src/mesa/main/extensions.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.3
   4  *
   5  * Copyright (C) 1999-2004  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 #include "glheader.h"
  27 #include "imports.h"
  28 #include "context.h"
  29 #include "extensions.h"
  30 #include "simple_list.h"
  31 #include "mtypes.h"
  32
  33
  34 #define F(x) (int)(unsigned long)&(((struct gl_extensions *)0)->x)
  35 #define ON GL_TRUE
  36 #define OFF GL_FALSE
  37
  38
  39 /*
  40  * Note: The GL_MESAX_* extensions are placeholders for future ARB extensions.
  41  */
  42 static const struct {
  43    GLboolean enabled;
  44    const char *name;
  45    int flag_offset;
  46 } default_extensions[] = {
  47    { OFF, "GL_ARB_depth_texture",              F(ARB_depth_texture) },
  48    { OFF, "GL_ARB_draw_buffers",               F(ARB_draw_buffers) },
  49    { OFF, "GL_ARB_fragment_program",           F(ARB_fragment_program) },
  50    { OFF, "GL_MESAX_half_float_pixel",         F(ARB_half_float_pixel) },
  51    { OFF, "GL_ARB_imaging",                    F(ARB_imaging) },
  52    { OFF, "GL_ARB_multisample",                F(ARB_multisample) },
  53    { OFF, "GL_ARB_multitexture",               F(ARB_multitexture) },
  54    { OFF, "GL_ARB_occlusion_query",            F(ARB_occlusion_query) },
  55    { OFF, "GL_ARB_point_parameters",           F(EXT_point_parameters) },
  56    { OFF, "GL_ARB_point_sprite",               F(ARB_point_sprite) },
  57    { OFF, "GL_ARB_shadow",                     F(ARB_shadow) },
  58    { OFF, "GL_ARB_shadow_ambient",             F(SGIX_shadow_ambient) },
  59    { OFF, "GL_ARB_texture_border_clamp",       F(ARB_texture_border_clamp) },
  60    { OFF, "GL_ARB_texture_compression",        F(ARB_texture_compression) },
  61    { OFF, "GL_ARB_texture_cube_map",           F(ARB_texture_cube_map) },
  62    { OFF, "GL_ARB_texture_env_add",            F(EXT_texture_env_add) },
  63    { OFF, "GL_ARB_texture_env_combine",        F(ARB_texture_env_combine) },
  64    { OFF, "GL_ARB_texture_env_crossbar",       F(ARB_texture_env_crossbar) },
  65    { OFF, "GL_ARB_texture_env_dot3",           F(ARB_texture_env_dot3) },
  66    { OFF, "GL_MESAX_texture_float",            F(ARB_texture_float) },
  67    { OFF, "GL_ARB_texture_mirrored_repeat",    F(ARB_texture_mirrored_repeat)},
  68    { OFF, "GL_ARB_texture_non_power_of_two",   F(ARB_texture_non_power_of_two)},
  69    { OFF, "GL_ARB_texture_rectangle",          F(NV_texture_rectangle) },
  70    { ON,  "GL_ARB_transpose_matrix",           F(ARB_transpose_matrix) },
  71    { OFF, "GL_ARB_vertex_buffer_object",       F(ARB_vertex_buffer_object) },
  72    { OFF, "GL_ARB_vertex_program",             F(ARB_vertex_program) },
  73    { ON,  "GL_ARB_window_pos",                 F(ARB_window_pos) },
  74    { ON,  "GL_EXT_abgr",                       F(EXT_abgr) },
  75    { ON,  "GL_EXT_bgra",                       F(EXT_bgra) },
  76    { OFF, "GL_EXT_blend_color",                F(EXT_blend_color) },
  77    { OFF, "GL_EXT_blend_equation_separate",    F(EXT_blend_equation_separate) },
  78    { OFF, "GL_EXT_blend_func_separate",        F(EXT_blend_func_separate) },
