src/mesa/drivers/dri/common/dri_util.c

   1 /**
   2  * \file dri_util.c
   3  * DRI utility functions.
   4  *
   5  * This module acts as glue between GLX and the actual hardware driver.  A DRI
   6  * driver doesn't really \e have to use any of this - it's optional.  But, some
   7  * useful stuff is done here that otherwise would have to be duplicated in most
   8  * drivers.
   9  *
  10  * Basically, these utility functions take care of some of the dirty details of
  11  * screen initialization, context creation, context binding, DRM setup, etc.
  12  *
  13  * These functions are compiled into each DRI driver so libGL.so knows nothing
  14  * about them.
  15  */
  16
  17
  18 #include <assert.h>
  19 #include <stdarg.h>
  20 #include <unistd.h>
  21 #include <sys/mman.h>
  22 #include <stdio.h>
  23
  24 #ifndef MAP_FAILED
  25 #define MAP_FAILED ((void *)-1)
  26 #endif
  27
  28 #include "main/imports.h"
  29 #define None 0
  30
  31 #include "dri_util.h"
  32 #include "drm_sarea.h"
  33 #include "utils.h"
  34 #include "xmlpool.h"
  35 #include "../glsl/glsl_parser_extras.h"
  36
  37 PUBLIC const char __dri2ConfigOptions[] =
  38    DRI_CONF_BEGIN
  39       DRI_CONF_SECTION_PERFORMANCE
  40          DRI_CONF_VBLANK_MODE(DRI_CONF_VBLANK_DEF_INTERVAL_1)
  41       DRI_CONF_SECTION_END
  42    DRI_CONF_END;
  43
  44 static const uint __dri2NConfigOptions = 1;
  45
  46 #ifndef GLX_OML_sync_control
  47 typedef GLboolean ( * PFNGLXGETMSCRATEOMLPROC) (__DRIdrawable *drawable, int32_t *numerator, int32_t *denominator);
  48 #endif
  49
  50 static void dri_get_drawable(__DRIdrawable *pdp);
  51 static void dri_put_drawable(__DRIdrawable *pdp);
  52
  53 GLint
  54 driIntersectArea( drm_clip_rect_t rect1, drm_clip_rect_t rect2 )
  55 {
  56    if (rect2.x1 > rect1.x1) rect1.x1 = rect2.x1;
  57    if (rect2.x2 < rect1.x2) rect1.x2 = rect2.x2;
  58    if (rect2.y1 > rect1.y1) rect1.y1 = rect2.y1;
  59    if (rect2.y2 < rect1.y2) rect1.y2 = rect2.y2;
  60
  61    if (rect1.x1 > rect1.x2 || rect1.y1 > rect1.y2) return 0;
  62
  63    return (rect1.x2 - rect1.x1) * (rect1.y2 - rect1.y1);
  64 }
  65
  66 /*****************************************************************/
  67 /** \name Context (un)binding functions                          */
  68 /*****************************************************************/
  69 /*@{*/
  70
  71 /**
  72  * Unbind context.
  73  *
  74  * \param scrn the screen.
  75  * \param gc context.
  76  *
  77  * \return \c GL_TRUE on success, or \c GL_FALSE on failure.
  78  *
  79  * \internal
  80  * This function calls __DriverAPIRec::UnbindContext, and then decrements
  81  * __DRIdrawableRec::refcount which must be non-zero for a successful
  82  * return.
  83  *
  84  * While casting the opaque private pointers associated with the parameters
  85  * into their respective real types it also assures they are not \c NULL.
  86  */
  87 static int driUnbindContext(__DRIcontext *pcp)
  88 {
  89     __DRIscreen *psp;
  90     __DRIdrawable *pdp;
  91     __DRIdrawable *prp;
  92
  93     /*
  94     ** Assume error checking is done properly in glXMakeCurrent before
  95     ** calling driUnbindContext.
