src/glx/x11/glxextensions.c

   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 "glapi.h"
  36 #include "glxextensions.h"
  37 #include "simple_list.h"
  38
  39 #define SET_BIT(m,b)   (m[ (b) / 8 ] |=  (1U << ((b) % 8)))
  40 #define CLR_BIT(m,b)   (m[ (b) / 8 ] &= ~(1U << ((b) % 8)))
  41 #define IS_SET(m,b)    ((m[ (b) / 8 ] & (1U << ((b) % 8))) != 0)
  42 #define CONCAT(a,b) a ## b
  43 #define GLX(n) "GLX_" # n, 4 + sizeof( # n ) - 1, CONCAT(n,_bit)
  44 #define GL(n)  "GL_" # n,  3 + sizeof( # n ) - 1, GL_ ## n ## _bit
  45 #define VER(a,b)  a, b
  46 #define Y  1
  47 #define N  0
  48 #define EXT_ENABLED(bit,supported) (IS_SET( supported, bit ))
  49
  50
  51 struct extension_info {
  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 static const struct extension_info known_glx_extensions[] = {
  73    { GLX(ARB_get_proc_address),        VER(1,4), Y, N, Y, N },
  74    { GLX(ARB_multisample),             VER(1,4), Y, Y, N, N },
  75    { GLX(ARB_render_texture),          VER(0,0), N, N, N, N },
  76    { GLX(ATI_pixel_format_float),      VER(0,0), N, N, N, N },
  77    { GLX(EXT_import_context),          VER(0,0), Y, Y, N, N },
  78    { GLX(EXT_visual_info),             VER(0,0), Y, Y, N, N },
  79    { GLX(EXT_visual_rating),           VER(0,0), Y, Y, N, N },
  80    { GLX(MESA_agp_offset),             VER(0,0), N, N, N, Y }, /* Deprecated */
  81    { GLX(MESA_allocate_memory),        VER(0,0), Y, N, N, Y },
  82    { GLX(MESA_copy_sub_buffer),        VER(0,0), Y, N, N, N },
  83    { GLX(MESA_pixmap_colormap),        VER(0,0), N, N, N, N }, /* Deprecated */
  84    { GLX(MESA_release_buffers),        VER(0,0), N, N, N, N }, /* Deprecated */
  85    { GLX(MESA_set_3dfx_mode),          VER(0,0), N, N, N, N }, /* Deprecated */
  86    { GLX(MESA_swap_control),           VER(0,0), Y, N, N, Y },
  87    { GLX(MESA_swap_frame_usage),       VER(0,0), Y, N, N, Y },
  88    { GLX(NV_float_buffer),             VER(0,0), N, N, N, N },
  89    { GLX(NV_render_depth_texture),     VER(0,0), N, N, N, N },
  90    { GLX(NV_render_texture_rectangle), VER(0,0), N, N, N, N },
  91    { GLX(NV_vertex_array_range),       VER(0,0), N, N, N, Y }, /* Deprecated */
  92    { GLX(OML_swap_method),             VER(0,0), Y, Y, N, N },
  93    { GLX(OML_sync_control),            VER(0,0), Y, N, N, Y },
  94    { GLX(SGI_cushion),                 VER(0,0), N, N, N, N },
  95    { GLX(SGI_make_current_read),       VER(1,3), Y, N, N, N },
  96    { GLX(SGI_swap_control),            VER(0,0), Y, N, N, N },
  97    { GLX(SGI_video_sync),              VER(0,0), Y, N, N, Y },
  98    { GLX(SGIS_blended_overlay),        VER(0,0), N, N, N, N },
  99    { GLX(SGIS_color_range),            VER(0,0), N, N, N, N },
 100    { GLX(SGIS_multisample),            VER(0,0), Y, Y, N, N },
 101    { GLX(SGIX_dm_buffer),              VER(0,0), N, N, N, N },
 102    { GLX(SGIX_fbconfig),               VER(1,3), Y, Y, N, N },
 103    { GLX(SGIX_pbuffer),                VER(1,3), Y, N, N, N },
 104    { GLX(SGIX_swap_barrier),           VER(0,0), N, N, N, N },
 105    { GLX(SGIX_swap_group),             VER(0,0), N, N, N, N },
 106    { GLX(SGIX_video_resize),           VER(0,0), N, N, N, N },
 107    { GLX(SGIX_video_source),           VER(0,0), N, N, N, N },
 108    { GLX(SGIX_visual_select_group),    VER(0,0), Y, Y, N, N },