  79    { OFF, "GL_EXT_blend_logic_op",             F(EXT_blend_logic_op) },
  80    { OFF, "GL_EXT_blend_minmax",               F(EXT_blend_minmax) },
  81    { OFF, "GL_EXT_blend_subtract",             F(EXT_blend_subtract) },
  82    { ON,  "GL_EXT_clip_volume_hint",           F(EXT_clip_volume_hint) },
  83    { OFF, "GL_EXT_cull_vertex",                F(EXT_cull_vertex) },
  84    { ON,  "GL_EXT_compiled_vertex_array",      F(EXT_compiled_vertex_array) },
  85    { OFF, "GL_EXT_convolution",                F(EXT_convolution) },
  86    { ON,  "GL_EXT_copy_texture",               F(EXT_copy_texture) },
  87    { OFF, "GL_EXT_depth_bounds_test",          F(EXT_depth_bounds_test) },
  88    { ON,  "GL_EXT_draw_range_elements",        F(EXT_draw_range_elements) },
  89    { OFF, "GL_EXT_fog_coord",                  F(EXT_fog_coord) },
  90    { OFF, "GL_EXT_histogram",                  F(EXT_histogram) },
  91    { OFF, "GL_EXT_multi_draw_arrays",          F(EXT_multi_draw_arrays) },
  92    { ON,  "GL_EXT_packed_pixels",              F(EXT_packed_pixels) },
  93    { OFF, "GL_EXT_paletted_texture",           F(EXT_paletted_texture) },
  94    { OFF, "GL_EXT_pixel_buffer_object",        F(EXT_pixel_buffer_object) },
  95    { OFF, "GL_EXT_point_parameters",           F(EXT_point_parameters) },
  96    { ON,  "GL_EXT_polygon_offset",             F(EXT_polygon_offset) },
  97    { ON,  "GL_EXT_rescale_normal",             F(EXT_rescale_normal) },
  98    { OFF, "GL_EXT_secondary_color",            F(EXT_secondary_color) },
  99    { ON,  "GL_EXT_separate_specular_color",    F(EXT_separate_specular_color) },
 100    { OFF, "GL_EXT_shadow_funcs",               F(EXT_shadow_funcs) },
 101    { OFF, "GL_EXT_shared_texture_palette",     F(EXT_shared_texture_palette) },
 102    { OFF, "GL_EXT_stencil_two_side",           F(EXT_stencil_two_side) },
 103    { OFF, "GL_EXT_stencil_wrap",               F(EXT_stencil_wrap) },
 104    { ON,  "GL_EXT_subtexture",                 F(EXT_subtexture) },
 105    { ON,  "GL_EXT_texture",                    F(EXT_texture) },
 106    { ON,  "GL_EXT_texture3D",                  F(EXT_texture3D) },
 107    { OFF, "GL_EXT_texture_compression_s3tc",   F(EXT_texture_compression_s3tc) },
 108    { ON,  "GL_EXT_texture_edge_clamp",         F(SGIS_texture_edge_clamp) },
 109    { OFF, "GL_EXT_texture_env_add",            F(EXT_texture_env_add) },
 110    { OFF, "GL_EXT_texture_env_combine",        F(EXT_texture_env_combine) },
 111    { OFF, "GL_EXT_texture_env_dot3",           F(EXT_texture_env_dot3) },
 112    { OFF, "GL_EXT_texture_filter_anisotropic", F(EXT_texture_filter_anisotropic) },
 113    { OFF, "GL_EXT_texture_lod_bias",           F(EXT_texture_lod_bias) },
 114    { OFF, "GL_EXT_texture_mirror_clamp",       F(EXT_texture_mirror_clamp) },
 115    { ON,  "GL_EXT_texture_object",             F(EXT_texture_object) },
 116    { OFF, "GL_EXT_texture_rectangle",          F(NV_texture_rectangle) },
 117    { ON,  "GL_EXT_vertex_array",               F(EXT_vertex_array) },
 118    { OFF, "GL_EXT_vertex_array_set",           F(EXT_vertex_array_set) },
