src/glx/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 "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_get_proc_address),        VER(1,4), Y, N, Y, N },
  75    { GLX(ARB_multisample),             VER(1,4), Y, Y, N, N },
  76    { GLX(ARB_render_texture),          VER(0,0), N, N, N, N },
  77    { GLX(ATI_pixel_format_float),      VER(0,0), N, N, N, N },
  78 #ifdef GLX_USE_APPLEGL
  79    { GLX(EXT_import_context),          VER(0,0), N, N, N, N },
  80    { GLX(EXT_visual_info),             VER(0,0), N, N, N, N },
  81 #else
  82    { GLX(EXT_import_context),          VER(0,0), Y, Y, N, N },
  83    { GLX(EXT_visual_info),             VER(0,0), Y, Y, N, N },
  84 #endif
  85    { GLX(EXT_visual_rating),           VER(0,0), Y, Y, N, N },
  86 #ifdef GLX_USE_APPLEGL
  87    { GLX(MESA_agp_offset),             VER(0,0), N, N, N, N }, /* Deprecated */
  88    { GLX(MESA_allocate_memory),        VER(0,0), N, N, N, N },
  89    { GLX(MESA_copy_sub_buffer),        VER(0,0), N, N, N, N },
  90 #else
  91    { GLX(MESA_agp_offset),             VER(0,0), N, N, N, Y }, /* Deprecated */
  92    { GLX(MESA_allocate_memory),        VER(0,0), Y, N, N, Y },
  93    { GLX(MESA_copy_sub_buffer),        VER(0,0), Y, N, N, N },
  94 #endif
  95    { GLX(MESA_pixmap_colormap),        VER(0,0), N, N, N, N }, /* Deprecated */
  96    { GLX(MESA_release_buffers),        VER(0,0), N, N, N, N }, /* Deprecated */
  97 #ifdef GLX_USE_APPLEGL
  98    { GLX(MESA_swap_control),           VER(0,0), N, N, N, N },
  99    { GLX(MESA_swap_frame_usage),       VER(0,0), N, N, N, N },
 100 #else
 101    { GLX(MESA_swap_control),           VER(0,0), Y, N, N, Y },
 102    { GLX(MESA_swap_frame_usage),       VER(0,0), Y, N, N, Y },
 103 #endif
 104    { GLX(NV_float_buffer),             VER(0,0), N, N, N, N },
 105    { GLX(NV_render_depth_texture),     VER(0,0), N, N, N, N },
 106    { GLX(NV_render_texture_rectangle), VER(0,0), N, N, N, N },
 107 #ifdef GLX_USE_APPLEGL
 108    { GLX(NV_vertex_array_range),       VER(0,0), N, N, N, N }, /* Deprecated */
 109    { GLX(OML_swap_method),             VER(0,0), N, N, N, N },
 110    { GLX(OML_sync_control),            VER(0,0), N, N, N, N },
 111    { GLX(SGI_make_current_read),       VER(1,3), N, N, N, N },
 112    { GLX(SGI_swap_control),            VER(0,0), N, N, N, N },
 113    { GLX(SGI_video_sync),              VER(0,0), N, N, N, N },
 114 #else
 115    { GLX(NV_vertex_array_range),       VER(0,0), N, N, N, Y }, /* Deprecated */
 116    { GLX(OML_swap_method),             VER(0,0), Y, Y, N, N },
 117    { GLX(OML_sync_control),            VER(0,0), Y, N, N, Y },
 118    { GLX(SGI_make_current_read),       VER(1,3), Y, N, N, N },
 119    { GLX(SGI_swap_control),            VER(0,0), Y, N, N, N },
 120    { GLX(SGI_video_sync),              VER(0,0), Y, N, N, Y },
 121 #endif
 122    { GLX(SGIS_blended_overlay),        VER(0,0), N, N, N, N },
 123    { GLX(SGIS_color_range),            VER(0,0), N, N, N, N },
 124 #ifdef GLX_USE_APPLEGL
 125    { GLX(SGIS_multisample),            VER(0,0), N, N, N, N },
 126 #else
 127    { GLX(SGIS_multisample),            VER(0,0), Y, Y, N, N },
 128 #endif
 129    { GLX(SGIX_fbconfig),               VER(1,3), Y, Y, N, N },
 130 #ifdef GLX_USE_APPLEGL
 131    { GLX(SGIX_pbuffer),                VER(1,3), N, N, N, N },
 132 #else
 133    { GLX(SGIX_pbuffer),                VER(1,3), Y, Y, N, N },
