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
  65    /**
  66     * The client (i.e., libGL) supports this extension.
  67     *
  68     * Except during bring up, all extensions should have this set to Y.  There
  69     * are a few cases of extensions that have partial (or speculative)
  70     * support, but these are rare.  There also shouldn't be any new ones
  71     * added.
  72     *
  73     * Generally, extensions require server support and ::client_support to be
  74     * enabled.  If the display is capable of direct rendering,
  75     * ::direct_support is also required.
  76     *
  77     * \sa ::client_only
  78     */
  79    unsigned char client_support;
  80
  81    /**
  82     * The direct-renderer (e.g., i965_dri.so) supports this extension.
  83     *
  84     * For cases where all of the infrastructure to support the extension is a
  85     * required part of the loader/driver interface, this can default to Y.
  86     * For most cases, extended functionality, usually in the form of DRI2
  87     * extensions, is necessary to support the extension.  The loader will set
  88     * the flag true if all the requirements are met.
  89     *
  90     * If the display is capable of direct rendering, ::direct_support is
  91     * required for the extension to be enabled.
  92     */
  93    unsigned char direct_support;
  94
  95    /**
  96     * The extension depends only on client support.
  97     *
  98     * This is for extensions like GLX_ARB_get_proc_address that are contained
  99     * entirely in the client library.  There is no dependency on the server or
 100     * the direct-renderer.
 101     *
 102     * These extensions will be enabled if ::client_support is set.
 103     *
 104     * \note
 105     * An extension \b cannot be both client-only and direct-only because being
 106     * direct-only implies a dependency on the direct renderer.
 107     *
 108     * \sa ::client_support, ::direct_only
 109     */
 110    unsigned char client_only;
 111
 112    /**
 113     * The extension only functions with direct-rendering contexts
 114     *
 115     * The extension has no GLX protocol, and, therefore, no explicit
 116     * dependency on the server.  The functionality is contained entirely in
 117     * the client library and the direct renderer.  A few of the swap-related
 118     * extensions are intended to behave this way.
 119     *
 120     * These extensions will be enabled if both ::client_support and
 121     * ::direct_support are set.
 122     *
 123     * \note
 124     * An extension \b cannot be both client-only and direct-only because being
 125     * client-only implies that all functionality is outside the
 126     * direct-renderer.
 127     *
 128     * \sa ::direct_support, ::client_only
 129     */
 130    unsigned char direct_only;
 131 };
 132
 133 /* *INDENT-OFF* */
 134 static const struct extension_info known_glx_extensions[] = {
 135    { GLX(ARB_create_context),          VER(0,0), Y, N, N, N },
 136    { GLX(ARB_create_context_profile),  VER(0,0), Y, N, N, N },
 137    { GLX(ARB_create_context_robustness), VER(0,0), Y, N, N, N },
 138    { GLX(ARB_fbconfig_float),          VER(0,0), Y, Y, N, N },
 139    { GLX(ARB_framebuffer_sRGB),        VER(0,0), Y, Y, N, N },
 140    { GLX(ARB_get_proc_address),        VER(1,4), Y, N, Y, N },
 141    { GLX(ARB_multisample),             VER(1,4), Y, Y, N, N },
 142    { GLX(ATI_pixel_format_float),      VER(0,0), N, N, N, N },
 143    { GLX(EXT_import_context),          VER(0,0), Y, Y, N, N },
 144    { GLX(EXT_visual_info),             VER(0,0), Y, Y, N, N },
