vg_build_utils_shader.h

   1 #include "vg.h"
   2
   3 #ifdef VG_GAME
   4   #error !
   5 #endif
   6
   7 #define STB_INCLUDE_IMPLEMENTATION
   8 #define STB_INCLUDE_LINE_GLSL
   9 #include "submodules/stb/stb_include.h"
  10
  11 struct
  12 {
  13    struct uniform
  14    {
  15       char name[32];
  16       char type[20];
  17       char uniform_code_id[128];
  18
  19       int array;
  20    }
  21    uniform_buffer[100];
  22
  23    int   uniform_count,
  24          uniform_uid;
  25    char  shader_dir[ 256 ];
  26    char  current_shader_name[ 128 ];
  27 }
  28 static vg_shaderbuild;
  29
  30 static void vg_shader_set_include_dir( char *dir )
  31 {
  32    strcpy( vg_shaderbuild.shader_dir, dir );
  33 }
  34
  35 static void parse_uniform_name( char *start, struct uniform *uf )
  36 {
  37    uf->array = 0;
  38    int type_set = 0;
  39
  40    for( int i=0;; i++ )
  41    {
  42       if( start[i] == '\0' )
  43          break;
  44
  45       if( start[i] == ';' )
  46       {
  47          start[i] = '\0';
  48          vg_strncpy( start, uf->name, sizeof(uf->name),
  49                      k_strncpy_always_add_null );
  50       }
  51
  52       if( start[i] == '[' )
  53       {
  54          start[i] = '\0';
  55          vg_strncpy( start, uf->name, sizeof(uf->name),
  56                      k_strncpy_always_add_null );
  57          uf->array = 1;
  58       }
  59
  60       if( start[i] == ' ' )
  61       {
  62          start[i] = '\0';
  63
  64          if( !type_set )
  65          {
  66             vg_strncpy( start, uf->type, sizeof(uf->type),
  67                         k_strncpy_always_add_null );
  68             type_set = 1;
  69          }
  70          start = start+i+1;
  71          i=0;
  72       }
  73    }
  74
  75    snprintf( uf->uniform_code_id, 64, "_uniform_%s_%s",
  76              vg_shaderbuild.current_shader_name,
  77              uf->name );
  78 }
  79
  80 static int compile_subshader( FILE *header, char *name )
  81 {
  82    char error[256];
  83    char *full = stb_include_file( name, "", vg_shaderbuild.shader_dir, error );
  84
  85    if( !full )
  86    {
  87       fprintf( stderr, "stb_include_file error:\n%s\n", error );
  88       return 0;
  89    }
  90    else
  91    {
  92       fprintf( header, "{\n"
  93                        ".orig_file = \"%s\",\n"
  94                        ".static_src = \n",
  95                        name );
  96
  97       char *cur = full, *start = full;
  98       while( 1 )
  99       {
 100          char c = *cur;
 101          if( c == '\n' || c == '\0' )
 102          {
 103             *cur = '\0';
 104             fputs( "\"", header );
 105             fputs( start, header );
 106
 107             if( !strncmp(start,"uniform",7) )
 108             {
 109                start += 8;
 110                struct uniform *uf =
 111                   &vg_shaderbuild.uniform_buffer[
 112                         vg_shaderbuild.uniform_count ++ ];
 113
 114                parse_uniform_name( start, uf );
 115             }
 116
 117             if( c == '\0' )
 118             {
 119                fputs( "\"", header );
 120                break;
 121             }
 122
 123             fputs( "\\n\"\n", header );
 124             start = cur+1;
 125          }
 126          cur ++;
 127       }
 128
 129       fputs( "},", header );
 130    }
 131
 132    free( full );
 133    return 1;
 134 }
 135
 136 int vg_build_shader( char *src_vert, /* path/to/vert.vs    */
 137                      char *src_frag, /* path/to/frag.fs    */
 138                      char *src_geo,  /* unused currently   */
 139                      char *dst_h,    /* folder where .h go */
 140                      char *name      /* shader name        */ )
 141 {
 142    char path[260];
 143
 144    strcpy( vg_shaderbuild.current_shader_name, name );
