src/gallium/state_trackers/dri/dri_drawable.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2009, VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27 /*
  28  * Author: Keith Whitwell <keithw@vmware.com>
  29  * Author: Jakob Bornecrantz <wallbraker@gmail.com>
  30  */
  31
  32 #include "dri_screen.h"
  33 #include "dri_context.h"
  34 #include "dri_drawable.h"
  35
  36 #include "pipe/p_context.h"
  37 #include "pipe/p_screen.h"
  38 #include "pipe/p_inlines.h"
  39 #include "state_tracker/drm_api.h"
  40 #include "state_tracker/dri1_api.h"
  41 #include "state_tracker/st_public.h"
  42 #include "state_tracker/st_context.h"
  43 #include "state_tracker/st_cb_fbo.h"
  44
  45 #include "util/u_memory.h"
  46
  47 static void
  48 dri_copy_to_front(__DRIdrawablePrivate * dPriv,
  49                   struct pipe_surface *from,
  50                   int x, int y, unsigned w, unsigned h)
  51 {
  52    /* TODO send a message to the Xserver to copy to the real front buffer */
  53 }
  54
  55 static struct pipe_surface *
  56 dri_surface_from_handle(struct pipe_screen *screen,
  57                         unsigned handle,
  58                         enum pipe_format format,
  59                         unsigned width, unsigned height, unsigned pitch)
  60 {
  61    struct pipe_surface *surface = NULL;
  62    struct pipe_texture *texture = NULL;
  63    struct pipe_texture templat;
  64    struct pipe_buffer *buf = NULL;
  65
  66    buf = drm_api_hooks.buffer_from_handle(screen, "dri2 buffer", handle);
  67    if (!buf)
  68       return NULL;
  69
  70    memset(&templat, 0, sizeof(templat));
  71    templat.tex_usage |= PIPE_TEXTURE_USAGE_RENDER_TARGET;
  72    templat.target = PIPE_TEXTURE_2D;
  73    templat.last_level = 0;
  74    templat.depth[0] = 1;
  75    templat.format = format;
  76    templat.width[0] = width;
  77    templat.height[0] = height;
  78    pf_get_block(templat.format, &templat.block);
  79
  80    texture = screen->texture_blanket(screen, &templat, &pitch, buf);
  81
  82    /* we don't need the buffer from this point on */
  83    pipe_buffer_reference(&buf, NULL);
  84
  85    if (!texture)
  86       return NULL;
  87
  88    surface = screen->get_tex_surface(screen, texture, 0, 0, 0,
  89                                      PIPE_BUFFER_USAGE_GPU_READ |
  90                                      PIPE_BUFFER_USAGE_GPU_WRITE);
  91
  92    /* we don't need the texture from this point on */
  93    pipe_texture_reference(&texture, NULL);
  94    return surface;
  95 }
  96
  97 /**
  98  * This will be called a drawable is known to have been resized.