 134 #endif
 135    { GLX(SGIX_swap_barrier),           VER(0,0), N, N, N, N },
 136    { GLX(SGIX_swap_group),             VER(0,0), N, N, N, N },
 137 #ifdef GLX_USE_APPLEGL
 138    { GLX(SGIX_visual_select_group),    VER(0,0), N, N, N, N },
 139    { GLX(EXT_texture_from_pixmap),     VER(0,0), N, N, N, N },
 140 #else
 141    { GLX(SGIX_visual_select_group),    VER(0,0), Y, Y, N, N },
 142    { GLX(EXT_texture_from_pixmap),     VER(0,0), Y, N, N, N },
 143 #endif
 144    { GLX(INTEL_swap_event),            VER(1,4), Y, Y, N, N },
 145    { NULL }
 146 };
 147
 148 static const struct extension_info known_gl_extensions[] = {
 149    { GL(ARB_depth_texture),              VER(1,4), Y, N, N, N },
 150    { GL(ARB_draw_buffers),               VER(0,0), Y, N, N, N },
 151    { GL(ARB_fragment_program),           VER(0,0), Y, N, N, N },
 152    { GL(ARB_fragment_program_shadow),    VER(0,0), Y, N, N, N },
 153    { GL(ARB_framebuffer_object),         VER(0,0), Y, N, N, N },
 154    { GL(ARB_imaging),                    VER(0,0), Y, N, N, N },
 155    { GL(ARB_multisample),                VER(1,3), Y, N, N, N },
 156    { GL(ARB_multitexture),               VER(1,3), Y, N, N, N },
 157    { GL(ARB_occlusion_query),            VER(1,5), Y, N, N, N },
 158    { GL(ARB_point_parameters),           VER(1,4), Y, N, N, N },
 159    { GL(ARB_point_sprite),               VER(0,0), Y, N, N, N },
 160    { GL(ARB_shadow),                     VER(1,4), Y, N, N, N },
 161    { GL(ARB_shadow_ambient),             VER(0,0), Y, N, N, N },
 162    { GL(ARB_texture_border_clamp),       VER(1,3), Y, N, N, N },
 163    { GL(ARB_texture_compression),        VER(1,3), Y, N, N, N },
 164    { GL(ARB_texture_cube_map),           VER(1,3), Y, N, N, N },
 165    { GL(ARB_texture_env_add),            VER(1,3), Y, N, N, N },
 166    { GL(ARB_texture_env_combine),        VER(1,3), Y, N, N, N },
 167    { GL(ARB_texture_env_crossbar),       VER(1,4), Y, N, N, N },
 168    { GL(ARB_texture_env_dot3),           VER(1,3), Y, N, N, N },
 169    { GL(ARB_texture_mirrored_repeat),    VER(1,4), Y, N, N, N },
 170    { GL(ARB_texture_non_power_of_two),   VER(1,5), Y, N, N, N },
 171    { GL(ARB_texture_rectangle),          VER(0,0), Y, N, N, N },
 172    { GL(ARB_transpose_matrix),           VER(1,3), Y, N, Y, N },
 173    { GL(ARB_vertex_buffer_object),       VER(1,5), N, N, N, N },
 174    { GL(ARB_vertex_program),             VER(0,0), Y, N, N, N },
 175    { GL(ARB_window_pos),                 VER(1,4), Y, N, N, N },
 176    { GL(EXT_abgr),                       VER(0,0), Y, N, N, N },
 177    { GL(EXT_bgra),                       VER(1,2), Y, N, N, N },
 178    { GL(EXT_blend_color),                VER(1,4), Y, N, N, N },
 179    { GL(EXT_blend_equation_separate),    VER(0,0), Y, N, N, N },
 180    { GL(EXT_blend_func_separate),        VER(1,4), Y, N, N, N },
 181    { GL(EXT_blend_logic_op),             VER(1,4), Y, N, N, N },
 182    { GL(EXT_blend_minmax),               VER(1,4), Y, N, N, N },
 183    { GL(EXT_blend_subtract),             VER(1,4), Y, N, N, N },
 184    { GL(EXT_clip_volume_hint),           VER(0,0), Y, N, N, N },
 185    { GL(EXT_compiled_vertex_array),      VER(0,0), N, N, N, N },
 186    { GL(EXT_convolution),                VER(0,0), N, N, N, N },
 187    { GL(EXT_copy_texture),               VER(1,1), Y, N, N, N },
 188    { GL(EXT_cull_vertex),                VER(0,0), N, N, N, N },
