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 drm_api *api,
  57                         struct pipe_screen *screen,
  58                         unsigned handle,
  59                         enum pipe_format format,
  60                         unsigned width, unsigned height, unsigned pitch)
  61 {
  62    struct pipe_surface *surface = NULL;
  63    struct pipe_texture *texture = NULL;
  64    struct pipe_texture templat;
  65    struct pipe_buffer *buf = NULL;
  66
  67    buf = api->buffer_from_handle(api, screen, "dri2 buffer", handle);
  68    if (!buf)
  69       return NULL;
  70
  71    memset(&templat, 0, sizeof(templat));
  72    templat.tex_usage |= PIPE_TEXTURE_USAGE_RENDER_TARGET;
  73    templat.target = PIPE_TEXTURE_2D;
  74    templat.last_level = 0;
  75    templat.depth[0] = 1;
  76    templat.format = format;
  77    templat.width[0] = width;
  78    templat.height[0] = height;
  79    pf_get_block(templat.format, &templat.block);
  80
  81    texture = screen->texture_blanket(screen, &templat, &pitch, buf);
  82
  83    /* we don't need the buffer from this point on */
  84    pipe_buffer_reference(&buf, NULL);
  85
  86    if (!texture)
  87       return NULL;
  88
  89    surface = screen->get_tex_surface(screen, texture, 0, 0, 0,
  90                                      PIPE_BUFFER_USAGE_GPU_READ |
  91                                      PIPE_BUFFER_USAGE_GPU_WRITE);
  92
  93    /* we don't need the texture from this point on */
  94    pipe_texture_reference(&texture, NULL);
  95    return surface;
  96 }
  97
  98 /**
  99  * This will be called a drawable is known to have been resized.
 100  */
 101 void
 102 dri_get_buffers(__DRIdrawablePrivate * dPriv)
 103 {
 104
 105    struct dri_drawable *drawable = dri_drawable(dPriv);
 106    struct pipe_surface *surface = NULL;
 107    struct pipe_screen *screen = dri_screen(drawable->sPriv)->pipe_screen;
 108    __DRIbuffer *buffers = NULL;
 109    __DRIscreen *dri_screen = drawable->sPriv;
 110    __DRIdrawable *dri_drawable = drawable->dPriv;
 111    struct drm_api *api = ((struct dri_screen*)(dri_screen->private))->api;
 112    boolean have_depth = FALSE;
 113    int i, count;
 114
 115    buffers = (*dri_screen->dri2.loader->getBuffers) (dri_drawable,
 116                                                      &dri_drawable->w,
 117                                                      &dri_drawable->h,
 118                                                      drawable->attachments,
 119                                                      drawable->
 120                                                      num_attachments, &count,
 121                                                      dri_drawable->
 122                                                      loaderPrivate);
 123
 124    if (buffers == NULL) {
 125       return;
 126    }
 127
 128    /* set one cliprect to cover the whole dri_drawable */
 129    dri_drawable->x = 0;
 130    dri_drawable->y = 0;
 131    dri_drawable->backX = 0;
 132    dri_drawable->backY = 0;
 133    dri_drawable->numClipRects = 1;
 134    dri_drawable->pClipRects[0].x1 = 0;
 135    dri_drawable->pClipRects[0].y1 = 0;
 136    dri_drawable->pClipRects[0].x2 = dri_drawable->w;
 137    dri_drawable->pClipRects[0].y2 = dri_drawable->h;
 138    dri_drawable->numBackClipRects = 1;
 139    dri_drawable->pBackClipRects[0].x1 = 0;
 140    dri_drawable->pBackClipRects[0].y1 = 0;
 141    dri_drawable->pBackClipRects[0].x2 = dri_drawable->w;
 142    dri_drawable->pBackClipRects[0].y2 = dri_drawable->h;
 143
 144    if (drawable->old_num == count &&
 145        drawable->old_w == dri_drawable->w &&
 146        drawable->old_h == dri_drawable->h &&
 147        memcmp(drawable->old, buffers, sizeof(__DRIbuffer) * count) == 0) {
 148        return;
 149    } else {
 150       drawable->old_num = count;
 151       drawable->old_w = dri_drawable->w;
 152       drawable->old_h = dri_drawable->h;
 153       memcpy(drawable->old, buffers, sizeof(__DRIbuffer) * count);
 154    }
 155