 119    { OFF, "GL_3DFX_texture_compression_FXT1",  F(TDFX_texture_compression_FXT1) },
 120    { OFF, "GL_APPLE_client_storage",           F(APPLE_client_storage) },
 121    { ON,  "GL_APPLE_packed_pixels",            F(APPLE_packed_pixels) },
 122    { OFF, "GL_ATI_blend_equation_separate",    F(EXT_blend_equation_separate) },
 123    { OFF, "GL_ATI_texture_env_combine3",       F(ATI_texture_env_combine3)},
 124    { OFF, "GL_ATI_texture_mirror_once",        F(ATI_texture_mirror_once)},
 125    { OFF, "GL_HP_occlusion_test",              F(HP_occlusion_test) },
 126    { OFF, "GL_IBM_multimode_draw_arrays",      F(IBM_multimode_draw_arrays) },
 127    { ON,  "GL_IBM_rasterpos_clip",             F(IBM_rasterpos_clip) },
 128    { OFF, "GL_IBM_texture_mirrored_repeat",    F(ARB_texture_mirrored_repeat)},
 129    { OFF, "GL_INGR_blend_func_separate",       F(EXT_blend_func_separate) },
 130    { OFF, "GL_MESA_pack_invert",               F(MESA_pack_invert) },
 131    { OFF, "GL_MESA_packed_depth_stencil",      F(MESA_packed_depth_stencil) },
 132    { OFF, "GL_MESA_program_debug",             F(MESA_program_debug) },
 133    { OFF, "GL_MESA_resize_buffers",            F(MESA_resize_buffers) },
 134    { OFF, "GL_MESA_ycbcr_texture",             F(MESA_ycbcr_texture) },
 135    { ON,  "GL_MESA_window_pos",                F(ARB_window_pos) },
 136    { OFF, "GL_NV_blend_square",                F(NV_blend_square) },
 137    { OFF, "GL_NV_fragment_program",            F(NV_fragment_program) },
 138    { ON,  "GL_NV_light_max_exponent",          F(NV_light_max_exponent) },
 139    { OFF, "GL_NV_point_sprite",                F(NV_point_sprite) },
 140    { OFF, "GL_NV_texture_rectangle",           F(NV_texture_rectangle) },
 141    { ON,  "GL_NV_texgen_reflection",           F(NV_texgen_reflection) },
 142    { OFF, "GL_NV_vertex_program",              F(NV_vertex_program) },
 143    { OFF, "GL_NV_vertex_program1_1",           F(NV_vertex_program1_1) },
 144    { OFF, "GL_SGI_color_matrix",               F(SGI_color_matrix) },
 145    { OFF, "GL_SGI_color_table",                F(SGI_color_table) },
 146    { OFF, "GL_SGI_texture_color_table",        F(SGI_texture_color_table) },
 147    { OFF, "GL_SGIS_generate_mipmap",           F(SGIS_generate_mipmap) },
 148    { OFF, "GL_SGIS_pixel_texture",             F(SGIS_pixel_texture) },
 149    { OFF, "GL_SGIS_texture_border_clamp",      F(ARB_texture_border_clamp) },
 150    { ON,  "GL_SGIS_texture_edge_clamp",        F(SGIS_texture_edge_clamp) },
 151    { ON,  "GL_SGIS_texture_lod",               F(SGIS_texture_lod) },
 152    { OFF, "GL_SGIX_depth_texture",             F(SGIX_depth_texture) },
 153    { OFF, "GL_SGIX_pixel_texture",             F(SGIX_pixel_texture) },
 154    { OFF, "GL_SGIX_shadow",                    F(SGIX_shadow) },
 155    { OFF, "GL_SGIX_shadow_ambient",            F(SGIX_shadow_ambient) },
 156    { OFF, "GL_SUN_multi_draw_arrays",          F(EXT_multi_draw_arrays) },
 157    { OFF, "GL_S3_s3tc",                        F(S3_s3tc) },
 158 };
 159
 160
 161
 162 /**
 163  * Enable all extensions suitable for a software-only renderer.