 109    { GLX(SUN_get_transparent_index),   VER(0,0), N, N, N, N },
 110    { GLX(EXT_texture_from_pixmap),     VER(0,0), Y, N, N, N },
 111    { NULL }
 112 };
 113
 114 static const struct extension_info known_gl_extensions[] = {
 115    { GL(ARB_depth_texture),              VER(1,4), Y, N, N, N },
 116    { GL(ARB_draw_buffers),               VER(0,0), Y, N, N, N },
 117    { GL(ARB_fragment_program),           VER(0,0), Y, N, N, N },
 118    { GL(ARB_fragment_program_shadow),    VER(0,0), Y, N, N, N },
 119    { GL(ARB_imaging),                    VER(0,0), Y, N, N, N },
 120    { GL(ARB_multisample),                VER(1,3), Y, N, N, N },
 121    { GL(ARB_multitexture),               VER(1,3), Y, N, N, N },
 122    { GL(ARB_occlusion_query),            VER(1,5), Y, N, N, N },
 123    { GL(ARB_point_parameters),           VER(1,4), Y, N, N, N },
 124    { GL(ARB_point_sprite),               VER(0,0), Y, N, N, N },
 125    { GL(ARB_shadow),                     VER(1,4), Y, N, N, N },
 126    { GL(ARB_shadow_ambient),             VER(0,0), Y, N, N, N },
 127    { GL(ARB_texture_border_clamp),       VER(1,3), Y, N, N, N },
 128    { GL(ARB_texture_compression),        VER(1,3), Y, N, N, N },
 129    { GL(ARB_texture_cube_map),           VER(1,3), Y, N, N, N },
 130    { GL(ARB_texture_env_add),            VER(1,3), Y, N, N, N },
 131    { GL(ARB_texture_env_combine),        VER(1,3), Y, N, N, N },
 132    { GL(ARB_texture_env_crossbar),       VER(1,4), Y, N, N, N },
 133    { GL(ARB_texture_env_dot3),           VER(1,3), Y, N, N, N },
 134    { GL(ARB_texture_mirrored_repeat),    VER(1,4), Y, N, N, N },
 135    { GL(ARB_texture_non_power_of_two),   VER(1,5), Y, N, N, N },
 136    { GL(ARB_texture_rectangle),          VER(0,0), Y, N, N, N },
 137    { GL(ARB_transpose_matrix),           VER(1,3), Y, N, Y, N },
 138    { GL(ARB_vertex_buffer_object),       VER(1,5), N, N, N, N },
 139    { GL(ARB_vertex_program),             VER(0,0), Y, N, N, N },
 140    { GL(ARB_window_pos),                 VER(1,4), Y, N, N, N },
 141    { GL(EXT_abgr),                       VER(0,0), Y, N, N, N },
 142    { GL(EXT_bgra),                       VER(1,2), Y, N, N, N },
 143    { GL(EXT_blend_color),                VER(1,4), Y, N, N, N },
 144    { GL(EXT_blend_equation_separate),    VER(0,0), N, N, N, N },
 145    { GL(EXT_blend_func_separate),        VER(1,4), Y, N, N, N },
 146    { GL(EXT_blend_logic_op),             VER(1,4), Y, N, N, N },
 147    { GL(EXT_blend_minmax),               VER(1,4), Y, N, N, N },
 148    { GL(EXT_blend_subtract),             VER(1,4), Y, N, N, N },
 149    { GL(EXT_clip_volume_hint),           VER(0,0), Y, N, N, N },
 150    { GL(EXT_compiled_vertex_array),      VER(0,0), N, N, N, N },
 151    { GL(EXT_convolution),                VER(0,0), N, N, N, N },
 152    { GL(EXT_copy_texture),               VER(1,1), Y, N, N, N },
 153    { GL(EXT_cull_vertex),                VER(0,0), N, N, N, N },
 154    { GL(EXT_depth_bounds_test),          VER(0,0), N, N, N, N },
 155    { GL(EXT_draw_range_elements),        VER(1,2), Y, N, Y, N },
 156    { GL(EXT_fog_coord),                  VER(1,4), Y, N, N, N },
 157    { GL(EXT_framebuffer_object),         VER(0,0), Y, N, N, N },
 158    { GL(EXT_multi_draw_arrays),          VER(1,4), Y, N, Y, N },
 159    { GL(EXT_packed_pixels),              VER(1,2), Y, N, N, N },
