1 /*
2  * (C) Copyright IBM Corporation 2002, 2004
3  * All Rights Reserved.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * on the rights to use, copy, modify, merge, publish, distribute, sub
9  * license, and/or sell copies of the Software, and to permit persons to whom
10  * the Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice (including the next
13  * paragraph) shall be included in all copies or substantial portions of the
14  * Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
19  * THE COPYRIGHT HOLDERS AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
20  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
21  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
22  * USE OR OTHER DEALINGS IN THE SOFTWARE.
23  */
24 
25 /**
26  * \file glxextensions.c
27  *
28  * \author Ian Romanick <idr@us.ibm.com>
29  */
30 
31 #include "glxclient.h"
32 #include <X11/extensions/extutil.h>
33 #include <X11/extensions/Xext.h>
34 #include <string.h>
35 #include "glxextensions.h"
36 
37 
38 #define SET_BIT(m,b)   (m[ (b) / 8 ] |=  (1U << ((b) % 8)))
39 #define CLR_BIT(m,b)   (m[ (b) / 8 ] &= ~(1U << ((b) % 8)))
40 #define IS_SET(m,b)    ((m[ (b) / 8 ] & (1U << ((b) % 8))) != 0)
41 #define CONCAT(a,b) a ## b
42 #define GLX(n) "GLX_" # n, 4 + sizeof( # n ) - 1, CONCAT(n,_bit)
43 #define GL(n)  "GL_" # n,  3 + sizeof( # n ) - 1, GL_ ## n ## _bit
44 #define VER(a,b)  a, b
45 #define Y  1
46 #define N  0
47 #define EXT_ENABLED(bit,supported) (IS_SET( supported, bit ))
48 
49 
50 struct extension_info
51 {
52    const char *const name;
53    unsigned name_len;
54 
55    unsigned char bit;
56 
57    /* This is the lowest version of GLX that "requires" this extension.
58     * For example, GLX 1.3 requires SGIX_fbconfig, SGIX_pbuffer, and
59     * SGI_make_current_read.  If the extension is not required by any known
60     * version of GLX, use 0, 0.
61     */
62    unsigned char version_major;
63    unsigned char version_minor;
64    unsigned char client_support;
65    unsigned char direct_support;
66    unsigned char client_only;        /** Is the extension client-side only? */
67    unsigned char direct_only;        /** Is the extension for direct
68 				      * contexts only?
69 				      */
70 };
71 
72 /* *INDENT-OFF* */
73 static const struct extension_info known_glx_extensions[] = {
74    { GLX(ARB_create_context),          VER(0,0), Y, N, N, N },
75    { GLX(ARB_create_context_profile),  VER(0,0), Y, N, N, N },
76    { GLX(ARB_create_context_robustness), VER(0,0), Y, N, N, N },
77    { GLX(ARB_get_proc_address),        VER(1,4), Y, N, Y, N },
78    { GLX(ARB_multisample),             VER(1,4), Y, Y, N, N },
79    { GLX(ATI_pixel_format_float),      VER(0,0), N, N, N, N },
80    { GLX(EXT_import_context),          VER(0,0), Y, Y, N, N },
81    { GLX(EXT_visual_info),             VER(0,0), Y, Y, N, N },
82    { GLX(EXT_visual_rating),           VER(0,0), Y, Y, N, N },
83    { GLX(EXT_framebuffer_sRGB),        VER(0,0), Y, Y, N, N },
84    { GLX(EXT_create_context_es2_profile), VER(0,0), Y, N, N, Y },
85    { GLX(MESA_copy_sub_buffer),        VER(0,0), Y, N, N, N },
86    { GLX(MESA_multithread_makecurrent),VER(0,0), Y, N, Y, N },
87    { GLX(MESA_swap_control),           VER(0,0), Y, N, N, Y },
88    { GLX(NV_float_buffer),             VER(0,0), N, N, N, N },
89    { GLX(OML_swap_method),             VER(0,0), Y, Y, N, N },
90    { GLX(OML_sync_control),            VER(0,0), Y, N, N, Y },
91    { GLX(SGI_make_current_read),       VER(1,3), Y, N, N, N },
92    { GLX(SGI_swap_control),            VER(0,0), Y, N, N, N },
93    { GLX(SGI_video_sync),              VER(0,0), Y, N, N, Y },
