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
  44 #ifndef RTLD_NOW
  45 #define RTLD_NOW 0
  46 #endif
  47 #ifndef RTLD_GLOBAL
  48 #define RTLD_GLOBAL 0
  49 #endif
  50
  51 /**
  52  * Print informational message to stderr if LIBGL_DEBUG is set to
  53  * "verbose".
  54  */
  55 _X_HIDDEN void
  56 InfoMessageF(const char *f, ...)
  57 {
  58    va_list args;
  59    const char *env;
  60
  61    if ((env = getenv("LIBGL_DEBUG")) && strstr(env, "verbose")) {
  62       fprintf(stderr, "libGL: ");
  63       va_start(args, f);
  64       vfprintf(stderr, f, args);
  65       va_end(args);
  66    }
  67 }
  68
  69 /**
  70  * Print error message to stderr if LIBGL_DEBUG is set to anything but
  71  * "quiet", (do nothing if LIBGL_DEBUG is unset).
  72  */
  73 _X_HIDDEN void
  74 ErrorMessageF(const char *f, ...)
  75 {
  76    va_list args;
  77    const char *env;
  78
  79    if ((env = getenv("LIBGL_DEBUG")) && !strstr(env, "quiet")) {
  80       fprintf(stderr, "libGL error: ");
  81       va_start(args, f);
  82       vfprintf(stderr, f, args);
  83       va_end(args);
  84    }
  85 }
  86
  87 /**
  88  * Print error message unless LIBGL_DEBUG is set to "quiet".
  89  *
  90  * The distinction between CriticalErrorMessageF and ErrorMessageF is
  91  * that critcial errors will be printed by default, (even when
  92  * LIBGL_DEBUG is unset).
  93  */
  94 _X_HIDDEN void
  95 CriticalErrorMessageF(const char *f, ...)
  96 {
  97    va_list args;
  98    const char *env;
  99
 100    if (!(env = getenv("LIBGL_DEBUG")) || !strstr(env, "quiet")) {
 101       fprintf(stderr, "libGL error: ");
 102       va_start(args, f);
 103       vfprintf(stderr, f, args);
 104       va_end(args);
 105
 106       if (!env || !strstr(env, "verbose"))
 107          fprintf(stderr, "libGL error: Try again with LIBGL_DEBUG=verbose for more details.\n");
 108    }
 109 }
 110
 111 #ifndef DEFAULT_DRIVER_DIR
 112 /* this is normally defined in Mesa/configs/default with DRI_DRIVER_SEARCH_PATH */
 113 #define DEFAULT_DRIVER_DIR "/usr/local/lib/dri"
 114 #endif
 115
 116 /**
 117  * Try to \c dlopen the named driver.
 118  *
 119  * This function adds the "_dri.so" suffix to the driver name and searches the
 120  * directories specified by the \c LIBGL_DRIVERS_PATH environment variable in
 121  * order to find the driver.
 122  *
 123  * \param driverName - a name like "i965", "radeon", "nouveau", etc.
 124  *
 125  * \returns
 126  * A handle from \c dlopen, or \c NULL if driver file not found.