 160    { GL(EXT_paletted_texture),           VER(0,0), Y, N, N, N },
 161    { GL(EXT_pixel_buffer_object),        VER(0,0), N, N, N, N },
 162    { GL(EXT_point_parameters),           VER(1,4), Y, N, N, N },
 163    { GL(EXT_polygon_offset),             VER(1,1), Y, N, N, N },
 164    { GL(EXT_rescale_normal),             VER(1,2), Y, N, N, N },
 165    { GL(EXT_secondary_color),            VER(1,4), Y, N, N, N },
 166    { GL(EXT_separate_specular_color),    VER(1,2), Y, N, N, N },
 167    { GL(EXT_shadow_funcs),               VER(1,5), Y, N, N, N },
 168    { GL(EXT_shared_texture_palette),     VER(0,0), Y, N, N, N },
 169    { GL(EXT_stencil_two_side),           VER(0,0), Y, N, N, N },
 170    { GL(EXT_stencil_wrap),               VER(1,4), Y, N, N, N },
 171    { GL(EXT_subtexture),                 VER(1,1), Y, N, N, N },
 172    { GL(EXT_texture),                    VER(1,1), Y, N, N, N },
 173    { GL(EXT_texture3D),                  VER(1,2), Y, N, N, N },
 174    { GL(EXT_texture_compression_dxt1),   VER(0,0), Y, N, N, N },
 175    { GL(EXT_texture_compression_s3tc),   VER(0,0), Y, N, N, N },
 176    { GL(EXT_texture_edge_clamp),         VER(1,2), Y, N, N, N },
 177    { GL(EXT_texture_env_add),            VER(1,3), Y, N, N, N },
 178    { GL(EXT_texture_env_combine),        VER(1,3), Y, N, N, N },
 179    { GL(EXT_texture_env_dot3),           VER(0,0), Y, N, N, N },
 180    { GL(EXT_texture_filter_anisotropic), VER(0,0), Y, N, N, N },
 181    { GL(EXT_texture_lod),                VER(1,2), Y, N, N, N },
 182    { GL(EXT_texture_lod_bias),           VER(1,4), Y, N, N, N },
 183    { GL(EXT_texture_mirror_clamp),       VER(0,0), Y, N, N, N },
 184    { GL(EXT_texture_object),             VER(1,1), Y, N, N, N },
 185    { GL(EXT_texture_rectangle),          VER(0,0), Y, N, N, N },
 186    { GL(EXT_vertex_array),               VER(0,0), Y, N, N, N },
 187    { GL(3DFX_texture_compression_FXT1),  VER(0,0), Y, N, N, N },
 188    { GL(APPLE_packed_pixels),            VER(1,2), Y, N, N, N },
 189    { GL(APPLE_ycbcr_422),                VER(0,0), Y, N, N, N },
 190    { GL(ATI_draw_buffers),               VER(0,0), Y, N, N, N },
 191    { GL(ATI_text_fragment_shader),       VER(0,0), Y, N, N, N },
 192    { GL(ATI_texture_env_combine3),       VER(0,0), Y, N, N, N },
 193    { GL(ATI_texture_float),              VER(0,0), Y, N, N, N },
 194    { GL(ATI_texture_mirror_once),        VER(0,0), Y, N, N, N },
 195    { GL(ATIX_texture_env_combine3),      VER(0,0), Y, N, N, N },
 196    { GL(HP_convolution_border_modes),    VER(0,0), Y, N, N, N },
 197    { GL(HP_occlusion_test),              VER(0,0), Y, N, N, N },
 198    { GL(IBM_cull_vertex),                VER(0,0), Y, N, N, N },
 199    { GL(IBM_pixel_filter_hint),          VER(0,0), Y, N, N, N },
 200    { GL(IBM_rasterpos_clip),             VER(0,0), Y, N, N, N },
 201    { GL(IBM_texture_clamp_nodraw),       VER(0,0), Y, N, N, N },
 202    { GL(IBM_texture_mirrored_repeat),    VER(0,0), Y, N, N, N },
 203    { GL(INGR_blend_func_separate),       VER(0,0), Y, N, N, N },
 204    { GL(INGR_interlace_read),            VER(0,0), Y, N, N, N },
 205    { GL(MESA_pack_invert),               VER(0,0), Y, N, N, N },
 206    { GL(MESA_ycbcr_texture),             VER(0,0), Y, N, N, N },
 207    { GL(NV_blend_square),                VER(1,4), Y, N, N, N },