 156    for (i = 0; i < count; i++) {
 157       enum pipe_format format = 0;
 158       int index = 0;
 159
 160       switch (buffers[i].attachment) {
 161       case __DRI_BUFFER_FRONT_LEFT:
 162          index = ST_SURFACE_FRONT_LEFT;
 163          format = drawable->color_format;
 164          break;
 165       case __DRI_BUFFER_FAKE_FRONT_LEFT:
 166          index = ST_SURFACE_FRONT_LEFT;
 167          format = drawable->color_format;
 168          break;
 169       case __DRI_BUFFER_BACK_LEFT:
 170          index = ST_SURFACE_BACK_LEFT;
 171          format = drawable->color_format;
 172          break;
 173       case __DRI_BUFFER_DEPTH:
 174          index = ST_SURFACE_DEPTH;
 175          format = drawable->depth_format;
 176          break;
 177       case __DRI_BUFFER_STENCIL:
 178          index = ST_SURFACE_DEPTH;
 179          format = drawable->stencil_format;
 180          break;
 181       case __DRI_BUFFER_ACCUM:
 182       default:
 183          assert(0);
 184       }
 185
 186       if (index == ST_SURFACE_DEPTH) {
 187          if (have_depth)
 188             continue;
 189          else
 190             have_depth = TRUE;
 191       }
 192
 193       surface = dri_surface_from_handle(api,
 194                                         screen,
 195                                         buffers[i].name,
 196                                         format,
 197                                         dri_drawable->w,
 198                                         dri_drawable->h, buffers[i].pitch);
 199
 200       st_set_framebuffer_surface(drawable->stfb, index, surface);
 201       pipe_surface_reference(&surface, NULL);
 202    }
 203    /* this needed, or else the state tracker fails to pick the new buffers */
 204    st_resize_framebuffer(drawable->stfb, dri_drawable->w, dri_drawable->h);
 205 }
 206
 207 void
 208 dri_flush_frontbuffer(struct pipe_screen *screen,
 209                       struct pipe_surface *surf, void *context_private)
 210 {
 211    struct dri_context *ctx = (struct dri_context *)context_private;
 212
 213    dri_copy_to_front(ctx->dPriv, surf, 0, 0, surf->width, surf->height);
 214 }
 215
 216 /**
 217  * This is called when we need to set up GL rendering to a new X window.
 218  */
 219 boolean
 220 dri_create_buffer(__DRIscreenPrivate * sPriv,
 221                   __DRIdrawablePrivate * dPriv,
 222                   const __GLcontextModes * visual, boolean isPixmap)
 223 {
 224    struct dri_screen *screen = sPriv->private;
 225    struct dri_drawable *drawable = NULL;
 226    int i;
 227
 228    if (isPixmap)
 229       goto fail;                       /* not implemented */
 230
 231    drawable = CALLOC_STRUCT(dri_drawable);
 232    if (drawable == NULL)
 233       goto fail;
 234
 235    drawable->color_format = (visual->redBits == 8) ?
 236       PIPE_FORMAT_A8R8G8B8_UNORM : PIPE_FORMAT_R5G6B5_UNORM;
 237
 238    debug_printf("Red bits is %d\n", visual->redBits);
 239
 240    switch(visual->depthBits) {
 241    default:
 242    case 0:
 243       debug_printf("Depth buffer 0.\n");
 244       drawable->depth_format = PIPE_FORMAT_NONE;
 245       break;
 246    case 16:
 247       debug_printf("Depth buffer 16.\n");
 248       drawable->depth_format = PIPE_FORMAT_Z16_UNORM;
 249       break;
 250    case 24:
 251       if (visual->stencilBits == 0) {
 252          debug_printf("Depth buffer 24. Stencil 0.\n");
 253          drawable->depth_format = (screen->d_depth_bits_last) ?
 254             PIPE_FORMAT_X8Z24_UNORM:
 255             PIPE_FORMAT_Z24X8_UNORM;
 256       } else {
 257          debug_printf("Combined depth stencil 24 / 8.\n");
 258          drawable->depth_format = (screen->sd_depth_bits_last) ?
 259             PIPE_FORMAT_S8Z24_UNORM:
 260             PIPE_FORMAT_Z24S8_UNORM;
 261       }
 262       break;
 263    }
 264
 265    switch(visual->stencilBits) {
 266    default:
 267    case 0:
 268       drawable->stencil_format = PIPE_FORMAT_NONE;
 269       break;
 270    case 8:
 271       drawable->stencil_format = (screen->sd_depth_bits_last) ?
