays(ctx, PIPE_PRIM_TRIANGLES, 0, 3);
     ctx->flush(ctx, NULL, 0);
  
     graw_save_surface_to_file(ctx, surf, NULL);
  
     screen->flush_frontbuffer(screen, rttex, 0, 0, window, NULL);
  }
  
  #define SIZE 16
  
  static void init_tex( void )
  { 
     struct pipe_sampler_view sv_template;
     struct pipe_sampler_state sampler_desc;
     struct pipe_resource templat;
     struct pipe_box box;
     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
  
     memset(&templat, 0, sizeof(templat));
     templat.target = PIPE_TEXTURE_2D;
     templat.format = PIPE_FORMAT_B8G8R8A8_UNORM;
     templat.width0 = SIZE;
     templat.height0 = SIZE;
     templat.depth0 = 1;
     templat.array_size = 1;
     templat.last_level = 0;
     templat.nr_samples = 1;
     templat.bind = PIPE_BIND_SAMPLER_VIEW;
  
     
     samptex = screen->resource_create(screen,
                                   &templat);
     if (samptex == NULL)
        exit(4);
  
     u_box_2d(0,0,SIZE,SIZE, &box);
  
     ctx->texture_subdata(ctx,
                          samptex,
                          0,
                          PIPE_TRANSFER_WRITE,
                          &box,
                          tex2d,
                          sizeof tex2d[0],
                          sizeof tex2d);
  
     /* Possibly read back & compare against original data:
      */
     if (0)
     {
        struct pipe_transfer *t;
        uint32_t *ptr;
        ptr = pipe_transfer_map(ctx, samptex,
                                0, 0, /* level, layer */
                                PIPE_TRANSFER_READ,
                                0, 0, SIZE, SIZE, &t); /* x, y, width, height */
  
        if (memcmp(ptr, tex2d, sizeof tex2d) != 0) {
           assert(0);
           exit(9);
        }
  
        ctx->transfer_unmap(ctx, t);
     }
  
     memset(&sv_template, 0, sizeof sv_template);
     sv_template.format = samptex->format;
     sv_template.texture = samptex;
     sv_template.swizzle_r = 0;
     sv_template.swizzle_g = 1;
     sv_template.swizzle_b = 2;
     sv_template.swizzle_a = 3;
     sv = ctx->create_sampler_view(ctx, samptex, &sv_template);
     if (sv == NULL)
        exit(5);
  
     ctx->set_sampler_views(ctx, PIPE_SHADER_FRAGMENT, 0, 1, &sv);
     
  
     memset(&sampler_desc, 0, sizeof sampler_desc);
     sampler_desc.wrap_s = PIPE_TEX_WRAP_REPEAT;
     sampler_desc.wrap_t = PIPE_TEX_WRAP_REPEAT;
     sampler_desc.wrap_r = PIPE_TEX_WRAP_REPEAT;
     sampler_desc.min_img_filter = PIPE_TEX_FILTER_NEAREST;
     sampler_desc.min_mip_filter = PIPE_TEX_MIPFILTER_NONE;
     sampler_desc.mag_img_filter = PIPE_TEX_FILTER_NEAREST;
     sampler_desc.compare_mode = PIPE_TEX_COMPARE_NONE;
     sampler_desc.compare_func = 0;
     sampler_desc.normalized_coords = 1;
     sampler_desc.max_anisotropy = 0;
     
     sampler = ctx->create_sampler_state(ctx, &sampler_desc);
     if (sampler == NULL)
        exit(6);
  
     ctx->bind_sampler_states(ctx, PIPE_SHADER_FRAGMENT, 0, 1, &sampler);
     
  }
  
  static void init( void )
  {
     struct pipe_framebuffer_state fb;
     struct pipe_resource templat;
     struct pipe_surface surf_tmpl;
     int i;
  
     /* It's hard to say whether window or screen should be created
      * first.  Different environments would prefer one or the other.
      *
      * Also, no easy way of querying supported formats if the screen
      * cannot be created first.
      */
     for (i = 0; formats[i] != PIPE_FORMAT_NONE; i++) {
        screen = graw_create_window_and_screen(0, 0, 300, 300,
                                               formats[i],
                                               &window);
        if (window && screen)
           break;
     }
     if (!screen || !window) {
        fprintf(stderr, "Unable to create window\n");
        exit(1);
     }
  
     ctx = screen->context_create(screen, NULL, 0);
     if (ctx == NULL)
        exit(3);
  
     memset(&templat, 0, sizeof(templat));
     templat.target = PIPE_TEXTURE_2D;
     templat.format = formats[i];
     templat.width0 = WIDTH;
     templat.height0 = HEIGHT;
     templat.depth0 = 1;
     templat.array_size = 1;
     templat.last_level = 0;
     templat.nr_samples = 1;
     templat.bind = (PIPE_BIND_RENDER_TARGET |
                     PIPE_BIND_DISPLAY_TARGET);
     
     rttex = screen->resource_create(screen,
                                   &templat);
     if (rttex == NULL)
        exit(4);
  
     surf_tmpl.format = templat.format;
     surf_tmpl.u.tex.level = 0;
     surf_tmpl.u.tex.first_layer = 0;
     surf_tmpl.u.tex.last_layer = 0;
     surf = ctx->create_surface(ctx, rttex, &surf_tmpl);
     if (surf == NULL)
        exit(5);
  
     memset(&fb, 0, sizeof fb);
     fb.nr_cbufs = 1;
     fb.width = WIDTH;
     fb.height = HEIGHT;
     fb.cbufs[0] = surf;
  
     ctx->set_framebuffer_state(ctx, &fb);
     
     {
        struct pipe_blend_state blend;
        void *handle;
        memset(&blend, 0, sizeof blend);
        blend.rt[0].colormask = PIPE_MASK_RGBA;
        handle = ctx->create_blend_state(ctx, &blend);
        ctx->bind_blend_state(ctx, handle);
     }
  
     {
        struct pipe_depth_stencil_alpha_state depthstencil;
        void *handle;
        memset(&depthstencil, 0, sizeof depthstencil);
        handle = ctx->create_depth_stencil_alpha_state(ctx, &depthstencil);
        ctx->bind_depth_stencil_alpha_state(ctx, handle);
     }
  
     {
        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 = 1;
        handle = ctx->create_rasterizer_state(ctx, &rasterizer);
        ctx->bind_rasterizer_state(ctx, handle);
     }
  
     set_viewport(0, 0, WIDTH, HEIGHT, 30, 1000);
  
     init_tex();
     init_fs_constbuf();
  
     set_vertices();
     set_vertex_shader();
     set_fragment_shader(filename);
  }
  
  static void args(int argc, char *argv[])
  {
     int i;
  
     for (i = 1; i < argc;) {
        if (graw_parse_args(&i, argc, argv)) {
           continue;
        }
        if (strcmp(argv[i], "-fps") == 0) {
           show_fps = 1;
           i++;
        }
        else if (i == argc - 1) {
           filename = argv[i];
           i++;
        }
        else {
           usage(argv[0]);
           exit(1);
        }
     }
  
     if (!filename) {
        usage(argv[0]);
        exit(1);
     }
  }
  
  int main( int argc, char *argv[] )
  {
     args(argc,argv);
     init();
  
     graw_set_display_func( draw );
     graw_main_loop();
     return 0;
  }
  