 189    { GL(EXT_depth_bounds_test),          VER(0,0), N, N, N, N },
 190    { GL(EXT_draw_range_elements),        VER(1,2), Y, N, Y, N },
 191    { GL(EXT_fog_coord),                  VER(1,4), Y, N, N, N },
 192    { GL(EXT_framebuffer_blit),           VER(0,0), Y, N, N, N },
 193    { GL(EXT_framebuffer_multisample),    VER(0,0), Y, N, N, N },
 194    { GL(EXT_framebuffer_object),         VER(0,0), Y, N, N, N },
 195    { GL(EXT_multi_draw_arrays),          VER(1,4), Y, N, Y, N },
 196    { GL(EXT_packed_depth_stencil),       VER(0,0), Y, N, N, N },
 197    { GL(EXT_packed_pixels),              VER(1,2), Y, N, N, N },
 198    { GL(EXT_paletted_texture),           VER(0,0), Y, N, N, N },
 199    { GL(EXT_pixel_buffer_object),        VER(0,0), N, N, N, N },
 200    { GL(EXT_point_parameters),           VER(1,4), Y, N, N, N },
 201    { GL(EXT_polygon_offset),             VER(1,1), Y, N, N, N },
 202    { GL(EXT_rescale_normal),             VER(1,2), Y, N, N, N },
 203    { GL(EXT_secondary_color),            VER(1,4), Y, N, N, N },
 204    { GL(EXT_separate_specular_color),    VER(1,2), Y, N, N, N },
 205    { GL(EXT_shadow_funcs),               VER(1,5), Y, N, N, N },
 206    { GL(EXT_shared_texture_palette),     VER(0,0), Y, N, N, N },
 207    { GL(EXT_stencil_two_side),           VER(0,0), Y, N, N, N },
 208    { GL(EXT_stencil_wrap),               VER(1,4), Y, N, N, N },
 209    { GL(EXT_subtexture),                 VER(1,1), Y, N, N, N },
 210    { GL(EXT_texture),                    VER(1,1), Y, N, N, N },
 211    { GL(EXT_texture3D),                  VER(1,2), Y, N, N, N },
 212    { GL(EXT_texture_compression_dxt1),   VER(0,0), Y, N, N, N },
 213    { GL(EXT_texture_compression_s3tc),   VER(0,0), Y, N, N, N },
 214    { GL(EXT_texture_edge_clamp),         VER(1,2), Y, N, N, N },
 215    { GL(EXT_texture_env_add),            VER(1,3), Y, N, N, N },
 216    { GL(EXT_texture_env_combine),        VER(1,3), Y, N, N, N },
 217    { GL(EXT_texture_env_dot3),           VER(0,0), Y, N, N, N },
 218    { GL(EXT_texture_filter_anisotropic), VER(0,0), Y, N, N, N },
 219    { GL(EXT_texture_lod),                VER(1,2), Y, N, N, N },
 220    { GL(EXT_texture_lod_bias),           VER(1,4), Y, N, N, N },
 221    { GL(EXT_texture_mirror_clamp),       VER(0,0), Y, N, N, N },
 222    { GL(EXT_texture_object),             VER(1,1), Y, N, N, N },
 223    { GL(EXT_texture_rectangle),          VER(0,0), Y, N, N, N },
 224    { GL(EXT_vertex_array),               VER(0,0), Y, N, N, N },
 225    { GL(3DFX_texture_compression_FXT1),  VER(0,0), Y, N, N, N },
 226    { GL(APPLE_packed_pixels),            VER(1,2), Y, N, N, N },
 227    { GL(APPLE_ycbcr_422),                VER(0,0), Y, N, N, N },
 228    { GL(ATI_draw_buffers),               VER(0,0), Y, N, N, N },
 229    { GL(ATI_text_fragment_shader),       VER(0,0), Y, N, N, N },
 230    { GL(ATI_texture_env_combine3),       VER(0,0), Y, N, N, N },
 231    { GL(ATI_texture_float),              VER(0,0), Y, N, N, N },
 232    { GL(ATI_texture_mirror_once),        VER(0,0), Y, N, N, N },
 233    { GL(ATIX_texture_env_combine3),      VER(0,0), Y, N, N, N },
 234    { GL(HP_convolution_border_modes),    VER(0,0), Y, N, N, N },
 235    { GL(HP_occlusion_test),              VER(0,0), Y, N, N, N },
 236    { GL(IBM_cull_vertex),                VER(0,0), Y, N, N, N },
 237    { GL(IBM_pixel_filter_hint),          VER(0,0), Y, N, N, N },
