src/glx/dri_common.c

   1 /*
   2  * Copyright 1998-1999 Precision Insight, Inc., Cedar Park, Texas.
   3  * Copyright © 2008 Red Hat, Inc.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Soft-
   7  * ware"), to deal in the Software without restriction, including without
   8  * limitation the rights to use, copy, modify, merge, publish, distribute,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, provided that the above copyright
  11  * notice(s) and this permission notice appear in all copies of the Soft-
  12  * ware and that both the above copyright notice(s) and this permission
  13  * notice appear in supporting documentation.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  16  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL-
  17  * ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY
  18  * RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN
  19  * THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSE-
  20  * QUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  21  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  22  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFOR-
  23  * MANCE OF THIS SOFTWARE.
  24  *
  25  * Except as contained in this notice, the name of a copyright holder shall
  26  * not be used in advertising or otherwise to promote the sale, use or
  27  * other dealings in this Software without prior written authorization of
  28  * the copyright holder.
  29  *
  30  * Authors:
  31  *   Kevin E. Martin <kevin@precisioninsight.com>
  32  *   Brian Paul <brian@precisioninsight.com>
  33  *   Kristian Høgsberg (krh@redhat.com)
  34  */
  35
  36 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
  37
  38 #include <unistd.h>
  39 #include <dlfcn.h>
  40 #include <stdarg.h>
  41 #include "glxclient.h"
  42 #include "dri_common.h"
  43 #include "loader.h"
  44
  45 #ifndef RTLD_NOW
  46 #define RTLD_NOW 0
  47 #endif
  48 #ifndef RTLD_GLOBAL
  49 #define RTLD_GLOBAL 0
  50 #endif
  51
  52 _X_HIDDEN void
  53 dri_message(int level, const char *f, ...)
  54 {
  55    va_list args;
  56    int threshold = _LOADER_WARNING;
  57    const char *libgl_debug;
  58
  59    libgl_debug = getenv("LIBGL_DEBUG");
  60    if (libgl_debug) {
  61       if (strstr(libgl_debug, "quiet"))
  62          threshold = _LOADER_FATAL;
  63       else if (strstr(libgl_debug, "verbose"))
  64          threshold = _LOADER_DEBUG;
  65    }
  66
  67    /* Note that the _LOADER_* levels are lower numbers for more severe. */
  68    if (level <= threshold) {
  69       fprintf(stderr, "libGL%s: ", level <= _LOADER_WARNING ? " error" : "");
  70       va_start(args, f);
  71       vfprintf(stderr, f, args);
  72       va_end(args);
  73    }
  74 }
  75
  76 #ifndef GL_LIB_NAME
  77 #define GL_LIB_NAME "libGL.so.1"
  78 #endif
  79
  80 #ifndef DEFAULT_DRIVER_DIR
  81 /* this is normally defined in Mesa/configs/default with DRI_DRIVER_SEARCH_PATH */
  82 #define DEFAULT_DRIVER_DIR "/usr/local/lib/dri"
  83 #endif
  84
  85 /**
  86  * Try to \c dlopen the named driver.
  87  *
  88  * This function adds the "_dri.so" suffix to the driver name and searches the
  89  * directories specified by the \c LIBGL_DRIVERS_PATH environment variable in
  90  * order to find the driver.
  91  *
  92  * \param driverName - a name like "i965", "radeon", "nouveau", etc.
  93  *
  94  * \returns
  95  * A handle from \c dlopen, or \c NULL if driver file not found.
