/* * (C) Copyright IBM Corporation 2002, 2004 * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * on the rights to use, copy, modify, merge, publish, distribute, sub * license, and/or sell copies of the Software, and to permit persons to whom * the Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL * THE COPYRIGHT HOLDERS AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE * USE OR OTHER DEALINGS IN THE SOFTWARE. */ /** * \file glxextensions.c * * \author Ian Romanick */ #include "glxclient.h" #include #include #include #include "glapi.h" #include "glxextensions.h" #include "simple_list.h" #define SET_BIT(m,b) (m[ (b) / 8 ] |= (1U << ((b) % 8))) #define CLR_BIT(m,b) (m[ (b) / 8 ] &= ~(1U << ((b) % 8))) #define IS_SET(m,b) ((m[ (b) / 8 ] & (1U << ((b) % 8))) != 0) #define CONCAT(a,b) a ## b #define GLX(n) "GLX_" # n, 4 + sizeof( # n ) - 1, CONCAT(n,_bit) #define GL(n) "GL_" # n, 3 + sizeof( # n ) - 1, GL_ ## n ## _bit #define VER(a,b) a, b #define Y 1 #define N 0 #define EXT_ENABLED(bit,supported) (IS_SET( supported, bit )) struct extension_info { const char * const name; unsigned name_len; unsigned char bit; /* This is the lowest version of GLX that "requires" this extension. * For example, GLX 1.3 requires SGIX_fbconfig, SGIX_pbuffer, and * SGI_make_current_read. If the extension is not required by any known * version of GLX, use 0, 0. */ unsigned char version_major; unsigned char version_minor; unsigned char client_support; unsigned char direct_support; unsigned char client_only; /** Is the extension client-side only? */ unsigned char direct_only; /** Is the extension for direct * contexts only? */ }; static const struct extension_info known_glx_extensions[] = { { GLX(ARB_get_proc_address), VER(1,4), Y, N, Y, N }, { GLX(ARB_multisample), VER(1,4), Y, Y, N, N }, { GLX(ARB_render_texture), VER(0,0), N, N, N, N }, { GLX(ATI_pixel_format_float), VER(0,0), N, N, N, N }, { GLX(EXT_import_context), VER(0,0), Y, Y, N, N }, { GLX(EXT_visual_info), VER(0,0), Y, Y, N, N }, { GLX(EXT_visual_rating), VER(0,0), Y, Y, N, N }, { GLX(MESA_agp_offset), VER(0,0), N, N, N, Y }, /* Deprecated */ { GLX(MESA_allocate_memory), VER(0,0), Y, N, N, Y }, { GLX(MESA_copy_sub_buffer), VER(0,0), N, N, N, N }, /* Deprecated? */ { GLX(MESA_pixmap_colormap), VER(0,0), N, N, N, N }, /* Deprecated */ { GLX(MESA_release_buffers), VER(0,0), N, N, N, N }, /* Deprecated */ { GLX(MESA_set_3dfx_mode), VER(0,0), N, N, N, N }, /* Deprecated */ { GLX(MESA_swap_control), VER(0,0), Y, N, N, Y }, { GLX(MESA_swap_frame_usage), VER(0,0), Y, N, N, Y }, { GLX(NV_float_buffer), VER(0,0), N, N, N, N }, { GLX(NV_render_depth_texture), VER(0,0), N, N, N, N }, { GLX(NV_render_texture_rectangle), VER(0,0), N, N, N, N }, { GLX(NV_vertex_array_range), VER(0,0), N, N, N, Y }, /* Deprecated */ { GLX(OML_swap_method), VER(0,0), Y, N, N, N }, { GLX(OML_sync_control), VER(0,0), Y, N, N, Y }, { GLX(SGI_cushion), VER(0,0), N, N, N, N }, { GLX(SGI_make_current_read), VER(1,3), Y, N, N, N }, { GLX(SGI_swap_control), VER(0,0), Y, N, N, N }, { GLX(SGI_video_sync), VER(0,0), Y, N, N, Y }, { GLX(SGIS_blended_overlay), VER(0,0), N, N, N, N }, { GLX(SGIS_color_range), VER(0,0), N, N, N, N }, { GLX(SGIS_multisample), VER(0,0), Y, Y, N, N }, { GLX(SGIX_dm_buffer), VER(0,0), N, N, N, N }, { GLX(SGIX_fbconfig), VER(1,3), Y, N, N, N }, { GLX(SGIX_pbuffer), VER(1,3), Y, N, N, N }, { GLX(SGIX_swap_barrier), VER(0,0), N, N, N, N }, { GLX(SGIX_swap_group), VER(0,0), N, N, N, N }, { GLX(SGIX_video_resize), VER(0,0), N, N, N, N }, { GLX(SGIX_video_source), VER(0,0), N, N, N, N }, { GLX(SGIX_visual_select_group), VER(0,0), Y, Y, N, N }, { GLX(SUN_get_transparent_index), VER(0,0), N, N, N, N }, { NULL } }; static const struct extension_info known_gl_extensions[] = { { GL(ARB_depth_texture), VER(1,4), Y, N, N, N }, { GL(ARB_fragment_program), VER(0,0), N, N, N, N }, { GL(ARB_imaging), VER(0,0), Y, N, N, N }, { GL(ARB_multisample), VER(1,3), Y, N, N, N }, { GL(ARB_multitexture), VER(1,3), Y, N, N, N }, { GL(ARB_occlusion_query), VER(1,5), N, N, N, N }, { GL(ARB_point_parameters), VER(1,4), Y, N, N, N }, { GL(ARB_point_sprite), VER(0,0), Y, N, N, N }, { GL(ARB_shadow), VER(1,4), Y, N, N, N }, { GL(ARB_shadow_ambient), VER(0,0), Y, N, N, N }, { GL(ARB_texture_border_clamp), VER(1,3), Y, N, N, N }, { GL(ARB_texture_compression), VER(1,3), Y, N, N, N }, { GL(ARB_texture_cube_map), VER(1,3), Y, N, N, N }, { GL(ARB_texture_env_add), VER(1,3), Y, N, N, N }, { GL(ARB_texture_env_combine), VER(1,3), Y, N, N, N }, { GL(ARB_texture_env_crossbar), VER(1,4), Y, N, N, N }, { GL(ARB_texture_env_dot3), VER(1,3), Y, N, N, N }, { GL(ARB_texture_mirrored_repeat), VER(1,4), Y, N, N, N }, { GL(ARB_texture_non_power_of_two), VER(1,5), Y, N, N, N }, { GL(ARB_texture_rectangle), VER(0,0), Y, N, N, N }, { GL(ARB_transpose_matrix), VER(1,3), Y, N, Y, N }, { GL(ARB_vertex_buffer_object), VER(1,5), N, N, N, N }, { GL(ARB_window_pos), VER(1,4), Y, N, N, N }, { GL(EXT_abgr), VER(0,0), Y, N, N, N }, { GL(EXT_bgra), VER(1,2), Y, N, N, N }, { GL(EXT_blend_color), VER(1,4), Y, N, N, N }, { GL(EXT_blend_equation_separate), VER(0,0), N, N, N, N }, { GL(EXT_blend_func_separate), VER(1,4), Y, N, N, N }, { GL(EXT_blend_logic_op), VER(1,4), Y, N, N, N }, { GL(EXT_blend_minmax), VER(1,4), Y, N, N, N }, { GL(EXT_blend_subtract), VER(1,4), Y, N, N, N }, { GL(EXT_clip_volume_hint), VER(0,0), Y, N, N, N }, { GL(EXT_compiled_vertex_array), VER(0,0), N, N, N, N }, { GL(EXT_convolution), VER(0,0), N, N, N, N }, { GL(EXT_copy_texture), VER(1,1), Y, N, N, N }, { GL(EXT_cull_vertex), VER(0,0), N, N, N, N }, { GL(EXT_depth_bounds_test), VER(0,0), N, N, N, N }, { GL(EXT_draw_range_elements), VER(1,2), Y, N, Y, N }, { GL(EXT_fog_coord), VER(1,4), Y, N, N, N }, { GL(EXT_multi_draw_arrays), VER(1,4), Y, N, Y, N }, { GL(EXT_packed_pixels), VER(1,2), Y, N, N, N }, { GL(EXT_paletted_texture), VER(0,0), Y, N, N, N }, { GL(EXT_pixel_buffer_object), VER(0,0), N, N, N, N }, { GL(EXT_point_parameters), VER(1,4), Y, N, N, N }, { GL(EXT_polygon_offset), VER(1,1), Y, N, N, N }, { GL(EXT_rescale_normal), VER(1,2), Y, N, N, N }, { GL(EXT_secondary_color), VER(1,4), Y, N, N, N }, { GL(EXT_separate_specular_color), VER(1,2), Y, N, N, N }, { GL(EXT_shadow_funcs), VER(1,5), Y, N, N, N }, { GL(EXT_shared_texture_palette), VER(0,0), Y, N, N, N }, { GL(EXT_stencil_two_side), VER(0,0), Y, N, N, N }, { GL(EXT_stencil_wrap), VER(1,4), Y, N, N, N }, { GL(EXT_subtexture), VER(1,1), Y, N, N, N }, { GL(EXT_texture), VER(1,1), Y, N, N, N }, { GL(EXT_texture3D), VER(1,2), Y, N, N, N }, { GL(EXT_texture_compression_dxt1), VER(0,0), Y, N, N, N }, { GL(EXT_texture_compression_s3tc), VER(0,0), Y, N, N, N }, { GL(EXT_texture_edge_clamp), VER(1,2), Y, N, N, N }, { GL(EXT_texture_env_add), VER(1,3), Y, N, N, N }, { GL(EXT_texture_env_combine), VER(1,3), Y, N, N, N }, { GL(EXT_texture_env_dot3), VER(0,0), Y, N, N, N }, { GL(EXT_texture_filter_anisotropic), VER(0,0), Y, N, N, N }, { GL(EXT_texture_lod), VER(1,2), Y, N, N, N }, { GL(EXT_texture_lod_bias), VER(1,4), Y, N, N, N }, { GL(EXT_texture_mirror_clamp), VER(0,0), Y, N, N, N }, { GL(EXT_texture_object), VER(1,1), Y, N, N, N }, { GL(EXT_texture_rectangle), VER(0,0), Y, N, N, N }, { GL(EXT_vertex_array), VER(0,0), Y, N, N, N }, { GL(3DFX_texture_compression_FXT1), VER(0,0), Y, N, N, N }, { GL(APPLE_packed_pixels), VER(1,2), Y, N, N, N }, { GL(APPLE_ycbcr_422), VER(0,0), Y, N, N, N }, { GL(ATI_texture_env_combine3), VER(0,0), Y, N, N, N }, { GL(ATI_texture_float), VER(0,0), Y, N, N, N }, { GL(ATI_texture_mirror_once), VER(0,0), Y, N, N, N }, { GL(ATIX_texture_env_combine3), VER(0,0), Y, N, N, N }, { GL(HP_convolution_border_modes), VER(0,0), Y, N, N, N }, { GL(HP_occlusion_test), VER(0,0), Y, N, N, N }, { GL(IBM_cull_vertex), VER(0,0), Y, N, N, N }, { GL(IBM_pixel_filter_hint), VER(0,0), Y, N, N, N }, { GL(IBM_rasterpos_clip), VER(0,0), Y, N, N, N }, { GL(IBM_texture_clamp_nodraw), VER(0,0), Y, N, N, N }, { GL(IBM_texture_mirrored_repeat), VER(0,0), Y, N, N, N }, { GL(INGR_blend_func_separate), VER(0,0), Y, N, N, N }, { GL(INGR_interlace_read), VER(0,0), Y, N, N, N }, { GL(MESA_pack_invert), VER(0,0), Y, N, N, N }, { GL(MESA_ycbcr_texture), VER(0,0), Y, N, N, N }, { GL(NV_blend_square), VER(1,4), Y, N, N, N }, { GL(NV_copy_depth_to_color), VER(0,0), Y, N, N, N }, { GL(NV_depth_clamp), VER(0,0), Y, N, N, N }, { GL(NV_fog_distance), VER(0,0), Y, N, N, N }, { GL(NV_light_max_exponent), VER(0,0), Y, N, N, N }, { GL(NV_multisample_filter_hint), VER(0,0), Y, N, N, N }, { GL(NV_point_sprite), VER(0,0), Y, N, N, N }, { GL(NV_texgen_reflection), VER(0,0), Y, N, N, N }, { GL(NV_texture_compression_vtc), VER(0,0), Y, N, N, N }, { GL(NV_texture_env_combine4), VER(0,0), Y, N, N, N }, { GL(NV_texture_rectangle), VER(0,0), Y, N, N, N }, { GL(OES_read_format), VER(0,0), Y, N, N, N }, { GL(OES_compressed_paletted_texture),VER(0,0), Y, N, N, N }, { GL(SGI_color_matrix), VER(0,0), Y, N, N, N }, { GL(SGI_texture_color_table), VER(0,0), Y, N, N, N }, { GL(SGIS_generate_mipmap), VER(1,4), Y, N, N, N }, { GL(SGIS_multisample), VER(0,0), Y, N, N, N }, { GL(SGIS_texture_border_clamp), VER(1,3), Y, N, N, N }, { GL(SGIS_texture_edge_clamp), VER(1,2), Y, N, N, N }, { GL(SGIS_texture_lod), VER(1,2), Y, N, N, N }, { GL(SGIX_blend_alpha_minmax), VER(0,0), Y, N, N, N }, { GL(SGIX_clipmap), VER(0,0), Y, N, N, N }, { GL(SGIX_depth_texture), VER(0,0), Y, N, N, N }, { GL(SGIX_fog_offset), VER(0,0), Y, N, N, N }, { GL(SGIX_shadow), VER(0,0), Y, N, N, N }, { GL(SGIX_shadow_ambient), VER(0,0), Y, N, N, N }, { GL(SGIX_texture_coordinate_clamp), VER(0,0), Y, N, N, N }, { GL(SGIX_texture_lod_bias), VER(0,0), Y, N, N, N }, { GL(SGIX_texture_range), VER(0,0), Y, N, N, N }, { GL(SGIX_texture_scale_bias), VER(0,0), Y, N, N, N }, { GL(SGIX_vertex_preclip), VER(0,0), Y, N, N, N }, { GL(SGIX_vertex_preclip_hint), VER(0,0), Y, N, N, N }, { GL(SGIX_ycrcb), VER(0,0), Y, N, N, N }, { GL(SUN_convolution_border_modes), VER(0,0), Y, N, N, N }, { GL(SUN_multi_draw_arrays), VER(0,0), Y, N, Y, N }, { GL(SUN_slice_accum), VER(0,0), Y, N, N, N }, { NULL } }; #define __GL_EXT_BYTES ((__NUM_GL_EXTS + 7) / 8) /* global bit-fields of available extensions and their characteristics */ static unsigned char client_glx_support[8]; static unsigned char client_glx_only[8]; static unsigned char direct_glx_only[8]; static unsigned char client_gl_support[ __GL_EXT_BYTES ]; static unsigned char client_gl_only[ __GL_EXT_BYTES ]; /** * Bits representing the set of extensions that are enabled by default in all * direct rendering drivers. */ static unsigned char direct_glx_support[8]; /** * Highest core GL version that can be supported for indirect rendering. */ static unsigned gl_major = 0; static unsigned gl_minor = 0; /* client extensions string */ static const char * __glXGLXClientExtensions = NULL; static void __glXExtensionsCtr( void ); static void __glXExtensionsCtrScreen( __GLXscreenConfigs *psc ); static void __glXProcessServerString( const struct extension_info * ext, const char * server_string, unsigned char * server_support ); /** * Set the state of a GLX extension. * * \param name Name of the extension. * \param name_len Length, in characters, of the extension name. * \param state New state (either enabled or disabled) of the extension. * \param supported Table in which the state of the extension is to be set. */ static void set_glx_extension( const struct extension_info * ext, const char * name, unsigned name_len, GLboolean state, unsigned char * supported ) { unsigned i; for ( i = 0 ; ext[i].name != NULL ; i++ ) { if ( (name_len == ext[i].name_len) && (strncmp( ext[i].name, name, name_len ) == 0) ) { if ( state ) { SET_BIT( supported, ext[i].bit ); } else { CLR_BIT( supported, ext[i].bit ); } return; } } } #define NUL '\0' #define SEPARATOR ' ' /** * Convert the server's extension string to a bit-field. * * \param server_string GLX extension string from the server. * \param server_support Bit-field of supported extensions. */ static void __glXProcessServerString( const struct extension_info * ext, const char * server_string, unsigned char * server_support ) { unsigned base; unsigned len; (void) memset( server_support, 0, sizeof( server_support ) ); for ( base = 0 ; server_string[ base ] != NUL ; /* empty */ ) { /* Determine the length of the next extension name. */ for ( len = 0 ; (server_string[ base + len ] != SEPARATOR) && (server_string[ base + len ] != NUL) ; len++ ) { /* empty */ } /* Set the bit for the extension in the server_support table. */ set_glx_extension( ext, & server_string[ base ], len, GL_TRUE, server_support ); /* Advance to the next extension