 127  */
 128 _X_HIDDEN void *
 129 driOpenDriver(const char *driverName)
 130 {
 131    void *glhandle, *handle;
 132    const char *libPaths, *p, *next;
 133    char realDriverName[200];
 134    int len;
 135
 136    /* Attempt to make sure libGL symbols will be visible to the driver */
 137    glhandle = dlopen("libGL.so.1", RTLD_NOW | RTLD_GLOBAL);
 138
 139    libPaths = NULL;
 140    if (geteuid() == getuid()) {
 141       /* don't allow setuid apps to use LIBGL_DRIVERS_PATH */
 142       libPaths = getenv("LIBGL_DRIVERS_PATH");
 143       if (!libPaths)
 144          libPaths = getenv("LIBGL_DRIVERS_DIR");        /* deprecated */
 145    }
 146    if (libPaths == NULL)
 147       libPaths = DEFAULT_DRIVER_DIR;
 148
 149    handle = NULL;
 150    for (p = libPaths; *p; p = next) {
 151       next = strchr(p, ':');
 152       if (next == NULL) {
 153          len = strlen(p);
 154          next = p + len;
 155       }
 156       else {
 157          len = next - p;
 158          next++;
 159       }
 160
 161 #ifdef GLX_USE_TLS
 162       snprintf(realDriverName, sizeof realDriverName,
 163                "%.*s/tls/%s_dri.so", len, p, driverName);
 164       InfoMessageF("OpenDriver: trying %s\n", realDriverName);
 165       handle = dlopen(realDriverName, RTLD_NOW | RTLD_GLOBAL);
 166 #endif
 167
 168       if (handle == NULL) {
 169          snprintf(realDriverName, sizeof realDriverName,
 170                   "%.*s/%s_dri.so", len, p, driverName);
 171          InfoMessageF("OpenDriver: trying %s\n", realDriverName);
 172          handle = dlopen(realDriverName, RTLD_NOW | RTLD_GLOBAL);
 173       }
 174
 175       if (handle != NULL)
 176          break;
 177       else
 178          ErrorMessageF("dlopen %s failed (%s)\n", realDriverName, dlerror());
 179    }
 180
 181    if (!handle)
 182       ErrorMessageF("unable to load driver: %s_dri.so\n", driverName);
 183
 184    if (glhandle)
 185       dlclose(glhandle);
 186
 187    return handle;
 188 }
 189
 190 static GLboolean
 191 __driGetMSCRate(__DRIdrawable *draw,
 192                 int32_t * numerator, int32_t * denominator,
 193                 void *loaderPrivate)
 194 {
 195    __GLXDRIdrawable *glxDraw = loaderPrivate;
 196
 197    return __glxGetMscRate(glxDraw, numerator, denominator);
 198 }
 199
 200 _X_HIDDEN const __DRIsystemTimeExtension systemTimeExtension = {
 201    {__DRI_SYSTEM_TIME, __DRI_SYSTEM_TIME_VERSION},
 202    __glXGetUST,
 203    __driGetMSCRate
 204 };
 205
 206 #define __ATTRIB(attrib, field) \
 207     { attrib, offsetof(struct glx_config, field) }
 208
 209 static const struct
 210 {
 211    unsigned int attrib, offset;
 212 } attribMap[] = {
 213    __ATTRIB(__DRI_ATTRIB_BUFFER_SIZE, rgbBits),
 214       __ATTRIB(__DRI_ATTRIB_LEVEL, level),
 215       __ATTRIB(__DRI_ATTRIB_RED_SIZE, redBits),
 216       __ATTRIB(__DRI_ATTRIB_GREEN_SIZE, greenBits),
 217       __ATTRIB(__DRI_ATTRIB_BLUE_SIZE, blueBits),
 218       __ATTRIB(__DRI_ATTRIB_ALPHA_SIZE, alphaBits),
 219       __ATTRIB(__DRI_ATTRIB_DEPTH_SIZE, depthBits),
 220       __ATTRIB(__DRI_ATTRIB_STENCIL_SIZE, stencilBits),
 221       __ATTRIB(__DRI_ATTRIB_ACCUM_RED_SIZE, accumRedBits),
 222       __ATTRIB(__DRI_ATTRIB_ACCUM_GREEN_SIZE, accumGreenBits),
 223       __ATTRIB(__DRI_ATTRIB_ACCUM_BLUE_SIZE, accumBlueBits),
 224       __ATTRIB(__DRI_ATTRIB_ACCUM_ALPHA_SIZE, accumAlphaBits),
 225       __ATTRIB(__DRI_ATTRIB_SAMPLE_BUFFERS, sampleBuffers),
 226       __ATTRIB(__DRI_ATTRIB_SAMPLES, samples),
 227       __ATTRIB(__DRI_ATTRIB_DOUBLE_BUFFER, doubleBufferMode),
 228       __ATTRIB(__DRI_ATTRIB_STEREO, stereoMode),
 229       __ATTRIB(__DRI_ATTRIB_AUX_BUFFERS, numAuxBuffers),
 230 #if 0
 231       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_TYPE, transparentPixel),
 232       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_INDEX_VALUE, transparentIndex),
 233       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_RED_VALUE, transparentRed),