  96  */
  97 _X_HIDDEN void *
  98 driOpenDriver(const char *driverName)
  99 {
 100    void *glhandle, *handle;
 101    const char *libPaths, *p, *next;
 102    char realDriverName[200];
 103    int len;
 104
 105    /* Attempt to make sure libGL symbols will be visible to the driver */
 106    glhandle = dlopen(GL_LIB_NAME, RTLD_NOW | RTLD_GLOBAL);
 107
 108    libPaths = NULL;
 109    if (geteuid() == getuid()) {
 110       /* don't allow setuid apps to use LIBGL_DRIVERS_PATH */
 111       libPaths = getenv("LIBGL_DRIVERS_PATH");
 112       if (!libPaths)
 113          libPaths = getenv("LIBGL_DRIVERS_DIR");        /* deprecated */
 114    }
 115    if (libPaths == NULL)
 116       libPaths = DEFAULT_DRIVER_DIR;
 117
 118    handle = NULL;
 119    for (p = libPaths; *p; p = next) {
 120       next = strchr(p, ':');
 121       if (next == NULL) {
 122          len = strlen(p);
 123          next = p + len;
 124       }
 125       else {
 126          len = next - p;
 127          next++;
 128       }
 129
 130 #ifdef GLX_USE_TLS
 131       snprintf(realDriverName, sizeof realDriverName,
 132                "%.*s/tls/%s_dri.so", len, p, driverName);
 133       InfoMessageF("OpenDriver: trying %s\n", realDriverName);
 134       handle = dlopen(realDriverName, RTLD_NOW | RTLD_GLOBAL);
 135 #endif
 136
 137       if (handle == NULL) {
 138          snprintf(realDriverName, sizeof realDriverName,
 139                   "%.*s/%s_dri.so", len, p, driverName);
 140          InfoMessageF("OpenDriver: trying %s\n", realDriverName);
 141          handle = dlopen(realDriverName, RTLD_NOW | RTLD_GLOBAL);
 142       }
 143
 144       if (handle != NULL)
 145          break;
 146       else
 147          InfoMessageF("dlopen %s failed (%s)\n", realDriverName, dlerror());
 148    }
 149
 150    if (!handle)
 151       ErrorMessageF("unable to load driver: %s_dri.so\n", driverName);
 152
 153    if (glhandle)
 154       dlclose(glhandle);
 155
 156    return handle;
 157 }
 158
 159 _X_HIDDEN const __DRIextension **
 160 driGetDriverExtensions(void *handle, const char *driver_name)
 161 {
 162    const __DRIextension **extensions = NULL;
 163    const __DRIextension **(*get_extensions)(void);
 164    char *get_extensions_name = loader_get_extensions_name(driver_name);
 165
 166    if (get_extensions_name) {
 167       get_extensions = dlsym(handle, get_extensions_name);
 168       if (get_extensions) {
 169          free(get_extensions_name);
 170          return get_extensions();
 171       } else {
 172          InfoMessageF("driver does not expose %s(): %s\n",
 173                       get_extensions_name, dlerror());
 174          free(get_extensions_name);
 175       }
 176    }
 177
 178    extensions = dlsym(handle, __DRI_DRIVER_EXTENSIONS);
 179    if (extensions == NULL) {
 180       ErrorMessageF("driver exports no extensions (%s)\n", dlerror());
 181       return NULL;
 182    }
 183
 184    return extensions;
 185 }
 186
 187 static GLboolean
 188 __driGetMSCRate(__DRIdrawable *draw,
 189                 int32_t * numerator, int32_t * denominator,
 190                 void *loaderPrivate)
 191 {
 192    __GLXDRIdrawable *glxDraw = loaderPrivate;
 193
 194    return __glxGetMscRate(glxDraw->psc, numerator, denominator);
 195 }
 196
 197 _X_HIDDEN const __DRIsystemTimeExtension systemTimeExtension = {
 198    .base = {__DRI_SYSTEM_TIME, 1 },
 199