 208    { GL(NV_copy_depth_to_color),         VER(0,0), Y, N, N, N },
 209    { GL(NV_depth_clamp),                 VER(0,0), Y, N, N, N },
 210    { GL(NV_fog_distance),                VER(0,0), Y, N, N, N },
 211    { GL(NV_fragment_program),            VER(0,0), Y, N, N, N },
 212    { GL(NV_fragment_program_option),     VER(0,0), Y, N, N, N },
 213    { GL(NV_fragment_program2),           VER(0,0), Y, N, N, N },
 214    { GL(NV_light_max_exponent),          VER(0,0), Y, N, N, N },
 215    { GL(NV_multisample_filter_hint),     VER(0,0), Y, N, N, N },
 216    { GL(NV_point_sprite),                VER(0,0), Y, N, N, N },
 217    { GL(NV_texgen_reflection),           VER(0,0), Y, N, N, N },
 218    { GL(NV_texture_compression_vtc),     VER(0,0), Y, N, N, N },
 219    { GL(NV_texture_env_combine4),        VER(0,0), Y, N, N, N },
 220    { GL(NV_texture_rectangle),           VER(0,0), Y, N, N, N },
 221    { GL(NV_vertex_program),              VER(0,0), Y, N, N, N },
 222    { GL(NV_vertex_program1_1),           VER(0,0), Y, N, N, N },
 223    { GL(NV_vertex_program2),             VER(0,0), Y, N, N, N },
 224    { GL(NV_vertex_program2_option),      VER(0,0), Y, N, N, N },
 225    { GL(NV_vertex_program3),             VER(0,0), Y, N, N, N },
 226    { GL(OES_read_format),                VER(0,0), Y, N, N, N },
 227    { GL(OES_compressed_paletted_texture),VER(0,0), Y, N, N, N },
 228    { GL(SGI_color_matrix),               VER(0,0), Y, N, N, N },
 229    { GL(SGI_texture_color_table),        VER(0,0), Y, N, N, N },
 230    { GL(SGIS_generate_mipmap),           VER(1,4), Y, N, N, N },
 231    { GL(SGIS_multisample),               VER(0,0), Y, N, N, N },
 232    { GL(SGIS_texture_border_clamp),      VER(1,3), Y, N, N, N },
 233    { GL(SGIS_texture_edge_clamp),        VER(1,2), Y, N, N, N },
 234    { GL(SGIS_texture_lod),               VER(1,2), Y, N, N, N },
 235    { GL(SGIX_blend_alpha_minmax),        VER(0,0), Y, N, N, N },
 236    { GL(SGIX_clipmap),                   VER(0,0), Y, N, N, N },
 237    { GL(SGIX_depth_texture),             VER(0,0), Y, N, N, N },
 238    { GL(SGIX_fog_offset),                VER(0,0), Y, N, N, N },
 239    { GL(SGIX_shadow),                    VER(0,0), Y, N, N, N },
 240    { GL(SGIX_shadow_ambient),            VER(0,0), Y, N, N, N },
 241    { GL(SGIX_texture_coordinate_clamp),  VER(0,0), Y, N, N, N },
 242    { GL(SGIX_texture_lod_bias),          VER(0,0), Y, N, N, N },
 243    { GL(SGIX_texture_range),             VER(0,0), Y, N, N, N },
 244    { GL(SGIX_texture_scale_bias),        VER(0,0), Y, N, N, N },
 245    { GL(SGIX_vertex_preclip),            VER(0,0), Y, N, N, N },
 246    { GL(SGIX_vertex_preclip_hint),       VER(0,0), Y, N, N, N },
 247    { GL(SGIX_ycrcb),                     VER(0,0), Y, N, N, N },
 248    { GL(SUN_convolution_border_modes),   VER(0,0), Y, N, N, N },
 249    { GL(SUN_multi_draw_arrays),          VER(0,0), Y, N, Y, N },
 250    { GL(SUN_slice_accum),                VER(0,0), Y, N, N, N },
 251    { NULL }
 252 };
 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( __GLXscreenConfigs *psc );
 279 static void __glXProcessServerString( const struct extension_info * ext,
 280     const char * server_string, unsigned char * server_support );
 281
 282 /**
 283  * Set the state of a GLX extension.