 145    { GLX(EXT_visual_rating),           VER(0,0), Y, Y, N, N },
 146    { GLX(EXT_fbconfig_packed_float),   VER(0,0), Y, Y, N, N },
 147    { GLX(EXT_framebuffer_sRGB),        VER(0,0), Y, Y, N, N },
 148    { GLX(EXT_create_context_es2_profile), VER(0,0), Y, N, N, N },
 149    { GLX(EXT_create_context_es_profile), VER(0,0), Y, N, N, N },
 150    { GLX(MESA_copy_sub_buffer),        VER(0,0), Y, N, N, N },
 151    { GLX(MESA_multithread_makecurrent),VER(0,0), Y, N, Y, N },
 152    { GLX(MESA_query_renderer),         VER(0,0), Y, N, N, Y },
 153    { GLX(MESA_swap_control),           VER(0,0), Y, N, N, Y },
 154    { GLX(NV_float_buffer),             VER(0,0), N, N, N, N },
 155    { GLX(OML_swap_method),             VER(0,0), Y, Y, N, N },
 156    { GLX(OML_sync_control),            VER(0,0), Y, N, N, Y },
 157    { GLX(SGI_make_current_read),       VER(1,3), Y, N, N, N },
 158    { GLX(SGI_swap_control),            VER(0,0), Y, N, N, N },
 159    { GLX(SGI_video_sync),              VER(0,0), Y, N, N, Y },
 160    { GLX(SGIS_multisample),            VER(0,0), Y, Y, N, N },
 161    { GLX(SGIX_fbconfig),               VER(1,3), Y, Y, N, N },
 162    { GLX(SGIX_pbuffer),                VER(1,3), Y, Y, N, N },
 163    { GLX(SGIX_swap_barrier),           VER(0,0), N, N, N, N },
 164    { GLX(SGIX_swap_group),             VER(0,0), N, N, N, N },
 165    { GLX(SGIX_visual_select_group),    VER(0,0), Y, Y, N, N },
 166    { GLX(EXT_texture_from_pixmap),     VER(0,0), Y, N, N, N },
 167    { GLX(INTEL_swap_event),            VER(0,0), Y, N, N, N },
 168    { GLX(EXT_buffer_age),              VER(0,0), Y, N, N, Y },
 169    { NULL }
 170 };
 171
 172 static const struct extension_info known_gl_extensions[] = {
 173    { GL(ARB_depth_texture),              VER(1,4), Y, N, N, N },
 174    { GL(ARB_draw_buffers),               VER(0,0), Y, N, N, N },
 175    { GL(ARB_fragment_program),           VER(0,0), Y, N, N, N },
 176    { GL(ARB_fragment_program_shadow),    VER(0,0), Y, N, N, N },
 177    { GL(ARB_framebuffer_object),         VER(0,0), Y, N, N, N },
 178    { GL(ARB_imaging),                    VER(0,0), Y, N, N, N },
 179    { GL(ARB_multisample),                VER(1,3), Y, N, N, N },
 180    { GL(ARB_multitexture),               VER(1,3), Y, N, N, N },
 181    { GL(ARB_occlusion_query),            VER(1,5), Y, N, N, N },
 182    { GL(ARB_point_parameters),           VER(1,4), Y, N, N, N },
 183    { GL(ARB_point_sprite),               VER(0,0), Y, N, N, N },
 184    { GL(ARB_shadow),                     VER(1,4), Y, N, N, N },
 185    { GL(ARB_shadow_ambient),             VER(0,0), Y, N, N, N },
 186    { GL(ARB_texture_border_clamp),       VER(1,3), Y, N, N, N },
 187    { GL(ARB_texture_compression),        VER(1,3), Y, N, N, N },
 188    { GL(ARB_texture_cube_map),           VER(1,3), Y, N, N, N },
 189    { GL(ARB_texture_env_add),            VER(1,3), Y, N, N, N },
 190    { GL(ARB_texture_env_combine),        VER(1,3), Y, N, N, N },
 191    { GL(ARB_texture_env_crossbar),       VER(1,4), Y, N, N, N },
 192    { GL(ARB_texture_env_dot3),           VER(1,3), Y, N, N, N },
 193    { GL(ARB_texture_mirrored_repeat),    VER(1,4), Y, N, N, N },
 194    { GL(ARB_texture_non_power_of_two),   VER(1,5), Y, N, N, N },
 195    { GL(ARB_texture_rectangle),          VER(0,0), Y, N, N, N },
 196    { GL(ARB_texture_rg),                 VER(0,0), Y, N, N, N },
 197    { GL(ARB_transpose_matrix),           VER(1,3), Y, N, Y, N },
 198    { GL(ARB_vertex_buffer_object),       VER(1,5), N, N, N, N },
 199    { GL(ARB_vertex_program),             VER(0,0), Y, N, N, N },
 200    { GL(ARB_window_pos),                 VER(1,4), Y, N, N, N },