 200    .getUST              = __glXGetUST,
 201    .getMSCRate          = __driGetMSCRate
 202 };
 203
 204 #define __ATTRIB(attrib, field) \
 205     { attrib, offsetof(struct glx_config, field) }
 206
 207 static const struct
 208 {
 209    unsigned int attrib, offset;
 210 } attribMap[] = {
 211    __ATTRIB(__DRI_ATTRIB_BUFFER_SIZE, rgbBits),
 212       __ATTRIB(__DRI_ATTRIB_LEVEL, level),
 213       __ATTRIB(__DRI_ATTRIB_RED_SIZE, redBits),
 214       __ATTRIB(__DRI_ATTRIB_GREEN_SIZE, greenBits),
 215       __ATTRIB(__DRI_ATTRIB_BLUE_SIZE, blueBits),
 216       __ATTRIB(__DRI_ATTRIB_ALPHA_SIZE, alphaBits),
 217       __ATTRIB(__DRI_ATTRIB_DEPTH_SIZE, depthBits),
 218       __ATTRIB(__DRI_ATTRIB_STENCIL_SIZE, stencilBits),
 219       __ATTRIB(__DRI_ATTRIB_ACCUM_RED_SIZE, accumRedBits),
 220       __ATTRIB(__DRI_ATTRIB_ACCUM_GREEN_SIZE, accumGreenBits),
 221       __ATTRIB(__DRI_ATTRIB_ACCUM_BLUE_SIZE, accumBlueBits),
 222       __ATTRIB(__DRI_ATTRIB_ACCUM_ALPHA_SIZE, accumAlphaBits),
 223       __ATTRIB(__DRI_ATTRIB_SAMPLE_BUFFERS, sampleBuffers),
 224       __ATTRIB(__DRI_ATTRIB_SAMPLES, samples),
 225       __ATTRIB(__DRI_ATTRIB_DOUBLE_BUFFER, doubleBufferMode),
 226       __ATTRIB(__DRI_ATTRIB_STEREO, stereoMode),
 227       __ATTRIB(__DRI_ATTRIB_AUX_BUFFERS, numAuxBuffers),
 228 #if 0
 229       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_TYPE, transparentPixel),
 230       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_INDEX_VALUE, transparentIndex),
 231       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_RED_VALUE, transparentRed),
 232       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_GREEN_VALUE, transparentGreen),
 233       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_BLUE_VALUE, transparentBlue),
 234       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_ALPHA_VALUE, transparentAlpha),
 235       __ATTRIB(__DRI_ATTRIB_RED_MASK, redMask),
 236       __ATTRIB(__DRI_ATTRIB_GREEN_MASK, greenMask),
 237       __ATTRIB(__DRI_ATTRIB_BLUE_MASK, blueMask),
 238       __ATTRIB(__DRI_ATTRIB_ALPHA_MASK, alphaMask),
 239 #endif
 240       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_WIDTH, maxPbufferWidth),
 241       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_HEIGHT, maxPbufferHeight),
 242       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_PIXELS, maxPbufferPixels),
 243       __ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_WIDTH, optimalPbufferWidth),
 244       __ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_HEIGHT, optimalPbufferHeight),
 245 #if 0
 246       __ATTRIB(__DRI_ATTRIB_SWAP_METHOD, swapMethod),
 247 #endif
 248 __ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGB, bindToTextureRgb),
 249       __ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGBA, bindToTextureRgba),
 250       __ATTRIB(__DRI_ATTRIB_BIND_TO_MIPMAP_TEXTURE,
 251                      bindToMipmapTexture),
 252       __ATTRIB(__DRI_ATTRIB_YINVERTED, yInverted),
 253       __ATTRIB(__DRI_ATTRIB_FRAMEBUFFER_SRGB_CAPABLE, sRGBCapable)
 254 };
 255
 256 static int
 257 scalarEqual(struct glx_config *mode, unsigned int attrib, unsigned int value)
 258 {
 259    unsigned glxValue, i;
 260
 261    for (i = 0; i < ARRAY_SIZE(attribMap); i++)
 262       if (attribMap[i].attrib == attrib) {
 263          glxValue = *(unsigned int *) ((char *) mode + attribMap[i].offset);