 284  *
 285  * \param name      Name of the extension.
 286  * \param name_len  Length, in characters, of the extension name.
 287  * \param state     New state (either enabled or disabled) of the extension.
 288  * \param supported Table in which the state of the extension is to be set.
 289  */
 290 static void
 291 set_glx_extension( const struct extension_info * ext,
 292                    const char * name, unsigned name_len, GLboolean state,
 293                    unsigned char * supported )
 294 {
 295    unsigned   i;
 296
 297
 298    for ( i = 0 ; ext[i].name != NULL ; i++ ) {
 299       if ( (name_len == ext[i].name_len)
 300            && (strncmp( ext[i].name, name, name_len ) == 0) ) {
 301          if ( state ) {
 302             SET_BIT( supported, ext[i].bit );
 303          }
 304          else {
 305             CLR_BIT( supported, ext[i].bit );
 306          }
 307
 308          return;
 309       }
 310    }
 311 }
 312
 313
 314 #define NUL '\0'
 315 #define SEPARATOR ' '
 316
 317 /**
 318  * Convert the server's extension string to a bit-field.
 319  *
 320  * \param server_string   GLX extension string from the server.
 321  * \param server_support  Bit-field of supported extensions.
 322  */
 323 static void
 324 __glXProcessServerString( const struct extension_info * ext,
 325                           const char * server_string,
 326                           unsigned char * server_support )
 327 {
 328    unsigned  base;
 329    unsigned  len;
 330
 331    (void) memset( server_support, 0, sizeof( server_support ) );
 332
 333    for ( base = 0 ; server_string[ base ] != NUL ; /* empty */ ) {
 334       /* Determine the length of the next extension name.
 335        */
 336       for ( len = 0
 337             ; (server_string[ base + len ] != SEPARATOR)
 338             && (server_string[ base + len ] != NUL)
 339             ; len++ ) {
 340          /* empty */
 341       }
 342
 343       /* Set the bit for the extension in the server_support table.
 344        */
 345       set_glx_extension( ext, & server_string[ base ], len, GL_TRUE,
 346                          server_support );
 347
 348
 349       /* Advance to the next extension string.  This means that we skip
 350        * over the previous string and any trialing white-space.
 351        */
 352       for ( base += len ;
 353             (server_string[ base ] == SEPARATOR)
 354             && (server_string[ base ] != NUL)
 355             ; base++ ) {
 356          /* empty */
 357       }
 358    }
 359 }
 360
 361
 362 /**
 363  * Enable a named GLX extension on a given screen.
 364  * Drivers should not call this function directly.  They should instead use
 365  * \c glXGetProcAddress to obtain a pointer to the function.
 366  *
 367  * \param psc   Pointer to GLX per-screen record.
 368  * \param name  Name of the extension to enable.
 369  *
 370  * \sa glXGetProcAddress
 371  *
 372  * \since Internal API version 20030813.
