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 /**
  81  * Try to \c dlopen the named driver.
  82  *
  83  * This function adds the "_dri.so" suffix to the driver name and searches the
  84  * directories specified by the \c LIBGL_DRIVERS_PATH environment variable in
  85  * order to find the driver.
  86  *
  87  * \param driverName - a name like "i965", "radeon", "nouveau", etc.
  88  * \param out_driver_handle - Address to return the resulting dlopen() handle.
  89  *
  90  * \returns
  91  * The __DRIextension entrypoint table for the driver, or \c NULL if driver
  92  * file not found.
  93  */
  94 _X_HIDDEN const __DRIextension **
  95 driOpenDriver(const char *driverName, void **out_driver_handle)
  96 {
  97    void *glhandle;
  98
  99    /* Attempt to make sure libGL symbols will be visible to the driver */
 100    glhandle = dlopen(GL_LIB_NAME, RTLD_NOW | RTLD_GLOBAL);
 101
 102    static const char *search_path_vars[] = {
 103       "LIBGL_DRIVERS_PATH",
 104       "LIBGL_DRIVERS_DIR", /* deprecated */
 105       NULL
 106    };
 107
 108    const __DRIextension **extensions =
 109       loader_open_driver(driverName, out_driver_handle, search_path_vars);
 110
 111    if (glhandle)
 112       dlclose(glhandle);
 113
 114    return extensions;
 115 }
 116
 117 static GLboolean
 118 __driGetMSCRate(__DRIdrawable *draw,
 119                 int32_t * numerator, int32_t * denominator,
 120                 void *loaderPrivate)
 121 {
 122    __GLXDRIdrawable *glxDraw = loaderPrivate;
 123
 124    return __glxGetMscRate(glxDraw->psc, numerator, denominator);
 125 }
 126
 127 _X_HIDDEN const __DRIsystemTimeExtension systemTimeExtension = {
 128    .base = {__DRI_SYSTEM_TIME, 1 },
 129
 130    .getUST              = __glXGetUST,
 131    .getMSCRate          = __driGetMSCRate
 132 };
 133
 134 #define __ATTRIB(attrib, field) \
 135     { attrib, offsetof(struct glx_config, field) }
 136
 137 static const struct
 138 {
 139    unsigned int attrib, offset;
 140 } attribMap[] = {
 141    __ATTRIB(__DRI_ATTRIB_BUFFER_SIZE, rgbBits),
 142       __ATTRIB(__DRI_ATTRIB_LEVEL, level),
 143       __ATTRIB(__DRI_ATTRIB_RED_SIZE, redBits),
 144       __ATTRIB(__DRI_ATTRIB_GREEN_SIZE, greenBits),
 145       __ATTRIB(__DRI_ATTRIB_BLUE_SIZE, blueBits),
 146       __ATTRIB(__DRI_ATTRIB_ALPHA_SIZE, alphaBits),
 147       __ATTRIB(__DRI_ATTRIB_DEPTH_SIZE, depthBits),
 148       __ATTRIB(__DRI_ATTRIB_STENCIL_SIZE, stencilBits),
 149       __ATTRIB(__DRI_ATTRIB_ACCUM_RED_SIZE, accumRedBits),
 150       __ATTRIB(__DRI_ATTRIB_ACCUM_GREEN_SIZE, accumGreenBits),
 151       __ATTRIB(__DRI_ATTRIB_ACCUM_BLUE_SIZE, accumBlueBits),
 152       __ATTRIB(__DRI_ATTRIB_ACCUM_ALPHA_SIZE, accumAlphaBits),
 153       __ATTRIB(__DRI_ATTRIB_SAMPLE_BUFFERS, sampleBuffers),
 154       __ATTRIB(__DRI_ATTRIB_SAMPLES, samples),
 155       __ATTRIB(__DRI_ATTRIB_DOUBLE_BUFFER, doubleBufferMode),
 156       __ATTRIB(__DRI_ATTRIB_STEREO, stereoMode),
 157       __ATTRIB(__DRI_ATTRIB_AUX_BUFFERS, numAuxBuffers),
 158 #if 0
 159       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_TYPE, transparentPixel),
 160       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_INDEX_VALUE, transparentIndex),
 161       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_RED_VALUE, transparentRed),
 162       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_GREEN_VALUE, transparentGreen),
 163       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_BLUE_VALUE, transparentBlue),
 164       __ATTRIB(__DRI_ATTRIB_TRANSPARENT_ALPHA_VALUE, transparentAlpha),
 165       __ATTRIB(__DRI_ATTRIB_RED_MASK, redMask),
 166       __ATTRIB(__DRI_ATTRIB_GREEN_MASK, greenMask),
 167       __ATTRIB(__DRI_ATTRIB_BLUE_MASK, blueMask),
 168       __ATTRIB(__DRI_ATTRIB_ALPHA_MASK, alphaMask),