 264          return glxValue == GLX_DONT_CARE || glxValue == value;
 265       }
 266
 267    return GL_TRUE;              /* Is a non-existing attribute equal to value? */
 268 }
 269
 270 static int
 271 driConfigEqual(const __DRIcoreExtension *core,
 272                struct glx_config *config, const __DRIconfig *driConfig)
 273 {
 274    unsigned int attrib, value, glxValue;
 275    int i;
 276
 277    i = 0;
 278    while (core->indexConfigAttrib(driConfig, i++, &attrib, &value)) {
 279       switch (attrib) {
 280       case __DRI_ATTRIB_RENDER_TYPE:
 281          glxValue = 0;
 282          if (value & __DRI_ATTRIB_RGBA_BIT) {
 283             glxValue |= GLX_RGBA_BIT;
 284          }
 285          if (value & __DRI_ATTRIB_COLOR_INDEX_BIT) {
 286             glxValue |= GLX_COLOR_INDEX_BIT;
 287          }
 288          if (value & __DRI_ATTRIB_FLOAT_BIT) {
 289             glxValue |= GLX_RGBA_FLOAT_BIT_ARB;
 290          }
 291          if (value & __DRI_ATTRIB_UNSIGNED_FLOAT_BIT) {
 292             glxValue |= GLX_RGBA_UNSIGNED_FLOAT_BIT_EXT;
 293          }
 294          if (glxValue != config->renderType)
 295             return GL_FALSE;
 296          break;
 297
 298       case __DRI_ATTRIB_CONFIG_CAVEAT:
 299          if (value & __DRI_ATTRIB_NON_CONFORMANT_CONFIG)
 300             glxValue = GLX_NON_CONFORMANT_CONFIG;
 301          else if (value & __DRI_ATTRIB_SLOW_BIT)
 302             glxValue = GLX_SLOW_CONFIG;
 303          else
 304             glxValue = GLX_NONE;
 305          if (glxValue != config->visualRating)
 306             return GL_FALSE;
 307          break;
 308
 309       case __DRI_ATTRIB_BIND_TO_TEXTURE_TARGETS:
 310          glxValue = 0;
 311          if (value & __DRI_ATTRIB_TEXTURE_1D_BIT)
 312             glxValue |= GLX_TEXTURE_1D_BIT_EXT;
 313          if (value & __DRI_ATTRIB_TEXTURE_2D_BIT)
 314             glxValue |= GLX_TEXTURE_2D_BIT_EXT;
 315          if (value & __DRI_ATTRIB_TEXTURE_RECTANGLE_BIT)
 316             glxValue |= GLX_TEXTURE_RECTANGLE_BIT_EXT;
 317          if (config->bindToTextureTargets != GLX_DONT_CARE &&
 318              glxValue != config->bindToTextureTargets)
 319             return GL_FALSE;
 320          break;
 321
 322       default:
 323          if (!scalarEqual(config, attrib, value))
 324             return GL_FALSE;
 325       }
 326    }
 327
 328    return GL_TRUE;
 329 }
 330
 331 static struct glx_config *
 332 createDriMode(const __DRIcoreExtension * core,
 333               struct glx_config *config, const __DRIconfig **driConfigs)
 334 {
 335    __GLXDRIconfigPrivate *driConfig;
 336    int i;
 337
 338    for (i = 0; driConfigs[i]; i++) {
 339       if (driConfigEqual(core, config, driConfigs[i]))
 340          break;
 341    }
 342
 343    if (driConfigs[i] == NULL)
 344       return NULL;
 345
 346    driConfig = malloc(sizeof *driConfig);
 347    if (driConfig == NULL)
 348       return NULL;
 349
 350    driConfig->base = *config;
 351    driConfig->driConfig = driConfigs[i];
 352
 353    return &driConfig->base;
 354 }
 355
 356 _X_HIDDEN struct glx_config *
 357 driConvertConfigs(const __DRIcoreExtension * core,
 358                   struct glx_config *configs, const __DRIconfig **driConfigs)
 359 {
 360    struct glx_config head, *tail, *m;
 361
 362    tail = &head;
 363    head.next = NULL;
 364    for (m = configs; m; m = m->next) {
 365       tail->next = createDriMode(core, m, driConfigs);