 201    { GL(EXT_abgr),                       VER(0,0), Y, N, N, N },
 202    { GL(EXT_bgra),                       VER(1,2), Y, N, N, N },
 203    { GL(EXT_blend_color),                VER(1,4), Y, N, N, N },
 204    { GL(EXT_blend_equation_separate),    VER(0,0), Y, N, N, N },
 205    { GL(EXT_blend_func_separate),        VER(1,4), Y, N, N, N },
 206    { GL(EXT_blend_logic_op),             VER(1,4), Y, N, N, N },
 207    { GL(EXT_blend_minmax),               VER(1,4), Y, N, N, N },
 208    { GL(EXT_blend_subtract),             VER(1,4), Y, N, N, N },
 209    { GL(EXT_clip_volume_hint),           VER(0,0), Y, N, N, N },
 210    { GL(EXT_compiled_vertex_array),      VER(0,0), N, N, N, N },
 211    { GL(EXT_convolution),                VER(0,0), N, N, N, N },
 212    { GL(EXT_copy_texture),               VER(1,1), Y, N, N, N },
 213    { GL(EXT_cull_vertex),                VER(0,0), N, N, N, N },
 214    { GL(EXT_depth_bounds_test),          VER(0,0), N, N, N, N },
 215    { GL(EXT_draw_range_elements),        VER(1,2), Y, N, Y, N },
 216    { GL(EXT_fog_coord),                  VER(1,4), Y, N, N, N },
 217    { GL(EXT_framebuffer_blit),           VER(0,0), Y, N, N, N },
 218    { GL(EXT_framebuffer_multisample),    VER(0,0), Y, N, N, N },
 219    { GL(EXT_framebuffer_object),         VER(0,0), Y, N, N, N },
 220    { GL(EXT_framebuffer_sRGB),           VER(0,0), Y, N, N, N },
 221    { GL(EXT_multi_draw_arrays),          VER(1,4), Y, N, Y, N },
 222    { GL(EXT_packed_depth_stencil),       VER(0,0), Y, N, N, N },
 223    { GL(EXT_packed_pixels),              VER(1,2), Y, N, N, N },
 224    { GL(EXT_paletted_texture),           VER(0,0), Y, N, N, N },
 225    { GL(EXT_pixel_buffer_object),        VER(0,0), N, N, N, N },
 226    { GL(EXT_point_parameters),           VER(1,4), Y, N, N, N },
 227    { GL(EXT_polygon_offset),             VER(1,1), Y, N, N, N },
 228    { GL(EXT_rescale_normal),             VER(1,2), Y, N, N, N },
 229    { GL(EXT_secondary_color),            VER(1,4), Y, N, N, N },
 230    { GL(EXT_separate_specular_color),    VER(1,2), Y, N, N, N },
 231    { GL(EXT_shadow_funcs),               VER(1,5), Y, N, N, N },
 232    { GL(EXT_shared_texture_palette),     VER(0,0), Y, N, N, N },
 233    { GL(EXT_stencil_two_side),           VER(0,0), Y, N, N, N },
 234    { GL(EXT_stencil_wrap),               VER(1,4), Y, N, N, N },
 235    { GL(EXT_subtexture),                 VER(1,1), Y, N, N, N },
 236    { GL(EXT_texture),                    VER(1,1), Y, N, N, N },
 237    { GL(EXT_texture3D),                  VER(1,2), Y, N, N, N },
 238    { GL(EXT_texture_compression_dxt1),   VER(0,0), Y, N, N, N },
 239    { GL(EXT_texture_compression_s3tc),   VER(0,0), Y, N, N, N },
 240    { GL(EXT_texture_edge_clamp),         VER(1,2), Y, N, N, N },
 241    { GL(EXT_texture_env_add),            VER(1,3), Y, N, N, N },
 242    { GL(EXT_texture_env_combine),        VER(1,3), Y, N, N, N },
 243    { GL(EXT_texture_env_dot3),           VER(0,0), Y, N, N, N },
 244    { GL(EXT_texture_filter_anisotropic), VER(0,0), Y, N, N, N },
 245    { GL(EXT_texture_integer),            VER(0,0), Y, N, N, N },
 246    { GL(EXT_texture_lod),                VER(1,2), Y, N, N, N },
 247    { GL(EXT_texture_lod_bias),           VER(1,4), Y, N, N, N },
 248    { GL(EXT_texture_mirror_clamp),       VER(0,0), Y, N, N, N },
 249    { GL(EXT_texture_object),             VER(1,1), Y, N, N, N },
 250    { GL(EXT_texture_rectangle),          VER(0,0), Y, N, N, N },
 251    { GL(EXT_vertex_array),               VER(0,0), Y, N, N, N },
 252    { GL(3DFX_texture_compression_FXT1),  VER(0,0), Y, N, N, N },