  96     */
  97
  98     if (pcp == NULL)
  99         return GL_FALSE;
 100
 101     psp = pcp->driScreenPriv;
 102     pdp = pcp->driDrawablePriv;
 103     prp = pcp->driReadablePriv;
 104
 105     /* already unbound */
 106     if (!pdp && !prp)
 107       return GL_TRUE;
 108     /* Let driver unbind drawable from context */
 109     (*psp->DriverAPI.UnbindContext)(pcp);
 110
 111     assert(pdp);
 112     if (pdp->refcount == 0) {
 113         /* ERROR!!! */
 114         return GL_FALSE;
 115     }
 116
 117     dri_put_drawable(pdp);
 118
 119     if (prp != pdp) {
 120         if (prp->refcount == 0) {
 121             /* ERROR!!! */
 122             return GL_FALSE;
 123         }
 124
 125         dri_put_drawable(prp);
 126     }
 127
 128
 129     /* XXX this is disabled so that if we call SwapBuffers on an unbound
 130      * window we can determine the last context bound to the window and
 131      * use that context's lock. (BrianP, 2-Dec-2000)
 132      */
 133     pcp->driDrawablePriv = pcp->driReadablePriv = NULL;
 134
 135     return GL_TRUE;
 136 }
 137
 138 /**
 139  * This function takes both a read buffer and a draw buffer.  This is needed
 140  * for \c glXMakeCurrentReadSGI or GLX 1.3's \c glXMakeContextCurrent
 141  * function.
 142  */
 143 static int driBindContext(__DRIcontext *pcp,
 144                           __DRIdrawable *pdp,
 145                           __DRIdrawable *prp)
 146 {
 147     __DRIscreen *psp = NULL;
 148
 149     /*
 150     ** Assume error checking is done properly in glXMakeCurrent before
 151     ** calling driUnbindContext.
 152     */
 153
 154     if (!pcp)
 155         return GL_FALSE;
 156
 157     /* Bind the drawable to the context */
 158     psp = pcp->driScreenPriv;
 159     pcp->driDrawablePriv = pdp;
 160     pcp->driReadablePriv = prp;
 161     if (pdp) {
 162         pdp->driContextPriv = pcp;
 163         dri_get_drawable(pdp);
 164     }
 165     if (prp && pdp != prp) {
 166         dri_get_drawable(prp);
 167     }
 168
 169     /*
 170     ** Now that we have a context associated with this drawable, we can
 171     ** initialize the drawable information if has not been done before.
 172     */
 173
 174     if (!psp->dri2.enabled) {
 175         if (pdp && !pdp->pStamp) {
 176             DRM_SPINLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
 177             __driUtilUpdateDrawableInfo(pdp);
 178             DRM_SPINUNLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
 179         }
 180         if (prp && pdp != prp && !prp->pStamp) {
 181             DRM_SPINLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
 182             __driUtilUpdateDrawableInfo(prp);
 183             DRM_SPINUNLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
 184         }
 185     }
 186
 187     /* Call device-specific MakeCurrent */
 188     return (*psp->DriverAPI.MakeCurrent)(pcp, pdp, prp);
 189 }
 190
 191 /*@}*/
 192
 193
 194 /*****************************************************************/
 195 /** \name Drawable handling functions                            */
 196 /*****************************************************************/
 197 /*@{*/
 198
 199 /**
 200  * Update private drawable information.
 201  *
 202  * \param pdp pointer to the private drawable information to update.
 203  *
 204  * This function basically updates the __DRIdrawable struct's
 205  * cliprect information by calling \c __DRIinterfaceMethods::getDrawableInfo.
 206  * This is usually called by the DRI_VALIDATE_DRAWABLE_INFO macro which
 207  * compares the __DRIdrwablePrivate pStamp and lastStamp values.  If
 208  * the values are different that means we have to update the clipping
 209  * info.
 210  */
 211 void
 212 __driUtilUpdateDrawableInfo(__DRIdrawable *pdp)
 213 {
 214     __DRIscreen *psp = pdp->driScreenPriv;
 215     __DRIcontext *pcp = pdp->driContextPriv;
 216
 217     if (!pcp
 218         || ((pdp != pcp->driDrawablePriv) && (pdp != pcp->driReadablePriv))) {
 219         /* ERROR!!!
 220          * ...but we must ignore it. There can be many contexts bound to a
 221          * drawable.