 164  * This is a convenience function used by the XMesa, OSMesa, GGI drivers, etc.
 165  */
 166 void
 167 _mesa_enable_sw_extensions(GLcontext *ctx)
 168 {
 169    ctx->Extensions.ARB_depth_texture = GL_TRUE;
 170    ctx->Extensions.ARB_draw_buffers = GL_TRUE;
 171 #if FEATURE_ARB_fragment_program
 172    ctx->Extensions.ARB_fragment_program = GL_TRUE;
 173 #endif
 174    /*ctx->Extensions.ARB_half_float_pixel = GL_TRUE;*/
 175    ctx->Extensions.ARB_imaging = GL_TRUE;
 176    ctx->Extensions.ARB_multitexture = GL_TRUE;
 177 #if FEATURE_ARB_occlusion_query
 178    ctx->Extensions.ARB_occlusion_query = GL_TRUE;
 179 #endif
 180    ctx->Extensions.ARB_point_sprite = GL_TRUE;
 181    ctx->Extensions.ARB_shadow = GL_TRUE;
 182    ctx->Extensions.ARB_texture_border_clamp = GL_TRUE;
 183    ctx->Extensions.ARB_texture_cube_map = GL_TRUE;
 184    ctx->Extensions.ARB_texture_env_combine = GL_TRUE;
 185    ctx->Extensions.ARB_texture_env_crossbar = GL_TRUE;
 186    ctx->Extensions.ARB_texture_env_dot3 = GL_TRUE;
 187    /*ctx->Extensions.ARB_texture_float = GL_TRUE;*/
 188    ctx->Extensions.ARB_texture_mirrored_repeat = GL_TRUE;
 189    ctx->Extensions.ARB_texture_non_power_of_two = GL_TRUE;
 190 #if FEATURE_ARB_vertex_program
 191    ctx->Extensions.ARB_vertex_program = GL_TRUE;
 192 #endif
 193 #if FEATURE_ARB_vertex_buffer_object
 194    ctx->Extensions.ARB_vertex_buffer_object = GL_TRUE;
 195 #endif
 196    ctx->Extensions.ATI_texture_env_combine3 = GL_TRUE;
 197    ctx->Extensions.ATI_texture_mirror_once = GL_TRUE;
 198    ctx->Extensions.EXT_blend_color = GL_TRUE;
 199    ctx->Extensions.EXT_blend_equation_separate = GL_TRUE;
 200    ctx->Extensions.EXT_blend_func_separate = GL_TRUE;
 201    ctx->Extensions.EXT_blend_logic_op = GL_TRUE;
 202    ctx->Extensions.EXT_blend_minmax = GL_TRUE;
 203    ctx->Extensions.EXT_blend_subtract = GL_TRUE;
 204    ctx->Extensions.EXT_convolution = GL_TRUE;
 205    ctx->Extensions.EXT_depth_bounds_test = GL_TRUE;
 206    ctx->Extensions.EXT_fog_coord = GL_TRUE;
 207    ctx->Extensions.EXT_histogram = GL_TRUE;
 208    ctx->Extensions.EXT_multi_draw_arrays = GL_TRUE;
 209    ctx->Extensions.EXT_paletted_texture = GL_TRUE;
 210 #if FEATURE_EXT_pixel_buffer_object
 211    ctx->Extensions.EXT_pixel_buffer_object = GL_TRUE;
 212 #endif
 213    ctx->Extensions.EXT_point_parameters = GL_TRUE;
 214    ctx->Extensions.EXT_shadow_funcs = GL_TRUE;
 215    ctx->Extensions.EXT_secondary_color = GL_TRUE;
 216    ctx->Extensions.EXT_shared_texture_palette = GL_TRUE;
 217    ctx->Extensions.EXT_stencil_wrap = GL_TRUE;