 253    { GL(APPLE_packed_pixels),            VER(1,2), Y, N, N, N },
 254    { GL(APPLE_ycbcr_422),                VER(0,0), Y, N, N, N },
 255    { GL(ATI_draw_buffers),               VER(0,0), Y, N, N, N },
 256    { GL(ATI_text_fragment_shader),       VER(0,0), Y, N, N, N },
 257    { GL(ATI_texture_env_combine3),       VER(0,0), Y, N, N, N },
 258    { GL(ATI_texture_float),              VER(0,0), Y, N, N, N },
 259    { GL(ATI_texture_mirror_once),        VER(0,0), Y, N, N, N },
 260    { GL(ATIX_texture_env_combine3),      VER(0,0), Y, N, N, N },
 261    { GL(HP_convolution_border_modes),    VER(0,0), Y, N, N, N },
 262    { GL(HP_occlusion_test),              VER(0,0), Y, N, N, N },
 263    { GL(IBM_cull_vertex),                VER(0,0), Y, N, N, N },
 264    { GL(IBM_pixel_filter_hint),          VER(0,0), Y, N, N, N },
 265    { GL(IBM_rasterpos_clip),             VER(0,0), Y, N, N, N },
 266    { GL(IBM_texture_clamp_nodraw),       VER(0,0), Y, N, N, N },
 267    { GL(IBM_texture_mirrored_repeat),    VER(0,0), Y, N, N, N },
 268    { GL(INGR_blend_func_separate),       VER(0,0), Y, N, N, N },
 269    { GL(INGR_interlace_read),            VER(0,0), Y, N, N, N },
 270    { GL(MESA_pack_invert),               VER(0,0), Y, N, N, N },
 271    { GL(MESA_ycbcr_texture),             VER(0,0), Y, N, N, N },
 272    { GL(NV_blend_square),                VER(1,4), Y, N, N, N },
 273    { GL(NV_copy_depth_to_color),         VER(0,0), Y, N, N, N },
 274    { GL(NV_depth_clamp),                 VER(0,0), Y, N, N, N },
 275    { GL(NV_fog_distance),                VER(0,0), Y, N, N, N },
 276    { GL(NV_fragment_program),            VER(0,0), Y, N, N, N },
 277    { GL(NV_fragment_program_option),     VER(0,0), Y, N, N, N },
 278    { GL(NV_fragment_program2),           VER(0,0), Y, N, N, N },
 279    { GL(NV_light_max_exponent),          VER(0,0), Y, N, N, N },
 280    { GL(NV_multisample_filter_hint),     VER(0,0), Y, N, N, N },
 281    { GL(NV_packed_depth_stencil),        VER(0,0), Y, N, N, N },
 282    { GL(NV_point_sprite),                VER(0,0), Y, N, N, N },
 283    { GL(NV_texgen_reflection),           VER(0,0), Y, N, N, N },
 284    { GL(NV_texture_compression_vtc),     VER(0,0), Y, N, N, N },
 285    { GL(NV_texture_env_combine4),        VER(0,0), Y, N, N, N },
 286    { GL(NV_texture_rectangle),           VER(0,0), Y, N, N, N },
 287    { GL(NV_vertex_program),              VER(0,0), Y, N, N, N },
 288    { GL(NV_vertex_program1_1),           VER(0,0), Y, N, N, N },
 289    { GL(NV_vertex_program2),             VER(0,0), Y, N, N, N },
 290    { GL(NV_vertex_program2_option),      VER(0,0), Y, N, N, N },
 291    { GL(NV_vertex_program3),             VER(0,0), Y, N, N, N },
 292    { GL(OES_read_format),                VER(0,0), Y, N, N, N },
 293    { GL(OES_compressed_paletted_texture),VER(0,0), Y, N, N, N },
 294    { GL(SGI_color_matrix),               VER(0,0), Y, N, N, N },
 295    { GL(SGI_color_table),                VER(0,0), Y, N, N, N },
 296    { GL(SGI_texture_color_table),        VER(0,0), Y, N, N, N },
 297    { GL(SGIS_generate_mipmap),           VER(1,4), Y, N, N, N },
 298    { GL(SGIS_multisample),               VER(0,0), Y, N, N, N },
 299    { GL(SGIS_texture_border_clamp),      VER(1,3), Y, N, N, N },
 300    { GL(SGIS_texture_edge_clamp),        VER(1,2), Y, N, N, N },
 301    { GL(SGIS_texture_lod),               VER(1,2), Y, N, N, N },
 302    { GL(SGIX_blend_alpha_minmax),        VER(0,0), Y, N, N, N },
 303    { GL(SGIX_clipmap),                   VER(0,0), Y, N, N, N },
 304    { GL(SGIX_depth_texture),             VER(0,0), Y, N, N, N },