 222          */
 223     }
 224
 225     if (pdp->pClipRects) {
 226         free(pdp->pClipRects);
 227         pdp->pClipRects = NULL;
 228     }
 229
 230     if (pdp->pBackClipRects) {
 231         free(pdp->pBackClipRects);
 232         pdp->pBackClipRects = NULL;
 233     }
 234
 235     DRM_SPINUNLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
 236
 237     if (! (*psp->getDrawableInfo->getDrawableInfo)(pdp,
 238                           &pdp->index, &pdp->lastStamp,
 239                           &pdp->x, &pdp->y, &pdp->w, &pdp->h,
 240                           &pdp->numClipRects, &pdp->pClipRects,
 241                           &pdp->backX,
 242                           &pdp->backY,
 243                           &pdp->numBackClipRects,
 244                           &pdp->pBackClipRects,
 245                           pdp->loaderPrivate)) {
 246         /* Error -- eg the window may have been destroyed.  Keep going
 247          * with no cliprects.
 248          */
 249         pdp->pStamp = &pdp->lastStamp; /* prevent endless loop */
 250         pdp->numClipRects = 0;
 251         pdp->pClipRects = NULL;
 252         pdp->numBackClipRects = 0;
 253         pdp->pBackClipRects = NULL;
 254     }
 255     else
 256        pdp->pStamp = &(psp->pSAREA->drawableTable[pdp->index].stamp);
 257
 258     DRM_SPINLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
 259 }
 260
 261 /*@}*/
 262
 263 /*****************************************************************/
 264 /** \name GLX callbacks                                          */
 265 /*****************************************************************/
 266 /*@{*/
 267
 268 static void driReportDamage(__DRIdrawable *pdp,
 269                             struct drm_clip_rect *pClipRects, int numClipRects)
 270 {
 271     __DRIscreen *psp = pdp->driScreenPriv;
 272
 273     /* Check that we actually have the new damage report method */
 274     if (psp->damage) {
 275         /* Report the damage.  Currently, all our drivers draw
 276          * directly to the front buffer, so we report the damage there
 277          * rather than to the backing storein (if any).
 278          */
 279         (*psp->damage->reportDamage)(pdp,
 280                                      pdp->x, pdp->y,
 281                                      pClipRects, numClipRects,
 282                                      GL_TRUE, pdp->loaderPrivate);
 283     }
 284 }
 285
 286
 287 /**
 288  * Swap buffers.
 289  *
 290  * \param drawablePrivate opaque pointer to the per-drawable private info.
 291  *
 292  * \internal
 293  * This function calls __DRIdrawable::swapBuffers.
 294  *
 295  * Is called directly from glXSwapBuffers().
 296  */
 297 static void driSwapBuffers(__DRIdrawable *dPriv)
 298 {
 299     __DRIscreen *psp = dPriv->driScreenPriv;
 300     drm_clip_rect_t *rects;
 301     int i;
 302
 303     psp->DriverAPI.SwapBuffers(dPriv);
 304
 305     if (!dPriv->numClipRects)
 306         return;
 307
 308     rects = malloc(sizeof(*rects) * dPriv->numClipRects);
 309
 310     if (!rects)
 311         return;
 312
 313     for (i = 0; i < dPriv->numClipRects; i++) {
 314         rects[i].x1 = dPriv->pClipRects[i].x1 - dPriv->x;
 315         rects[i].y1 = dPriv->pClipRects[i].y1 - dPriv->y;
 316         rects[i].x2 = dPriv->pClipRects[i].x2 - dPriv->x;
 317         rects[i].y2 = dPriv->pClipRects[i].y2 - dPriv->y;
 318     }
 319
 320     driReportDamage(dPriv, rects, dPriv->numClipRects);
 321     free(rects);
 322 }
 323
 324 static __DRIdrawable *
 325 dri2CreateNewDrawable(__DRIscreen *screen,
 326                       const __DRIconfig *config,
 327                       void *loaderPrivate)
 328 {
 329     __DRIdrawable *pdraw;
 330
 331     pdraw = malloc(sizeof *pdraw);
 332     if (!pdraw)
 333         return NULL;
 334
 335     pdraw->driContextPriv = NULL;
 336     pdraw->loaderPrivate = loaderPrivate;
 337     pdraw->hHWDrawable = 0;
 338     pdraw->refcount = 1;
 339     pdraw->pStamp = NULL;
 340     pdraw->lastStamp = 0;
 341     pdraw->index = 0;
 342     pdraw->x = 0;
 343     pdraw->y = 0;
 344     pdraw->w = 0;
 345     pdraw->h = 0;
 346     pdraw->numClipRects = 0;
 347     pdraw->numBackClipRects = 0;
 348     pdraw->pClipRects = NULL;
 349     pdraw->pBackClipRects = NULL;
 350     pdraw->vblSeq = 0;
 351     pdraw->vblFlags = 0;
 352
 353     pdraw->driScreenPriv = screen;
 354
 355     if (!(*screen->DriverAPI.CreateBuffer)(screen, pdraw, &config->modes, 0)) {
 356        free(pdraw);
 357        return NULL;
 358     }
 359
 360     pdraw->msc_base = 0;
 361
 362     /* This special default value is replaced with the configured
 363      * default value when the drawable is first bound to a direct
 364      * rendering context.