 218    ctx->Extensions.EXT_stencil_two_side = GL_TRUE;
 219    ctx->Extensions.EXT_texture_env_add = GL_TRUE;
 220    ctx->Extensions.EXT_texture_env_combine = GL_TRUE;
 221    ctx->Extensions.EXT_texture_env_dot3 = GL_TRUE;
 222    ctx->Extensions.EXT_texture_mirror_clamp = GL_TRUE;
 223    ctx->Extensions.EXT_texture_lod_bias = GL_TRUE;
 224    ctx->Extensions.HP_occlusion_test = GL_TRUE;
 225    ctx->Extensions.IBM_multimode_draw_arrays = GL_TRUE;
 226    ctx->Extensions.MESA_pack_invert = GL_TRUE;
 227 #if FEATURE_MESA_program_debug
 228    ctx->Extensions.MESA_program_debug = GL_TRUE;
 229 #endif
 230    ctx->Extensions.MESA_resize_buffers = GL_TRUE;
 231    ctx->Extensions.MESA_ycbcr_texture = GL_TRUE;
 232    ctx->Extensions.NV_blend_square = GL_TRUE;
 233    /*ctx->Extensions.NV_light_max_exponent = GL_TRUE;*/
 234    ctx->Extensions.NV_point_sprite = GL_TRUE;
 235    ctx->Extensions.NV_texture_rectangle = GL_TRUE;
 236    /*ctx->Extensions.NV_texgen_reflection = GL_TRUE;*/
 237 #if FEATURE_NV_vertex_program
 238    ctx->Extensions.NV_vertex_program = GL_TRUE;
 239    ctx->Extensions.NV_vertex_program1_1 = GL_TRUE;
 240 #endif
 241 #if FEATURE_NV_fragment_program
 242    ctx->Extensions.NV_fragment_program = GL_TRUE;
 243 #endif
 244    ctx->Extensions.SGI_color_matrix = GL_TRUE;
 245    ctx->Extensions.SGI_color_table = GL_TRUE;
 246    ctx->Extensions.SGI_texture_color_table = GL_TRUE;
 247    ctx->Extensions.SGIS_generate_mipmap = GL_TRUE;
 248    ctx->Extensions.SGIS_pixel_texture = GL_TRUE;
 249    ctx->Extensions.SGIS_texture_edge_clamp = GL_TRUE;
 250    ctx->Extensions.SGIX_depth_texture = GL_TRUE;
 251    ctx->Extensions.SGIX_pixel_texture = GL_TRUE;
 252    ctx->Extensions.SGIX_shadow = GL_TRUE;
 253    ctx->Extensions.SGIX_shadow_ambient = GL_TRUE;
 254 }
 255
 256
 257 /**
 258  * Enable GL_ARB_imaging and all the EXT extensions that are subsets of it.
 259  */
 260 void
 261 _mesa_enable_imaging_extensions(GLcontext *ctx)
 262 {
 263    ctx->Extensions.ARB_imaging = GL_TRUE;
 264    ctx->Extensions.EXT_blend_color = GL_TRUE;
 265    ctx->Extensions.EXT_blend_minmax = GL_TRUE;
 266    ctx->Extensions.EXT_blend_subtract = GL_TRUE;
 267    ctx->Extensions.EXT_convolution = GL_TRUE;
 268    ctx->Extensions.EXT_histogram = GL_TRUE;
 269    ctx->Extensions.SGI_color_matrix = GL_TRUE;
 270    ctx->Extensions.SGI_color_table = GL_TRUE;
 271 }
 272
 273
 274
 275 /**
 276  * Enable all OpenGL 1.3 features and extensions.
 277  * A convenience function to be called by drivers.
