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;
 165
 166    if (asprintf(&get_extensions_name, "%s_%s",
 167                 __DRI_DRIVER_GET_EXTENSIONS, driver_name) != -1) {
 168       get_extensions = dlsym(handle, get_extensions_name);
 169       if (get_extensions) {
 170          free(get_extensions_name);
 171          return get_extensions();
 172       } else {
 173          InfoMessageF("driver does not expose %s(): %s\n",
 174                       get_extensions_name, dlerror());
 175          free(get_extensions_name);
 176       }
 177    }
 178
 179    extensions = dlsym(handle, __DRI_DRIVER_EXTENSIONS);
 180    if (extensions == NULL) {
 181       ErrorMessageF("driver exports no extensions (%s)\n", dlerror());
 182       return NULL;
 183    }
 184
 185    return extensions;
 186 }
 187
 188 static GLboolean
 189 __driGetMSCRate(__DRIdrawable *draw,
 190                 int32_t * numerator, int32_t * denominator,
 191                 void *loaderPrivate)
 192 {
 193    __GLXDRIdrawable *glxDraw = loaderPrivate;
 194
 195    return __glxGetMscRate(glxDraw->psc, numerator, denominator);
 196 }
 197
 198 _X_HIDDEN const __DRIsystemTimeExtension systemTimeExtension = {
 199    .base = {__DRI_SYSTEM_TIME, 1 },
 200
 201    .getUST              = __glXGetUST,
 202    .getMSCRate          = __driGetMSCRate
 203 };
 204
 205 #define __ATTRIB(attrib, field) \
 206     { attrib, offsetof(struct glx_config, field) }
 207
 208 static const struct
 209 {
 210    unsigned int attrib, offset;
 211 } attribMap[] = {
 212    __ATTRIB(__DRI_ATTRIB_BUFFER_SIZE, rgbBits),
 213       __ATTRIB(__DRI_ATTRIB_LEVEL, level),
 214       __ATTRIB(__DRI_ATTRIB_RED_SIZE, redBits),
 215       __ATTRIB(__DRI_ATTRIB_GREEN_SIZE, greenBits),
 216       __ATTRIB(__DRI_ATTRIB_BLUE_SIZE, blueBits),
 217       __ATTRIB(__DRI_ATTRIB_ALPHA_SIZE, alphaBits),
 218       __ATTRIB(__DRI_ATTRIB_DEPTH_SIZE, depthBits),
 219       __ATTRIB(__DRI_ATTRIB_STENCIL_SIZE, stencilBits),
 220       __ATTRIB(__DRI_ATTRIB_ACCUM_RED_SIZE, accumRedBits),
 221       __ATTRIB(__DRI_ATTRIB_ACCUM_GREEN_SIZE, accumGreenBits),
 222       __ATTRIB(__DRI_ATTRIB_ACCUM_BLUE_SIZE, accumBlueBits),
 223       __ATTRIB(__DRI_ATTRIB_ACCUM_ALPHA_SIZE, accumAlphaBits),
 224       __ATTRIB(__DRI_ATTRIB_SAMPLE_BUFFERS, sampleBuffers),
 225       __ATTRIB(__DRI_ATTRIB_SAMPLES, samples),
 226       __ATTRIB(__DRI_ATTRIB_DOUBLE_BUFFER, doubleBufferMode),
 227       __ATTRIB(__DRI_ATTRIB_STEREO, stereoMode),
 228       __ATTRIB(__DRI_ATTRIB_AUX_BUFFERS, numAuxBuffers),
 229 #if 0
 230       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_TYPE, transparentPixel),
 231       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_INDEX_VALUE, transparentIndex),
 232       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_RED_VALUE, transparentRed),
 233       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_GREEN_VALUE, transparentGreen),
 234       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_BLUE_VALUE, transparentBlue),
 235       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_ALPHA_VALUE, transparentAlpha),
 236       __ATTRIB(__DRI_ATTRIB_RED_MASK, redMask),
 237       __ATTRIB(__DRI_ATTRIB_GREEN_MASK, greenMask),
 238       __ATTRIB(__DRI_ATTRIB_BLUE_MASK, blueMask),
 239       __ATTRIB(__DRI_ATTRIB_ALPHA_MASK, alphaMask),
 240 #endif
 241       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_WIDTH, maxPbufferWidth),
 242       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_HEIGHT, maxPbufferHeight),
 243       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_PIXELS, maxPbufferPixels),
 244       __ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_WIDTH, optimalPbufferWidth),
 245       __ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_HEIGHT, optimalPbufferHeight),
 246 #if 0
