2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2008 Brian Paul All Rights Reserved.
6 * Copyright (C) 2009 VMware, Inc. All Rights Reserved.
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the "Software"),
10 * to deal in the Software without restriction, including without limitation
11 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
12 * and/or sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following conditions:
15 * The above copyright notice and this permission notice shall be included
16 * in all copies or substantial portions of the Software.
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
22 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
23 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
29 * \brief Extension handling
36 #include "extensions.h"
37 #include "mfeatures.h"
40 #define ALIGN(value, alignment) (((value) + alignment - 1) & ~(alignment - 1))
43 * \brief An element of the \c extension_table.
46 /** Name of extension, such as "GL_ARB_depth_clamp". */
49 /** Offset (in bytes) of the corresponding member in struct gl_extensions. */
52 /** Year the extension was proposed or approved. Used to sort the
53 * extension string chronologically. */
59 * Given a member \c x of struct gl_extensions, return offset of
62 #define o(x) offsetof(struct gl_extensions, x)
66 * \brief Table of supported OpenGL extensions for all API's.
68 static const struct extension extension_table
[] = {
70 { "GL_ARB_half_float_pixel", o(ARB_half_float_pixel
), 2003 },
71 { "GL_ARB_half_float_vertex", o(ARB_half_float_vertex
), 2008 },
72 { "GL_ARB_map_buffer_range", o(ARB_map_buffer_range
), 2008 },
73 { "GL_ARB_multisample", o(dummy_true
), 1994 },
74 { "GL_ARB_multitexture", o(dummy_true
), 1998 },
75 { "GL_ARB_pixel_buffer_object", o(EXT_pixel_buffer_object
), 2004 },
76 { "GL_ARB_point_parameters", o(EXT_point_parameters
), 1997 },
77 { "GL_ARB_point_sprite", o(ARB_point_sprite
), 2003 },
78 { "GL_ARB_robustness", o(dummy_true
), 2010 },
79 { "GL_ARB_texture_border_clamp", o(ARB_texture_border_clamp
), 2000 },
80 { "GL_ARB_texture_cube_map", o(ARB_texture_cube_map
), 1999 },
81 { "GL_ARB_texture_env_add", o(dummy_true
), 1999 },
82 { "GL_ARB_texture_env_combine", o(ARB_texture_env_combine
), 2001 },
83 { "GL_ARB_texture_env_crossbar", o(ARB_texture_env_crossbar
), 2001 },
84 { "GL_ARB_texture_env_dot3", o(ARB_texture_env_dot3
), 2001 },
85 { "GL_ARB_texture_float", o(ARB_texture_float
), 2004 },
86 { "GL_ARB_texture_mirrored_repeat", o(dummy_true
), 2001 },
87 { "GL_ARB_texture_non_power_of_two", o(ARB_texture_non_power_of_two
), 2003 },
88 { "GL_ARB_texture_storage", o(ARB_texture_storage
), 2011 },
89 { "GL_ARB_transpose_matrix", o(ARB_transpose_matrix
), 1999 },
90 { "GL_ARB_vertex_array_object", o(ARB_vertex_array_object
), 2006 },
91 { "GL_ARB_vertex_buffer_object", o(dummy_true
), 2003 },
92 { "GL_ARB_window_pos", o(ARB_window_pos
), 2001 },
94 { "GL_EXT_abgr", o(dummy_true
), 1995 },
95 { "GL_EXT_bgra", o(dummy_true
), 1995 },
96 { "GL_EXT_blend_color", o(EXT_blend_color
), 1995 },
97 { "GL_EXT_blend_equation_separate", o(EXT_blend_equation_separate
), 2003 },
98 { "GL_EXT_blend_func_separate", o(EXT_blend_func_separate
), 1999 },
99 { "GL_EXT_blend_minmax", o(EXT_blend_minmax
), 1995 },
100 { "GL_EXT_blend_subtract", o(dummy_true
), 1995 },
101 { "GL_EXT_clip_volume_hint", o(EXT_clip_volume_hint
), 1996 },
102 { "GL_EXT_compiled_vertex_array", o(EXT_compiled_vertex_array
), 1996 },
103 { "GL_EXT_copy_texture", o(dummy_true
), 1995 },
104 { "GL_EXT_depth_bounds_test", o(EXT_depth_bounds_test
), 2002 },
105 { "GL_EXT_draw_range_elements", o(EXT_draw_range_elements