 278  */
 279 void
 280 _mesa_enable_1_3_extensions(GLcontext *ctx)
 281 {
 282    ctx->Extensions.ARB_multisample = GL_TRUE;
 283    ctx->Extensions.ARB_multitexture = GL_TRUE;
 284    ctx->Extensions.ARB_texture_border_clamp = GL_TRUE;
 285    ctx->Extensions.ARB_texture_compression = GL_TRUE;
 286    ctx->Extensions.ARB_texture_cube_map = GL_TRUE;
 287    ctx->Extensions.ARB_texture_env_combine = GL_TRUE;
 288    ctx->Extensions.ARB_texture_env_dot3 = GL_TRUE;
 289    ctx->Extensions.EXT_texture_env_add = GL_TRUE;
 290    /*ctx->Extensions.ARB_transpose_matrix = GL_TRUE;*/
 291 }
 292
 293
 294
 295 /**
 296  * Enable all OpenGL 1.4 features and extensions.
 297  * A convenience function to be called by drivers.
 298  */
 299 void
 300 _mesa_enable_1_4_extensions(GLcontext *ctx)
 301 {
 302    ctx->Extensions.ARB_depth_texture = GL_TRUE;
 303    ctx->Extensions.ARB_shadow = GL_TRUE;
 304    ctx->Extensions.ARB_texture_env_crossbar = GL_TRUE;
 305    ctx->Extensions.ARB_texture_mirrored_repeat = GL_TRUE;
 306    ctx->Extensions.ARB_window_pos = GL_TRUE;
 307    ctx->Extensions.EXT_blend_color = GL_TRUE;
 308    ctx->Extensions.EXT_blend_func_separate = GL_TRUE;
 309    ctx->Extensions.EXT_blend_logic_op = GL_TRUE;
 310    ctx->Extensions.EXT_blend_minmax = GL_TRUE;
 311    ctx->Extensions.EXT_blend_subtract = GL_TRUE;
 312    ctx->Extensions.EXT_fog_coord = GL_TRUE;
 313    ctx->Extensions.EXT_multi_draw_arrays = GL_TRUE;
 314    ctx->Extensions.EXT_point_parameters = GL_TRUE;
 315    ctx->Extensions.EXT_secondary_color = GL_TRUE;
 316    ctx->Extensions.EXT_stencil_wrap = GL_TRUE;
 317    ctx->Extensions.EXT_texture_lod_bias = GL_TRUE;
 318    ctx->Extensions.SGIS_generate_mipmap = GL_TRUE;
 319 }
 320
 321
 322 /**
 323  * Enable all OpenGL 1.5 features and extensions.
 324  * A convenience function to be called by drivers.
 325  */
 326 void
 327 _mesa_enable_1_5_extensions(GLcontext *ctx)
 328 {
 329    ctx->Extensions.ARB_occlusion_query = GL_TRUE;
 330    ctx->Extensions.ARB_vertex_buffer_object = GL_TRUE;
 331    ctx->Extensions.EXT_shadow_funcs = GL_TRUE;
 332 }
 333
 334
 335 /**
 336  * Enable all OpenGL 2.0 features and extensions.
 337  * A convenience function to be called by drivers.
 338  */
 339 void
 340 _mesa_enable_2_0_extensions(GLcontext *ctx)
 341 {
 342    ctx->Extensions.ARB_draw_buffers = GL_TRUE;
 343    ctx->Extensions.ARB_point_sprite = GL_TRUE;
 344    ctx->Extensions.ARB_texture_non_power_of_two = GL_TRUE;
 345    ctx->Extensions.EXT_stencil_two_side = GL_TRUE;
 346    /* Also, shading language */
 347 }
 348
 349
 350
 351 /**
 352  * Either enable or disable the named extension.
 353  */
 354 static void
 355 set_extension( GLcontext *ctx, const char *name, GLboolean state )
 356 {
 357    GLboolean *base = (GLboolean *) &ctx->Extensions;
 358    GLuint i;
 359
 360    if (ctx->Extensions.String) {
 361       /* The string was already queried - can't change it now! */
 362       _mesa_problem(ctx, "Trying to enable/disable extension after glGetString(GL_EXTENSIONS): %s", name);
 363       return;
 364    }
 365
 366    for (i = 0 ; i < Elements(default_extensions) ; i++) {
 367       if (_mesa_strcmp(default_extensions[i].name, name) == 0) {
 368          if (default_extensions[i].flag_offset) {
 369             GLboolean *enabled = base + default_extensions[i].flag_offset;
 370             *enabled = state;
 371          }
 372          return;
 373       }
 374    }
 375    _mesa_problem(ctx, "Trying to enable unknown extension: %s", name);
 376 }
 377
 378
 379 /**
 380  * Enable the named extension.