  99  */
 100 void
 101 dri_get_buffers(__DRIdrawablePrivate * dPriv)
 102 {
 103    struct dri_drawable *drawable = dri_drawable(dPriv);
 104    struct pipe_surface *surface = NULL;
 105    struct pipe_screen *screen = dri_screen(drawable->sPriv)->pipe_screen;
 106    __DRIbuffer *buffers = NULL;
 107    __DRIscreen *dri_screen = drawable->sPriv;
 108    __DRIdrawable *dri_drawable = drawable->dPriv;
 109    boolean have_depth = FALSE;
 110    int i, count;
 111
 112    buffers = (*dri_screen->dri2.loader->getBuffers) (dri_drawable,
 113                                                      &dri_drawable->w,
 114                                                      &dri_drawable->h,
 115                                                      drawable->attachments,
 116                                                      drawable->
 117                                                      num_attachments, &count,
 118                                                      dri_drawable->
 119                                                      loaderPrivate);
 120
 121    if (buffers == NULL) {
 122       return;
 123    }
 124
 125    /* set one cliprect to cover the whole dri_drawable */
 126    dri_drawable->x = 0;
 127    dri_drawable->y = 0;
 128    dri_drawable->backX = 0;
 129    dri_drawable->backY = 0;
 130    dri_drawable->numClipRects = 1;
 131    dri_drawable->pClipRects[0].x1 = 0;
 132    dri_drawable->pClipRects[0].y1 = 0;
 133    dri_drawable->pClipRects[0].x2 = dri_drawable->w;
 134    dri_drawable->pClipRects[0].y2 = dri_drawable->h;
 135    dri_drawable->numBackClipRects = 1;
 136    dri_drawable->pBackClipRects[0].x1 = 0;
 137    dri_drawable->pBackClipRects[0].y1 = 0;
 138    dri_drawable->pBackClipRects[0].x2 = dri_drawable->w;
 139    dri_drawable->pBackClipRects[0].y2 = dri_drawable->h;
 140
 141    if (drawable->old_num == count &&
 142        drawable->old_w == dri_drawable->w &&
 143        drawable->old_h == dri_drawable->h &&
 144        memcmp(drawable->old, buffers, sizeof(__DRIbuffer) * count) == 0) {
 145        return;
 146    } else {
 147       drawable->old_num = count;
 148       drawable->old_w = dri_drawable->w;
 149       drawable->old_h = dri_drawable->h;
 150       memcpy(drawable->old, buffers, sizeof(__DRIbuffer) * count);
 151    }
 152
 153    for (i = 0; i < count; i++) {
 154       enum pipe_format format = 0;
 155       int index = 0;
 156
 157       switch (buffers[i].attachment) {
 158       case __DRI_BUFFER_FRONT_LEFT:
 159          index = ST_SURFACE_FRONT_LEFT;
 160          format = PIPE_FORMAT_A8R8G8B8_UNORM;
 161          break;
 162       case __DRI_BUFFER_FAKE_FRONT_LEFT:
 163          index = ST_SURFACE_FRONT_LEFT;
 164          format = PIPE_FORMAT_A8R8G8B8_UNORM;
 165          break;
 166       case __DRI_BUFFER_BACK_LEFT:
 167          index = ST_SURFACE_BACK_LEFT;
 168          format = PIPE_FORMAT_A8R8G8B8_UNORM;
 169          break;
 170       case __DRI_BUFFER_DEPTH:
 171          index = ST_SURFACE_DEPTH;
 172          format = PIPE_FORMAT_Z24S8_UNORM;
 173          break;
 174       case __DRI_BUFFER_STENCIL:
 175          index = ST_SURFACE_DEPTH;
 176          format = PIPE_FORMAT_Z24S8_UNORM;
 177          break;
 178       case __DRI_BUFFER_ACCUM:
 179       default:
 180          assert(0);
 181       }
 182       assert(buffers[i].cpp == 4);
 183
 184       if (index == ST_SURFACE_DEPTH) {
 185          if (have_depth)
 186             continue;
 187          else
 188             have_depth = TRUE;
 189       }
 190
 191       surface = dri_surface_from_handle(screen,
 192                                         buffers[i].name,
 193                                         format,
 194                                         dri_drawable->w,
 195                                         dri_drawable->h, buffers[i].pitch);
 196
 197       st_set_framebuffer_surface(drawable->stfb, index, surface);
 198       pipe_surface_reference(&surface, NULL);
 199    }
 200    /* this needed, or else the state tracker fails to pick the new buffers */
 201    st_resize_framebuffer(drawable->stfb, dri_drawable->w, dri_drawable->h);
 202 }
 203
 204 void
 205 dri_flush_frontbuffer(struct pipe_screen *screen,
 206                       struct pipe_surface *surf, void *context_private)
 207 {
 208    struct dri_context *ctx = (struct dri_context *)context_private;
 209
 210    dri_copy_to_front(ctx->dPriv, surf, 0, 0, surf->width, surf->height);
 211 }
 212
 213 /**
 214  * This is called when we need to set up GL rendering to a new X window.
