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 DEFAULT_DRIVER_DIR
  77 /* this is normally defined in Mesa/configs/default with DRI_DRIVER_SEARCH_PATH */
  78 #define DEFAULT_DRIVER_DIR "/usr/local/lib/dri"
  79 #endif
  80
  81 /**
  82  * Try to \c dlopen the named driver.
  83  *
  84  * This function adds the "_dri.so" suffix to the driver name and searches the
  85  * directories specified by the \c LIBGL_DRIVERS_PATH environment variable in
  86  * order to find the driver.
  87  *
  88  * \param driverName - a name like "i965", "radeon", "nouveau", etc.
  89  *
  90  * \returns
  91  * A handle from \c dlopen, or \c NULL if driver file not found.
  92  */
  93 _X_HIDDEN void *
  94 driOpenDriver(const char *driverName)
  95 {
  96    void *glhandle, *handle;
  97    const char *libPaths, *p, *next;
  98    char realDriverName[200];
  99    int len;
 100
 101    /* Attempt to make sure libGL symbols will be visible to the driver */
 102    glhandle = dlopen("libGL.so.1", RTLD_NOW | RTLD_GLOBAL);
 103
 104    libPaths = NULL;
 105    if (geteuid() == getuid()) {
 106       /* don't allow setuid apps to use LIBGL_DRIVERS_PATH */
 107       libPaths = getenv("LIBGL_DRIVERS_PATH");
 108       if (!libPaths)
 109          libPaths = getenv("LIBGL_DRIVERS_DIR");        /* deprecated */
 110    }
 111    if (libPaths == NULL)
 112       libPaths = DEFAULT_DRIVER_DIR;
 113
 114    handle = NULL;
 115    for (p = libPaths; *p; p = next) {
 116       next = strchr(p, ':');
 117       if (next == NULL) {
 118          len = strlen(p);
 119          next = p + len;
 120       }
 121       else {
 122          len = next - p;
 123          next++;
 124       }
 125
 126 #ifdef GLX_USE_TLS
 127       snprintf(realDriverName, sizeof realDriverName,
 128                "%.*s/tls/%s_dri.so", len, p, driverName);
 129       InfoMessageF("OpenDriver: trying %s\n", realDriverName);
 130       handle = dlopen(realDriverName, RTLD_NOW | RTLD_GLOBAL);
 131 #endif
 132
 133       if (handle == NULL) {
 134          snprintf(realDriverName, sizeof realDriverName,
 135                   "%.*s/%s_dri.so", len, p, driverName);
 136          InfoMessageF("OpenDriver: trying %s\n", realDriverName);
 137          handle = dlopen(realDriverName, RTLD_NOW | RTLD_GLOBAL);
 138       }
 139
 140       if (handle != NULL)
 141          break;
 142       else
 143          ErrorMessageF("dlopen %s failed (%s)\n", realDriverName, dlerror());
 144    }
 145
 146    if (!handle)
 147       ErrorMessageF("unable to load driver: %s_dri.so\n", driverName);
 148
 149    if (glhandle)
 150       dlclose(glhandle);
 151
 152    return handle;
 153 }
 154
 155 _X_HIDDEN const __DRIextension **
 156 driGetDriverExtensions(void *handle, const char *driver_name)
 157 {
 158    const __DRIextension **extensions = NULL;
 159    const __DRIextension **(*get_extensions)(void);
 160    char *get_extensions_name;
 161
 162    if (asprintf(&get_extensions_name, "%s_%s",
 163                 __DRI_DRIVER_GET_EXTENSIONS, driver_name) != -1) {
 164       get_extensions = dlsym(handle, get_extensions_name);
 165       if (get_extensions) {
 166          free(get_extensions_name);
 167          return get_extensions();
 168       } else {
 169          InfoMessageF("driver does not expose %s(): %s\n",
 170                       get_extensions_name, dlerror());
 171          free(get_extensions_name);
 172       }
 173    }
 174
 175    extensions = dlsym(handle, __DRI_DRIVER_EXTENSIONS);
 176    if (extensions == NULL) {
 177       ErrorMessageF("driver exports no extensions (%s)\n", dlerror());