), 1997 },
106 { "GL_EXT_fog_coord", o(EXT_fog_coord
), 1999 },
107 { "GL_EXT_multi_draw_arrays", o(dummy_true
), 1999 },
108 { "GL_EXT_packed_pixels", o(EXT_packed_pixels
), 1997 },
109 { "GL_EXT_pixel_buffer_object", o(EXT_pixel_buffer_object
), 2004 },
110 { "GL_EXT_point_parameters", o(EXT_point_parameters
), 1997 },
111 { "GL_EXT_polygon_offset", o(dummy_true
), 1995 },
112 { "GL_EXT_rescale_normal", o(EXT_rescale_normal
), 1997 },
113 { "GL_EXT_secondary_color", o(EXT_secondary_color
), 1999 },
114 { "GL_EXT_separate_shader_objects", o(EXT_separate_shader_objects
), 2008 },
115 { "GL_EXT_separate_specular_color", o(EXT_separate_specular_color
), 1997 },
116 { "GL_EXT_shadow_funcs", o(EXT_shadow_funcs
), 2002 },
117 { "GL_EXT_stencil_two_side", o(EXT_stencil_two_side
), 2001 },
118 { "GL_EXT_stencil_wrap", o(dummy_true
), 2002 },
119 { "GL_EXT_subtexture", o(dummy_true
), 1995 },
120 { "GL_EXT_texture3D", o(EXT_texture3D
), 1996 },
121 { "GL_EXT_texture_cube_map", o(ARB_texture_cube_map
), 2001 },
122 { "GL_EXT_texture_edge_clamp", o(dummy_true
), 1997 },
123 { "GL_EXT_texture_env_add", o(dummy_true
), 1999 },
124 { "GL_EXT_texture_env_combine", o(dummy_true
), 2000 },
125 { "GL_EXT_texture_env_dot3", o(EXT_texture_env_dot3
), 2000 },
126 { "GL_EXT_texture_filter_anisotropic", o(EXT_texture_filter_anisotropic
), 1999 },
127 { "GL_EXT_texture_integer", o(EXT_texture_integer
), 2006 },
128 { "GL_EXT_texture_mirror_clamp", o(EXT_texture_mirror_clamp
), 2004 },
129 { "GL_EXT_texture_object", o(dummy_true
), 1995 },
130 { "GL_EXT_texture", o(dummy_true
), 1996 },
131 { "GL_EXT_vertex_array", o(dummy_true
), 1995 },
133 /* Vendor extensions */
134 { "GL_APPLE_object_purgeable", o(APPLE_object_purgeable
), 2006 },
135 { "GL_APPLE_packed_pixels", o(APPLE_packed_pixels
), 2002 },
136 { "GL_APPLE_vertex_array_object", o(APPLE_vertex_array_object
), 2002 },
137 { "GL_ATI_blend_equation_separate", o(EXT_blend_equation_separate
), 2003 },
138 { "GL_ATI_separate_stencil", o(ATI_separate_stencil
), 2006 },
139 { "GL_ATI_texture_env_combine3", o(ATI_texture_env_combine3
), 2002 },
140 { "GL_ATI_texture_float", o(ARB_texture_float
), 2002 },
141 { "GL_ATI_texture_mirror_once", o(ATI_texture_mirror_once
), 2006 },
142 { "GL_IBM_multimode_draw_arrays", o(IBM_multimode_draw_arrays
), 1998 },
143 { "GL_IBM_rasterpos_clip", o(IBM_rasterpos_clip
), 1996 },
144 { "GL_IBM_texture_mirrored_repeat", o(dummy_true
), 1998 },
145 { "GL_INGR_blend_func_separate", o(EXT_blend_func_separate
), 1999 },
146 { "GL_MESA_pack_invert", o(MESA_pack_invert
), 2002 },
147 { "GL_MESA_resize_buffers", o(MESA_resize_buffers
), 1999 },
148 { "GL_MESA_window_pos", o(ARB_window_pos
), 2000 },
149 { "GL_MESA_ycbcr_texture", o(MESA_ycbcr_texture
), 2002 },
150 { "GL_NV_blend_square", o(NV_blend_square
), 1999 },
151 { "GL_NV_fog_distance", o(NV_fog_distance
), 2001 },
152 { "GL_NV_light_max_exponent", o(NV_light_max_exponent
), 1999 },
153 { "GL_NV_point_sprite", o(NV_point_sprite
), 2001 },
154 { "GL_NV_texgen_reflection", o(NV_texgen_reflection
), 1999 },
155 { "GL_NV_texture_barrier", o(NV_texture_barrier
), 2009 },
156 { "GL_NV_texture_env_combine4", o(NV_texture_env_combine4
), 1999 },
157 { "GL_SGIS_texture_border_clamp", o(ARB_texture_border_clamp
), 1997 },
158 { "GL_SGIS_texture_edge_clamp", o(dummy_true
), 1997 },
159 { "GL_SUN_multi_draw_arrays", o(dummy_true
), 1999 },
166 * Given an extension name, lookup up the corresponding member of struct
167 * gl_extensions and return that member's offset (in bytes). If the name is
168 * not found in the \c extension_table, return 0.