 247       __ATTRIB(__DRI_ATTRIB_SWAP_METHOD, swapMethod),
 248 #endif
 249 __ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGB, bindToTextureRgb),
 250       __ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGBA, bindToTextureRgba),
 251       __ATTRIB(__DRI_ATTRIB_BIND_TO_MIPMAP_TEXTURE,
 252                      bindToMipmapTexture),
 253       __ATTRIB(__DRI_ATTRIB_YINVERTED, yInverted),
 254       __ATTRIB(__DRI_ATTRIB_FRAMEBUFFER_SRGB_CAPABLE, sRGBCapable)
 255 };
 256
 257 static int
 258 scalarEqual(struct glx_config *mode, unsigned int attrib, unsigned int value)
 259 {
 260    unsigned glxValue, i;
 261
 262    for (i = 0; i < ARRAY_SIZE(attribMap); i++)
 263       if (attribMap[i].attrib == attrib) {
 264          glxValue = *(unsigned int *) ((char *) mode + attribMap[i].offset);
 265          return glxValue == GLX_DONT_CARE || glxValue == value;
 266       }
 267
 268    return GL_TRUE;              /* Is a non-existing attribute equal to value? */
 269 }
 270
 271 static int
 272 driConfigEqual(const __DRIcoreExtension *core,
 273                struct glx_config *config, const __DRIconfig *driConfig)
 274 {
 275    unsigned int attrib, value, glxValue;
 276    int i;
 277
 278    i = 0;
 279    while (core->indexConfigAttrib(driConfig, i++, &attrib, &value)) {
 280       switch (attrib) {
 281       case __DRI_ATTRIB_RENDER_TYPE:
 282          glxValue = 0;
 283          if (value & __DRI_ATTRIB_RGBA_BIT) {
 284             glxValue |= GLX_RGBA_BIT;
 285          }
 286          if (value & __DRI_ATTRIB_COLOR_INDEX_BIT) {
 287             glxValue |= GLX_COLOR_INDEX_BIT;
 288          }
 289          if (value & __DRI_ATTRIB_FLOAT_BIT) {
 290             glxValue |= GLX_RGBA_FLOAT_BIT_ARB;
 291          }
 292          if (value & __DRI_ATTRIB_UNSIGNED_FLOAT_BIT) {
 293             glxValue |= GLX_RGBA_UNSIGNED_FLOAT_BIT_EXT;
 294          }
 295          if (glxValue != config->renderType)
 296             return GL_FALSE;
 297          break;
 298
 299       case __DRI_ATTRIB_CONFIG_CAVEAT:
 300          if (value & __DRI_ATTRIB_NON_CONFORMANT_CONFIG)
 301             glxValue = GLX_NON_CONFORMANT_CONFIG;
 302          else if (value & __DRI_ATTRIB_SLOW_BIT)
 303             glxValue = GLX_SLOW_CONFIG;
 304          else
 305             glxValue = GLX_NONE;
 306          if (glxValue != config->visualRating)
 307             return GL_FALSE;
 308          break;
 309
 310       case __DRI_ATTRIB_BIND_TO_TEXTURE_TARGETS:
 311          glxValue = 0;
 312          if (value & __DRI_ATTRIB_TEXTURE_1D_BIT)
 313             glxValue |= GLX_TEXTURE_1D_BIT_EXT;
 314          if (value & __DRI_ATTRIB_TEXTURE_2D_BIT)
 315             glxValue |= GLX_TEXTURE_2D_BIT_EXT;
 316          if (value & __DRI_ATTRIB_TEXTURE_RECTANGLE_BIT)
 317             glxValue |= GLX_TEXTURE_RECTANGLE_BIT_EXT;
 318          if (config->bindToTextureTargets != GLX_DONT_CARE &&
 319              glxValue != config->bindToTextureTargets)
 320             return GL_FALSE;
 321          break;
 322
 323       default:
 324          if (!scalarEqual(config, attrib, value))
 325             return GL_FALSE;
 326       }
 327    }
 328
 329    return GL_TRUE;
 330 }
 331
 332 static struct glx_config *
 333 createDriMode(const __DRIcoreExtension * core,
 334               struct glx_config *config, const __DRIconfig **driConfigs)
 335 {
 336    __GLXDRIconfigPrivate *driConfig;
 337    int i;
 338
 339    for (i = 0; driConfigs[i]; i++) {
 340       if (driConfigEqual(core, config, driConfigs[i]))
 341          break;
 342    }
 343
 344    if (driConfigs[i] == NULL)
 345       return NULL;
 346
 347    driConfig = malloc(sizeof *driConfig);
 348    if (driConfig == NULL)
 349       return NULL;
 350
 351    driConfig->base = *config;
 352    driConfig->driConfig = driConfigs[i];
 353