 169       __ATTRIB(__DRI_ATTRIB_RED_SHIFT, redShift),
 170       __ATTRIB(__DRI_ATTRIB_GREEN_SHIFT, greenShift),
 171       __ATTRIB(__DRI_ATTRIB_BLUE_SHIFT, blueShift),
 172       __ATTRIB(__DRI_ATTRIB_ALPHA_SHIFT, alphaShift),
 173 #endif
 174       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_WIDTH, maxPbufferWidth),
 175       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_HEIGHT, maxPbufferHeight),
 176       __ATTRIB(__DRI_ATTRIB_MAX_PBUFFER_PIXELS, maxPbufferPixels),
 177       __ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_WIDTH, optimalPbufferWidth),
 178       __ATTRIB(__DRI_ATTRIB_OPTIMAL_PBUFFER_HEIGHT, optimalPbufferHeight),
 179       __ATTRIB(__DRI_ATTRIB_SWAP_METHOD, swapMethod),
 180       __ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGB, bindToTextureRgb),
 181       __ATTRIB(__DRI_ATTRIB_BIND_TO_TEXTURE_RGBA, bindToTextureRgba),
 182       __ATTRIB(__DRI_ATTRIB_BIND_TO_MIPMAP_TEXTURE,
 183                      bindToMipmapTexture),
 184       __ATTRIB(__DRI_ATTRIB_YINVERTED, yInverted),
 185       __ATTRIB(__DRI_ATTRIB_FRAMEBUFFER_SRGB_CAPABLE, sRGBCapable)
 186 };
 187
 188 static int
 189 scalarEqual(struct glx_config *mode, unsigned int attrib, unsigned int value)
 190 {
 191    unsigned glxValue, i;
 192
 193    for (i = 0; i < ARRAY_SIZE(attribMap); i++)
 194       if (attribMap[i].attrib == attrib) {
 195          glxValue = *(unsigned int *) ((char *) mode + attribMap[i].offset);
 196          return glxValue == GLX_DONT_CARE || glxValue == value;
 197       }
 198
 199    return GL_TRUE;              /* Is a non-existing attribute equal to value? */
 200 }
 201
 202 static int
 203 driConfigEqual(const __DRIcoreExtension *core,
 204                struct glx_config *config, const __DRIconfig *driConfig)
 205 {
 206    unsigned int attrib, value, glxValue;
 207    int i;
 208
 209    i = 0;
 210    while (core->indexConfigAttrib(driConfig, i++, &attrib, &value)) {
 211       switch (attrib) {
 212       case __DRI_ATTRIB_RENDER_TYPE:
 213          glxValue = 0;
 214          if (value & __DRI_ATTRIB_RGBA_BIT) {
 215             glxValue |= GLX_RGBA_BIT;
 216          }
 217          if (value & __DRI_ATTRIB_COLOR_INDEX_BIT) {
 218             glxValue |= GLX_COLOR_INDEX_BIT;
 219          }
 220          if (value & __DRI_ATTRIB_FLOAT_BIT) {
 221             glxValue |= GLX_RGBA_FLOAT_BIT_ARB;
 222          }
 223          if (value & __DRI_ATTRIB_UNSIGNED_FLOAT_BIT) {
 224             glxValue |= GLX_RGBA_UNSIGNED_FLOAT_BIT_EXT;
 225          }
 226          if (glxValue != config->renderType)
 227             return GL_FALSE;
 228          break;
 229
 230       case __DRI_ATTRIB_CONFIG_CAVEAT:
 231          if (value & __DRI_ATTRIB_NON_CONFORMANT_CONFIG)
 232             glxValue = GLX_NON_CONFORMANT_CONFIG;
 233          else if (value & __DRI_ATTRIB_SLOW_BIT)
 234             glxValue = GLX_SLOW_CONFIG;
 235          else
 236             glxValue = GLX_NONE;
 237          if (glxValue != config->visualRating)
 238             return GL_FALSE;
 239          break;
 240
 241       case __DRI_ATTRIB_BIND_TO_TEXTURE_TARGETS:
 242          glxValue = 0;
 243          if (value & __DRI_ATTRIB_TEXTURE_1D_BIT)
 244             glxValue |= GLX_TEXTURE_1D_BIT_EXT;
 245          if (value & __DRI_ATTRIB_TEXTURE_2D_BIT)
 246             glxValue |= GLX_TEXTURE_2D_BIT_EXT;
 247          if (value & __DRI_ATTRIB_TEXTURE_RECTANGLE_BIT)
 248             glxValue |= GLX_TEXTURE_RECTANGLE_BIT_EXT;
 249          if (config->bindToTextureTargets != GLX_DONT_CARE &&
 250              glxValue != config->bindToTextureTargets)
 251             return GL_FALSE;
 252          break;
 253
 254       case __DRI_ATTRIB_SWAP_METHOD:
 255          if (value == __DRI_ATTRIB_SWAP_EXCHANGE)
 256             glxValue = GLX_SWAP_EXCHANGE_OML;