 234       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_GREEN_VALUE, transparentGreen),
 235       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_BLUE_VALUE, transparentBlue),
 236       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_ALPHA_VALUE, transparentAlpha),
 237       __ATTRIB(__DRI_ATTRIB_RED_MASK, redMask),
 238       __ATTRIB(__DRI_ATTRIB_GREEN_MASK, greenMask),
 239       __ATTRIB(__DRI_ATTRIB_BLUE_MASK, blueMask),
 240       __ATTRIB(__DRI_ATTRIB_ALPHA_MASK, alphaMask),
 241 #endif
 242       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_WIDTH, maxPbufferWidth),
 243       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_HEIGHT, maxPbufferHeight),
 244       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_PIXELS, maxPbufferPixels),
 245       __ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_WIDTH, optimalPbufferWidth),
 246       __ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_HEIGHT, optimalPbufferHeight),
 247 #if 0
 248       __ATTRIB(__DRI_ATTRIB_SWAP_METHOD, swapMethod),
 249 #endif
 250 __ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGB, bindToTextureRgb),
 251       __ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGBA, bindToTextureRgba),
 252       __ATTRIB(__DRI_ATTRIB_BIND_TO_MIPMAP_TEXTURE,
 253                      bindToMipmapTexture),
 254       __ATTRIB(__DRI_ATTRIB_YINVERTED, yInverted),
 255       __ATTRIB(__DRI_ATTRIB_FRAMEBUFFER_SRGB_CAPABLE, sRGBCapable)
 256 };
 257
 258 static int
 259 scalarEqual(struct glx_config *mode, unsigned int attrib, unsigned int value)
 260 {
 261    unsigned int glxValue;
 262    int i;
 263
 264    for (i = 0; i < ARRAY_SIZE(attribMap); i++)
 265       if (attribMap[i].attrib == attrib) {
 266          glxValue = *(unsigned int *) ((char *) mode + attribMap[i].offset);
 267          return glxValue == GLX_DONT_CARE || glxValue == value;
 268       }
 269
 270    return GL_TRUE;              /* Is a non-existing attribute equal to value? */
 271 }
 272
 273 static int
 274 driConfigEqual(const __DRIcoreExtension *core,
 275                struct glx_config *config, const __DRIconfig *driConfig)
 276 {
 277    unsigned int attrib, value, glxValue;
 278    int i;
 279
 280    i = 0;
 281    while (core->indexConfigAttrib(driConfig, i++, &attrib, &value)) {
 282       switch (attrib) {
 283       case __DRI_ATTRIB_RENDER_TYPE:
 284          glxValue = 0;
 285          if (value & __DRI_ATTRIB_RGBA_BIT) {
 286             glxValue |= GLX_RGBA_BIT;
 287          }
 288          if (value & __DRI_ATTRIB_COLOR_INDEX_BIT) {
 289             glxValue |= GLX_COLOR_INDEX_BIT;
 290          }
 291          if (value & __DRI_ATTRIB_FLOAT_BIT) {
 292             glxValue |= GLX_RGBA_FLOAT_BIT_ARB;
 293          }
 294          if (value & __DRI_ATTRIB_UNSIGNED_FLOAT_BIT) {
 295             glxValue |= GLX_RGBA_UNSIGNED_FLOAT_BIT_EXT;
 296          }
 297          if (glxValue != config->renderType)
 298             return GL_FALSE;
 299          break;
 300
 301       case __DRI_ATTRIB_CONFIG_CAVEAT:
 302          if (value & __DRI_ATTRIB_NON_CONFORMANT_CONFIG)
 303             glxValue = GLX_NON_CONFORMANT_CONFIG;
 304          else if (value & __DRI_ATTRIB_SLOW_BIT)
 305             glxValue = GLX_SLOW_CONFIG;
 306          else
 307             glxValue = GLX_NONE;
 308          if (glxValue != config->visualRating)
 309             return GL_FALSE;
 310          break;
 311
 312       case __DRI_ATTRIB_BIND_TO_TEXTURE_TARGETS:
 313          glxValue = 0;
 314          if (value & __DRI_ATTRIB_TEXTURE_1D_BIT)
 315             glxValue |= GLX_TEXTURE_1D_BIT_EXT;
 316          if (value & __DRI_ATTRIB_TEXTURE_2D_BIT)
 317             glxValue |= GLX_TEXTURE_2D_BIT_EXT;
 318          if (value & __DRI_ATTRIB_TEXTURE_RECTANGLE_BIT)
 319             glxValue |= GLX_TEXTURE_RECTANGLE_BIT_EXT;
 320          if (config->bindToTextureTargets != GLX_DONT_CARE &&