 354    return &driConfig->base;
 355 }
 356
 357 _X_HIDDEN struct glx_config *
 358 driConvertConfigs(const __DRIcoreExtension * core,
 359                   struct glx_config *configs, const __DRIconfig **driConfigs)
 360 {
 361    struct glx_config head, *tail, *m;
 362
 363    tail = &head;
 364    head.next = NULL;
 365    for (m = configs; m; m = m->next) {
 366       tail->next = createDriMode(core, m, driConfigs);
 367       if (tail->next == NULL) {
 368          /* no matching dri config for m */
 369          continue;
 370       }
 371
 372
 373       tail = tail->next;
 374    }
 375
 376    return head.next;
 377 }
 378
 379 _X_HIDDEN void
 380 driDestroyConfigs(const __DRIconfig **configs)
 381 {
 382    int i;
 383
 384    for (i = 0; configs[i]; i++)
 385       free((__DRIconfig *) configs[i]);
 386    free(configs);
 387 }
 388
 389 _X_HIDDEN __GLXDRIdrawable *
 390 driFetchDrawable(struct glx_context *gc, GLXDrawable glxDrawable)
 391 {
 392    struct glx_display *const priv = __glXInitialize(gc->psc->dpy);
 393    __GLXDRIdrawable *pdraw;
 394    struct glx_screen *psc;
 395
 396    if (priv == NULL)
 397       return NULL;
 398
 399    if (glxDrawable == None)
 400       return NULL;
 401
 402    psc = priv->screens[gc->screen];
 403    if (priv->drawHash == NULL)
 404       return NULL;
 405
 406    if (__glxHashLookup(priv->drawHash, glxDrawable, (void *) &pdraw) == 0) {
 407       pdraw->refcount ++;
 408       return pdraw;
 409    }
 410
 411    pdraw = psc->driScreen->createDrawable(psc, glxDrawable,
 412                                           glxDrawable, gc->config);
 413
 414    if (pdraw == NULL) {
 415       ErrorMessageF("failed to create drawable\n");
 416       return NULL;
 417    }
 418
 419    if (__glxHashInsert(priv->drawHash, glxDrawable, pdraw)) {
 420       (*pdraw->destroyDrawable) (pdraw);
 421       return NULL;
 422    }
 423    pdraw->refcount = 1;
 424
 425    return pdraw;
 426 }
 427
 428 _X_HIDDEN void
 429 driReleaseDrawables(struct glx_context *gc)
 430 {
 431    const struct glx_display *priv = gc->psc->display;
 432    __GLXDRIdrawable *pdraw;
 433
 434    if (priv == NULL)
 435       return;
 436
 437    if (__glxHashLookup(priv->drawHash,
 438                        gc->currentDrawable, (void *) &pdraw) == 0) {
 439       if (pdraw->drawable == pdraw->xDrawable) {
 440          pdraw->refcount --;
 441          if (pdraw->refcount == 0) {
 442             (*pdraw->destroyDrawable)(pdraw);
 443             __glxHashDelete(priv->drawHash, gc->currentDrawable);
 444          }
 445       }
 446    }
 447
 448    if (__glxHashLookup(priv->drawHash,
 449                        gc->currentReadable, (void *) &pdraw) == 0) {
 450       if (pdraw->drawable == pdraw->xDrawable) {
 451          pdraw->refcount --;
 452          if (pdraw->refcount == 0) {
 453             (*pdraw->destroyDrawable)(pdraw);
 454             __glxHashDelete(priv->drawHash, gc->currentReadable);
 455          }
 456       }
 457    }
 458
 459    gc->currentDrawable = None;
 460    gc->currentReadable = None;
 461
 462 }
 463
 464 _X_HIDDEN bool
 465 dri2_convert_glx_attribs(unsigned num_attribs, const uint32_t *attribs,
 466                          unsigned *major_ver, unsigned *minor_ver,
 467                          uint32_t *render_type, uint32_t *flags, unsigned *api,
 468                          int *reset, unsigned *error)
 469 {
 470    unsigned i;
 471    bool got_profile = false;
 472    uint32_t profile;
 473
 474    *major_ver = 1;
 475    *minor_ver = 0;
 476    *render_type = GLX_RGBA_TYPE;
 477    *reset = __DRI_CTX_RESET_NO_NOTIFICATION;
 478    *flags = 0;
 479    *api = __DRI_API_OPENGL;
 480
 481    if (num_attribs == 0) {
 482       return true;
 483    }
 484
 485    /* This is actually an internal error, but what the heck.