 305    { GL(SGIX_fog_offset),                VER(0,0), Y, N, N, N },
 306    { GL(SGIX_shadow),                    VER(0,0), Y, N, N, N },
 307    { GL(SGIX_shadow_ambient),            VER(0,0), Y, N, N, N },
 308    { GL(SGIX_texture_coordinate_clamp),  VER(0,0), Y, N, N, N },
 309    { GL(SGIX_texture_lod_bias),          VER(0,0), Y, N, N, N },
 310    { GL(SGIX_texture_range),             VER(0,0), Y, N, N, N },
 311    { GL(SGIX_texture_scale_bias),        VER(0,0), Y, N, N, N },
 312    { GL(SGIX_vertex_preclip),            VER(0,0), Y, N, N, N },
 313    { GL(SGIX_vertex_preclip_hint),       VER(0,0), Y, N, N, N },
 314    { GL(SGIX_ycrcb),                     VER(0,0), Y, N, N, N },
 315    { GL(SUN_convolution_border_modes),   VER(0,0), Y, N, N, N },
 316    { GL(SUN_multi_draw_arrays),          VER(0,0), Y, N, Y, N },
 317    { GL(SUN_slice_accum),                VER(0,0), Y, N, N, N },
 318    { NULL }
 319 };
 320 /* *INDENT-ON* */
 321
 322
 323 /* global bit-fields of available extensions and their characteristics */
 324 static unsigned char client_glx_support[8];
 325 static unsigned char client_glx_only[8];
 326 static unsigned char direct_glx_only[8];
 327 static unsigned char client_gl_support[__GL_EXT_BYTES];
 328 static unsigned char client_gl_only[__GL_EXT_BYTES];
 329
 330 /**
 331  * Bits representing the set of extensions that are enabled by default in all
 332  * direct rendering drivers.
 333  */
 334 static unsigned char direct_glx_support[8];
 335
 336 /**
 337  * Highest core GL version that can be supported for indirect rendering.
 338  */
 339 static const unsigned gl_major = 1;
 340 static const unsigned gl_minor = 4;
 341
 342 /* client extensions string */
 343 static const char *__glXGLXClientExtensions = NULL;
 344
 345 static void __glXExtensionsCtr(void);
 346 static void __glXExtensionsCtrScreen(struct glx_screen * psc);
 347 static void __glXProcessServerString(const struct extension_info *ext,
 348                                      const char *server_string,
 349                                      unsigned char *server_support);
 350
 351 /**
 352  * Set the state of a GLX extension.
 353  *
 354  * \param name      Name of the extension.
 355  * \param name_len  Length, in characters, of the extension name.
 356  * \param state     New state (either enabled or disabled) of the extension.
 357  * \param supported Table in which the state of the extension is to be set.
 358  */
 359 static void
 360 set_glx_extension(const struct extension_info *ext,
 361                   const char *name, unsigned name_len, GLboolean state,
 362                   unsigned char *supported)
 363 {
 364    unsigned i;
 365
 366
 367    for (i = 0; ext[i].name != NULL; i++) {
 368       if ((name_len == ext[i].name_len)
 369           && (strncmp(ext[i].name, name, name_len) == 0)) {
 370          if (state) {
 371             SET_BIT(supported, ext[i].bit);
 372          }
 373          else {
 374             CLR_BIT(supported, ext[i].bit);
 375          }
 376
 377          return;
 378       }
 379    }
 380 }
 381
 382
 383 #define NUL '\0'
 384 #define SEPARATOR ' '
 385
 386 /**
 387  * Convert the server's extension string to a bit-field.
 388  *
 389  * \param server_string   GLX extension string from the server.
 390  * \param server_support  Bit-field of supported extensions.
 391  *
 392  * \note
 393  * This function is used to process both GLX and GL extension strings.  The
 394  * bit-fields used to track each of these have different sizes.  Therefore,
 395  * the data pointed by \c server_support must be preinitialized to zero.