170 * \param name Name of extension.
171 * \return Offset of member in struct gl_extensions.
174 name_to_offset(const char* name
)
176 const struct extension
*i
;
181 for (i
= extension_table
; i
->name
!= 0; ++i
) {
182 if (strcmp(name
, i
->name
) == 0)
191 * \brief Extensions enabled by default.
193 * These extensions are enabled by _mesa_init_extensions().
195 * XXX: Should these defaults also apply to GLES?
197 static const size_t default_extensions
[] = {
198 o(ARB_transpose_matrix
),
201 o(EXT_compiled_vertex_array
),
202 o(EXT_draw_range_elements
),
203 o(EXT_packed_pixels
),
204 o(EXT_rescale_normal
),
205 o(EXT_separate_specular_color
),
208 /* Vendor Extensions */
209 o(APPLE_packed_pixels
),
210 o(IBM_multimode_draw_arrays
),
211 o(IBM_rasterpos_clip
),
212 o(NV_light_max_exponent
),
213 o(NV_texgen_reflection
),
220 * Enable all extensions suitable for a software-only renderer.
221 * This is a convenience function used by the XMesa, OSMesa, GGI drivers, etc.
224 _mesa_enable_sw_extensions(struct gl_context
*ctx
)
226 ctx
->Extensions
.ARB_half_float_pixel
= GL_TRUE
;
227 ctx
->Extensions
.ARB_half_float_vertex
= GL_TRUE
;
228 ctx
->Extensions
.ARB_map_buffer_range
= GL_TRUE
;
229 ctx
->Extensions
.ARB_point_sprite
= GL_TRUE
;
230 ctx
->Extensions
.ARB_texture_border_clamp
= GL_TRUE
;
231 ctx
->Extensions
.ARB_texture_cube_map
= GL_TRUE
;
232 ctx
->Extensions
.ARB_texture_env_combine
= GL_TRUE
;
233 ctx
->Extensions
.ARB_texture_env_crossbar
= GL_TRUE
;
234 ctx
->Extensions
.ARB_texture_env_dot3
= GL_TRUE
;
235 /*ctx->Extensions.ARB_texture_float = GL_TRUE;*/
236 ctx
->Extensions
.ARB_texture_non_power_of_two
= GL_TRUE
;
237 ctx
->Extensions
.ARB_texture_storage
= GL_TRUE
;
238 ctx
->Extensions
.ARB_vertex_array_object
= GL_TRUE
;
239 ctx
->Extensions
.APPLE_vertex_array_object
= GL_TRUE
;
240 #if FEATURE_APPLE_object_purgeable
241 ctx
->Extensions
.APPLE_object_purgeable
= GL_TRUE
;
243 ctx
->Extensions
.ATI_texture_env_combine3
= GL_TRUE
;
244 ctx
->Extensions
.ATI_texture_mirror_once
= GL_TRUE
;
245 ctx
->Extensions
.ATI_separate_stencil
= GL_TRUE
;
246 ctx
->Extensions
.EXT_blend_color
= GL_TRUE
;
247 ctx
->Extensions
.EXT_blend_equation_separate
= GL_TRUE
;
248 ctx
->Extensions
.EXT_blend_func_separate
= GL_TRUE
;
249 ctx
->Extensions
.EXT_blend_minmax
= GL_TRUE
;
250 ctx
->Extensions
.EXT_depth_bounds_test
= GL_TRUE
;
251 ctx
->Extensions
.EXT_fog_coord
= GL_TRUE
;
252 #if FEATURE_EXT_pixel_buffer_object
253 ctx
->Extensions
.EXT_pixel_buffer_object
= GL_TRUE
;
255 ctx
->Extensions
.EXT_point_parameters
= GL_TRUE
;
256 ctx
->Extensions