 145
 146    strcpy( path, dst_h );
 147    strcat( path, "/" );
 148    strcat( path, name );
 149    strcat( path, ".h" );
 150
 151    printf( "Compiling shader called '%s'\n", name );
 152
 153    FILE *header = fopen( path, "w" );
 154    if( !header )
 155    {
 156       fprintf(stderr, "Could not open '%s'\n", path );
 157       return 0;
 158    }
 159
 160    fprintf( header, "#ifndef SHADER_%s_H\n"
 161                     "#define SHADER_%s_H\n", name, name );
 162    fprintf( header, "static void shader_%s_link(void);\n", name );
 163    fprintf( header, "static void shader_%s_register(void);\n", name );
 164    fprintf( header, "static struct vg_shader _shader_%s = {\n"
 165                     "   .name = \"%s\",\n"
 166                     "   .link = shader_%s_link,\n"
 167                     "   .vs = \n", name, name, name );
 168
 169    vg_shaderbuild.uniform_count = 0;
 170    if( !compile_subshader(header,src_vert) )
 171    {
 172       fclose( header );
 173       return 0;
 174    }
 175
 176    fprintf( header, "\n   .fs = \n" );
 177    if( !compile_subshader(header,src_frag) )
 178    {
 179       fclose( header );
 180       return 0;
 181    }
 182
 183    fprintf( header, "\n};\n\n" );
 184
 185    for( int i=0; i<vg_shaderbuild.uniform_count; i++ )
 186    {
 187       struct uniform *uf = &vg_shaderbuild.uniform_buffer[i];
 188       fprintf( header, "static GLuint %s;\n", uf->uniform_code_id );
 189    }
 190
 191    struct type_info
 192    {
 193       const char *glsl_type,
 194                  *args,
 195                  *gl_call_pattern;
 196    }
 197    types[] =
 198    {
 199       { "float", "float f", "glUniform1f(%s,f);" },
 200
 201       { "vec2", "v2f v", "glUniform2fv(%s,1,v);" },
 202       { "vec3", "v3f v", "glUniform3fv(%s,1,v);" },
 203       { "vec4", "v4f v", "glUniform4fv(%s,1,v);" },
 204
 205       { "sampler2D", "int i", "glUniform1i(%s,i);" },
 206       { "mat4x3", "m4x3f m", "glUniformMatrix4x3fv(%s,1,GL_FALSE,(float*)m);" },
 207       { "mat3", "m3x3f m", "glUniformMatrix3fv(%s,1,GL_FALSE,(float*)m);" },
 208       { "mat4", "m4x4f m", "glUniformMatrix4fv(%s,1,GL_FALSE,(float*)m);" },
 209    };
 210
 211    for( int i=0; i<vg_shaderbuild.uniform_count; i++ )
 212    {
 213       struct uniform *uf = &vg_shaderbuild.uniform_buffer[i];
 214       if( uf->array )
 215          continue;
 216
 217       for( int j=0; j<vg_list_size(types); j ++ )
 218       {
 219          struct type_info *inf = &types[j];
 220
 221          if( !strcmp( inf->glsl_type, uf->type ) )
 222          {
 223             fprintf( header, "static void shader_%s_%s(%s){\n",
 224                               name, uf->name, inf->args );
 225             fprintf( header, "   " );
 226             fprintf( header, inf->gl_call_pattern, uf->uniform_code_id );
 227             fprintf( header, "\n}\n" );
 228          }
 229       }
 230    }
 231
 232    fprintf( header,
 233          "static void shader_%s_register(void){\n"
 234          "   vg_shader_register( &_shader_%s );\n"
 235          "}\n",
 236             name,name );
 237
 238    fprintf( header,
 239          "static void shader_%s_use(void){ glUseProgram(_shader_%s.id); }\n",
 240             name, name );
 241
 242    fprintf( header,
 243          "static void shader_%s_link(void){\n",
 244             name );
 245
 246    for( int i=0; i<vg_shaderbuild.uniform_count; i++ )
 247    {
 248       struct uniform *uf = &vg_shaderbuild.uniform_buffer[i];
 249       fprintf( header,
 250          "   _uniform_%s_%s = "
 251             "glGetUniformLocation( _shader_%s.id, \"%s\" );\n",
 252          name, uf->name,
 253          name, uf->name );
 254    }
 255
 256    fprintf( header, "}\n" );
 257    fprintf( header, "#endif /* SHADER_%s_H */\n", name );
 258    fclose( header );
 259
 260    return 1;
 261 }