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