 257          else if (value == __DRI_ATTRIB_SWAP_COPY)
 258             glxValue = GLX_SWAP_COPY_OML;
 259          else
 260             glxValue = GLX_SWAP_UNDEFINED_OML;
 261
 262          if (!scalarEqual(config, attrib, glxValue))
 263             return GL_FALSE;
 264
 265          break;
 266
 267       default:
 268          if (!scalarEqual(config, attrib, value))
 269             return GL_FALSE;
 270       }
 271    }
 272
 273    return GL_TRUE;
 274 }
 275
 276 static struct glx_config *
 277 createDriMode(const __DRIcoreExtension * core,
 278               struct glx_config *config, const __DRIconfig **driConfigs)
 279 {
 280    __GLXDRIconfigPrivate *driConfig;
 281    int i;
 282
 283    for (i = 0; driConfigs[i]; i++) {
 284       if (driConfigEqual(core, config, driConfigs[i]))
 285          break;
 286    }
 287
 288    if (driConfigs[i] == NULL)
 289       return NULL;
 290
 291    driConfig = malloc(sizeof *driConfig);
 292    if (driConfig == NULL)
 293       return NULL;
 294
 295    driConfig->base = *config;
 296    driConfig->driConfig = driConfigs[i];
 297
 298    return &driConfig->base;
 299 }
 300
 301 _X_HIDDEN struct glx_config *
 302 driConvertConfigs(const __DRIcoreExtension * core,
 303                   struct glx_config *configs, const __DRIconfig **driConfigs)
 304 {
 305    struct glx_config head, *tail, *m;
 306
 307    tail = &head;
 308    head.next = NULL;
 309    for (m = configs; m; m = m->next) {
 310       tail->next = createDriMode(core, m, driConfigs);
 311       if (tail->next == NULL) {
 312          /* no matching dri config for m */
 313          continue;
 314       }
 315
 316
 317       tail = tail->next;
 318    }
 319
 320    return head.next;
 321 }
 322
 323 _X_HIDDEN void
 324 driDestroyConfigs(const __DRIconfig **configs)
 325 {
 326    int i;
 327
 328    for (i = 0; configs[i]; i++)
 329       free((__DRIconfig *) configs[i]);
 330    free(configs);
 331 }
 332
 333 static struct glx_config *
 334 driInferDrawableConfig(struct glx_screen *psc, GLXDrawable draw)
 335 {
 336    unsigned int fbconfig = 0;
 337
 338    if (__glXGetDrawableAttribute(psc->dpy, draw, GLX_FBCONFIG_ID, &fbconfig)) {
 339       return glx_config_find_fbconfig(psc->configs, fbconfig);
 340    }
 341
 342    return NULL;
 343 }
 344
 345 _X_HIDDEN __GLXDRIdrawable *
 346 driFetchDrawable(struct glx_context *gc, GLXDrawable glxDrawable)
 347 {
 348    struct glx_display *const priv = __glXInitialize(gc->psc->dpy);
 349    __GLXDRIdrawable *pdraw;
 350    struct glx_screen *psc;
 351    struct glx_config *config = gc->config;
 352
 353    if (priv == NULL)
 354       return NULL;
 355
 356    if (glxDrawable == None)
 357       return NULL;
 358
 359    psc = priv->screens[gc->screen];
 360    if (priv->drawHash == NULL)
 361       return NULL;
 362
 363    if (__glxHashLookup(priv->drawHash, glxDrawable, (void *) &pdraw) == 0) {
 364       pdraw->refcount ++;
 365       return pdraw;
 366    }
 367
 368    if (config == NULL)
 369       config = driInferDrawableConfig(gc->psc, glxDrawable);
 370    if (config == NULL)
 371       return NULL;
 372
 373    pdraw = psc->driScreen->createDrawable(psc, glxDrawable, glxDrawable,
 374                                           config);
 375
 376    if (pdraw == NULL) {
 377       ErrorMessageF("failed to create drawable\n");
 378       return NULL;
 379    }
 380
 381    if (__glxHashInsert(priv->drawHash, glxDrawable, pdraw)) {
 382       (*pdraw->destroyDrawable) (pdraw);
 383       return NULL;
 384    }
 385    pdraw->refcount = 1;
 386
 387    return pdraw;
 388 }
 389
 390 _X_HIDDEN void
 391 driReleaseDrawables(struct glx_context *gc)
 392 {
 393    const struct glx_display *priv = gc->psc->display;
 394    __GLXDRIdrawable *pdraw;
 395
 396    if (priv == NULL)
 397       return;
 398