 238    { GL(IBM_rasterpos_clip),             VER(0,0), Y, N, N, N },
 239    { GL(IBM_texture_clamp_nodraw),       VER(0,0), Y, N, N, N },
 240    { GL(IBM_texture_mirrored_repeat),    VER(0,0), Y, N, N, N },
 241    { GL(INGR_blend_func_separate),       VER(0,0), Y, N, N, N },
 242    { GL(INGR_interlace_read),            VER(0,0), Y, N, N, N },
 243    { GL(MESA_pack_invert),               VER(0,0), Y, N, N, N },
 244    { GL(MESA_ycbcr_texture),             VER(0,0), Y, N, N, N },
 245    { GL(NV_blend_square),                VER(1,4), Y, N, N, N },
 246    { GL(NV_copy_depth_to_color),         VER(0,0), Y, N, N, N },
 247    { GL(NV_depth_clamp),                 VER(0,0), Y, N, N, N },
 248    { GL(NV_fog_distance),                VER(0,0), Y, N, N, N },
 249    { GL(NV_fragment_program),            VER(0,0), Y, N, N, N },
 250    { GL(NV_fragment_program_option),     VER(0,0), Y, N, N, N },
 251    { GL(NV_fragment_program2),           VER(0,0), Y, N, N, N },
 252    { GL(NV_light_max_exponent),          VER(0,0), Y, N, N, N },
 253    { GL(NV_multisample_filter_hint),     VER(0,0), Y, N, N, N },
 254    { GL(NV_packed_depth_stencil),        VER(0,0), Y, N, N, N },
 255    { GL(NV_point_sprite),                VER(0,0), Y, N, N, N },
 256    { GL(NV_texgen_reflection),           VER(0,0), Y, N, N, N },
 257    { GL(NV_texture_compression_vtc),     VER(0,0), Y, N, N, N },
 258    { GL(NV_texture_env_combine4),        VER(0,0), Y, N, N, N },
 259    { GL(NV_texture_rectangle),           VER(0,0), Y, N, N, N },
 260    { GL(NV_vertex_program),              VER(0,0), Y, N, N, N },
 261    { GL(NV_vertex_program1_1),           VER(0,0), Y, N, N, N },
 262    { GL(NV_vertex_program2),             VER(0,0), Y, N, N, N },
 263    { GL(NV_vertex_program2_option),      VER(0,0), Y, N, N, N },
 264    { GL(NV_vertex_program3),             VER(0,0), Y, N, N, N },
 265    { GL(OES_read_format),                VER(0,0), Y, N, N, N },
 266    { GL(OES_compressed_paletted_texture),VER(0,0), Y, N, N, N },
 267    { GL(SGI_color_matrix),               VER(0,0), Y, N, N, N },
 268    { GL(SGI_color_table),                VER(0,0), Y, N, N, N },
 269    { GL(SGI_texture_color_table),        VER(0,0), Y, N, N, N },
 270    { GL(SGIS_generate_mipmap),           VER(1,4), Y, N, N, N },
 271    { GL(SGIS_multisample),               VER(0,0), Y, N, N, N },
 272    { GL(SGIS_texture_border_clamp),      VER(1,3), Y, N, N, N },
 273    { GL(SGIS_texture_edge_clamp),        VER(1,2), Y, N, N, N },
 274    { GL(SGIS_texture_lod),               VER(1,2), Y, N, N, N },
 275    { GL(SGIX_blend_alpha_minmax),        VER(0,0), Y, N, N, N },
 276    { GL(SGIX_clipmap),                   VER(0,0), Y, N, N, N },
 277    { GL(SGIX_depth_texture),             VER(0,0), Y, N, N, N },
 278    { GL(SGIX_fog_offset),                VER(0,0), Y, N, N, N },
 279    { GL(SGIX_shadow),                    VER(0,0), Y, N, N, N },
 280    { GL(SGIX_shadow_ambient),            VER(0,0), Y, N, N, N },
 281    { GL(SGIX_texture_coordinate_clamp),  VER(0,0), Y, N, N, N },
 282    { GL(SGIX_texture_lod_bias),          VER(0,0), Y, N, N, N },
 283    { GL(SGIX_texture_range),             VER(0,0), Y, N, N, N },
 284    { GL(SGIX_texture_scale_bias),        VER(0,0), Y, N, N, N },
 285    { GL(SGIX_vertex_preclip),            VER(0,0), Y, N, N, N },
 286    { GL(SGIX_vertex_preclip_hint),       VER(0,0), Y, N, N, N },