 486     */
 487    if (attribs == NULL) {
 488       *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 489       return false;
 490    }
 491
 492    for (i = 0; i < num_attribs; i++) {
 493       switch (attribs[i * 2]) {
 494       case GLX_CONTEXT_MAJOR_VERSION_ARB:
 495          *major_ver = attribs[i * 2 + 1];
 496          break;
 497       case GLX_CONTEXT_MINOR_VERSION_ARB:
 498          *minor_ver = attribs[i * 2 + 1];
 499          break;
 500       case GLX_CONTEXT_FLAGS_ARB:
 501          *flags = attribs[i * 2 + 1];
 502          break;
 503       case GLX_CONTEXT_PROFILE_MASK_ARB:
 504          profile = attribs[i * 2 + 1];
 505          got_profile = true;
 506          break;
 507       case GLX_RENDER_TYPE:
 508          *render_type = attribs[i * 2 + 1];
 509          break;
 510       case GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB:
 511          switch (attribs[i * 2 + 1]) {
 512          case GLX_NO_RESET_NOTIFICATION_ARB:
 513             *reset = __DRI_CTX_RESET_NO_NOTIFICATION;
 514             break;
 515          case GLX_LOSE_CONTEXT_ON_RESET_ARB:
 516             *reset = __DRI_CTX_RESET_LOSE_CONTEXT;
 517             break;
 518          default:
 519             *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 520             return false;
 521          }
 522          break;
 523       default:
 524          /* If an unknown attribute is received, fail.
 525           */
 526          *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 527          return false;
 528       }
 529    }
 530
 531    if (!got_profile) {
 532       if (*major_ver > 3 || (*major_ver == 3 && *minor_ver >= 2))
 533          *api = __DRI_API_OPENGL_CORE;
 534    } else {
 535       switch (profile) {
 536       case GLX_CONTEXT_CORE_PROFILE_BIT_ARB:
 537          /* There are no profiles before OpenGL 3.2.  The
 538           * GLX_ARB_create_context_profile spec says:
 539           *
 540           *     "If the requested OpenGL version is less than 3.2,
 541           *     GLX_CONTEXT_PROFILE_MASK_ARB is ignored and the functionality
 542           *     of the context is determined solely by the requested version."
 543           */
 544          *api = (*major_ver > 3 || (*major_ver == 3 && *minor_ver >= 2))
 545             ? __DRI_API_OPENGL_CORE : __DRI_API_OPENGL;
 546          break;
 547       case GLX_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB:
 548          *api = __DRI_API_OPENGL;
 549          break;
 550       case GLX_CONTEXT_ES_PROFILE_BIT_EXT:
 551          if (*major_ver >= 3)
 552             *api = __DRI_API_GLES3;
 553          else if (*major_ver == 2 && *minor_ver == 0)
 554             *api = __DRI_API_GLES2;
 555          else if (*major_ver == 1 && *minor_ver < 2)
 556             *api = __DRI_API_GLES;
 557          else {
 558             *error = __DRI_CTX_ERROR_BAD_API;
 559             return false;
 560          }
 561          break;
 562       default:
 563          *error = __DRI_CTX_ERROR_BAD_API;
 564          return false;
 565       }
 566    }
 567
 568    /* Unknown flag value.
 569     */
 570    if (*flags & ~(__DRI_CTX_FLAG_DEBUG | __DRI_CTX_FLAG_FORWARD_COMPATIBLE
 571                   | __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS)) {
 572       *error = __DRI_CTX_ERROR_UNKNOWN_FLAG;
 573       return false;
 574    }
 575
 576    /* There are no forward-compatible contexts before OpenGL 3.0.  The
 577     * GLX_ARB_create_context spec says:
 578     *
 579     *     "Forward-compatible contexts are defined only for OpenGL versions
 580     *     3.0 and later."
 581     */
 582    if (*major_ver < 3 && (*flags & __DRI_CTX_FLAG_FORWARD_COMPATIBLE) != 0) {
 583       *error = __DRI_CTX_ERROR_BAD_FLAG;
 584       return false;
 585    }
 586
 587    if (*major_ver >= 3 && *render_type == GLX_COLOR_INDEX_TYPE) {
 588       *error = __DRI_CTX_ERROR_BAD_FLAG;
 589       return false;
 590    }
 591
 592    *error = __DRI_CTX_ERROR_SUCCESS;
 593    return true;
 594 }
 595
 596 #endif /* GLX_DIRECT_RENDERING */