 381  * Typically called by drivers.
 382  */
 383 void
 384 _mesa_enable_extension( GLcontext *ctx, const char *name )
 385 {
 386    set_extension(ctx, name, GL_TRUE);
 387 }
 388
 389
 390 /**
 391  * Disable the named extension.
 392  * XXX is this really needed???
 393  */
 394 void
 395 _mesa_disable_extension( GLcontext *ctx, const char *name )
 396 {
 397    set_extension(ctx, name, GL_FALSE);
 398 }
 399
 400
 401 /**
 402  * Test if the named extension is enabled in this context.
 403  */
 404 GLboolean
 405 _mesa_extension_is_enabled( GLcontext *ctx, const char *name )
 406 {
 407    const GLboolean *base = (const GLboolean *) &ctx->Extensions;
 408    GLuint i;
 409
 410    for (i = 0 ; i < Elements(default_extensions) ; i++) {
 411       if (_mesa_strcmp(default_extensions[i].name, name) == 0) {
 412          if (!default_extensions[i].flag_offset)
 413             return GL_TRUE;
 414          return *(base + default_extensions[i].flag_offset);
 415       }
 416    }
 417    return GL_FALSE;
 418 }
 419
 420
 421 /**
 422  * Run through the default_extensions array above and set the
 423  * ctx->Extensions.ARB/EXT_* flags accordingly.
 424  * To be called during context initialization.
 425  */
 426 void
 427 _mesa_init_extensions( GLcontext *ctx )
 428 {
 429    GLboolean *base = (GLboolean *) &ctx->Extensions;
 430    GLuint i;
 431
 432    for (i = 0 ; i < Elements(default_extensions) ; i++) {
 433       if (default_extensions[i].enabled &&
 434           default_extensions[i].flag_offset) {
 435          *(base + default_extensions[i].flag_offset) = GL_TRUE;
 436       }
 437    }
 438 }
 439
 440
 441 /**
 442  * Construct the GL_EXTENSIONS string.  Called the first time that
 443  * glGetString(GL_EXTENSIONS) is called.
 444  */
 445 GLubyte *
 446 _mesa_make_extension_string( GLcontext *ctx )
 447 {
 448    const GLboolean *base = (const GLboolean *) &ctx->Extensions;
 449    GLuint extStrLen = 0;
 450    GLubyte *s;
 451    GLuint i;
 452
 453    /* first, compute length of the extension string */
 454    for (i = 0 ; i < Elements(default_extensions) ; i++) {
 455       if (!default_extensions[i].flag_offset ||
 456           *(base + default_extensions[i].flag_offset)) {
 457          extStrLen += _mesa_strlen(default_extensions[i].name) + 1;
 458       }
 459    }
 460    s = (GLubyte *) _mesa_malloc(extStrLen);
 461
 462    /* second, build the extension string */
 463    extStrLen = 0;
 464    for (i = 0 ; i < Elements(default_extensions) ; i++) {
 465       if (!default_extensions[i].flag_offset ||
 466           *(base + default_extensions[i].flag_offset)) {
 467          GLuint len = _mesa_strlen(default_extensions[i].name);
 468          _mesa_memcpy(s + extStrLen, default_extensions[i].name, len);
 469          extStrLen += len;
 470          s[extStrLen] = (GLubyte) ' ';
 471          extStrLen++;
 472       }
 473    }
 474    ASSERT(extStrLen > 0);
 475
 476    s[extStrLen - 1] = 0;
 477
 478    return s;
 479 }