94    { GLX(SGIS_multisample),            VER(0,0), Y, Y, N, N },
95    { GLX(SGIX_fbconfig),               VER(1,3), Y, Y, N, N },
96    { GLX(SGIX_pbuffer),                VER(1,3), Y, Y, N, N },
97    { GLX(SGIX_swap_barrier),           VER(0,0), N, N, N, N },
98    { GLX(SGIX_swap_group),             VER(0,0), N, N, N, N },
99    { GLX(SGIX_visual_select_group),    VER(0,0), Y, Y, N, N },
100    { GLX(EXT_texture_from_pixmap),     VER(0,0), Y, N, N, N },
101    { GLX(INTEL_swap_event),            VER(0,0), Y, N, N, N },
102    { NULL }
103 };
104 
105 static const struct extension_info known_gl_extensions[] = {
106    { GL(ARB_depth_texture),              VER(1,4), Y, N, N, N },
107    { GL(ARB_draw_buffers),               VER(0,0), Y, N, N, N },
108    { GL(ARB_fragment_program),           VER(0,0), Y, N, N, N },
109    { GL(ARB_fragment_program_shadow),    VER(0,0), Y, N, N, N },
110    { GL(ARB_framebuffer_object),         VER(0,0), Y, N, N, N },
111    { GL(ARB_imaging),                    VER(0,0), Y, N, N, N },
112    { GL(ARB_multisample),                VER(1,3), Y, N, N, N },
113    { GL(ARB_multitexture),               VER(1,3), Y, N, N, N },
114    { GL(ARB_occlusion_query),            VER(1,5), Y, N, N, N },
115    { GL(ARB_point_parameters),           VER(1,4), Y, N, N, N },
116    { GL(ARB_point_sprite),               VER(0,0), Y, N, N, N },
117    { GL(ARB_shadow),                     VER(1,4), Y, N, N, N },
118    { GL(ARB_shadow_ambient),             VER(0,0), Y, N, N, N },
119    { GL(ARB_texture_border_clamp),       VER(1,3), Y, N, N, N },
120    { GL(ARB_texture_compression),        VER(1,3), Y, N, N, N },
121    { GL(ARB_texture_cube_map),           VER(1,3), Y, N, N, N },
122    { GL(ARB_texture_env_add),            VER(1,3), Y, N, N, N },
123    { GL(ARB_texture_env_combine),        VER(1,3), Y, N, N, N },
124    { GL(ARB_texture_env_crossbar),       VER(1,4), Y, N, N, N },
125    { GL(ARB_texture_env_dot3),           VER(1,3), Y, N, N, N },
126    { GL(ARB_texture_mirrored_repeat),    VER(1,4), Y, N, N, N },
127    { GL(ARB_texture_non_power_of_two),   VER(1,5), Y, N, N, N },
128    { GL(ARB_texture_rectangle),          VER(0,0), Y, N, N, N },
129    { GL(ARB_texture_rg),                 VER(0,0), Y, N, N, N },
130    { GL(ARB_transpose_matrix),           VER(1,3), Y, N, Y, N },
131    { GL(ARB_vertex_buffer_object),       VER(1,5), N, N, N, N },
132    { GL(ARB_vertex_program),             VER(0,0), Y, N, N, N },
133    { GL(ARB_window_pos),                 VER(1,4), Y, N, N, N },
134    { GL(EXT_abgr),                       VER(0,0), Y, N, N, N },
135    { GL(EXT_bgra),                       VER(1,2), Y, N, N, N },
136    { GL(EXT_blend_color),                VER(1,4), Y, N, N, N },
137    { GL(EXT_blend_equation_separate),    VER(0,0), Y, N, N, N },
138    { GL(EXT_blend_func_separate),        VER(1,4), Y, N, N, N },
139    { GL(EXT_blend_logic_op),             VER(1,4), Y, N, N, N },
140    { GL(EXT_blend_minmax),               VER(1,4), Y, N, N, N },
141    { GL(EXT_blend_subtract),             VER(1,4), Y, N, N, N },
142    { GL(EXT_clip_volume_hint),           VER(0,0), Y, N, N, N },
143    { GL(EXT_compiled_vertex_array),      VER(0,0), N, N, N, N },
144    { GL(EXT_convolution),                VER(0,0), N, N, N, N },
145    { GL(EXT_copy_texture),               VER(1,1), Y, N, N, N },
146    { GL(EXT_cull_vertex),                VER(0,0), N, N, N, N },
147    { GL(EXT_depth_bounds_test),          VER(0,0), N, N, N, N },
148    { GL(EXT_draw_range_elements),        VER(1,2), Y, N, Y, N },
149    { GL(EXT_fog_coord),                  VER(1,4), Y, N, N, N },
150    { GL(EXT_framebuffer_blit),           VER(0,0), Y, N, N, N },