 178       return NULL;
 179    }
 180
 181    return extensions;
 182 }
 183
 184 static GLboolean
 185 __driGetMSCRate(__DRIdrawable *draw,
 186                 int32_t * numerator, int32_t * denominator,
 187                 void *loaderPrivate)
 188 {
 189    __GLXDRIdrawable *glxDraw = loaderPrivate;
 190
 191    return __glxGetMscRate(glxDraw->psc, numerator, denominator);
 192 }
 193
 194 _X_HIDDEN const __DRIsystemTimeExtension systemTimeExtension = {
 195    {__DRI_SYSTEM_TIME, __DRI_SYSTEM_TIME_VERSION},
 196    __glXGetUST,
 197    __driGetMSCRate
 198 };
 199
 200 #define __ATTRIB(attrib, field) \
 201     { attrib, offsetof(struct glx_config, field) }
 202
 203 static const struct
 204 {
 205    unsigned int attrib, offset;
 206 } attribMap[] = {
 207    __ATTRIB(__DRI_ATTRIB_BUFFER_SIZE, rgbBits),
 208       __ATTRIB(__DRI_ATTRIB_LEVEL, level),
 209       __ATTRIB(__DRI_ATTRIB_RED_SIZE, redBits),
 210       __ATTRIB(__DRI_ATTRIB_GREEN_SIZE, greenBits),
 211       __ATTRIB(__DRI_ATTRIB_BLUE_SIZE, blueBits),
 212       __ATTRIB(__DRI_ATTRIB_ALPHA_SIZE, alphaBits),
 213       __ATTRIB(__DRI_ATTRIB_DEPTH_SIZE, depthBits),
 214       __ATTRIB(__DRI_ATTRIB_STENCIL_SIZE, stencilBits),
 215       __ATTRIB(__DRI_ATTRIB_ACCUM_RED_SIZE, accumRedBits),
 216       __ATTRIB(__DRI_ATTRIB_ACCUM_GREEN_SIZE, accumGreenBits),
 217       __ATTRIB(__DRI_ATTRIB_ACCUM_BLUE_SIZE, accumBlueBits),
 218       __ATTRIB(__DRI_ATTRIB_ACCUM_ALPHA_SIZE, accumAlphaBits),
 219       __ATTRIB(__DRI_ATTRIB_SAMPLE_BUFFERS, sampleBuffers),
 220       __ATTRIB(__DRI_ATTRIB_SAMPLES, samples),
 221       __ATTRIB(__DRI_ATTRIB_DOUBLE_BUFFER, doubleBufferMode),
 222       __ATTRIB(__DRI_ATTRIB_STEREO, stereoMode),
 223       __ATTRIB(__DRI_ATTRIB_AUX_BUFFERS, numAuxBuffers),
 224 #if 0
 225       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_TYPE, transparentPixel),
 226       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_INDEX_VALUE, transparentIndex),
 227       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_RED_VALUE, transparentRed),
 228       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_GREEN_VALUE, transparentGreen),
 229       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_BLUE_VALUE, transparentBlue),
 230       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_ALPHA_VALUE, transparentAlpha),
 231       __ATTRIB(__DRI_ATTRIB_RED_MASK, redMask),
 232       __ATTRIB(__DRI_ATTRIB_GREEN_MASK, greenMask),
 233       __ATTRIB(__DRI_ATTRIB_BLUE_MASK, blueMask),
 234       __ATTRIB(__DRI_ATTRIB_ALPHA_MASK, alphaMask),
 235 #endif
 236       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_WIDTH, maxPbufferWidth),
 237       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_HEIGHT, maxPbufferHeight),
 238       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_PIXELS, maxPbufferPixels),
 239       __ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_WIDTH, optimalPbufferWidth),
 240       __ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_HEIGHT, optimalPbufferHeight),
 241 #if 0
 242       __ATTRIB(__DRI_ATTRIB_SWAP_METHOD, swapMethod),
 243 #endif
 244 __ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGB, bindToTextureRgb),
 245       __ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGBA, bindToTextureRgba),
 246       __ATTRIB(__DRI_ATTRIB_BIND_TO_MIPMAP_TEXTURE,
 247                      bindToMipmapTexture),
 248       __ATTRIB(__DRI_ATTRIB_YINVERTED, yInverted),
 249       __ATTRIB(__DRI_ATTRIB_FRAMEBUFFER_SRGB_CAPABLE, sRGBCapable)