 287    { GL(SGIX_ycrcb),                     VER(0,0), Y, N, N, N },
 288    { GL(SUN_convolution_border_modes),   VER(0,0), Y, N, N, N },
 289    { GL(SUN_multi_draw_arrays),          VER(0,0), Y, N, Y, N },
 290    { GL(SUN_slice_accum),                VER(0,0), Y, N, N, N },
 291    { NULL }
 292 };
 293 /* *INDENT-ON* */
 294
 295
 296 /* global bit-fields of available extensions and their characteristics */
 297 static unsigned char client_glx_support[8];
 298 static unsigned char client_glx_only[8];
 299 static unsigned char direct_glx_only[8];
 300 static unsigned char client_gl_support[__GL_EXT_BYTES];
 301 static unsigned char client_gl_only[__GL_EXT_BYTES];
 302
 303 /**
 304  * Bits representing the set of extensions that are enabled by default in all
 305  * direct rendering drivers.
 306  */
 307 static unsigned char direct_glx_support[8];
 308
 309 /**
 310  * Highest core GL version that can be supported for indirect rendering.
 311  */
 312 static const unsigned gl_major = 1;
 313 static const unsigned gl_minor = 4;
 314
 315 /* client extensions string */
 316 static const char *__glXGLXClientExtensions = NULL;
 317
 318 static void __glXExtensionsCtr(void);
 319 static void __glXExtensionsCtrScreen(__GLXscreenConfigs * psc);
 320 static void __glXProcessServerString(const struct extension_info *ext,
 321                                      const char *server_string,
 322                                      unsigned char *server_support);
 323
 324 /**
 325  * Set the state of a GLX extension.
 326  *
 327  * \param name      Name of the extension.
 328  * \param name_len  Length, in characters, of the extension name.
 329  * \param state     New state (either enabled or disabled) of the extension.
 330  * \param supported Table in which the state of the extension is to be set.
 331  */
 332 static void
 333 set_glx_extension(const struct extension_info *ext,
 334                   const char *name, unsigned name_len, GLboolean state,
 335                   unsigned char *supported)
 336 {
 337    unsigned i;
 338
 339
 340    for (i = 0; ext[i].name != NULL; i++) {
 341       if ((name_len == ext[i].name_len)
 342           && (strncmp(ext[i].name, name, name_len) == 0)) {
 343          if (state) {
 344             SET_BIT(supported, ext[i].bit);
 345          }
 346          else {
 347             CLR_BIT(supported, ext[i].bit);
 348          }
 349
 350          return;
 351       }
 352    }
 353 }
 354
 355
 356 #define NUL '\0'
 357 #define SEPARATOR ' '
 358
 359 /**
 360  * Convert the server's extension string to a bit-field.
 361  *
 362  * \param server_string   GLX extension string from the server.
 363  * \param server_support  Bit-field of supported extensions.
 364  *
 365  * \note
 366  * This function is used to process both GLX and GL extension strings.  The
 367  * bit-fields used to track each of these have different sizes.  Therefore,
 368  * the data pointed by \c server_support must be preinitialized to zero.
 369  */
 370 static void
 371 __glXProcessServerString(const struct extension_info *ext,
 372                          const char *server_string,
 373                          unsigned char *server_support)
 374 {
 375    unsigned base;
 376    unsigned len;
 377
 378    for (base = 0; server_string[base] != NUL; /* empty */ ) {
 379       /* Determine the length of the next extension name.