151    { GL(EXT_framebuffer_multisample),    VER(0,0), Y, N, N, N },
152    { GL(EXT_framebuffer_object),         VER(0,0), Y, N, N, N },
153    { GL(EXT_framebuffer_sRGB),           VER(0,0), Y, N, N, N },
154    { GL(EXT_multi_draw_arrays),          VER(1,4), Y, N, Y, N },
155    { GL(EXT_packed_depth_stencil),       VER(0,0), Y, N, N, N },
156    { GL(EXT_packed_pixels),              VER(1,2), Y, N, N, N },
157    { GL(EXT_paletted_texture),           VER(0,0), Y, N, N, N },
158    { GL(EXT_pixel_buffer_object),        VER(0,0), N, N, N, N },
159    { GL(EXT_point_parameters),           VER(1,4), Y, N, N, N },
160    { GL(EXT_polygon_offset),             VER(1,1), Y, N, N, N },
161    { GL(EXT_rescale_normal),             VER(1,2), Y, N, N, N },
162    { GL(EXT_secondary_color),            VER(1,4), Y, N, N, N },
163    { GL(EXT_separate_specular_color),    VER(1,2), Y, N, N, N },
164    { GL(EXT_shadow_funcs),               VER(1,5), Y, N, N, N },
165    { GL(EXT_shared_texture_palette),     VER(0,0), Y, N, N, N },
166    { GL(EXT_stencil_two_side),           VER(0,0), Y, N, N, N },
167    { GL(EXT_stencil_wrap),               VER(1,4), Y, N, N, N },
168    { GL(EXT_subtexture),                 VER(1,1), Y, N, N, N },
169    { GL(EXT_texture),                    VER(1,1), Y, N, N, N },
170    { GL(EXT_texture3D),                  VER(1,2), Y, N, N, N },
171    { GL(EXT_texture_compression_dxt1),   VER(0,0), Y, N, N, N },
172    { GL(EXT_texture_compression_s3tc),   VER(0,0), Y, N, N, N },
173    { GL(EXT_texture_edge_clamp),         VER(1,2), Y, N, N, N },
174    { GL(EXT_texture_env_add),            VER(1,3), Y, N, N, N },
175    { GL(EXT_texture_env_combine),        VER(1,3), Y, N, N, N },
176    { GL(EXT_texture_env_dot3),           VER(0,0), Y, N, N, N },
177    { GL(EXT_texture_filter_anisotropic), VER(0,0), Y, N, N, N },
178    { GL(EXT_texture_lod),                VER(1,2), Y, N, N, N },
179    { GL(EXT_texture_lod_bias),           VER(1,4), Y, N, N, N },
180    { GL(EXT_texture_mirror_clamp),       VER(0,0), Y, N, N, N },
181    { GL(EXT_texture_object),             VER(1,1), Y, N, N, N },
182    { GL(EXT_texture_rectangle),          VER(0,0), Y, N, N, N },
183    { GL(EXT_vertex_array),               VER(0,0), Y, N, N, N },
184    { GL(3DFX_texture_compression_FXT1),  VER(0,0), Y, N, N, N },
185    { GL(APPLE_packed_pixels),            VER(1,2), Y, N, N, N },
186    { GL(APPLE_ycbcr_422),                VER(0,0), Y, N, N, N },
187    { GL(ATI_draw_buffers),               VER(0,0), Y, N, N, N },
188    { GL(ATI_text_fragment_shader),       VER(0,0), Y, N, N, N },
189    { GL(ATI_texture_env_combine3),       VER(0,0), Y, N, N, N },
190    { GL(ATI_texture_float),              VER(0,0), Y, N, N, N },
191    { GL(ATI_texture_mirror_once),        VER(0,0), Y, N, N, N },
192    { GL(ATIX_texture_env_combine3),      VER(0,0), Y, N, N, N },
193    { GL(HP_convolution_border_modes),    VER(0,0), Y, N, N, N },
194    { GL(HP_occlusion_test),              VER(0,0), Y, N, N, N },
195    { GL(IBM_cull_vertex),                VER(0,0), Y, N, N, N },
196    { GL(IBM_pixel_filter_hint),          VER(0,0), Y, N, N, N },
197    { GL(IBM_rasterpos_clip),             VER(0,0), Y, N, N, N },
198    { GL(IBM_texture_clamp_nodraw),       VER(0,0), Y, N, N, N },
199    { GL(IBM_texture_mirrored_repeat),    VER(0,0), Y, N, N, N },
200    { GL(INGR_blend_func_separate),       VER(0,0), Y, N, N, N },
201    { GL(INGR_interlace_read),            VER(0,0), Y, N, N, N },
202    { GL(MESA_pack_invert),               VER(0,0), Y, N, N, N },
203    { GL(MESA_ycbcr_texture),             VER(0,0), Y, N, N, N },