 365      */
 366     pdraw->swap_interval = (unsigned)-1;
 367
 368     pdraw->pClipRects = &pdraw->dri2.clipRect;
 369     pdraw->pBackClipRects = &pdraw->dri2.clipRect;
 370
 371     pdraw->pStamp = &pdraw->dri2.stamp;
 372     *pdraw->pStamp = pdraw->lastStamp + 1;
 373
 374     return pdraw;
 375 }
 376
 377 static __DRIbuffer *
 378 dri2AllocateBuffer(__DRIscreen *screen,
 379                    unsigned int attachment, unsigned int format,
 380                    int width, int height)
 381 {
 382     return (*screen->DriverAPI.AllocateBuffer)(screen, attachment, format,
 383                                                width, height);
 384 }
 385
 386 static void
 387 dri2ReleaseBuffer(__DRIscreen *screen, __DRIbuffer *buffer)
 388 {
 389    (*screen->DriverAPI.ReleaseBuffer)(screen, buffer);
 390 }
 391
 392
 393 static int
 394 dri2ConfigQueryb(__DRIscreen *screen, const char *var, GLboolean *val)
 395 {
 396    if (!driCheckOption(&screen->optionCache, var, DRI_BOOL))
 397       return -1;
 398
 399    *val = driQueryOptionb(&screen->optionCache, var);
 400
 401    return 0;
 402 }
 403
 404 static int
 405 dri2ConfigQueryi(__DRIscreen *screen, const char *var, GLint *val)
 406 {
 407    if (!driCheckOption(&screen->optionCache, var, DRI_INT) &&
 408        !driCheckOption(&screen->optionCache, var, DRI_ENUM))
 409       return -1;
 410
 411     *val = driQueryOptioni(&screen->optionCache, var);
 412
 413     return 0;
 414 }
 415
 416 static int
 417 dri2ConfigQueryf(__DRIscreen *screen, const char *var, GLfloat *val)
 418 {
 419    if (!driCheckOption(&screen->optionCache, var, DRI_FLOAT))
 420       return -1;
 421
 422     *val = driQueryOptionf(&screen->optionCache, var);
 423
 424     return 0;
 425 }
 426
 427
 428 static void dri_get_drawable(__DRIdrawable *pdp)
 429 {
 430     pdp->refcount++;
 431 }
 432
 433 static void dri_put_drawable(__DRIdrawable *pdp)
 434 {
 435     __DRIscreen *psp;
 436
 437     if (pdp) {
 438         pdp->refcount--;
 439         if (pdp->refcount)
 440             return;
 441
 442         psp = pdp->driScreenPriv;
 443         (*psp->DriverAPI.DestroyBuffer)(pdp);
 444         if (pdp->pClipRects && pdp->pClipRects != &pdp->dri2.clipRect) {
 445             free(pdp->pClipRects);
 446             pdp->pClipRects = NULL;
 447         }
 448         if (pdp->pBackClipRects && pdp->pClipRects != &pdp->dri2.clipRect) {
 449             free(pdp->pBackClipRects);
 450             pdp->pBackClipRects = NULL;
 451         }
 452         free(pdp);
 453     }
 454 }
 455
 456 static void
 457 driDestroyDrawable(__DRIdrawable *pdp)
 458 {
 459     dri_put_drawable(pdp);
 460 }
 461
 462 /*@}*/
 463
 464
 465 /*****************************************************************/
 466 /** \name Context handling functions                             */
 467 /*****************************************************************/
 468 /*@{*/
 469
 470 /**
 471  * Destroy the per-context private information.