 366       if (tail->next == NULL) {
 367          /* no matching dri config for m */
 368          continue;
 369       }
 370
 371
 372       tail = tail->next;
 373    }
 374
 375    return head.next;
 376 }
 377
 378 _X_HIDDEN void
 379 driDestroyConfigs(const __DRIconfig **configs)
 380 {
 381    int i;
 382
 383    for (i = 0; configs[i]; i++)
 384       free((__DRIconfig *) configs[i]);
 385    free(configs);
 386 }
 387
 388 _X_HIDDEN __GLXDRIdrawable *
 389 driFetchDrawable(struct glx_context *gc, GLXDrawable glxDrawable)
 390 {
 391    struct glx_display *const priv = __glXInitialize(gc->psc->dpy);
 392    __GLXDRIdrawable *pdraw;
 393    struct glx_screen *psc;
 394
 395    if (priv == NULL)
 396       return NULL;
 397
 398    if (glxDrawable == None)
 399       return NULL;
 400
 401    psc = priv->screens[gc->screen];
 402    if (priv->drawHash == NULL)
 403       return NULL;
 404
 405    if (__glxHashLookup(priv->drawHash, glxDrawable, (void *) &pdraw) == 0) {
 406       pdraw->refcount ++;
 407       return pdraw;
 408    }
 409
 410    pdraw = psc->driScreen->createDrawable(psc, glxDrawable,
 411                                           glxDrawable, gc->config);
 412
 413    if (pdraw == NULL) {
 414       ErrorMessageF("failed to create drawable\n");
 415       return NULL;
 416    }
 417
 418    if (__glxHashInsert(priv->drawHash, glxDrawable, pdraw)) {
 419       (*pdraw->destroyDrawable) (pdraw);
 420       return NULL;
 421    }
 422    pdraw->refcount = 1;
 423
 424    return pdraw;
 425 }
 426
 427 _X_HIDDEN void
 428 driReleaseDrawables(struct glx_context *gc)
 429 {
 430    const struct glx_display *priv = gc->psc->display;
 431    __GLXDRIdrawable *pdraw;
 432
 433    if (priv == NULL)
 434       return;
 435
 436    if (__glxHashLookup(priv->drawHash,
 437                        gc->currentDrawable, (void *) &pdraw) == 0) {
 438       if (pdraw->drawable == pdraw->xDrawable) {
 439          pdraw->refcount --;
 440          if (pdraw->refcount == 0) {
 441             (*pdraw->destroyDrawable)(pdraw);
 442             __glxHashDelete(priv->drawHash, gc->currentDrawable);
 443          }
 444       }
 445    }
 446
 447    if (__glxHashLookup(priv->drawHash,
 448                        gc->currentReadable, (void *) &pdraw) == 0) {
 449       if (pdraw->drawable == pdraw->xDrawable) {
 450          pdraw->refcount --;
 451          if (pdraw->refcount == 0) {
 452             (*pdraw->destroyDrawable)(pdraw);
 453             __glxHashDelete(priv->drawHash, gc->currentReadable);
 454          }
 455       }
 456    }
 457
 458    gc->currentDrawable = None;
 459    gc->currentReadable = None;
 460
 461 }
 462
 463 _X_HIDDEN bool
 464 dri2_convert_glx_attribs(unsigned num_attribs, const uint32_t *attribs,
 465                          unsigned *major_ver, unsigned *minor_ver,
 466                          uint32_t *render_type, uint32_t *flags, unsigned *api,
 467                          int *reset, unsigned *error)
 468 {
 469    unsigned i;
 470    bool got_profile = false;
 471    uint32_t profile;
 472
 473    *major_ver = 1;
 474    *minor_ver = 0;
 475    *render_type = GLX_RGBA_TYPE;
 476    *reset = __DRI_CTX_RESET_NO_NOTIFICATION;
 477    *flags = 0;
 478    *api = __DRI_API_OPENGL;
 479
 480    if (num_attribs == 0) {
 481       return true;
 482    }
 483
 484    /* This is actually an internal error, but what the heck.