204    { GL(NV_blend_square),                VER(1,4), Y, N, N, N },
205    { GL(NV_copy_depth_to_color),         VER(0,0), Y, N, N, N },
206    { GL(NV_depth_clamp),                 VER(0,0), Y, N, N, N },
207    { GL(NV_fog_distance),                VER(0,0), Y, N, N, N },
208    { GL(NV_fragment_program),            VER(0,0), Y, N, N, N },
209    { GL(NV_fragment_program_option),     VER(0,0), Y, N, N, N },
210    { GL(NV_fragment_program2),           VER(0,0), Y, N, N, N },
211    { GL(NV_light_max_exponent),          VER(0,0), Y, N, N, N },
212    { GL(NV_multisample_filter_hint),     VER(0,0), Y, N, N, N },
213    { GL(NV_packed_depth_stencil),        VER(0,0), Y, N, N, N },
214    { GL(NV_point_sprite),                VER(0,0), Y, N, N, N },
215    { GL(NV_texgen_reflection),           VER(0,0), Y, N, N, N },
216    { GL(NV_texture_compression_vtc),     VER(0,0), Y, N, N, N },
217    { GL(NV_texture_env_combine4),        VER(0,0), Y, N, N, N },
218    { GL(NV_texture_rectangle),           VER(0,0), Y, N, N, N },
219    { GL(NV_vertex_program),              VER(0,0), Y, N, N, N },
220    { GL(NV_vertex_program1_1),           VER(0,0), Y, N, N, N },
221    { GL(NV_vertex_program2),             VER(0,0), Y, N, N, N },
222    { GL(NV_vertex_program2_option),      VER(0,0), Y, N, N, N },
223    { GL(NV_vertex_program3),             VER(0,0), Y, N, N, N },
224    { GL(OES_read_format),                VER(0,0), Y, N, N, N },
225    { GL(OES_compressed_paletted_texture),VER(0,0), Y, N, N, N },
226    { GL(SGI_color_matrix),               VER(0,0), Y, N, N, N },
227    { GL(SGI_color_table),                VER(0,0), Y, N, N, N },
228    { GL(SGI_texture_color_table),        VER(0,0), Y, N, N, N },
229    { GL(SGIS_generate_mipmap),           VER(1,4), Y, N, N, N },
230    { GL(SGIS_multisample),               VER(0,0), Y, N, N, N },
231    { GL(SGIS_texture_border_clamp),      VER(1,3), Y, N, N, N },
232    { GL(SGIS_texture_edge_clamp),        VER(1,2), Y, N, N, N },
233    { GL(SGIS_texture_lod),               VER(1,2), Y, N, N, N },
234    { GL(SGIX_blend_alpha_minmax),        VER(0,0), Y, N, N, N },
235    { GL(SGIX_clipmap),                   VER(0,0), Y, N, N, N },
236    { GL(SGIX_depth_texture),             VER(0,0), Y, N, N, N },
237    { GL(SGIX_fog_offset),                VER(0,0), Y, N, N, N },
238    { GL(SGIX_shadow),                    VER(0,0), Y, N, N, N },
239    { GL(SGIX_shadow_ambient),            VER(0,0), Y, N, N, N },
240    { GL(SGIX_texture_coordinate_clamp),  VER(0,0), Y, N, N, N },
241    { GL(SGIX_texture_lod_bias),          VER(0,0), Y, N, N, N },
242    { GL(SGIX_texture_range),             VER(0,0), Y, N, N, N },
243    { GL(SGIX_texture_scale_bias),        VER(0,0), Y, N, N, N },
244    { GL(SGIX_vertex_preclip),            VER(0,0), Y, N, N, N },
245    { GL(SGIX_vertex_preclip_hint),       VER(0,0), Y, N, N, N },
246    { GL(SGIX_ycrcb),                     VER(0,0), Y, N, N, N },
247    { GL(SUN_convolution_border_modes),   VER(0,0), Y, N, N, N },
248    { GL(SUN_multi_draw_arrays),          VER(0,0), Y, N, Y, N },
249    { GL(SUN_slice_accum),                VER(0,0), Y, N, N, N },
250    { NULL }
251 };
252 /* *INDENT-ON* */
253 
254 
255 /* global bit-fields of available extensions and their characteristics */
256 static unsigned char client_glx_support[8];
257 static unsigned char client_glx_only[8];
258 static unsigned char direct_glx_only[8];
259 static unsigned char client_gl_support[__GL_EXT_BYTES];
260 static unsigned char client_gl_only[__GL_EXT_BYTES];
261 
262 /**
263  * Bits representing the set of extensions that are enabled by default in all
264  * direct rendering drivers.