 380        */
 381       for (len = 0; (server_string[base + len] != SEPARATOR)
 382            && (server_string[base + len] != NUL); len++) {
 383          /* empty */
 384       }
 385
 386       /* Set the bit for the extension in the server_support table.
 387        */
 388       set_glx_extension(ext, &server_string[base], len, GL_TRUE,
 389                         server_support);
 390
 391
 392       /* Advance to the next extension string.  This means that we skip
 393        * over the previous string and any trialing white-space.
 394        */
 395       for (base += len; (server_string[base] == SEPARATOR)
 396            && (server_string[base] != NUL); base++) {
 397          /* empty */
 398       }
 399    }
 400 }
 401
 402 void
 403 __glXEnableDirectExtension(__GLXscreenConfigs * psc, const char *name)
 404 {
 405    __glXExtensionsCtr();
 406    __glXExtensionsCtrScreen(psc);
 407
 408    set_glx_extension(known_glx_extensions,
 409                      name, strlen(name), GL_TRUE, psc->direct_support);
 410 }
 411
 412 /**
 413  * Initialize global extension support tables.
 414  */
 415
 416 static void
 417 __glXExtensionsCtr(void)
 418 {
 419    unsigned i;
 420    static GLboolean ext_list_first_time = GL_TRUE;
 421
 422
 423    if (ext_list_first_time) {
 424       ext_list_first_time = GL_FALSE;
 425
 426       (void) memset(client_glx_support, 0, sizeof(client_glx_support));
 427       (void) memset(direct_glx_support, 0, sizeof(direct_glx_support));
 428       (void) memset(client_glx_only, 0, sizeof(client_glx_only));
 429       (void) memset(direct_glx_only, 0, sizeof(direct_glx_only));
 430
 431       (void) memset(client_gl_support, 0, sizeof(client_gl_support));
 432       (void) memset(client_gl_only, 0, sizeof(client_gl_only));
 433
 434       for (i = 0; known_glx_extensions[i].name != NULL; i++) {
 435          const unsigned bit = known_glx_extensions[i].bit;
 436
 437          if (known_glx_extensions[i].client_support) {
 438             SET_BIT(client_glx_support, bit);
 439          }
 440
 441          if (known_glx_extensions[i].direct_support) {
 442             SET_BIT(direct_glx_support, bit);
 443          }
 444
 445          if (known_glx_extensions[i].client_only) {
 446             SET_BIT(client_glx_only, bit);
 447          }
 448
 449          if (known_glx_extensions[i].direct_only) {
 450             SET_BIT(direct_glx_only, bit);
 451          }
 452       }
 453
 454       for (i = 0; known_gl_extensions[i].name != NULL; i++) {
 455          const unsigned bit = known_gl_extensions[i].bit;
 456
 457          if (known_gl_extensions[i].client_support) {
 458             SET_BIT(client_gl_support, bit);
 459          }
 460
 461          if (known_gl_extensions[i].client_only) {
 462             SET_BIT(client_gl_only, bit);
 463          }
 464       }
 465
 466 #if 0
 467       fprintf(stderr, "[%s:%u] Maximum client library version: %u.%u\n",
 468               __func__, __LINE__, gl_major, gl_minor);
 469 #endif
 470    }
 471 }
 472
 473
 474 /**
 475  * Make sure that per-screen direct-support table is initialized.
 476  *
 477  * \param psc  Pointer to GLX per-screen record.
 478  */
 479
 480 static void
 481 __glXExtensionsCtrScreen(__GLXscreenConfigs * psc)
 482 {
 483    if (psc->ext_list_first_time) {
 484       psc->ext_list_first_time = GL_FALSE;
 485       (void) memcpy(psc->direct_support, direct_glx_support,
 486                     sizeof(direct_glx_support));
 487    }
 488 }
 489
 490
 491 /**
 492  * Check if a certain extension is enabled on a given screen.
 493  *
 494  * \param psc  Pointer to GLX per-screen record.
 495  * \param bit  Bit index in the direct-support table.
 496  * \returns If the extension bit is enabled for the screen, \c GL_TRUE is
 497  *          returned.  If the extension bit is not enabled or if \c psc is
 498  *          \c NULL, then \c GL_FALSE is returned.