 215  */
 216 boolean
 217 dri_create_buffer(__DRIscreenPrivate * sPriv,
 218                   __DRIdrawablePrivate * dPriv,
 219                   const __GLcontextModes * visual, boolean isPixmap)
 220 {
 221    enum pipe_format colorFormat, depthFormat, stencilFormat;
 222    struct dri_screen *screen = sPriv->private;
 223    struct dri_drawable *drawable = NULL;
 224    struct pipe_screen *pscreen = screen->pipe_screen;
 225    int i;
 226
 227    if (isPixmap)
 228       goto fail;                       /* not implemented */
 229
 230    drawable = CALLOC_STRUCT(dri_drawable);
 231    if (drawable == NULL)
 232       goto fail;
 233
 234    /* XXX: todo: use the pipe_screen queries to figure out which
 235     * render targets are supportable.
 236     */
 237    assert(visual->redBits == 8);
 238    assert(visual->depthBits == 24 || visual->depthBits == 0);
 239    assert(visual->stencilBits == 8 || visual->stencilBits == 0);
 240
 241    colorFormat = PIPE_FORMAT_A8R8G8B8_UNORM;
 242
 243    if (visual->depthBits) {
 244       if (pscreen->is_format_supported(pscreen, PIPE_FORMAT_Z24S8_UNORM,
 245                                        PIPE_TEXTURE_2D,
 246                                        PIPE_TEXTURE_USAGE_DEPTH_STENCIL, 0))
 247          depthFormat = PIPE_FORMAT_Z24S8_UNORM;
 248       else
 249          depthFormat = PIPE_FORMAT_S8Z24_UNORM;
 250    } else
 251       depthFormat = PIPE_FORMAT_NONE;
 252
 253    if (visual->stencilBits) {
 254       if (pscreen->is_format_supported(pscreen, PIPE_FORMAT_Z24S8_UNORM,
 255                                        PIPE_TEXTURE_2D,
 256                                        PIPE_TEXTURE_USAGE_DEPTH_STENCIL, 0))
 257          stencilFormat = PIPE_FORMAT_Z24S8_UNORM;
 258       else
 259          stencilFormat = PIPE_FORMAT_S8Z24_UNORM;
 260    } else
 261       stencilFormat = PIPE_FORMAT_NONE;
 262
 263    drawable->stfb = st_create_framebuffer(visual,
 264                                           colorFormat,
 265                                           depthFormat,
 266                                           stencilFormat,
 267                                           dPriv->w,
 268                                           dPriv->h, (void *)drawable);
 269    if (drawable->stfb == NULL)
 270       goto fail;
 271
 272    drawable->sPriv = sPriv;
 273    drawable->dPriv = dPriv;
 274    dPriv->driverPrivate = (void *)drawable;
 275
 276    /* setup dri2 buffers information */
 277    i = 0;
 278    drawable->attachments[i++] = __DRI_BUFFER_FRONT_LEFT;
 279 #if 0
 280    /* TODO incase of double buffer visual, delay fake creation */
 281    drawable->attachments[i++] = __DRI_BUFFER_FAKE_FRONT_LEFT;
 282 #endif
 283    if (visual->doubleBufferMode)
 284       drawable->attachments[i++] = __DRI_BUFFER_BACK_LEFT;
 285    if (visual->depthBits)
 286       drawable->attachments[i++] = __DRI_BUFFER_DEPTH;
 287    if (visual->stencilBits)
 288       drawable->attachments[i++] = __DRI_BUFFER_STENCIL;
 289    drawable->num_attachments = i;
 290
 291    drawable->desired_fences = 2;
 292
 293    return GL_TRUE;
 294  fail:
 295    FREE(drawable);
 296    return GL_FALSE;
 297 }
 298
 299 static struct pipe_fence_handle *
 300 dri_swap_fences_pop_front(struct dri_drawable *draw)
 301 {
 302    struct pipe_screen *screen = dri_screen(draw->sPriv)->pipe_screen;
 303    struct pipe_fence_handle *fence = NULL;
 304
 305    if (draw->cur_fences >= draw->desired_fences) {
 306       screen->fence_reference(screen, &fence, draw->swap_fences[draw->tail]);