 472  *
 473  * \internal
 474  * This function calls __DriverAPIRec::DestroyContext on \p contextPrivate, calls
 475  * drmDestroyContext(), and finally frees \p contextPrivate.
 476  */
 477 static void
 478 driDestroyContext(__DRIcontext *pcp)
 479 {
 480     if (pcp) {
 481         (*pcp->driScreenPriv->DriverAPI.DestroyContext)(pcp);
 482         free(pcp);
 483     }
 484 }
 485
 486 static unsigned int
 487 dri2GetAPIMask(__DRIscreen *screen)
 488 {
 489     return screen->api_mask;
 490 }
 491
 492 static __DRIcontext *
 493 dri2CreateNewContextForAPI(__DRIscreen *screen, int api,
 494                            const __DRIconfig *config,
 495                            __DRIcontext *shared, void *data)
 496 {
 497     __DRIcontext *context;
 498     const struct gl_config *modes = (config != NULL) ? &config->modes : NULL;
 499     void *shareCtx = (shared != NULL) ? shared->driverPrivate : NULL;
 500     gl_api mesa_api;
 501
 502     if (!(screen->api_mask & (1 << api)))
 503         return NULL;
 504
 505     switch (api) {
 506     case __DRI_API_OPENGL:
 507             mesa_api = API_OPENGL;
 508             break;
 509     case __DRI_API_GLES:
 510             mesa_api = API_OPENGLES;
 511             break;
 512     case __DRI_API_GLES2:
 513             mesa_api = API_OPENGLES2;
 514             break;
 515     default:
 516             return NULL;
 517     }
 518
 519     context = malloc(sizeof *context);
 520     if (!context)
 521         return NULL;
 522
 523     context->driScreenPriv = screen;
 524     context->driDrawablePriv = NULL;
 525     context->loaderPrivate = data;
 526
 527     if (!(*screen->DriverAPI.CreateContext)(mesa_api, modes,
 528                                             context, shareCtx) ) {
 529         free(context);
 530         return NULL;
 531     }
 532
 533     return context;
 534 }
 535
 536
 537 static __DRIcontext *
 538 dri2CreateNewContext(__DRIscreen *screen, const __DRIconfig *config,
 539                       __DRIcontext *shared, void *data)
 540 {
 541    return dri2CreateNewContextForAPI(screen, __DRI_API_OPENGL,
 542                                      config, shared, data);
 543 }
 544
 545 static int
 546 driCopyContext(__DRIcontext *dest, __DRIcontext *src, unsigned long mask)
 547 {
 548     (void) dest;
 549     (void) src;
 550     (void) mask;
 551     return GL_FALSE;
 552 }
 553
 554 /*@}*/
 555
 556
 557 /*****************************************************************/
 558 /** \name Screen handling functions                              */
 559 /*****************************************************************/
 560 /*@{*/
 561
 562 /**
 563  * Destroy the per-screen private information.
 564  *
 565  * \internal
 566  * This function calls __DriverAPIRec::DestroyScreen on \p screenPrivate, calls
 567  * drmClose(), and finally frees \p screenPrivate.
 568  */
 569 static void driDestroyScreen(__DRIscreen *psp)
 570 {
 571     if (psp) {
 572         /* No interaction with the X-server is possible at this point.  This
 573          * routine is called after XCloseDisplay, so there is no protocol
 574          * stream open to the X-server anymore.