 250 };
 251
 252 static int
 253 scalarEqual(struct glx_config *mode, unsigned int attrib, unsigned int value)
 254 {
 255    unsigned int glxValue;
 256    int i;
 257
 258    for (i = 0; i < ARRAY_SIZE(attribMap); i++)
 259       if (attribMap[i].attrib == attrib) {
 260          glxValue = *(unsigned int *) ((char *) mode + attribMap[i].offset);
 261          return glxValue == GLX_DONT_CARE || glxValue == value;
 262       }
 263
 264    return GL_TRUE;              /* Is a non-existing attribute equal to value? */
 265 }
 266
 267 static int
 268 driConfigEqual(const __DRIcoreExtension *core,
 269                struct glx_config *config, const __DRIconfig *driConfig)
 270 {
 271    unsigned int attrib, value, glxValue;
 272    int i;
 273
 274    i = 0;
 275    while (core->indexConfigAttrib(driConfig, i++, &attrib, &value)) {
 276       switch (attrib) {
 277       case __DRI_ATTRIB_RENDER_TYPE:
 278          glxValue = 0;
 279          if (value & __DRI_ATTRIB_RGBA_BIT) {
 280             glxValue |= GLX_RGBA_BIT;
 281          }
 282          if (value & __DRI_ATTRIB_COLOR_INDEX_BIT) {
 283             glxValue |= GLX_COLOR_INDEX_BIT;
 284          }
 285          if (value & __DRI_ATTRIB_FLOAT_BIT) {
 286             glxValue |= GLX_RGBA_FLOAT_BIT_ARB;
 287          }
 288          if (value & __DRI_ATTRIB_UNSIGNED_FLOAT_BIT) {
 289             glxValue |= GLX_RGBA_UNSIGNED_FLOAT_BIT_EXT;
 290          }
 291          if (glxValue != config->renderType)
 292             return GL_FALSE;
 293          break;
 294
 295       case __DRI_ATTRIB_CONFIG_CAVEAT:
 296          if (value & __DRI_ATTRIB_NON_CONFORMANT_CONFIG)
 297             glxValue = GLX_NON_CONFORMANT_CONFIG;
 298          else if (value & __DRI_ATTRIB_SLOW_BIT)
 299             glxValue = GLX_SLOW_CONFIG;
 300          else
 301             glxValue = GLX_NONE;
 302          if (glxValue != config->visualRating)
 303             return GL_FALSE;
 304          break;
 305
 306       case __DRI_ATTRIB_BIND_TO_TEXTURE_TARGETS:
 307          glxValue = 0;
 308          if (value & __DRI_ATTRIB_TEXTURE_1D_BIT)
 309             glxValue |= GLX_TEXTURE_1D_BIT_EXT;
 310          if (value & __DRI_ATTRIB_TEXTURE_2D_BIT)
 311             glxValue |= GLX_TEXTURE_2D_BIT_EXT;
 312          if (value & __DRI_ATTRIB_TEXTURE_RECTANGLE_BIT)
 313             glxValue |= GLX_TEXTURE_RECTANGLE_BIT_EXT;
 314          if (config->bindToTextureTargets != GLX_DONT_CARE &&
 315              glxValue != config->bindToTextureTargets)
 316             return GL_FALSE;
 317          break;
 318
 319       default:
 320          if (!scalarEqual(config, attrib, value))
 321             return GL_FALSE;
 322       }
 323    }
 324
 325    return GL_TRUE;
 326 }
 327
 328 static struct glx_config *
 329 createDriMode(const __DRIcoreExtension * core,
 330               struct glx_config *config, const __DRIconfig **driConfigs)
 331 {
 332    __GLXDRIconfigPrivate *driConfig;
 333    int i;
 334
 335    for (i = 0; driConfigs[i]; i++) {
 336       if (driConfigEqual(core, config, driConfigs[i]))
 337          break;
 338    }
 339
 340    if (driConfigs[i] == NULL)
 341       return NULL;
 342
 343    driConfig = malloc(sizeof *driConfig);
 344    if (driConfig == NULL)
 345       return NULL;
 346
 347    driConfig->base = *config;
 348    driConfig->driConfig = driConfigs[i];
 349
 350    return &driConfig->base;
 351 }
 352
 353 _X_HIDDEN struct glx_config *
 354 driConvertConfigs(const __DRIcoreExtension * core,
 355                   struct glx_config *configs, const __DRIconfig **driConfigs)