 307       screen->fence_reference(screen, &draw->swap_fences[draw->tail++], NULL);
 308       --draw->cur_fences;
 309       draw->tail &= DRI_SWAP_FENCES_MASK;
 310    }
 311    return fence;
 312 }
 313
 314 static void
 315 dri_swap_fences_push_back(struct dri_drawable *draw,
 316                           struct pipe_fence_handle *fence)
 317 {
 318    struct pipe_screen *screen = dri_screen(draw->sPriv)->pipe_screen;
 319
 320    if (!fence)
 321       return;
 322
 323    if (draw->cur_fences < DRI_SWAP_FENCES_MAX) {
 324       draw->cur_fences++;
 325       screen->fence_reference(screen, &draw->swap_fences[draw->head++],
 326                               fence);
 327       draw->head &= DRI_SWAP_FENCES_MASK;
 328    }
 329 }
 330
 331 void
 332 dri_destroy_buffer(__DRIdrawablePrivate * dPriv)
 333 {
 334    struct dri_drawable *drawable = dri_drawable(dPriv);
 335    struct pipe_fence_handle *fence;
 336    struct pipe_screen *screen = dri_screen(drawable->sPriv)->pipe_screen;
 337
 338    st_unreference_framebuffer(drawable->stfb);
 339    drawable->desired_fences = 0;
 340    while (drawable->cur_fences) {
 341       fence = dri_swap_fences_pop_front(drawable);
 342       screen->fence_reference(screen, &fence, NULL);
 343    }
 344
 345    FREE(drawable);
 346 }
 347
 348 static void
 349 dri1_update_drawables_locked(struct dri_context *ctx,
 350                              __DRIdrawablePrivate * driDrawPriv,
 351                              __DRIdrawablePrivate * driReadPriv)
 352 {
 353    if (ctx->stLostLock) {
 354       ctx->stLostLock = FALSE;
 355       if (driDrawPriv == driReadPriv)
 356          DRI_VALIDATE_DRAWABLE_INFO(ctx->sPriv, driDrawPriv);
 357       else
 358          DRI_VALIDATE_TWO_DRAWABLES_INFO(ctx->sPriv, driDrawPriv,
 359                                          driReadPriv);
 360    }
 361 }
 362
 363 /**
 364  * This ensures all contexts which bind to a drawable pick up the
 365  * drawable change and signal new buffer state.
 366  * Calling st_resize_framebuffer for each context may seem like overkill,
 367  * but no new buffers will actually be allocated if the dimensions don't
 368  * change.
 369  */
 370
 371 static void
 372 dri1_propagate_drawable_change(struct dri_context *ctx)
 373 {
 374    __DRIdrawablePrivate *dPriv = ctx->dPriv;
 375    __DRIdrawablePrivate *rPriv = ctx->rPriv;
 376    boolean flushed = FALSE;
 377
 378    if (dPriv && ctx->d_stamp != dPriv->lastStamp) {
 379
 380       st_flush(ctx->st, PIPE_FLUSH_RENDER_CACHE, NULL);
 381       flushed = TRUE;
 382       ctx->d_stamp = dPriv->lastStamp;
 383       st_resize_framebuffer(dri_drawable(dPriv)->stfb, dPriv->w, dPriv->h);
 384
 385    }
 386
 387    if (rPriv && dPriv != rPriv && ctx->r_stamp != rPriv->lastStamp) {
 388
 389       if (!flushed)
 390          st_flush(ctx->st, PIPE_FLUSH_RENDER_CACHE, NULL);
 391       ctx->r_stamp = rPriv->lastStamp;
 392       st_resize_framebuffer(dri_drawable(rPriv)->stfb, rPriv->w, rPriv->h);
 393
 394    } else if (rPriv && dPriv == rPriv) {
 395
 396       ctx->r_stamp = ctx->d_stamp;
 397
 398    }
 399 }
 400
 401 void
 402 dri1_update_drawables(struct dri_context *ctx,
 403                       struct dri_drawable *draw, struct dri_drawable *read)
 404 {
 405    dri_lock(ctx);
 406    dri1_update_drawables_locked(ctx, draw->dPriv, read->dPriv);
 407    dri_unlock(ctx);
 408
 409    dri1_propagate_drawable_change(ctx);
 410 }
 411
 412 static INLINE boolean
 413 dri1_intersect_src_bbox(struct drm_clip_rect *dst,