 399    if (__glxHashLookup(priv->drawHash,
 400                        gc->currentDrawable, (void *) &pdraw) == 0) {
 401       if (pdraw->drawable == pdraw->xDrawable) {
 402          pdraw->refcount --;
 403          if (pdraw->refcount == 0) {
 404             pdraw->destroyDrawable(pdraw);
 405             __glxHashDelete(priv->drawHash, gc->currentDrawable);
 406          }
 407       }
 408    }
 409
 410    if (__glxHashLookup(priv->drawHash,
 411                        gc->currentReadable, (void *) &pdraw) == 0) {
 412       if (pdraw->drawable == pdraw->xDrawable) {
 413          pdraw->refcount --;
 414          if (pdraw->refcount == 0) {
 415             pdraw->destroyDrawable(pdraw);
 416             __glxHashDelete(priv->drawHash, gc->currentReadable);
 417          }
 418       }
 419    }
 420
 421    gc->currentDrawable = None;
 422    gc->currentReadable = None;
 423
 424 }
 425
 426 _X_HIDDEN bool
 427 dri2_convert_glx_attribs(unsigned num_attribs, const uint32_t *attribs,
 428                          unsigned *major_ver, unsigned *minor_ver,
 429                          uint32_t *render_type, uint32_t *flags, unsigned *api,
 430                          int *reset, int *release, unsigned *error)
 431 {
 432    unsigned i;
 433    bool got_profile = false;
 434    int no_error = 0;
 435    uint32_t profile;
 436
 437    *major_ver = 1;
 438    *minor_ver = 0;
 439    *render_type = GLX_RGBA_TYPE;
 440    *reset = __DRI_CTX_RESET_NO_NOTIFICATION;
 441    *release = __DRI_CTX_RELEASE_BEHAVIOR_FLUSH;
 442    *flags = 0;
 443    *api = __DRI_API_OPENGL;
 444
 445    if (num_attribs == 0) {
 446       return true;
 447    }
 448
 449    /* This is actually an internal error, but what the heck.
 450     */
 451    if (attribs == NULL) {
 452       *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 453       return false;
 454    }
 455
 456    for (i = 0; i < num_attribs; i++) {
 457       switch (attribs[i * 2]) {
 458       case GLX_CONTEXT_MAJOR_VERSION_ARB:
 459          *major_ver = attribs[i * 2 + 1];
 460          break;
 461       case GLX_CONTEXT_MINOR_VERSION_ARB:
 462          *minor_ver = attribs[i * 2 + 1];
 463          break;
 464       case GLX_CONTEXT_FLAGS_ARB:
 465          *flags = attribs[i * 2 + 1];
 466          break;
 467       case GLX_CONTEXT_OPENGL_NO_ERROR_ARB:
 468          no_error = attribs[i * 2 + 1];
 469          break;
 470       case GLX_CONTEXT_PROFILE_MASK_ARB:
 471          profile = attribs[i * 2 + 1];
 472          got_profile = true;
 473          break;
 474       case GLX_RENDER_TYPE:
 475          *render_type = attribs[i * 2 + 1];
 476          break;
 477       case GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB:
 478          switch (attribs[i * 2 + 1]) {
 479          case GLX_NO_RESET_NOTIFICATION_ARB:
 480             *reset = __DRI_CTX_RESET_NO_NOTIFICATION;
 481             break;
 482          case GLX_LOSE_CONTEXT_ON_RESET_ARB:
 483             *reset = __DRI_CTX_RESET_LOSE_CONTEXT;
 484             break;
 485          default:
 486             *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 487             return false;
 488          }
 489          break;
 490       case GLX_CONTEXT_RELEASE_BEHAVIOR_ARB:
 491          switch (attribs[i * 2 + 1]) {
 492          case GLX_CONTEXT_RELEASE_BEHAVIOR_NONE_ARB:
 493             *release = __DRI_CTX_RELEASE_BEHAVIOR_NONE;
 494             break;
 495          case GLX_CONTEXT_RELEASE_BEHAVIOR_FLUSH_ARB:
 496             *release = __DRI_CTX_RELEASE_BEHAVIOR_FLUSH;
 497             break;
 498          default:
 499             *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 500             return false;
 501          }
 502          break;
 503       default:
 504          /* If an unknown attribute is received, fail.