 396  */
 397 static void
 398 __glXProcessServerString(const struct extension_info *ext,
 399                          const char *server_string,
 400                          unsigned char *server_support)
 401 {
 402    unsigned base;
 403    unsigned len;
 404
 405    for (base = 0; server_string[base] != NUL; /* empty */ ) {
 406       /* Determine the length of the next extension name.
 407        */
 408       for (len = 0; (server_string[base + len] != SEPARATOR)
 409            && (server_string[base + len] != NUL); len++) {
 410          /* empty */
 411       }
 412
 413       /* Set the bit for the extension in the server_support table.
 414        */
 415       set_glx_extension(ext, &server_string[base], len, GL_TRUE,
 416                         server_support);
 417
 418
 419       /* Advance to the next extension string.  This means that we skip
 420        * over the previous string and any trialing white-space.
 421        */
 422       for (base += len; (server_string[base] == SEPARATOR)
 423            && (server_string[base] != NUL); base++) {
 424          /* empty */
 425       }
 426    }
 427 }
 428
 429 void
 430 __glXEnableDirectExtension(struct glx_screen * psc, const char *name)
 431 {
 432    __glXExtensionsCtr();
 433    __glXExtensionsCtrScreen(psc);
 434
 435    set_glx_extension(known_glx_extensions,
 436                      name, strlen(name), GL_TRUE, psc->direct_support);
 437 }
 438
 439 /**
 440  * Initialize global extension support tables.
 441  */
 442
 443 static void
 444 __glXExtensionsCtr(void)
 445 {
 446    unsigned i;
 447    static GLboolean ext_list_first_time = GL_TRUE;
 448
 449
 450    if (ext_list_first_time) {
 451       ext_list_first_time = GL_FALSE;
 452
 453       (void) memset(client_glx_support, 0, sizeof(client_glx_support));
 454       (void) memset(direct_glx_support, 0, sizeof(direct_glx_support));
 455       (void) memset(client_glx_only, 0, sizeof(client_glx_only));
 456       (void) memset(direct_glx_only, 0, sizeof(direct_glx_only));
 457
 458       (void) memset(client_gl_support, 0, sizeof(client_gl_support));
 459       (void) memset(client_gl_only, 0, sizeof(client_gl_only));
 460
 461       for (i = 0; known_glx_extensions[i].name != NULL; i++) {
 462          const unsigned bit = known_glx_extensions[i].bit;
 463
 464          if (known_glx_extensions[i].client_support) {
 465             SET_BIT(client_glx_support, bit);
 466          }
 467
 468          if (known_glx_extensions[i].direct_support) {
 469             SET_BIT(direct_glx_support, bit);
 470          }
 471
 472          if (known_glx_extensions[i].client_only) {
 473             SET_BIT(client_glx_only, bit);
 474          }
 475
 476          if (known_glx_extensions[i].direct_only) {
 477             SET_BIT(direct_glx_only, bit);
 478          }
 479       }
 480
 481       for (i = 0; known_gl_extensions[i].name != NULL; i++) {
 482          const unsigned bit = known_gl_extensions[i].bit;
 483
 484          if (known_gl_extensions[i].client_support) {
 485             SET_BIT(client_gl_support, bit);
 486          }
 487
 488          if (known_gl_extensions[i].client_only) {
 489             SET_BIT(client_gl_only, bit);
 490          }
 491       }
 492
 493 #if 0
 494       fprintf(stderr, "[%s:%u] Maximum client library version: %u.%u\n",
 495               __func__, __LINE__, gl_major, gl_minor);
 496 #endif
 497    }
 498 }
 499
 500
 501 /**
 502  * Make sure that per-screen direct-support table is initialized.
 503  *
 504  * \param psc  Pointer to GLX per-screen record.
 505  */
 506
 507 static void
 508 __glXExtensionsCtrScreen(struct glx_screen * psc)
 509 {
 510    if (psc->ext_list_first_time) {
 511       psc->ext_list_first_time = GL_FALSE;
 512       (void) memcpy(psc->direct_support, direct_glx_support,
 513                     sizeof(direct_glx_support));
 514    }
 515 }
 516
 517
 518 /**
 519  * Check if a certain extension is enabled on a given screen.
 520  *
 521  * \param psc  Pointer to GLX per-screen record.
 522  * \param bit  Bit index in the direct-support table.
 523  * \returns If the extension bit is enabled for the screen, \c GL_TRUE is
 524  *          returned.  If the extension bit is not enabled or if \c psc is
 525  *          \c NULL, then \c GL_FALSE is returned.