 414                         int dst_x,
 415                         int dst_y,
 416                         const struct drm_clip_rect *src,
 417                         const struct drm_clip_rect *bbox)
 418 {
 419    int xy1;
 420    int xy2;
 421
 422    xy1 = ((int)src->x1 > (int)bbox->x1 + dst_x) ? src->x1 :
 423       (int)bbox->x1 + dst_x;
 424    xy2 = ((int)src->x2 < (int)bbox->x2 + dst_x) ? src->x2 :
 425       (int)bbox->x2 + dst_x;
 426    if (xy1 >= xy2 || xy1 < 0)
 427       return FALSE;
 428
 429    dst->x1 = xy1;
 430    dst->x2 = xy2;
 431
 432    xy1 = ((int)src->y1 > (int)bbox->y1 + dst_y) ? src->y1 :
 433       (int)bbox->y1 + dst_y;
 434    xy2 = ((int)src->y2 < (int)bbox->y2 + dst_y) ? src->y2 :
 435       (int)bbox->y2 + dst_y;
 436    if (xy1 >= xy2 || xy1 < 0)
 437       return FALSE;
 438
 439    dst->y1 = xy1;
 440    dst->y2 = xy2;
 441    return TRUE;
 442 }
 443
 444 static void
 445 dri1_swap_copy(struct dri_context *ctx,
 446                struct pipe_surface *dst,
 447                struct pipe_surface *src,
 448                __DRIdrawablePrivate * dPriv, const struct drm_clip_rect *bbox)
 449 {
 450    struct pipe_context *pipe = ctx->pipe;
 451    struct drm_clip_rect clip;
 452    struct drm_clip_rect *cur;
 453    int i;
 454
 455    cur = dPriv->pClipRects;
 456
 457    for (i = 0; i < dPriv->numClipRects; ++i) {
 458       if (dri1_intersect_src_bbox(&clip, dPriv->x, dPriv->y, cur++, bbox))
 459          pipe->surface_copy(pipe, dst, clip.x1, clip.y1,
 460                             src,
 461                             (int)clip.x1 - dPriv->x,
 462                             (int)clip.y1 - dPriv->y,
 463                             clip.x2 - clip.x1, clip.y2 - clip.y1);
 464    }
 465 }
 466
 467 static void
 468 dri1_copy_to_front(struct dri_context *ctx,
 469                    struct pipe_surface *surf,
 470                    __DRIdrawablePrivate * dPriv,
 471                    const struct drm_clip_rect *sub_box,
 472                    struct pipe_fence_handle **fence)
 473 {
 474    struct pipe_context *pipe = ctx->pipe;
 475    boolean save_lost_lock;
 476    uint cur_w;
 477    uint cur_h;
 478    struct drm_clip_rect bbox;
 479    boolean visible = TRUE;
 480
 481    *fence = NULL;
 482
 483    dri_lock(ctx);
 484    save_lost_lock = ctx->stLostLock;
 485    dri1_update_drawables_locked(ctx, dPriv, dPriv);
 486    st_get_framebuffer_dimensions(dri_drawable(dPriv)->stfb, &cur_w, &cur_h);
 487
 488    bbox.x1 = 0;
 489    bbox.x2 = cur_w;
 490    bbox.y1 = 0;
 491    bbox.y2 = cur_h;
 492
 493    if (sub_box)
 494       visible = dri1_intersect_src_bbox(&bbox, 0, 0, &bbox, sub_box);
 495
 496    if (visible && __dri1_api_hooks->present_locked) {
 497
 498       __dri1_api_hooks->present_locked(pipe,
 499                                        surf,
 500                                        dPriv->pClipRects,
 501                                        dPriv->numClipRects,
 502                                        dPriv->x, dPriv->y, &bbox, fence);
 503
 504    } else if (visible && __dri1_api_hooks->front_srf_locked) {
 505
 506       struct pipe_surface *front = __dri1_api_hooks->front_srf_locked(pipe);
 507
 508       if (front)
 509          dri1_swap_copy(ctx, front, surf, dPriv, &bbox);
 510
 511       st_flush(ctx->st, PIPE_FLUSH_RENDER_CACHE, fence);
 512    }
 513
 514    ctx->stLostLock = save_lost_lock;
 515
 516    /**
 517     * FIXME: Revisit this: Update drawables on copy_sub_buffer ?