 356 {
 357    struct glx_config head, *tail, *m;
 358
 359    tail = &head;
 360    head.next = NULL;
 361    for (m = configs; m; m = m->next) {
 362       tail->next = createDriMode(core, m, driConfigs);
 363       if (tail->next == NULL) {
 364          /* no matching dri config for m */
 365          continue;
 366       }
 367
 368
 369       tail = tail->next;
 370    }
 371
 372    return head.next;
 373 }
 374
 375 _X_HIDDEN void
 376 driDestroyConfigs(const __DRIconfig **configs)
 377 {
 378    int i;
 379
 380    for (i = 0; configs[i]; i++)
 381       free((__DRIconfig *) configs[i]);
 382    free(configs);
 383 }
 384
 385 _X_HIDDEN __GLXDRIdrawable *
 386 driFetchDrawable(struct glx_context *gc, GLXDrawable glxDrawable)
 387 {
 388    struct glx_display *const priv = __glXInitialize(gc->psc->dpy);
 389    __GLXDRIdrawable *pdraw;
 390    struct glx_screen *psc;
 391
 392    if (priv == NULL)
 393       return NULL;
 394
 395    psc = priv->screens[gc->screen];
 396    if (priv->drawHash == NULL)
 397       return NULL;
 398
 399    if (__glxHashLookup(priv->drawHash, glxDrawable, (void *) &pdraw) == 0) {
 400       pdraw->refcount ++;
 401       return pdraw;
 402    }
 403
 404    pdraw = psc->driScreen->createDrawable(psc, glxDrawable,
 405                                           glxDrawable, gc->config);
 406
 407    if (pdraw == NULL) {
 408       ErrorMessageF("failed to create drawable\n");
 409       return NULL;
 410    }
 411
 412    if (__glxHashInsert(priv->drawHash, glxDrawable, pdraw)) {
 413       (*pdraw->destroyDrawable) (pdraw);
 414       return NULL;
 415    }
 416    pdraw->refcount = 1;
 417
 418    return pdraw;
 419 }
 420
 421 _X_HIDDEN void
 422 driReleaseDrawables(struct glx_context *gc)
 423 {
 424    const struct glx_display *priv = gc->psc->display;
 425    __GLXDRIdrawable *pdraw;
 426
 427    if (priv == NULL)
 428       return;
 429
 430    if (__glxHashLookup(priv->drawHash,
 431                        gc->currentDrawable, (void *) &pdraw) == 0) {
 432       if (pdraw->drawable == pdraw->xDrawable) {
 433          pdraw->refcount --;
 434          if (pdraw->refcount == 0) {
 435             (*pdraw->destroyDrawable)(pdraw);
 436             __glxHashDelete(priv->drawHash, gc->currentDrawable);
 437          }
 438       }
 439    }
 440
 441    if (__glxHashLookup(priv->drawHash,
 442                        gc->currentReadable, (void *) &pdraw) == 0) {
 443       if (pdraw->drawable == pdraw->xDrawable) {
 444          pdraw->refcount --;
 445          if (pdraw->refcount == 0) {
 446             (*pdraw->destroyDrawable)(pdraw);
 447             __glxHashDelete(priv->drawHash, gc->currentReadable);
 448          }
 449       }
 450    }
 451
 452    gc->currentDrawable = None;
 453    gc->currentReadable = None;
 454
 455 }
 456
 457 _X_HIDDEN bool
 458 dri2_convert_glx_attribs(unsigned num_attribs, const uint32_t *attribs,
 459                          unsigned *major_ver, unsigned *minor_ver,
 460                          uint32_t *render_type, uint32_t *flags, unsigned *api,
 461                          int *reset, unsigned *error)
 462 {
 463    unsigned i;
 464    bool got_profile = false;
 465    uint32_t profile;
 466
 467    *major_ver = 1;
 468    *minor_ver = 0;
 469    *render_type = GLX_RGBA_TYPE;
 470    *reset = __DRI_CTX_RESET_NO_NOTIFICATION;
 471    *flags = 0;
 472    *api = __DRI_API_OPENGL;
 473
 474    if (num_attribs == 0) {
 475       return true;
 476    }
 477
 478    /* This is actually an internal error, but what the heck.