 505           */
 506          *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 507          return false;
 508       }
 509    }
 510
 511    if (no_error) {
 512       *flags |= __DRI_CTX_FLAG_NO_ERROR;
 513    }
 514
 515    if (!got_profile) {
 516       if (*major_ver > 3 || (*major_ver == 3 && *minor_ver >= 2))
 517          *api = __DRI_API_OPENGL_CORE;
 518    } else {
 519       switch (profile) {
 520       case GLX_CONTEXT_CORE_PROFILE_BIT_ARB:
 521          /* There are no profiles before OpenGL 3.2.  The
 522           * GLX_ARB_create_context_profile spec says:
 523           *
 524           *     "If the requested OpenGL version is less than 3.2,
 525           *     GLX_CONTEXT_PROFILE_MASK_ARB is ignored and the functionality
 526           *     of the context is determined solely by the requested version."
 527           */
 528          *api = (*major_ver > 3 || (*major_ver == 3 && *minor_ver >= 2))
 529             ? __DRI_API_OPENGL_CORE : __DRI_API_OPENGL;
 530          break;
 531       case GLX_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB:
 532          *api = __DRI_API_OPENGL;
 533          break;
 534       case GLX_CONTEXT_ES_PROFILE_BIT_EXT:
 535          if (*major_ver >= 3)
 536             *api = __DRI_API_GLES3;
 537          else if (*major_ver == 2 && *minor_ver == 0)
 538             *api = __DRI_API_GLES2;
 539          else if (*major_ver == 1 && *minor_ver < 2)
 540             *api = __DRI_API_GLES;
 541          else {
 542             *error = __DRI_CTX_ERROR_BAD_API;
 543             return false;
 544          }
 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                   | __DRI_CTX_FLAG_NO_ERROR)) {
 557       *error = __DRI_CTX_ERROR_UNKNOWN_FLAG;
 558       return false;
 559    }
 560
 561    /* There are no forward-compatible contexts before OpenGL 3.0.  The
 562     * GLX_ARB_create_context spec says:
 563     *
 564     *     "Forward-compatible contexts are defined only for OpenGL versions
 565     *     3.0 and later."
 566     */
 567    if (*major_ver < 3 && (*flags & __DRI_CTX_FLAG_FORWARD_COMPATIBLE) != 0) {
 568       *error = __DRI_CTX_ERROR_BAD_FLAG;
 569       return false;
 570    }
 571
 572    if (*major_ver >= 3 && *render_type == GLX_COLOR_INDEX_TYPE) {
 573       *error = __DRI_CTX_ERROR_BAD_FLAG;
 574       return false;
 575    }
 576
 577    *error = __DRI_CTX_ERROR_SUCCESS;
 578    return true;
 579 }
 580
 581 _X_HIDDEN bool
 582 dri2_check_no_error(uint32_t flags, struct glx_context *share_context,
 583                     int major, unsigned *error)
 584 {
 585    Bool noError = flags & __DRI_CTX_FLAG_NO_ERROR;
 586
 587    /* The KHR_no_error specs say:
 588     *
 589     *    Requires OpenGL ES 2.0 or OpenGL 2.0.
 590     */
 591    if (noError && major < 2) {
 592       *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 593       return false;
 594    }
 595
 596    /* The GLX_ARB_create_context_no_error specs say:
 597     *
 598     *    BadMatch is generated if the value of GLX_CONTEXT_OPENGL_NO_ERROR_ARB
 599     *    used to create <share_context> does not match the value of
 600     *    GLX_CONTEXT_OPENGL_NO_ERROR_ARB for the context being created.
 601     */
 602    if (share_context && !!share_context->noError != !!noError) {
 603       *error = __DRI_CTX_ERROR_BAD_FLAG;
 604       return false;
 605    }
 606
 607    /* The GLX_ARB_create_context_no_error specs say:
 608     *
 609     *    BadMatch is generated if the GLX_CONTEXT_OPENGL_NO_ERROR_ARB is TRUE at
 610     *    the same time as a debug or robustness context is specified.
 611     *
 612     */
 613    if (noError && ((flags & __DRI_CTX_FLAG_DEBUG) ||
 614                    (flags & __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS))) {
 615       *error = __DRI_CTX_ERROR_BAD_FLAG;
 616       return false;
 617    }
 618
 619    return true;
 620 }
 621
 622 #endif /* GLX_DIRECT_RENDERING */