 373  */
 374 void
 375 __glXScrEnableExtension( __GLXscreenConfigs *psc, const char * name )
 376 {
 377    __glXExtensionsCtr();
 378    __glXExtensionsCtrScreen(psc);
 379    set_glx_extension( known_glx_extensions, name, strlen( name ), GL_TRUE,
 380                       psc->direct_support );
 381 }
 382
 383
 384 /**
 385  * Initialize global extension support tables.
 386  */
 387
 388 static void
 389 __glXExtensionsCtr( void )
 390 {
 391    unsigned   i;
 392    static GLboolean ext_list_first_time = GL_TRUE;
 393
 394
 395    if ( ext_list_first_time ) {
 396       ext_list_first_time = GL_FALSE;
 397
 398       (void) memset( client_glx_support, 0, sizeof( client_glx_support ) );
 399       (void) memset( direct_glx_support, 0, sizeof( direct_glx_support ) );
 400       (void) memset( client_glx_only,    0, sizeof( client_glx_only ) );
 401       (void) memset( direct_glx_only,    0, sizeof( direct_glx_only ) );
 402
 403       (void) memset( client_gl_support,  0, sizeof( client_gl_support ) );
 404       (void) memset( client_gl_only,     0, sizeof( client_gl_only ) );
 405
 406       for ( i = 0 ; known_glx_extensions[i].name != NULL ; i++ ) {
 407          const unsigned  bit = known_glx_extensions[i].bit;
 408
 409          if ( known_glx_extensions[i].client_support ) {
 410             SET_BIT( client_glx_support, bit );
 411          }
 412
 413          if ( known_glx_extensions[i].direct_support ) {
 414             SET_BIT( direct_glx_support, bit );
 415          }
 416
 417          if ( known_glx_extensions[i].client_only ) {
 418             SET_BIT( client_glx_only, bit );
 419          }
 420
 421          if ( known_glx_extensions[i].direct_only ) {
 422             SET_BIT( direct_glx_only, bit );
 423          }
 424       }
 425
 426       for ( i = 0 ; known_gl_extensions[i].name != NULL ; i++ ) {
 427          const unsigned  bit = known_gl_extensions[i].bit;
 428
 429          if ( known_gl_extensions[i].client_support ) {
 430             SET_BIT( client_gl_support, bit );
 431          }
 432
 433          if ( known_gl_extensions[i].client_only ) {
 434             SET_BIT( client_gl_only, bit );
 435          }
 436       }
 437
 438 #if 0
 439       fprintf( stderr, "[%s:%u] Maximum client library version: %u.%u\n",
 440                __func__, __LINE__, gl_major, gl_minor );
 441 #endif
 442    }
 443 }
 444
 445
 446 /**
 447  * Make sure that per-screen direct-support table is initialized.
 448  *
 449  * \param psc  Pointer to GLX per-screen record.
 450  */
 451
 452 static void
 453 __glXExtensionsCtrScreen( __GLXscreenConfigs *psc )
 454 {
 455     if (psc->ext_list_first_time) {
 456         psc->ext_list_first_time = GL_FALSE;
 457         (void) memcpy( psc->direct_support, direct_glx_support,
 458                        sizeof( direct_glx_support ) );
 459     }
 460 }
 461
 462
 463 /**
 464  * Check if a certain extension is enabled on a given screen.
 465  *
 466  * \param psc  Pointer to GLX per-screen record.
 467  * \param bit  Bit index in the direct-support table.
 468  * \returns If the extension bit is enabled for the screen, \c GL_TRUE is
 469  *          returned.  If the extension bit is not enabled or if \c psc is
 470  *          \c NULL, then \c GL_FALSE is returned.
 471  */
 472 GLboolean
 473 __glXExtensionBitIsEnabled( __GLXscreenConfigs *psc, unsigned bit )
 474 {
 475    GLboolean enabled = GL_FALSE;
 476
 477    if ( psc != NULL ) {
 478       __glXExtensionsCtr();
 479       __glXExtensionsCtrScreen( psc );
 480       enabled = EXT_ENABLED( bit, psc->direct_support );
 481    }
 482
 483    return enabled;
 484 }
 485
 486
 487 /**
 488  * Check if a certain extension is enabled in a given context.