 518     */
 519
 520    if (!sub_box)
 521       dri1_update_drawables_locked(ctx, ctx->dPriv, ctx->rPriv);
 522
 523    dri_unlock(ctx);
 524    dri1_propagate_drawable_change(ctx);
 525 }
 526
 527 void
 528 dri1_flush_frontbuffer(struct pipe_screen *screen,
 529                        struct pipe_surface *surf, void *context_private)
 530 {
 531    struct dri_context *ctx = (struct dri_context *)context_private;
 532    struct pipe_fence_handle *dummy_fence;
 533
 534    dri1_copy_to_front(ctx, surf, ctx->dPriv, NULL, &dummy_fence);
 535    screen->fence_reference(screen, &dummy_fence, NULL);
 536
 537    /**
 538     * FIXME: Do we need swap throttling here?
 539     */
 540 }
 541
 542 void
 543 dri_swap_buffers(__DRIdrawablePrivate * dPriv)
 544 {
 545    struct dri_context *ctx;
 546    struct pipe_surface *back_surf;
 547    struct dri_drawable *draw = dri_drawable(dPriv);
 548    struct pipe_screen *screen = dri_screen(draw->sPriv)->pipe_screen;
 549    struct pipe_fence_handle *fence;
 550    struct st_context *st = st_get_current();
 551
 552    assert(__dri1_api_hooks != NULL);
 553
 554    if (!st)
 555       return;                          /* For now */
 556
 557    ctx = (struct dri_context *)st->pipe->priv;
 558
 559    st_get_framebuffer_surface(draw->stfb, ST_SURFACE_BACK_LEFT, &back_surf);
 560    if (back_surf) {
 561       st_notify_swapbuffers(draw->stfb);
 562       st_flush(ctx->st, PIPE_FLUSH_RENDER_CACHE, NULL);
 563       fence = dri_swap_fences_pop_front(draw);
 564       if (fence) {
 565          (void)screen->fence_finish(screen, fence, 0);
 566          screen->fence_reference(screen, &fence, NULL);
 567       }
 568       dri1_copy_to_front(ctx, back_surf, dPriv, NULL, &fence);
 569       dri_swap_fences_push_back(draw, fence);
 570       screen->fence_reference(screen, &fence, NULL);
 571    }
 572 }
 573
 574 void
 575 dri_copy_sub_buffer(__DRIdrawablePrivate * dPriv, int x, int y, int w, int h)
 576 {
 577    struct pipe_screen *screen = dri_screen(dPriv->driScreenPriv)->pipe_screen;
 578    struct drm_clip_rect sub_bbox;
 579    struct dri_context *ctx;
 580    struct pipe_surface *back_surf;
 581    struct dri_drawable *draw = dri_drawable(dPriv);
 582    struct pipe_fence_handle *dummy_fence;
 583    struct st_context *st = st_get_current();
 584
 585    assert(__dri1_api_hooks != NULL);
 586
 587    if (!st)
 588       return;
 589
 590    ctx = (struct dri_context *)st->pipe->priv;
 591
 592    sub_bbox.x1 = x;
 593    sub_bbox.x2 = x + w;
 594    sub_bbox.y1 = y;
 595    sub_bbox.y2 = y + h;
 596
 597    st_get_framebuffer_surface(draw->stfb, ST_SURFACE_BACK_LEFT, &back_surf);
 598    if (back_surf) {
 599       st_flush(ctx->st, PIPE_FLUSH_RENDER_CACHE, NULL);
 600       dri1_copy_to_front(ctx, back_surf, dPriv, &sub_bbox, &dummy_fence);
 601       screen->fence_reference(screen, &dummy_fence, NULL);
 602    }
 603 }
 604
 605 /* vim: set sw=3 ts=8 sts=3 expandtab: */