 526  */
 527 GLboolean
 528 __glXExtensionBitIsEnabled(struct glx_screen * psc, unsigned bit)
 529 {
 530    GLboolean enabled = GL_FALSE;
 531
 532    if (psc != NULL) {
 533       __glXExtensionsCtr();
 534       __glXExtensionsCtrScreen(psc);
 535       enabled = EXT_ENABLED(bit, psc->direct_support);
 536    }
 537
 538    return enabled;
 539 }
 540
 541
 542 /**
 543  * Check if a certain extension is enabled in a given context.
 544  *
 545  */
 546 GLboolean
 547 __glExtensionBitIsEnabled(struct glx_context *gc, unsigned bit)
 548 {
 549    GLboolean enabled = GL_FALSE;
 550
 551    if (gc != NULL) {
 552       enabled = EXT_ENABLED(bit, gc->gl_extension_bits);
 553    }
 554
 555    return enabled;
 556 }
 557
 558
 559
 560 /**
 561  * Convert a bit-field to a string of supported extensions.
 562  */
 563 static char *
 564 __glXGetStringFromTable(const struct extension_info *ext,
 565                         const unsigned char *supported)
 566 {
 567    unsigned i;
 568    unsigned ext_str_len;
 569    char *ext_str;
 570    char *point;
 571
 572
 573    ext_str_len = 0;
 574    for (i = 0; ext[i].name != NULL; i++) {
 575       if (EXT_ENABLED(ext[i].bit, supported)) {
 576          ext_str_len += ext[i].name_len + 1;
 577       }
 578    }
 579
 580    ext_str = malloc(ext_str_len + 1);
 581    if (ext_str != NULL) {
 582       point = ext_str;
 583
 584       for (i = 0; ext[i].name != NULL; i++) {
 585          if (EXT_ENABLED(ext[i].bit, supported)) {
 586             (void) memcpy(point, ext[i].name, ext[i].name_len);
 587             point += ext[i].name_len;
 588
 589             *point = ' ';
 590             point++;
 591          }
 592       }
 593
 594       *point = '\0';
 595    }
 596
 597    return ext_str;
 598 }
 599
 600
 601 /**
 602  * Get the string of client library supported extensions.
 603  */
 604 const char *
 605 __glXGetClientExtensions(void)
 606 {
 607    if (__glXGLXClientExtensions == NULL) {
 608       __glXExtensionsCtr();
 609       __glXGLXClientExtensions = __glXGetStringFromTable(known_glx_extensions,
 610                                                          client_glx_support);
 611    }
 612
 613    return __glXGLXClientExtensions;
 614 }
 615
 616
 617 /**
 618  * Calculate the list of application usable extensions.  The resulting
 619  * string is stored in \c psc->effectiveGLXexts.
 620  *
 621  * \param psc                        Pointer to GLX per-screen record.
 622  * \param display_is_direct_capable  True if the display is capable of
 623  *                                   direct rendering.
 624  * \param minor_version              GLX minor version from the server.
 625  */
 626
 627 void
 628 __glXCalculateUsableExtensions(struct glx_screen * psc,
 629                                GLboolean display_is_direct_capable,
 630                                int minor_version)
 631 {
 632    unsigned char server_support[8];
 633    unsigned char usable[8];
 634    unsigned i;
 635
 636    __glXExtensionsCtr();
 637    __glXExtensionsCtrScreen(psc);
 638
 639    (void) memset(server_support, 0, sizeof(server_support));
 640    __glXProcessServerString(known_glx_extensions,
 641                             psc->serverGLXexts, server_support);
 642
 643
 644    /* This is a hack.  Some servers support GLX 1.3 but don't export
 645     * all of the extensions implied by GLX 1.3.  If the server claims
 646     * support for GLX 1.3, enable support for the extensions that can be
 647     * "emulated" as well.
 648     */
 649 #ifndef GLX_USE_APPLEGL
 650    if (minor_version >= 3) {
 651       SET_BIT(server_support, EXT_visual_info_bit);
 652       SET_BIT(server_support, EXT_visual_rating_bit);
 653       SET_BIT(server_support, SGI_make_current_read_bit);
 654       SET_BIT(server_support, SGIX_fbconfig_bit);
 655       SET_BIT(server_support, SGIX_pbuffer_bit);
 656
 657       /* This one is a little iffy.  GLX 1.3 doesn't incorporate all of this
 658        * extension.  However, the only part that is not strictly client-side
 659        * is shared.  That's the glXQueryContext / glXQueryContextInfoEXT
 660        * function.