265  */
266 static unsigned char direct_glx_support[8];
267 
268 /**
269  * Highest core GL version that can be supported for indirect rendering.
270  */
271 static const unsigned gl_major = 1;
272 static const unsigned gl_minor = 4;
273 
274 /* client extensions string */
275 static const char *__glXGLXClientExtensions = NULL;
276 
277 static void __glXExtensionsCtr(void);
278 static void __glXExtensionsCtrScreen(struct glx_screen * psc);
279 static void __glXProcessServerString(const struct extension_info *ext,
280                                      const char *server_string,
281                                      unsigned char *server_support);
282 
283 /**
284  * Set the state of a GLX extension.
285  *
286  * \param name      Name of the extension.
287  * \param name_len  Length, in characters, of the extension name.
288  * \param state     New state (either enabled or disabled) of the extension.
289  * \param supported Table in which the state of the extension is to be set.
290  */
291 static void
set_glx_extension(const struct extension_info * ext,const char * name,unsigned name_len,GLboolean state,unsigned char * supported)292 set_glx_extension(const struct extension_info *ext,
293                   const char *name, unsigned name_len, GLboolean state,
294                   unsigned char *supported)
295 {
296    unsigned i;
297 
298 
299    for (i = 0; ext[i].name != NULL; i++) {
300       if ((name_len == ext[i].name_len)
301           && (strncmp(ext[i].name, name, name_len) == 0)) {
302          if (state) {
303             SET_BIT(supported, ext[i].bit);
304          }
305          else {
306             CLR_BIT(supported, ext[i].bit);
307          }
308 
309          return;
310       }
311    }
312 }
313 
314 
315 #define NUL '\0'
316 #define SEPARATOR ' '
317 
318 /**
319  * Convert the server's extension string to a bit-field.
320  *
321  * \param server_string   GLX extension string from the server.
322  * \param server_support  Bit-field of supported extensions.
323  *
324  * \note
325  * This function is used to process both GLX and GL extension strings.  The
326  * bit-fields used to track each of these have different sizes.  Therefore,
327  * the data pointed by \c server_support must be preinitialized to zero.
328  */
329 static void
__glXProcessServerString(const struct extension_info * ext,const char * server_string,unsigned char * server_support)330 __glXProcessServerString(const struct extension_info *ext,
331                          const char *server_string,
332                          unsigned char *server_support)
333 {
334    unsigned base;
335    unsigned len;
336 
337    for (base = 0; server_string[base] != NUL; /* empty */ ) {
338       /* Determine the length of the next extension name.
339        */
340       for (len = 0; (server_string[base + len] != SEPARATOR)
341            && (server_string[base + len] != NUL); len++) {
342          /* empty */
343       }
344 
345       /* Set the bit for the extension in the server_support table.
346        */
347       set_glx_extension(ext, &server_string[base], len, GL_TRUE,
348                         server_support);
349 
350 
351       /* Advance to the next extension string.  This means that we skip
352        * over the previous string and any trialing white-space.