.EXT_shadow_funcs
= GL_TRUE
;
257 ctx
->Extensions
.EXT_secondary_color
= GL_TRUE
;
258 ctx
->Extensions
.EXT_stencil_two_side
= GL_TRUE
;
259 ctx
->Extensions
.EXT_texture_env_dot3
= GL_TRUE
;
260 ctx
->Extensions
.EXT_texture_filter_anisotropic
= GL_TRUE
;
261 ctx
->Extensions
.EXT_texture_mirror_clamp
= GL_TRUE
;
262 /*ctx->Extensions.IBM_multimode_draw_arrays = GL_TRUE;*/
263 ctx
->Extensions
.MESA_pack_invert
= GL_TRUE
;
264 ctx
->Extensions
.MESA_resize_buffers
= GL_TRUE
;
265 ctx
->Extensions
.MESA_ycbcr_texture
= GL_TRUE
;
266 ctx
->Extensions
.NV_blend_square
= GL_TRUE
;
267 /*ctx->Extensions.NV_light_max_exponent = GL_TRUE;*/
268 ctx
->Extensions
.NV_point_sprite
= GL_TRUE
;
269 ctx
->Extensions
.NV_texture_env_combine4
= GL_TRUE
;
270 /*ctx->Extensions.NV_texgen_reflection = GL_TRUE;*/
271 #if FEATURE_texture_fxt1
272 _mesa_enable_extension(ctx
, "GL_3DFX_texture_compression_FXT1");
278 * Enable all OpenGL 1.3 features and extensions.
279 * A convenience function to be called by drivers.
282 _mesa_enable_1_3_extensions(struct gl_context
*ctx
)
284 ctx
->Extensions
.ARB_texture_border_clamp
= GL_TRUE
;
285 ctx
->Extensions
.ARB_texture_cube_map
= GL_TRUE
;
286 ctx
->Extensions
.ARB_texture_env_combine
= GL_TRUE
;
287 ctx
->Extensions
.ARB_texture_env_dot3
= GL_TRUE
;
288 /*ctx->Extensions.ARB_transpose_matrix = GL_TRUE;*/
294 * Enable all OpenGL 1.4 features and extensions.
295 * A convenience function to be called by drivers.
298 _mesa_enable_1_4_extensions(struct gl_context
*ctx
)
300 ctx
->Extensions
.ARB_texture_env_crossbar
= GL_TRUE
;
301 ctx
->Extensions
.ARB_window_pos
= GL_TRUE
;
302 ctx
->Extensions
.EXT_blend_color
= GL_TRUE
;
303 ctx
->Extensions
.EXT_blend_func_separate
= GL_TRUE
;
304 ctx
->Extensions
.EXT_blend_minmax
= GL_TRUE
;
305 ctx
->Extensions
.EXT_fog_coord
= GL_TRUE
;
306 ctx
->Extensions
.EXT_point_parameters
= GL_TRUE
;
307 ctx
->Extensions
.EXT_secondary_color
= GL_TRUE
;
312 * Enable all OpenGL 1.5 features and extensions.
313 * A convenience function to be called by drivers.
316 _mesa_enable_1_5_extensions(struct gl_context
*ctx
)
318 ctx
->Extensions
.EXT_shadow_funcs
= GL_TRUE
;
323 * Enable all OpenGL 2.0 features and extensions.
324 * A convenience function to be called by drivers.
327 _mesa_enable_2_0_extensions(struct gl_context
*ctx
)
329 ctx
->Extensions
.ARB_point_sprite
= GL_TRUE
;
330 ctx
->Extensions
.EXT_blend_equation_separate
= GL_TRUE
;
331 ctx
->Extensions
.ARB_texture_non_power_of_two
= GL_TRUE
;
332 ctx
->Extensions
.EXT_stencil_two_side
= GL_TRUE
;
337 * Enable all OpenGL 2.1 features and extensions.