string. This means that we skip * over the previous string and any trialing white-space. */ for ( base += len ; (server_string[ base ] == SEPARATOR) && (server_string[ base ] != NUL) ; base++ ) { /* empty */ } } } /** * Enable a named GLX extension on a given screen. * Drivers should not call this function directly. They should instead use * \c glXGetProcAddress to obtain a pointer to the function. * * \param psc Pointer to GLX per-screen record. * \param name Name of the extension to enable. * * \sa glXGetProcAddress * * \since Internal API version 20030813. */ void __glXScrEnableExtension( __GLXscreenConfigs *psc, const char * name ) { __glXExtensionsCtr(); __glXExtensionsCtrScreen(psc); set_glx_extension( known_glx_extensions, name, strlen( name ), GL_TRUE, psc->direct_support ); } /** * Initialize global extension support tables. */ static void __glXExtensionsCtr( void ) { static const char major_table[32] = { 1, 1, 1, 1, 1, 1, 2, }; static const char minor_table[32] = { 0, 1, 2, 3, 4, 5, 0, }; unsigned i; static GLboolean ext_list_first_time = GL_TRUE; unsigned full_support = ~0; if ( ext_list_first_time ) { ext_list_first_time = GL_FALSE; (void) memset( client_glx_support, 0, sizeof( client_glx_support ) ); (void) memset( direct_glx_support, 0, sizeof( direct_glx_support ) ); (void) memset( client_glx_only, 0, sizeof( client_glx_only ) ); (void) memset( direct_glx_only, 0, sizeof( direct_glx_only ) ); (void) memset( client_gl_support, 0, sizeof( client_gl_support ) ); (void) memset( client_gl_only, 0, sizeof( client_gl_only ) ); for ( i = 0 ; known_glx_extensions[i].name != NULL ; i++ ) { const unsigned bit = known_glx_extensions[i].bit; if ( known_glx_extensions[i].client_support ) { SET_BIT( client_glx_support, bit ); } if ( known_glx_extensions[i].direct_support ) { SET_BIT( direct_glx_support, bit ); } if ( known_glx_extensions[i].client_only ) { SET_BIT( client_glx_only, bit ); } if ( known_glx_extensions[i].direct_only ) { SET_BIT( direct_glx_only, bit ); } } for ( i = 0 ; known_gl_extensions[i].name != NULL ; i++ ) { const unsigned bit = known_gl_extensions[i].bit; if ( known_gl_extensions[i].client_support ) { SET_BIT( client_gl_support, bit ); } else if ( known_gl_extensions[i].version_major != 0 ) { /* If an extension that is required for some core GL version is * not supported, clear the bit for that core GL version as well. */ unsigned ver_bit = (6 * (known_gl_extensions[i].version_major - 1)) + (known_gl_extensions[i].version_minor); full_support &= ~(1U << ver_bit); } if ( known_gl_extensions[i].client_only ) { SET_BIT( client_gl_only, bit ); } } /* Determine the lowest unsupported core GL version. The version before * that is, therefore, the highest supported core GL version. */ for ( i = 0 ; (full_support & (1 << i)) != 0 ; i++ ) /* empty */ ; i--; gl_major = major_table[i]; gl_minor = minor_table[i]; #if 0 fprintf( stderr, "[%s:%u] Maximum client library version: %u.