353        */
354       for (base += len; (server_string[base] == SEPARATOR)
355            && (server_string[base] != NUL); base++) {
356          /* empty */
357       }
358    }
359 }
360 
361 void
__glXEnableDirectExtension(struct glx_screen * psc,const char * name)362 __glXEnableDirectExtension(struct glx_screen * psc, const char *name)
363 {
364    __glXExtensionsCtr();
365    __glXExtensionsCtrScreen(psc);
366 
367    set_glx_extension(known_glx_extensions,
368                      name, strlen(name), GL_TRUE, psc->direct_support);
369 }
370 
371 /**
372  * Initialize global extension support tables.
373  */
374 
375 static void
__glXExtensionsCtr(void)376 __glXExtensionsCtr(void)
377 {
378    unsigned i;
379    static GLboolean ext_list_first_time = GL_TRUE;
380 
381 
382    if (ext_list_first_time) {
383       ext_list_first_time = GL_FALSE;
384 
385       (void) memset(client_glx_support, 0, sizeof(client_glx_support));
386       (void) memset(direct_glx_support, 0, sizeof(direct_glx_support));
387       (void) memset(client_glx_only, 0, sizeof(client_glx_only));
388       (void) memset(direct_glx_only, 0, sizeof(direct_glx_only));
389 
390       (void) memset(client_gl_support, 0, sizeof(client_gl_support));
391       (void) memset(client_gl_only, 0, sizeof(client_gl_only));
392 
393       for (i = 0; known_glx_extensions[i].name != NULL; i++) {
394          const unsigned bit = known_glx_extensions[i].bit;
395 
396          if (known_glx_extensions[i].client_support) {
397             SET_BIT(client_glx_support, bit);
398          }
399 
400          if (known_glx_extensions[i].direct_support) {
401             SET_BIT(direct_glx_support, bit);
402          }
403 
404          if (known_glx_extensions[i].client_only) {
405             SET_BIT(client_glx_only, bit);
406          }
407 
408          if (known_glx_extensions[i].direct_only) {
409             SET_BIT(direct_glx_only, bit);
410          }
411       }
412 
413       for (i = 0; known_gl_extensions[i].name != NULL; i++) {
414          const unsigned bit = known_gl_extensions[i].bit;
415 
416          if (known_gl_extensions[i].client_support) {
417             SET_BIT(client_gl_support, bit);
418          }
419 
420          if (known_gl_extensions[i].client_only) {
421             SET_BIT(client_gl_only, bit);
422          }
423       }
424 
425 #if 0
426       fprintf(stderr, "[%s:%u] Maximum client library version: %u.%u\n",
427               __func__, __LINE__, gl_major, gl_minor);
428 #endif
429    }
430 }
431 
432 
433 /**
434  * Make sure that per-screen direct-support table is initialized.
435  *
436  * \param psc  Pointer to GLX per-screen record.
437  */
438 
439 static void
__glXExtensionsCtrScreen(struct glx_screen * psc)440 __glXExtensionsCtrScreen(struct glx_screen * psc)
441 {
442    if (psc->ext_list_first_time) {
443       psc->ext_list_first_time = GL_FALSE;
444       (void) memcpy(psc->direct_support, direct_glx_support,
445                     sizeof(direct_glx_support));
446    }
447 }
448 
449 
450 /**
451  * Check if a certain extension is enabled on a given screen.
452  *
453  * \param psc  Pointer to GLX per-screen record.
454  * \param bit  Bit index in the direct-support table.
455  * \returns If the extension bit is enabled for the screen, \c GL_TRUE is
456  *          returned.  If the extension bit is not enabled or if \c psc is
457  *          \c NULL, then \c GL_FALSE is returned.
458  */
459 GLboolean
__glXExtensionBitIsEnabled(struct glx_screen * psc,unsigned bit)460 __glXExtensionBitIsEnabled(struct glx_screen * psc, unsigned bit)
461 {
462    GLboolean enabled = GL_FALSE;
463 
464    if (psc != NULL) {
465       __glXExtensionsCtr();
466       __glXExtensionsCtrScreen(psc);
467       enabled = EXT_ENABLED(bit, psc->direct_support);
468    }
469 
470    return enabled;
471 }
472 
473 
474 /**
475  * Check if a certain extension is enabled in a given context.