338 * A convenience function to be called by drivers.
341 _mesa_enable_2_1_extensions(struct gl_context
*ctx
)
343 #if FEATURE_EXT_pixel_buffer_object
344 ctx
->Extensions
.EXT_pixel_buffer_object
= GL_TRUE
;
350 * Either enable or disable the named extension.
351 * \return GL_TRUE for success, GL_FALSE if invalid extension name
354 set_extension( struct gl_context
*ctx
, const char *name
, GLboolean state
)
358 if (ctx
->Extensions
.String
) {
359 /* The string was already queried - can't change it now! */
360 _mesa_problem(ctx
, "Trying to enable/disable extension after glGetString(GL_EXTENSIONS): %s", name
);
364 offset
= name_to_offset(name
);
366 _mesa_problem(ctx
, "Trying to enable/disable unknown extension %s",
369 } else if (offset
== o(dummy_true
) && state
== GL_FALSE
) {
370 _mesa_problem(ctx
, "Trying to disable a permanently enabled extension: "
374 GLboolean
*base
= (GLboolean
*) &ctx
->Extensions
;
375 base
[offset
] = state
;
382 * Enable the named extension.
383 * Typically called by drivers.
386 _mesa_enable_extension( struct gl_context
*ctx
, const char *name
)
388 if (!set_extension(ctx
, name
, GL_TRUE
))
389 _mesa_problem(ctx
, "Trying to enable unknown extension: %s", name
);
394 * Disable the named extension.
395 * XXX is this really needed???
398 _mesa_disable_extension( struct gl_context
*ctx
, const char *name
)
400 if (!set_extension(ctx
, name
, GL_FALSE
))
401 _mesa_problem(ctx
, "Trying to disable unknown extension: %s", name
);
406 * Test if the named extension is enabled in this context.
409 _mesa_extension_is_enabled( struct gl_context
*ctx
, const char *name
)
417 offset
= name_to_offset(name
);
420 base
= (GLboolean
*) &ctx
->Extensions
;
426 * \brief Apply the \c MESA_EXTENSION_OVERRIDE environment variable.
428 * \c MESA_EXTENSION_OVERRIDE is a space-separated list of extensions to
429 * enable or disable. The list is processed thus:
430 * - Enable recognized extension names that are prefixed with '+'.
431 * - Disable recognized extension names that are prefixed with '-'.
432 * - Enable recognized extension names that are not prefixed.
433 * - Collect unrecognized extension names in a new string.
435 * \return Space-separated list of unrecognized extension names (which must
436 * be freed). Does not return \c NULL.
439 get_extension_override( struct gl_context
*ctx
)
441 const char *env_const
= _mesa_getenv("MESA_EXTENSION_OVERRIDE");
447 if (env_const
== NULL
) {
448 /* Return the empty string rather than NULL. This simplifies the logic
449 * of client functions. */
450 return calloc(4, sizeof(char));
453 /* extra_exts: List of unrecognized extensions. */
454 extra_exts
= calloc(ALIGN(strlen(env_const
) + 2, 4), sizeof(char));
456 /* Copy env_const because strtok() is destructive. */
457 env
= _strdup(env_const
);
458 for (ext
= strtok(env
, " "); ext
!= NULL
; ext
= strtok(NULL
, " ")) {
474 recognized
= set_extension(ctx
, ext
, enable
);
476 strcat(extra_exts
, ext
);
477 strcat(extra_exts
, " ");
483 /* Remove trailing space. */
484 len
= strlen(extra_exts
);
485 if (extra_exts
[len
- 1] == ' ')
486 extra_exts
[len
- 1] = '\0';
493 * \brief Initialize extension tables and enable default extensions.
495 * This should be called during context initialization.
496 * Note: Sets gl_extensions.dummy_true to true.
499 _mesa_init_extensions( struct gl_context
*ctx
)
501 GLboolean
*base
= (GLboolean
*) &ctx
->Extensions
;
502 GLboolean
*sentinel
= base
+ o(extension_sentinel
);
506 /* First, turn all extensions off. */
507 for (i
= base
; i
!= sentinel
; ++i
)
510 /* Then, selectively turn default extensions on. */
511 ctx
->Extensions
.dummy_true
= GL_TRUE
;
512 for (j
= default_extensions
; *j
!= 0; ++j
)
517 typedef unsigned short extension_index
;
521 * Compare two entries of the extensions table. Sorts first by year,
524 * Arguments are indices into extension_table.