 489  *
 490  */
 491 GLboolean
 492 __glExtensionBitIsEnabled( const __GLXcontext * gc, unsigned bit )
 493 {
 494    GLboolean enabled = GL_FALSE;
 495
 496    if ( gc != NULL ) {
 497       enabled = EXT_ENABLED( bit, gc->gl_extension_bits );
 498    }
 499
 500    return enabled;
 501 }
 502
 503
 504
 505 /**
 506  * Convert a bit-field to a string of supported extensions.
 507  */
 508 static char *
 509 __glXGetStringFromTable( const struct extension_info * ext,
 510                          const unsigned char * supported )
 511 {
 512    unsigned   i;
 513    unsigned   ext_str_len;
 514    char * ext_str;
 515    char * point;
 516
 517
 518    ext_str_len = 0;
 519    for ( i = 0 ; ext[i].name != NULL ; i++ ) {
 520       if ( EXT_ENABLED( ext[i].bit, supported ) ) {
 521          ext_str_len += ext[i].name_len + 1;
 522       }
 523    }
 524
 525    ext_str = Xmalloc( ext_str_len + 1 );
 526    if ( ext_str != NULL ) {
 527       point = ext_str;
 528
 529       for ( i = 0 ; ext[i].name != NULL ; i++ ) {
 530          if ( EXT_ENABLED( ext[i].bit, supported ) ) {
 531             (void) memcpy( point, ext[i].name, ext[i].name_len );
 532             point += ext[i].name_len;
 533
 534             *point = ' ';
 535             point++;
 536          }
 537       }
 538
 539       *point = '\0';
 540    }
 541
 542    return ext_str;
 543 }
 544
 545
 546 /**
 547  * Get the string of client library supported extensions.
 548  */
 549 const char *
 550 __glXGetClientExtensions( void )
 551 {
 552    if ( __glXGLXClientExtensions == NULL ) {
 553       __glXExtensionsCtr();
 554       __glXGLXClientExtensions = __glXGetStringFromTable( known_glx_extensions,
 555                                                           client_glx_support );
 556    }
 557
 558    return __glXGLXClientExtensions;
 559 }
 560
 561
 562 /**
 563  * Calculate the list of application usable extensions.  The resulting
 564  * string is stored in \c psc->effectiveGLXexts.
 565  *
 566  * \param psc                        Pointer to GLX per-screen record.
 567  * \param display_is_direct_capable  True if the display is capable of
 568  *                                   direct rendering.
 569  * \param minor_version              GLX minor version from the server.
 570  */
 571
 572 void
 573 __glXCalculateUsableExtensions( __GLXscreenConfigs *psc,
 574                                 GLboolean display_is_direct_capable,
 575                                 int minor_version )
 576 {
 577    unsigned char server_support[8];
 578    unsigned char usable[8];
 579    unsigned      i;
 580
 581    __glXExtensionsCtr();
 582    __glXExtensionsCtrScreen( psc );
 583    __glXProcessServerString( known_glx_extensions,
 584                              psc->serverGLXexts, server_support );
 585
 586
 587    /* This is a hack.  Some servers support GLX 1.3 but don't export
 588     * all of the extensions implied by GLX 1.3.  If the server claims
 589     * support for GLX 1.3, enable support for the extensions that can be
 590     * "emulated" as well.
 591     */
 592
 593    if ( minor_version >= 3 ) {
 594       SET_BIT( server_support, EXT_visual_info_bit );
 595       SET_BIT( server_support, EXT_visual_rating_bit );
 596       SET_BIT( server_support, SGI_make_current_read_bit );
 597       SET_BIT( server_support, SGIX_fbconfig_bit );
 598       SET_BIT( server_support, SGIX_pbuffer_bit );
 599
 600       /* This one is a little iffy.  GLX 1.3 doesn't incorporate all of this
 601        * extension.  However, the only part that is not strictly client-side
 602        * is shared.  That's the glXQueryContext / glXQueryContextInfoEXT
 603        * function.