 485     */
 486    if (attribs == NULL) {
 487       *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 488       return false;
 489    }
 490
 491    for (i = 0; i < num_attribs; i++) {
 492       switch (attribs[i * 2]) {
 493       case GLX_CONTEXT_MAJOR_VERSION_ARB:
 494          *major_ver = attribs[i * 2 + 1];
 495          break;
 496       case GLX_CONTEXT_MINOR_VERSION_ARB:
 497          *minor_ver = attribs[i * 2 + 1];
 498          break;
 499       case GLX_CONTEXT_FLAGS_ARB:
 500          *flags = attribs[i * 2 + 1];
 501          break;
 502       case GLX_CONTEXT_PROFILE_MASK_ARB:
 503          profile = attribs[i * 2 + 1];
 504          got_profile = true;
 505          break;
 506       case GLX_RENDER_TYPE:
 507          *render_type = attribs[i * 2 + 1];
 508          break;
 509       case GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB:
 510          switch (attribs[i * 2 + 1]) {
 511          case GLX_NO_RESET_NOTIFICATION_ARB:
 512             *reset = __DRI_CTX_RESET_NO_NOTIFICATION;
 513             break;
 514          case GLX_LOSE_CONTEXT_ON_RESET_ARB:
 515             *reset = __DRI_CTX_RESET_LOSE_CONTEXT;
 516             break;
 517          default:
 518             *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 519             return false;
 520          }
 521          break;
 522       default:
 523          /* If an unknown attribute is received, fail.
 524           */
 525          *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 526          return false;
 527       }
 528    }
 529
 530    if (!got_profile) {
 531       if (*major_ver > 3 || (*major_ver == 3 && *minor_ver >= 2))
 532          *api = __DRI_API_OPENGL_CORE;
 533    } else {
 534       switch (profile) {
 535       case GLX_CONTEXT_CORE_PROFILE_BIT_ARB:
 536          /* There are no profiles before OpenGL 3.2.  The
 537           * GLX_ARB_create_context_profile spec says:
 538           *
 539           *     "If the requested OpenGL version is less than 3.2,
 540           *     GLX_CONTEXT_PROFILE_MASK_ARB is ignored and the functionality
 541           *     of the context is determined solely by the requested version."
 542           */
 543          *api = (*major_ver > 3 || (*major_ver == 3 && *minor_ver >= 2))
 544             ? __DRI_API_OPENGL_CORE : __DRI_API_OPENGL;
 545          break;
 546       case GLX_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB:
 547          *api = __DRI_API_OPENGL;
 548          break;
 549       case GLX_CONTEXT_ES_PROFILE_BIT_EXT:
 550          if (*major_ver >= 3)
 551             *api = __DRI_API_GLES3;
 552          else if (*major_ver == 2 && *minor_ver == 0)
 553             *api = __DRI_API_GLES2;
 554          else if (*major_ver == 1 && *minor_ver < 2)
 555             *api = __DRI_API_GLES;
 556          else {
 557             *error = __DRI_CTX_ERROR_BAD_API;
 558             return false;
 559          }
 560          break;
 561       default:
 562          *error = __DRI_CTX_ERROR_BAD_API;
 563          return false;
 564       }
 565    }
 566
 567    /* Unknown flag value.
 568     */
 569    if (*flags & ~(__DRI_CTX_FLAG_DEBUG | __DRI_CTX_FLAG_FORWARD_COMPATIBLE
 570                   | __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS)) {
 571       *error = __DRI_CTX_ERROR_UNKNOWN_FLAG;
 572       return false;
 573    }
 574
 575    /* There are no forward-compatible contexts before OpenGL 3.0.  The
 576     * GLX_ARB_create_context spec says:
 577     *
 578     *     "Forward-compatible contexts are defined only for OpenGL versions
 579     *     3.0 and later."
 580     */
 581    if (*major_ver < 3 && (*flags & __DRI_CTX_FLAG_FORWARD_COMPATIBLE) != 0) {
 582       *error = __DRI_CTX_ERROR_BAD_FLAG;
 583       return false;
 584    }
 585
 586    if (*major_ver >= 3 && *render_type == GLX_COLOR_INDEX_TYPE) {
 587       *error = __DRI_CTX_ERROR_BAD_FLAG;
 588       return false;
 589    }
 590
 591    *error = __DRI_CTX_ERROR_SUCCESS;
 592    return true;
 593 }
 594
 595 #endif /* GLX_DIRECT_RENDERING */