476  *
477  */
478 GLboolean
__glExtensionBitIsEnabled(struct glx_context * gc,unsigned bit)479 __glExtensionBitIsEnabled(struct glx_context *gc, unsigned bit)
480 {
481    GLboolean enabled = GL_FALSE;
482 
483    if (gc != NULL) {
484       enabled = EXT_ENABLED(bit, gc->gl_extension_bits);
485    }
486 
487    return enabled;
488 }
489 
490 
491 
492 /**
493  * Convert a bit-field to a string of supported extensions.
494  */
495 static char *
__glXGetStringFromTable(const struct extension_info * ext,const unsigned char * supported)496 __glXGetStringFromTable(const struct extension_info *ext,
497                         const unsigned char *supported)
498 {
499    unsigned i;
500    unsigned ext_str_len;
501    char *ext_str;
502    char *point;
503 
504 
505    ext_str_len = 0;
506    for (i = 0; ext[i].name != NULL; i++) {
507       if (EXT_ENABLED(ext[i].bit, supported)) {
508          ext_str_len += ext[i].name_len + 1;
509       }
510    }
511 
512    ext_str = Xmalloc(ext_str_len + 1);
513    if (ext_str != NULL) {
514       point = ext_str;
515 
516       for (i = 0; ext[i].name != NULL; i++) {
517          if (EXT_ENABLED(ext[i].bit, supported)) {
518             (void) memcpy(point, ext[i].name, ext[i].name_len);
519             point += ext[i].name_len;
520 
521             *point = ' ';
522             point++;
523          }
524       }
525 
526       *point = '\0';
527    }
528 
529    return ext_str;
530 }
531 
532 
533 /**
534  * Get the string of client library supported extensions.
535  */
536 const char *
__glXGetClientExtensions(void)537 __glXGetClientExtensions(void)
538 {
539    if (__glXGLXClientExtensions == NULL) {
540       __glXExtensionsCtr();
541       __glXGLXClientExtensions = __glXGetStringFromTable(known_glx_extensions,
542                                                          client_glx_support);
543    }
544 
545    return __glXGLXClientExtensions;
546 }
547 
548 
549 /**
550  * Calculate the list of application usable extensions.  The resulting
551  * string is stored in \c psc->effectiveGLXexts.
552  *
553  * \param psc                        Pointer to GLX per-screen record.
554  * \param display_is_direct_capable  True if the display is capable of
555  *                                   direct rendering.
556  * \param minor_version              GLX minor version from the server.
557  */
558 
559 void
__glXCalculateUsableExtensions(struct glx_screen * psc,GLboolean display_is_direct_capable,int minor_version)560 __glXCalculateUsableExtensions(struct glx_screen * psc,
561                                GLboolean display_is_direct_capable,
562                                int minor_version)
563 {
564    unsigned char server_support[8];
565    unsigned char usable[8];
566    unsigned i;
567 
568    __glXExtensionsCtr();
569    __glXExtensionsCtrScreen(psc);
570 
571    (void) memset(server_support, 0, sizeof(server_support));
572    __glXProcessServerString(known_glx_extensions,
573                             psc->serverGLXexts, server_support);
574 
575 
576    /* This is a hack.  Some servers support GLX 1.3 but don't export
577     * all of the extensions implied by GLX 1.3.  If the server claims
578     * support for GLX 1.3, enable support for the extensions that can be
579     * "emulated" as well.
580     */
581 #ifndef GLX_USE_APPLEGL
582    if (minor_version >= 3) {
583       SET_BIT(server_support, EXT_visual_info_bit);
584       SET_BIT(server_support, EXT_visual_rating_bit);
585       SET_BIT(server_support, SGI_make_current_read_bit);
586       SET_BIT(server_support, SGIX_fbconfig_bit);
587       SET_BIT(server_support, SGIX_pbuffer_bit);
588 
589       /* This one is a little iffy.  GLX 1.3 doesn't incorporate all of this
590        * extension.  However, the only part that is not strictly client-side
591        * is shared.  That's the glXQueryContext / glXQueryContextInfoEXT
592        * function.
593        */
594 
595       SET_BIT(server_support, EXT_import_context_bit);
596    }
597 #endif
598 
599    /* An extension is supported if the client-side (i.e., libGL) supports
600     * it and the "server" supports it.  In this case that means that either
601     * the true server supports it or it is only for direct-rendering and
602     * the direct rendering driver supports it.