 479     */
 480    if (attribs == NULL) {
 481       *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 482       return false;
 483    }
 484
 485    for (i = 0; i < num_attribs; i++) {
 486       switch (attribs[i * 2]) {
 487       case GLX_CONTEXT_MAJOR_VERSION_ARB:
 488          *major_ver = attribs[i * 2 + 1];
 489          break;
 490       case GLX_CONTEXT_MINOR_VERSION_ARB:
 491          *minor_ver = attribs[i * 2 + 1];
 492          break;
 493       case GLX_CONTEXT_FLAGS_ARB:
 494          *flags = attribs[i * 2 + 1];
 495          break;
 496       case GLX_CONTEXT_PROFILE_MASK_ARB:
 497          profile = attribs[i * 2 + 1];
 498          got_profile = true;
 499          break;
 500       case GLX_RENDER_TYPE:
 501          *render_type = attribs[i * 2 + 1];
 502          break;
 503       case GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB:
 504          switch (attribs[i * 2 + 1]) {
 505          case GLX_NO_RESET_NOTIFICATION_ARB:
 506             *reset = __DRI_CTX_RESET_NO_NOTIFICATION;
 507             break;
 508          case GLX_LOSE_CONTEXT_ON_RESET_ARB:
 509             *reset = __DRI_CTX_RESET_LOSE_CONTEXT;
 510             break;
 511          default:
 512             *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 513             return false;
 514          }
 515          break;
 516       default:
 517          /* If an unknown attribute is received, fail.
 518           */
 519          *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 520          return false;
 521       }
 522    }
 523
 524    if (!got_profile) {
 525       if (*major_ver > 3 || (*major_ver == 3 && *minor_ver >= 2))
 526          *api = __DRI_API_OPENGL_CORE;
 527    } else {
 528       switch (profile) {
 529       case GLX_CONTEXT_CORE_PROFILE_BIT_ARB:
 530          /* There are no profiles before OpenGL 3.2.  The
 531           * GLX_ARB_create_context_profile spec says:
 532           *
 533           *     "If the requested OpenGL version is less than 3.2,
 534           *     GLX_CONTEXT_PROFILE_MASK_ARB is ignored and the functionality
 535           *     of the context is determined solely by the requested version."
 536           */
 537          *api = (*major_ver > 3 || (*major_ver == 3 && *minor_ver >= 2))
 538             ? __DRI_API_OPENGL_CORE : __DRI_API_OPENGL;
 539          break;
 540       case GLX_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB:
 541          *api = __DRI_API_OPENGL;
 542          break;
 543       case GLX_CONTEXT_ES2_PROFILE_BIT_EXT:
 544          *api = __DRI_API_GLES2;
 545          break;
 546       default:
 547          *error = __DRI_CTX_ERROR_BAD_API;
 548          return false;
 549       }
 550    }
 551
 552    /* Unknown flag value.
 553     */
 554    if (*flags & ~(__DRI_CTX_FLAG_DEBUG | __DRI_CTX_FLAG_FORWARD_COMPATIBLE
 555                   | __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS)) {
 556       *error = __DRI_CTX_ERROR_UNKNOWN_FLAG;
 557       return false;
 558    }
 559
 560    /* There are no forward-compatible contexts before OpenGL 3.0.  The
 561     * GLX_ARB_create_context spec says:
 562     *
 563     *     "Forward-compatible contexts are defined only for OpenGL versions
 564     *     3.0 and later."
 565     */
 566    if (*major_ver < 3 && (*flags & __DRI_CTX_FLAG_FORWARD_COMPATIBLE) != 0) {
 567       *error = __DRI_CTX_ERROR_BAD_FLAG;
 568       return false;
 569    }
 570
 571    if (*major_ver >= 3 && *render_type == GLX_COLOR_INDEX_TYPE) {
 572       *error = __DRI_CTX_ERROR_BAD_FLAG;
 573       return false;
 574    }
 575
 576    /* The GLX_EXT_create_context_es2_profile spec says:
 577     *
 578     *     "... If the version requested is 2.0, and the
 579     *     GLX_CONTEXT_ES2_PROFILE_BIT_EXT bit is set in the
 580     *     GLX_CONTEXT_PROFILE_MASK_ARB attribute (see below), then the context
 581     *     returned will implement OpenGL ES 2.0. This is the only way in which
 582     *     an implementation may request an OpenGL ES 2.0 context."
 583     */
 584    if (*api == __DRI_API_GLES2 && (*major_ver != 2 || *minor_ver != 0)) {
 585       *error = __DRI_CTX_ERROR_BAD_API;
 586       return false;
 587    }
 588
 589    *error = __DRI_CTX_ERROR_SUCCESS;
 590    return true;
 591 }
 592
 593 #endif /* GLX_DIRECT_RENDERING */