 321              glxValue != config->bindToTextureTargets)
 322             return GL_FALSE;
 323          break;
 324
 325       default:
 326          if (!scalarEqual(config, attrib, value))
 327             return GL_FALSE;
 328       }
 329    }
 330
 331    return GL_TRUE;
 332 }
 333
 334 static struct glx_config *
 335 createDriMode(const __DRIcoreExtension * core,
 336               struct glx_config *config, const __DRIconfig **driConfigs)
 337 {
 338    __GLXDRIconfigPrivate *driConfig;
 339    int i;
 340
 341    for (i = 0; driConfigs[i]; i++) {
 342       if (driConfigEqual(core, config, driConfigs[i]))
 343          break;
 344    }
 345
 346    if (driConfigs[i] == NULL)
 347       return NULL;
 348
 349    driConfig = malloc(sizeof *driConfig);
 350    if (driConfig == NULL)
 351       return NULL;
 352
 353    driConfig->base = *config;
 354    driConfig->driConfig = driConfigs[i];
 355
 356    return &driConfig->base;
 357 }
 358
 359 _X_HIDDEN struct glx_config *
 360 driConvertConfigs(const __DRIcoreExtension * core,
 361                   struct glx_config *configs, const __DRIconfig **driConfigs)
 362 {
 363    struct glx_config head, *tail, *m;
 364
 365    tail = &head;
 366    head.next = NULL;
 367    for (m = configs; m; m = m->next) {
 368       tail->next = createDriMode(core, m, driConfigs);
 369       if (tail->next == NULL) {
 370          /* no matching dri config for m */
 371          continue;
 372       }
 373
 374
 375       tail = tail->next;
 376    }
 377
 378    return head.next;
 379 }
 380
 381 _X_HIDDEN void
 382 driDestroyConfigs(const __DRIconfig **configs)
 383 {
 384    int i;
 385
 386    for (i = 0; configs[i]; i++)
 387       free((__DRIconfig *) configs[i]);
 388    free(configs);
 389 }
 390
 391 _X_HIDDEN __GLXDRIdrawable *
 392 driFetchDrawable(struct glx_context *gc, GLXDrawable glxDrawable)
 393 {
 394    struct glx_display *const priv = __glXInitialize(gc->psc->dpy);
 395    __GLXDRIdrawable *pdraw;
 396    struct glx_screen *psc;
 397
 398    if (priv == NULL)
 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_ES2_PROFILE_BIT_EXT:
 550          *api = __DRI_API_GLES2;
 551          break;
 552       default:
 553          *error = __DRI_CTX_ERROR_BAD_API;
 554          return false;
 555       }
 556    }
 557
 558    /* Unknown flag value.
 559     */
 560    if (*flags & ~(__DRI_CTX_FLAG_DEBUG | __DRI_CTX_FLAG_FORWARD_COMPATIBLE
 561                   | __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS)) {
 562       *error = __DRI_CTX_ERROR_UNKNOWN_FLAG;
 563       return false;
 564    }
 565
 566    /* There are no forward-compatible contexts before OpenGL 3.0.  The
 567     * GLX_ARB_create_context spec says:
 568     *
 569     *     "Forward-compatible contexts are defined only for OpenGL versions
 570     *     3.0 and later."
 571     */
 572    if (*major_ver < 3 && (*flags & __DRI_CTX_FLAG_FORWARD_COMPATIBLE) != 0) {
 573       *error = __DRI_CTX_ERROR_BAD_FLAG;
 574       return false;
 575    }
 576
 577    if (*major_ver >= 3 && *render_type == GLX_COLOR_INDEX_TYPE) {
 578       *error = __DRI_CTX_ERROR_BAD_FLAG;
 579       return false;
 580    }
 581
 582    /* The GLX_EXT_create_context_es2_profile spec says:
 583     *
 584     *     "... If the version requested is 2.0, and the
 585     *     GLX_CONTEXT_ES2_PROFILE_BIT_EXT bit is set in the
 586     *     GLX_CONTEXT_PROFILE_MASK_ARB attribute (see below), then the context
 587     *     returned will implement OpenGL ES 2.0. This is the only way in which
 588     *     an implementation may request an OpenGL ES 2.0 context."
 589     */
 590    if (*api == __DRI_API_GLES2 && (*major_ver != 2 || *minor_ver != 0)) {
 591       *error = __DRI_CTX_ERROR_BAD_API;
 592       return false;
 593    }
 594
 595    *error = __DRI_CTX_ERROR_SUCCESS;
 596    return true;
 597 }
 598
 599 #endif /* GLX_DIRECT_RENDERING */