527 extension_compare(const void *p1
, const void *p2
)
529 extension_index i1
= * (const extension_index
*) p1
;
530 extension_index i2
= * (const extension_index
*) p2
;
531 const struct extension
*e1
= &extension_table
[i1
];
532 const struct extension
*e2
= &extension_table
[i2
];
535 res
= (int)e1
->year
- (int)e2
->year
;
538 res
= strcmp(e1
->name
, e2
->name
);
546 * Construct the GL_EXTENSIONS string. Called the first time that
547 * glGetString(GL_EXTENSIONS) is called.
550 _mesa_make_extension_string(struct gl_context
*ctx
)
552 /* The extension string. */
554 /* Length of extension string. */
556 /* Number of extensions */
558 /* Indices of the extensions sorted by year */
559 extension_index
*extension_indices
;
560 /* String of extra extensions. */
561 char *extra_extensions
= get_extension_override(ctx
);
562 GLboolean
*base
= (GLboolean
*) &ctx
->Extensions
;
563 const struct extension
*i
;
565 unsigned maxYear
= ~0;
567 /* Check if the MESA_EXTENSION_MAX_YEAR env var is set */
569 const char *env
= getenv("MESA_EXTENSION_MAX_YEAR");
572 _mesa_debug(ctx
, "Note: limiting GL extensions to %u or earlier\n",
577 /* Compute length of the extension string. */
579 for (i
= extension_table
; i
->name
!= 0; ++i
) {
580 if (base
[i
->offset
] &&
581 i
->year
<= maxYear
) {
582 length
+= strlen(i
->name
) + 1; /* +1 for space */
586 if (extra_extensions
!= NULL
)
587 length
+= 1 + strlen(extra_extensions
); /* +1 for space */
589 exts
= (char *) calloc(ALIGN(length
+ 1, 4), sizeof(char));
591 free(extra_extensions
);
595 extension_indices
= malloc(count
* sizeof(extension_index
));
596 if (extension_indices
== NULL
) {
598 free(extra_extensions
);
602 /* Sort extensions in chronological order because certain old applications (e.g.,
603 * Quake3 demo) store the extension list in a static size buffer so chronologically
604 * order ensure that the extensions that such applications expect will fit into
608 for (i
= extension_table
; i
->name
!= 0; ++i
) {
609 if (base
[i
->offset
] &&
610 i
->year
<= maxYear
) {
611 extension_indices
[j
++] = i
- extension_table
;
615 qsort(extension_indices
, count
, sizeof *extension_indices
, extension_compare
);
617 /* Build the extension string.*/
618 for (j
= 0; j
< count
; ++j
) {
619 i
= &extension_table
[extension_indices
[j
]];
620 assert(base
[i
->offset
]);
621 strcat(exts
, i
->name
);
624 free(extension_indices
);
625 if (extra_extensions
!= 0) {
626 strcat(exts
, extra_extensions
);
627 free(extra_extensions
);
630 return (GLubyte
*) exts
;
634 * Return number of enabled extensions.
637 _mesa_get_extension_count(struct gl_context
*ctx
)
640 const struct extension
*i
;
642 /* only count once */
643 if (ctx
->Extensions
.Count
!= 0)
644 return ctx
->Extensions
.Count
;
646 base
= (GLboolean
*) &ctx
->Extensions
;
647 for (i
= extension_table
; i
->name
!= 0; ++i
) {
648 if (base
[i
->offset
]) {
649 ctx
->Extensions
.Count
++;
652 return ctx
->Extensions
.Count
;
656 * Return name of i-th enabled extension
659 _mesa_get_enabled_extension(struct gl_context
*ctx
, GLuint index
)
661 const GLboolean
*base
;
663 const struct extension
*i
;
668 base
= (GLboolean
*) &ctx
->Extensions
;
670 for (i
= extension_table
; i
->name
!= 0; ++i
) {
671 if (n
== index
&& base
[i
->offset
]) {
672 return (GLubyte
*) i
->name
;
673 } else if (base
[i
->offset
]) {