603     *
604     * If the display is not capable of direct rendering, then the extension
605     * is enabled if and only if the client-side library and the server
606     * support it.
607     */
608 
609    if (display_is_direct_capable) {
610       for (i = 0; i < 8; i++) {
611          usable[i] = (client_glx_support[i] & client_glx_only[i])
612             | (client_glx_support[i] & psc->direct_support[i] &
613                server_support[i])
614             | (client_glx_support[i] & psc->direct_support[i] &
615                direct_glx_only[i]);
616       }
617    }
618    else {
619       for (i = 0; i < 8; i++) {
620          usable[i] = (client_glx_support[i] & client_glx_only[i])
621             | (client_glx_support[i] & server_support[i]);
622       }
623    }
624 
625    /* This hack is necessary because GLX_ARB_create_context_profile depends on
626     * server support, but GLX_EXT_create_context_es2_profile is direct-only.
627     * Without this hack, it would be possible to advertise
628     * GLX_EXT_create_context_es2_profile without
629     * GLX_ARB_create_context_profile.  That would be a problem.
630     */
631    if (!IS_SET(server_support, ARB_create_context_profile_bit)) {
632       CLR_BIT(usable, EXT_create_context_es2_profile_bit);
633    }
634 
635    psc->effectiveGLXexts = __glXGetStringFromTable(known_glx_extensions,
636                                                    usable);
637 }
638 
639 
640 /**
641  * Calculate the list of application usable extensions.  The resulting
642  * string is stored in \c gc->extensions.
643  *
644  * \param gc             Pointer to GLX context.
645  * \param server_string  Extension string from the server.
646  * \param major_version  GL major version from the server.
647  * \param minor_version  GL minor version from the server.
648  */
649 
650 void
__glXCalculateUsableGLExtensions(struct glx_context * gc,const char * server_string,int major_version,int minor_version)651 __glXCalculateUsableGLExtensions(struct glx_context * gc,
652                                  const char *server_string,
653                                  int major_version, int minor_version)
654 {
655    unsigned char server_support[__GL_EXT_BYTES];
656    unsigned char usable[__GL_EXT_BYTES];
657    unsigned i;
658 
659 
660    __glXExtensionsCtr();
661 
662    (void) memset(server_support, 0, sizeof(server_support));
663    __glXProcessServerString(known_gl_extensions, server_string,
664                             server_support);
665 
666 
667    /* Handle lazy servers that don't export all the extensions strings that
668     * are part of the GL core version that they support.
669     */
670 
671    for (i = 0; i < __GL_EXT_BYTES; i++) {
672       if ((known_gl_extensions[i].version_major != 0)
673           && ((major_version > known_gl_extensions[i].version_major)
674               || ((major_version == known_gl_extensions[i].version_major)
675                   && (minor_version >=
676                       known_gl_extensions[i].version_minor)))) {
677          SET_BIT(server_support, known_gl_extensions[i].bit);
678       }
679    }
680 
681 
682    /* An extension is supported if the client-side (i.e., libGL) supports
683     * it and the server supports it or the client-side library supports it
684     * and it only needs client-side support.
685     */
686 
687    for (i = 0; i < __GL_EXT_BYTES; i++) {
688       usable[i] = (client_gl_support[i] & client_gl_only[i])
689          | (client_gl_support[i] & server_support[i]);
690    }
691 
692    gc->extensions = (unsigned char *)
693       __glXGetStringFromTable(known_gl_extensions, usable);
694    (void) memcpy(gc->gl_extension_bits, usable, sizeof(usable));
695 }
696 
697 
698 /**
699  * Calculates the maximum core GL version that can be supported for indirect
700  * rendering.
701  */
702 void
__glXGetGLVersion(int * major_version,int * minor_version)703 __glXGetGLVersion(int *major_version, int *minor_version)
704 {
705    __glXExtensionsCtr();
706    *major_version = gl_major;
707    *minor_version = gl_minor;
708 }
709 
710 
711 /**
712  * Get a string representing the set of extensions supported by the client
713  * library.  This is currently only used to send the list of extensions
714  * supported by the client to the server.
715  */
716 char *
__glXGetClientGLExtensionString(void)717 __glXGetClientGLExtensionString(void)
718 {
719    __glXExtensionsCtr();
720    return __glXGetStringFromTable(known_gl_extensions, client_gl_support);
721 }
722