 604        */
 605
 606       SET_BIT( server_support, EXT_import_context_bit );
 607    }
 608
 609
 610    /* An extension is supported if the client-side (i.e., libGL) supports
 611     * it and the "server" supports it.  In this case that means that either
 612     * the true server supports it or it is only for direct-rendering and
 613     * the direct rendering driver supports it.
 614     *
 615     * If the display is not capable of direct rendering, then the extension
 616     * is enabled if and only if the client-side library and the server
 617     * support it.
 618     */
 619
 620    if ( display_is_direct_capable ) {
 621       for ( i = 0 ; i < 8 ; i++ ) {
 622          usable[i] = (client_glx_support[i] & client_glx_only[i])
 623              | (client_glx_support[i] & psc->direct_support[i] & server_support[i])
 624              | (client_glx_support[i] & psc->direct_support[i] & direct_glx_only[i]);
 625       }
 626    }
 627    else {
 628       for ( i = 0 ; i < 8 ; i++ ) {
 629          usable[i] = (client_glx_support[i] & client_glx_only[i])
 630              | (client_glx_support[i] & server_support[i]);
 631       }
 632    }
 633
 634    psc->effectiveGLXexts = __glXGetStringFromTable( known_glx_extensions,
 635                                                     usable );
 636 }
 637
 638
 639 /**
 640  * Calculate the list of application usable extensions.  The resulting
 641  * string is stored in \c gc->extensions.
 642  *
 643  * \param gc             Pointer to GLX context.
 644  * \param server_string  Extension string from the server.
 645  * \param major_version  GL major version from the server.
 646  * \param minor_version  GL minor version from the server.
 647  */
 648
 649 void
 650 __glXCalculateUsableGLExtensions( __GLXcontext * gc,
 651                                   const char * server_string,
 652                                   int major_version, int minor_version )
 653 {
 654    unsigned char server_support[ __GL_EXT_BYTES ];
 655    unsigned char usable[ __GL_EXT_BYTES ];
 656    unsigned      i;
 657
 658
 659    __glXExtensionsCtr();
 660
 661    (void) memset( server_support, 0, sizeof( server_support ) );
 662    __glXProcessServerString( known_gl_extensions, server_string,
 663                              server_support );
 664
 665
 666    /* Handle lazy servers that don't export all the extensions strings that
 667     * are part of the GL core version that they support.
 668     */
 669
 670    for ( i = 0 ; i < __GL_EXT_BYTES ; i++ ) {
 671       if ( (known_gl_extensions[i].version_major != 0)
 672            && ((major_version > known_gl_extensions[i].version_major)
 673                || ((major_version == known_gl_extensions[i].version_major)
 674                    && (minor_version >= known_gl_extensions[i].version_minor))) ) {
 675          SET_BIT( server_support, known_gl_extensions[i].bit );
 676       }
 677    }
 678
 679
 680    /* An extension is supported if the client-side (i.e., libGL) supports
 681     * it and the server supports it or the client-side library supports it
 682     * and it only needs client-side support.
 683     */
 684
 685    for ( i = 0 ; i < __GL_EXT_BYTES ; i++ ) {
 686       usable[i] = (client_gl_support[i] & client_gl_only[i])
 687         | (client_gl_support[i] & server_support[i]);
 688    }
 689
 690    gc->extensions = (unsigned char *)
 691      __glXGetStringFromTable( known_gl_extensions, usable );
 692    (void) memcpy( gc->gl_extension_bits, usable, sizeof( usable ) );
 693 }
 694
 695
 696 /**
 697  * Calculates the maximum core GL version that can be supported for indirect
 698  * rendering.
 699  */
 700 void
 701 __glXGetGLVersion( int * major_version, int * minor_version )
 702 {
 703     __glXExtensionsCtr();
 704     *major_version = gl_major;
 705     *minor_version = gl_minor;
 706 }
 707
 708
 709 /**
 710  * Get a string representing the set of extensions supported by the client
 711  * library.  This is currently only used to send the list of extensions
 712  * supported by the client to the server.
 713  */
 714 char *
 715 __glXGetClientGLExtensionString( void )
 716 {
 717     __glXExtensionsCtr();
 718     return __glXGetStringFromTable( known_gl_extensions, client_gl_support );
 719 }