 575          */
 576
 577        _mesa_destroy_shader_compiler();
 578
 579         if (psp->DriverAPI.DestroyScreen)
 580             (*psp->DriverAPI.DestroyScreen)(psp);
 581
 582         if (!psp->dri2.enabled) {
 583            (void)drmUnmap((drmAddress)psp->pSAREA, SAREA_MAX);
 584            (void)drmUnmap((drmAddress)psp->pFB, psp->fbSize);
 585            (void)drmCloseOnce(psp->fd);
 586         } else {
 587            driDestroyOptionCache(&psp->optionCache);
 588            driDestroyOptionInfo(&psp->optionInfo);
 589         }
 590
 591         free(psp);
 592     }
 593 }
 594
 595 static void
 596 setupLoaderExtensions(__DRIscreen *psp,
 597                       const __DRIextension **extensions)
 598 {
 599     int i;
 600
 601     for (i = 0; extensions[i]; i++) {
 602         if (strcmp(extensions[i]->name, __DRI_GET_DRAWABLE_INFO) == 0)
 603             psp->getDrawableInfo = (__DRIgetDrawableInfoExtension *) extensions[i];
 604         if (strcmp(extensions[i]->name, __DRI_DAMAGE) == 0)
 605             psp->damage = (__DRIdamageExtension *) extensions[i];
 606         if (strcmp(extensions[i]->name, __DRI_SYSTEM_TIME) == 0)
 607             psp->systemTime = (__DRIsystemTimeExtension *) extensions[i];
 608         if (strcmp(extensions[i]->name, __DRI_DRI2_LOADER) == 0)
 609             psp->dri2.loader = (__DRIdri2LoaderExtension *) extensions[i];
 610         if (strcmp(extensions[i]->name, __DRI_IMAGE_LOOKUP) == 0)
 611             psp->dri2.image = (__DRIimageLookupExtension *) extensions[i];
 612         if (strcmp(extensions[i]->name, __DRI_USE_INVALIDATE) == 0)
 613             psp->dri2.useInvalidate = (__DRIuseInvalidateExtension *) extensions[i];
 614     }
 615 }
 616
 617 /**
 618  * DRI2
 619  */
 620 static __DRIscreen *
 621 dri2CreateNewScreen(int scrn, int fd,
 622                     const __DRIextension **extensions,
 623                     const __DRIconfig ***driver_configs, void *data)
 624 {
 625     static const __DRIextension *emptyExtensionList[] = { NULL };
 626     __DRIscreen *psp;
 627     drmVersionPtr version;
 628
 629     if (driDriverAPI.InitScreen2 == NULL)
 630         return NULL;
 631
 632     psp = calloc(1, sizeof(*psp));
 633     if (!psp)
 634         return NULL;
 635
 636     setupLoaderExtensions(psp, extensions);
 637
 638     version = drmGetVersion(fd);
 639     if (version) {
 640         psp->drm_version.major = version->version_major;
 641         psp->drm_version.minor = version->version_minor;
 642         psp->drm_version.patch = version->version_patchlevel;
 643         drmFreeVersion(version);
 644     }
 645
 646     psp->extensions = emptyExtensionList;
 647     psp->fd = fd;
 648     psp->myNum = scrn;
 649     psp->dri2.enabled = GL_TRUE;
 650
 651     psp->DriverAPI = driDriverAPI;
 652     psp->api_mask = (1 << __DRI_API_OPENGL);
 653     *driver_configs = driDriverAPI.InitScreen2(psp);
 654     if (*driver_configs == NULL) {
 655         free(psp);
 656         return NULL;
 657     }
 658
 659     psp->DriverAPI = driDriverAPI;
 660     psp->loaderPrivate = data;
 661
 662     driParseOptionInfo(&psp->optionInfo, __dri2ConfigOptions,
 663                        __dri2NConfigOptions);
 664     driParseConfigFiles(&psp->optionCache, &psp->optionInfo, psp->myNum,
 665                         "dri2");
 666
 667     return psp;
 668 }
 669
 670 static const __DRIextension **driGetExtensions(__DRIscreen *psp)
 671 {
 672     return psp->extensions;
 673 }
 674
 675 /** Core interface */
 676 const __DRIcoreExtension driCoreExtension = {
 677     { __DRI_CORE, __DRI_CORE_VERSION },
 678     NULL,
 679     driDestroyScreen,
 680     driGetExtensions,
 681     driGetConfigAttrib,
 682     driIndexConfigAttrib,
 683     NULL,
 684     driDestroyDrawable,
 685     driSwapBuffers,
 686     NULL,
 687     driCopyContext,
 688     driDestroyContext,
 689     driBindContext,
 690     driUnbindContext
 691 };
 692
 693 /** DRI2 interface */
 694 const __DRIdri2Extension driDRI2Extension = {
 695     { __DRI_DRI2, __DRI_DRI2_VERSION },
 696     dri2CreateNewScreen,
 697     dri2CreateNewDrawable,
 698     dri2CreateNewContext,
 699     dri2GetAPIMask,
 700     dri2CreateNewContextForAPI,
 701     dri2AllocateBuffer,
 702     dri2ReleaseBuffer
 703 };
 704
 705 const __DRI2configQueryExtension dri2ConfigQueryExtension = {
 706    { __DRI2_CONFIG_QUERY, __DRI2_CONFIG_QUERY_VERSION },
 707    dri2ConfigQueryb,
 708    dri2ConfigQueryi,
 709    dri2ConfigQueryf,
 710 };
 711
 712 /**
 713  * Calculate amount of swap interval used between GLX buffer swaps.