 499  */
 500 GLboolean
 501 __glXExtensionBitIsEnabled(__GLXscreenConfigs * psc, unsigned bit)
 502 {
 503    GLboolean enabled = GL_FALSE;
 504
 505    if (psc != NULL) {
 506       __glXExtensionsCtr();
 507       __glXExtensionsCtrScreen(psc);
 508       enabled = EXT_ENABLED(bit, psc->direct_support);
 509    }
 510
 511    return enabled;
 512 }
 513
 514
 515 /**
 516  * Check if a certain extension is enabled in a given context.
 517  *
 518  */
 519 GLboolean
 520 __glExtensionBitIsEnabled(const __GLXcontext * gc, unsigned bit)
 521 {
 522    GLboolean enabled = GL_FALSE;
 523
 524    if (gc != NULL) {
 525       enabled = EXT_ENABLED(bit, gc->gl_extension_bits);
 526    }
 527
 528    return enabled;
 529 }
 530
 531
 532
 533 /**
 534  * Convert a bit-field to a string of supported extensions.
 535  */
 536 static char *
 537 __glXGetStringFromTable(const struct extension_info *ext,
 538                         const unsigned char *supported)
 539 {
 540    unsigned i;
 541    unsigned ext_str_len;
 542    char *ext_str;
 543    char *point;
 544
 545
 546    ext_str_len = 0;
 547    for (i = 0; ext[i].name != NULL; i++) {
 548       if (EXT_ENABLED(ext[i].bit, supported)) {
 549          ext_str_len += ext[i].name_len + 1;
 550       }
 551    }
 552
 553    ext_str = Xmalloc(ext_str_len + 1);
 554    if (ext_str != NULL) {
 555       point = ext_str;
 556
 557       for (i = 0; ext[i].name != NULL; i++) {
 558          if (EXT_ENABLED(ext[i].bit, supported)) {
 559             (void) memcpy(point, ext[i].name, ext[i].name_len);
 560             point += ext[i].name_len;
 561
 562             *point = ' ';
 563             point++;
 564          }
 565       }
 566
 567       *point = '\0';
 568    }
 569
 570    return ext_str;
 571 }
 572
 573
 574 /**
 575  * Get the string of client library supported extensions.
 576  */
 577 const char *
 578 __glXGetClientExtensions(void)
 579 {
 580    if (__glXGLXClientExtensions == NULL) {
 581       __glXExtensionsCtr();
 582       __glXGLXClientExtensions = __glXGetStringFromTable(known_glx_extensions,
 583                                                          client_glx_support);
 584    }
 585
 586    return __glXGLXClientExtensions;
 587 }
 588
 589
 590 /**
 591  * Calculate the list of application usable extensions.  The resulting
 592  * string is stored in \c psc->effectiveGLXexts.
 593  *
 594  * \param psc                        Pointer to GLX per-screen record.
 595  * \param display_is_direct_capable  True if the display is capable of
 596  *                                   direct rendering.
 597  * \param minor_version              GLX minor version from the server.
 598  */
 599
 600 void
 601 __glXCalculateUsableExtensions(__GLXscreenConfigs * psc,
 602                                GLboolean display_is_direct_capable,
 603                                int minor_version)
 604 {
 605    unsigned char server_support[8];
 606    unsigned char usable[8];
 607    unsigned i;
 608
 609    __glXExtensionsCtr();
 610    __glXExtensionsCtrScreen(psc);
 611
 612    (void) memset(server_support, 0, sizeof(server_support));
 613    __glXProcessServerString(known_glx_extensions,
 614                             psc->serverGLXexts, server_support);
 615
 616
 617    /* This is a hack.  Some servers support GLX 1.3 but don't export
 618     * all of the extensions implied by GLX 1.3.  If the server claims
 619     * support for GLX 1.3, enable support for the extensions that can be
 620     * "emulated" as well.
 621     */
 622
 623    if (minor_version >= 3) {
 624       SET_BIT(server_support, EXT_visual_info_bit);
 625       SET_BIT(server_support, EXT_visual_rating_bit);
 626       SET_BIT(server_support, SGI_make_current_read_bit);
 627       SET_BIT(server_support, SGIX_fbconfig_bit);
 628       SET_BIT(server_support, SGIX_pbuffer_bit);
 629
 630       /* This one is a little iffy.  GLX 1.3 doesn't incorporate all of this
 631        * extension.  However, the only part that is not strictly client-side
 632        * is shared.  That's the glXQueryContext / glXQueryContextInfoEXT
 633        * function.