 661        */
 662
 663       SET_BIT(server_support, EXT_import_context_bit);
 664    }
 665 #endif
 666
 667    /* An extension is supported if the client-side (i.e., libGL) supports
 668     * it and the "server" supports it.  In this case that means that either
 669     * the true server supports it or it is only for direct-rendering and
 670     * the direct rendering driver supports it.
 671     *
 672     * If the display is not capable of direct rendering, then the extension
 673     * is enabled if and only if the client-side library and the server
 674     * support it.
 675     */
 676
 677    if (display_is_direct_capable) {
 678       for (i = 0; i < 8; i++) {
 679          usable[i] = (client_glx_support[i] & client_glx_only[i])
 680             | (client_glx_support[i] & psc->direct_support[i] &
 681                server_support[i])
 682             | (client_glx_support[i] & psc->direct_support[i] &
 683                direct_glx_only[i]);
 684       }
 685    }
 686    else {
 687       for (i = 0; i < 8; i++) {
 688          usable[i] = (client_glx_support[i] & client_glx_only[i])
 689             | (client_glx_support[i] & server_support[i]);
 690       }
 691    }
 692
 693    psc->effectiveGLXexts = __glXGetStringFromTable(known_glx_extensions,
 694                                                    usable);
 695 }
 696
 697
 698 /**
 699  * Calculate the list of application usable extensions.  The resulting
 700  * string is stored in \c gc->extensions.
 701  *
 702  * \param gc             Pointer to GLX context.
 703  * \param server_string  Extension string from the server.
 704  * \param major_version  GL major version from the server.
 705  * \param minor_version  GL minor version from the server.
 706  */
 707
 708 void
 709 __glXCalculateUsableGLExtensions(struct glx_context * gc,
 710                                  const char *server_string,
 711                                  int major_version, int minor_version)
 712 {
 713    unsigned char server_support[__GL_EXT_BYTES];
 714    unsigned char usable[__GL_EXT_BYTES];
 715    unsigned i;
 716
 717
 718    __glXExtensionsCtr();
 719
 720    (void) memset(server_support, 0, sizeof(server_support));
 721    __glXProcessServerString(known_gl_extensions, server_string,
 722                             server_support);
 723
 724
 725    /* Handle lazy servers that don't export all the extensions strings that
 726     * are part of the GL core version that they support.
 727     */
 728
 729    for (i = 0; i < __GL_EXT_BYTES; i++) {
 730       if ((known_gl_extensions[i].version_major != 0)
 731           && ((major_version > known_gl_extensions[i].version_major)
 732               || ((major_version == known_gl_extensions[i].version_major)
 733                   && (minor_version >=
 734                       known_gl_extensions[i].version_minor)))) {
 735          SET_BIT(server_support, known_gl_extensions[i].bit);
 736       }
 737    }
 738
 739
 740    /* An extension is supported if the client-side (i.e., libGL) supports
 741     * it and the server supports it or the client-side library supports it
 742     * and it only needs client-side support.
 743     */
 744
 745    for (i = 0; i < __GL_EXT_BYTES; i++) {
 746       usable[i] = (client_gl_support[i] & client_gl_only[i])
 747          | (client_gl_support[i] & server_support[i]);
 748    }
 749
 750    gc->extensions = (unsigned char *)
 751       __glXGetStringFromTable(known_gl_extensions, usable);
 752    (void) memcpy(gc->gl_extension_bits, usable, sizeof(usable));
 753 }
 754
 755
 756 /**
 757  * Calculates the maximum core GL version that can be supported for indirect
 758  * rendering.
 759  */
 760 void
 761 __glXGetGLVersion(int *major_version, int *minor_version)
 762 {
 763    __glXExtensionsCtr();
 764    *major_version = gl_major;
 765    *minor_version = gl_minor;
 766 }
 767
 768
 769 /**
 770  * Get a string representing the set of extensions supported by the client
 771  * library.  This is currently only used to send the list of extensions
 772  * supported by the client to the server.
 773  */
 774 char *
 775 __glXGetClientGLExtensionString(void)
 776 {
 777    __glXExtensionsCtr();
 778    return __glXGetStringFromTable(known_gl_extensions, client_gl_support);
 779 }