 714  *
 715  * The usage value, on the range [0,max], is the fraction of total swap
 716  * interval time used between GLX buffer swaps is calculated.
 717  *
 718  *            \f$p = t_d / (i * t_r)\f$
 719  *
 720  * Where \f$t_d\f$ is the time since the last GLX buffer swap, \f$i\f$ is the
 721  * swap interval (as set by \c glXSwapIntervalSGI), and \f$t_r\f$ time
 722  * required for a single vertical refresh period (as returned by \c
 723  * glXGetMscRateOML).
 724  *
 725  * See the documentation for the GLX_MESA_swap_frame_usage extension for more
 726  * details.
 727  *
 728  * \param   dPriv  Pointer to the private drawable structure.
 729  * \return  If less than a single swap interval time period was required
 730  *          between GLX buffer swaps, a number greater than 0 and less than
 731  *          1.0 is returned.  If exactly one swap interval time period is
 732  *          required, 1.0 is returned, and if more than one is required then
 733  *          a number greater than 1.0 will be returned.
 734  *
 735  * \sa glXSwapIntervalSGI glXGetMscRateOML
 736  *
 737  * \todo Instead of caching the \c glXGetMscRateOML function pointer, would it
 738  *       be possible to cache the sync rate?
 739  */
 740 float
 741 driCalculateSwapUsage( __DRIdrawable *dPriv, int64_t last_swap_ust,
 742                        int64_t current_ust )
 743 {
 744    int32_t   n;
 745    int32_t   d;
 746    int       interval;
 747    float     usage = 1.0;
 748    __DRIscreen *psp = dPriv->driScreenPriv;
 749
 750    if ( (*psp->systemTime->getMSCRate)(dPriv, &n, &d, dPriv->loaderPrivate) ) {
 751       interval = (dPriv->swap_interval != 0) ? dPriv->swap_interval : 1;
 752
 753
 754       /* We want to calculate
 755        * (current_UST - last_swap_UST) / (interval * us_per_refresh).  We get
 756        * current_UST by calling __glXGetUST.  last_swap_UST is stored in
 757        * dPriv->swap_ust.  interval has already been calculated.
 758        *
 759        * The only tricky part is us_per_refresh.  us_per_refresh is
 760        * 1000000 / MSC_rate.  We know the MSC_rate is n / d.  We can flip it
 761        * around and say us_per_refresh = 1000000 * d / n.  Since this goes in
 762        * the denominator of the final calculation, we calculate
 763        * (interval * 1000000 * d) and move n into the numerator.
 764        */
 765
 766       usage = (current_ust - last_swap_ust);
 767       usage *= n;
 768       usage /= (interval * d);
 769       usage /= 1000000.0;
 770    }
 771
 772    return usage;
 773 }
 774
 775 void
 776 dri2InvalidateDrawable(__DRIdrawable *drawable)
 777 {
 778     drawable->dri2.stamp++;
 779 }
 780
 781 /*@}*/