 634        */
 635
 636       SET_BIT(server_support, EXT_import_context_bit);
 637    }
 638
 639
 640    /* An extension is supported if the client-side (i.e., libGL) supports
 641     * it and the "server" supports it.  In this case that means that either
 642     * the true server supports it or it is only for direct-rendering and
 643     * the direct rendering driver supports it.
 644     *
 645     * If the display is not capable of direct rendering, then the extension
 646     * is enabled if and only if the client-side library and the server
 647     * support it.
 648     */
 649
 650    if (display_is_direct_capable) {
 651       for (i = 0; i < 8; i++) {
 652          usable[i] = (client_glx_support[i] & client_glx_only[i])
 653             | (client_glx_support[i] & psc->direct_support[i] &
 654                server_support[i])
 655             | (client_glx_support[i] & psc->direct_support[i] &
 656                direct_glx_only[i]);
 657       }
 658    }
 659    else {
 660       for (i = 0; i < 8; i++) {
 661          usable[i] = (client_glx_support[i] & client_glx_only[i])
 662             | (client_glx_support[i] & server_support[i]);
 663       }
 664    }
 665
 666    psc->effectiveGLXexts = __glXGetStringFromTable(known_glx_extensions,
 667                                                    usable);
 668 }
 669
 670
 671 /**
 672  * Calculate the list of application usable extensions.  The resulting
 673  * string is stored in \c gc->extensions.
 674  *
 675  * \param gc             Pointer to GLX context.
 676  * \param server_string  Extension string from the server.
 677  * \param major_version  GL major version from the server.
 678  * \param minor_version  GL minor version from the server.
 679  */
 680
 681 void
 682 __glXCalculateUsableGLExtensions(__GLXcontext * gc,
 683                                  const char *server_string,
 684                                  int major_version, int minor_version)
 685 {
 686    unsigned char server_support[__GL_EXT_BYTES];
 687    unsigned char usable[__GL_EXT_BYTES];
 688    unsigned i;
 689
 690
 691    __glXExtensionsCtr();
 692
 693    (void) memset(server_support, 0, sizeof(server_support));
 694    __glXProcessServerString(known_gl_extensions, server_string,
 695                             server_support);
 696
 697
 698    /* Handle lazy servers that don't export all the extensions strings that
 699     * are part of the GL core version that they support.
 700     */
 701
 702    for (i = 0; i < __GL_EXT_BYTES; i++) {
 703       if ((known_gl_extensions[i].version_major != 0)
 704           && ((major_version > known_gl_extensions[i].version_major)
 705               || ((major_version == known_gl_extensions[i].version_major)
 706                   && (minor_version >=
 707                       known_gl_extensions[i].version_minor)))) {
 708          SET_BIT(server_support, known_gl_extensions[i].bit);
 709       }
 710    }
 711
 712
 713    /* An extension is supported if the client-side (i.e., libGL) supports
 714     * it and the server supports it or the client-side library supports it
 715     * and it only needs client-side support.
 716     */
 717
 718    for (i = 0; i < __GL_EXT_BYTES; i++) {
 719       usable[i] = (client_gl_support[i] & client_gl_only[i])
 720          | (client_gl_support[i] & server_support[i]);
 721    }
 722
 723    gc->extensions = (unsigned char *)
 724       __glXGetStringFromTable(known_gl_extensions, usable);
 725    (void) memcpy(gc->gl_extension_bits, usable, sizeof(usable));
 726 }
 727
 728
 729 /**
 730  * Calculates the maximum core GL version that can be supported for indirect
 731  * rendering.
 732  */
 733 void
 734 __glXGetGLVersion(int *major_version, int *minor_version)
 735 {
 736    __glXExtensionsCtr();
 737    *major_version = gl_major;
 738    *minor_version = gl_minor;
 739 }
 740
 741
 742 /**
 743  * Get a string representing the set of extensions supported by the client
 744  * library.  This is currently only used to send the list of extensions
 745  * supported by the client to the server.
 746  */
 747 char *
 748 __glXGetClientGLExtensionString(void)
 749 {
 750    __glXExtensionsCtr();
 751    return __glXGetStringFromTable(known_gl_extensions, client_gl_support);
 752 }