%u\n", __func__, __LINE__, gl_major, gl_minor ); #endif } } /** * Make sure that per-screen direct-support table is initialized. * * \param psc Pointer to GLX per-screen record. */ static void __glXExtensionsCtrScreen( __GLXscreenConfigs *psc ) { if (psc->ext_list_first_time) { psc->ext_list_first_time = GL_FALSE; (void) memcpy( psc->direct_support, direct_glx_support, sizeof( direct_glx_support ) ); } } /** * Check if a certain extension is enabled on a given screen. * * \param psc Pointer to GLX per-screen record. * \param bit Bit index in the direct-support table. * \returns If the extension bit is enabled for the screen, \c GL_TRUE is * returned. If the extension bit is not enabled or if \c psc is * \c NULL, then \c GL_FALSE is returned. */ GLboolean __glXExtensionBitIsEnabled( __GLXscreenConfigs *psc, unsigned bit ) { GLboolean enabled = GL_FALSE; if ( psc != NULL ) { __glXExtensionsCtr(); __glXExtensionsCtrScreen( psc ); enabled = EXT_ENABLED( bit, psc->direct_support ); } return enabled; } /** * Convert a bit-field to a string of supported extensions. */ static char * __glXGetStringFromTable( const struct extension_info * ext, const unsigned char * supported ) { unsigned i; unsigned ext_str_len; char * ext_str; char * point; ext_str_len = 0; for ( i = 0 ; ext[i].name != NULL ; i++ ) { if ( EXT_ENABLED( ext[i].bit, supported ) ) { ext_str_len += ext[i].name_len + 1; } } ext_str = Xmalloc( ext_str_len + 1 ); if ( ext_str != NULL ) { point = ext_str; for ( i = 0 ; ext[i].name != NULL ; i++ ) { if ( EXT_ENABLED( ext[i].bit, supported ) ) { (void) memcpy( point, ext[i].name, ext[i].name_len ); point += ext[i].name_len; *point = ' '; point++; } } *point = '\0'; } return ext_str; } /** * Get the string of client library supported extensions. */ const char * __glXGetClientExtensions( void ) { if ( __glXGLXClientExtensions == NULL ) { __glXExtensionsCtr(); __glXGLXClientExtensions = __glXGetStringFromTable( known_glx_extensions, client_glx_support ); } return __glXGLXClientExtensions; } /** * Calculate the list of application usable extensions. The resulting * string is stored in \c psc->effectiveGLXexts. * * \param psc Pointer to GLX per-screen record. * \param display_is_direct_capable True if the display is capable of * direct rendering. * \param minor_version GLX minor version from the server. */ void __glXCalculateUsableExtensions( __GLXscreenConfigs *psc, GLboolean display_is_direct_capable, int minor_version ) { unsigned char server_support[8]; unsigned char usable[8]; unsigned i; __glXExtensionsCtr(); __glXExtensionsCtrScreen( psc ); __glXProcessServerString( known_glx_extensions, psc->serverGLXexts, server_support ); /* This is a hack. Some servers support GLX 1.3 but don't export * all of the extensions implied by GLX 1.3. If the server claims * support for GLX 1.3, enable support for the extensions that can be * "emulated" as well. */ if ( minor_version >= 3 ) { SET_BIT( server_support, EXT_visual_info_bit ); SET_BIT( server_support, EXT_visual_rating_bit ); SET_BIT( server_support, SGI_make_current_read_bit ); SET_BIT( server_support, SGIX_fbconfig_bit ); SET_BIT( server_support, SGIX_pbuffer_bit ); /* This one is a little iffy. GLX 1.3 doesn't incorporate all of this * extension. However, the only part that is not strictly client-side * is shared. That's the glXQueryContext / glXQueryContextInfoEXT * function. */ SET_BIT( server_support, EXT_import_context_bit ); } /* An extension is supported if the client-side (i.e., libGL) supports * it and the "server" supports it. In this case that means that either * the true server supports it or it is only for direct-rendering and * the direct rendering driver supports it. * * If the display is not capable of direct rendering, then the extension * is enabled if and only if the client-side library and the server * support it. */ if ( display_is_direct_capable ) { for ( i = 0 ; i < 8 ; i++ ) { usable[i] = (client_glx_support[i] & client_glx_only[i]) | (client_glx_support[i] & psc->direct_support[i] & server_support[i]) | (client_glx_support[i] & psc->direct_support[i] & direct_glx_only[i]); } } else { for ( i = 0 ; i < 8 ; i++ ) { usable[i] = (client_glx_support[i] & client_glx_only[i]) | (client_glx_support[i] & server_support[i]); } } psc->effectiveGLXexts = __glXGetStringFromTable( known_glx_extensions, usable ); } /** * Calculate the list of application usable extensions. The resulting * string is stored in \c gc->extensions. * * \param gc Pointer to GLX context. * \param server_string Extension string from the server. * \param major_version GL major version from the server. * \param minor_version GL minor version from the server. */ void __glXCalculateUsableGLExtensions( __GLXcontext * gc, const char * server_string, int major_version, int minor_version ) { unsigned char server_support[ __GL_EXT_BYTES ]; unsigned char usable[ __GL_EXT_BYTES ]; unsigned i; __glXExtensionsCtr(); (void) memset( server_support, 0, sizeof( server_support ) ); __glXProcessServerString( known_gl_extensions, server_string, server_support ); /* Handle lazy servers that don't export all the extensions strings that * are part of the GL core version that they support. */ for ( i = 0 ; i < __GL_EXT_BYTES ; i++ ) { if ( (known_gl_extensions[i].version_major != 0) && ((major_version > known_gl_extensions[i].version_major) || ((major_version == known_gl_extensions[i].version_major) && (minor_version >= known_gl_extensions[i].version_minor))) ) { SET_BIT( server_support, known_gl_extensions[i].bit ); } } /* An extension is supported if the client-side (i.e., libGL) supports * it and the server supports it or the client-side library supports it * and it only needs client-side support. */ for ( i = 0 ; i < __GL_EXT_BYTES ; i++ ) { usable[i] = (client_gl_support[i] & client_gl_only[i]) | (client_gl_support[i] & server_support[i]); } gc->extensions = (unsigned char *) __glXGetStringFromTable( known_gl_extensions, usable ); } /** * Calculates the maximum core GL version that can be supported for indirect * rendering. */ void __glXGetGLVersion( int * major_version, int * minor_version ) { __glXExtensionsCtr(); *major_version = gl_major; *minor_version = gl_minor; } /** * Get a string representing the set of extensions supported by the client * library. This is currently only used to send the list of extensions * supported by the client to the server. */ char * __glXGetClientGLExtensionString( void ) { __glXExtensionsCtr(); return __glXGetStringFromTable( known_gl_extensions, client_gl_support ); }