 272          PIPE_FORMAT_S8Z24_UNORM:
 273          PIPE_FORMAT_Z24S8_UNORM;
 274       break;
 275    }
 276
 277    drawable->stfb = st_create_framebuffer(visual,
 278                                           drawable->color_format,
 279                                           drawable->depth_format,
 280                                           drawable->stencil_format,
 281                                           dPriv->w,
 282                                           dPriv->h, (void *)drawable);
 283    if (drawable->stfb == NULL)
 284       goto fail;
 285
 286    drawable->sPriv = sPriv;
 287    drawable->dPriv = dPriv;
 288    dPriv->driverPrivate = (void *)drawable;
 289
 290    /* setup dri2 buffers information */
 291    i = 0;
 292    drawable->attachments[i++] = __DRI_BUFFER_FRONT_LEFT;
 293 #if 0
 294    /* TODO incase of double buffer visual, delay fake creation */
 295    drawable->attachments[i++] = __DRI_BUFFER_FAKE_FRONT_LEFT;
 296 #endif
 297    if (visual->doubleBufferMode)
 298       drawable->attachments[i++] = __DRI_BUFFER_BACK_LEFT;
 299    if (visual->depthBits)
 300       drawable->attachments[i++] = __DRI_BUFFER_DEPTH;
 301    if (visual->stencilBits)
 302       drawable->attachments[i++] = __DRI_BUFFER_STENCIL;
 303    drawable->num_attachments = i;
 304
 305    drawable->desired_fences = 2;
 306
 307    return GL_TRUE;
 308  fail:
 309    FREE(drawable);
 310    return GL_FALSE;
 311 }
 312
 313 static struct pipe_fence_handle *
 314 dri_swap_fences_pop_front(struct dri_drawable *draw)
 315 {
 316    struct pipe_screen *screen = dri_screen(draw->sPriv)->pipe_screen;
 317    struct pipe_fence_handle *fence = NULL;
 318
 319    if (draw->cur_fences >= draw->desired_fences) {
 320       screen->fence_reference(screen, &fence, draw->swap_fences[draw->tail]);
 321       screen->fence_reference(screen, &draw->swap_fences[draw->tail++], NULL);
 322       --draw->cur_fences;
 323       draw->tail &= DRI_SWAP_FENCES_MASK;
 324    }
 325    return fence;
 326 }
 327
 328 static void
 329 dri_swap_fences_push_back(struct dri_drawable *draw,
 330                           struct pipe_fence_handle *fence)
 331 {
 332    struct pipe_screen *screen = dri_screen(draw->sPriv)->pipe_screen;
 333
 334    if (!fence)
 335       return;
 336
 337    if (draw->cur_fences < DRI_SWAP_FENCES_MAX) {
 338       draw->cur_fences++;
 339       screen->fence_reference(screen, &draw->swap_fences[draw->head++],
 340                               fence);
 341       draw->head &= DRI_SWAP_FENCES_MASK;
 342    }
 343 }
 344
 345 void
 346 dri_destroy_buffer(__DRIdrawablePrivate * dPriv)
 347 {
 348    struct dri_drawable *drawable = dri_drawable(dPriv);
 349    struct pipe_fence_handle *fence;
 350    struct pipe_screen *screen = dri_screen(drawable->sPriv)->pipe_screen;
 351
 352    st_unreference_framebuffer(drawable->stfb);
 353    drawable->desired_fences = 0;
 354    while (drawable->cur_fences) {
 355       fence = dri_swap_fences_pop_front(drawable);
 356       screen->fence_reference(screen, &fence, NULL);
 357    }
 358
 359    FREE(drawable);
 360 }
 361
 362 static void
 363 dri1_update_drawables_locked(struct dri_context *ctx,
 364                              __DRIdrawablePrivate * driDrawPriv,
 365                              __DRIdrawablePrivate * driReadPriv)
 366 {
 367    if (ctx->stLostLock) {
 368       ctx->stLostLock = FALSE;
 369       if (driDrawPriv == driReadPriv)
 370          DRI_VALIDATE_DRAWABLE_INFO(ctx->sPriv, driDrawPriv);
 371       else
 372          DRI_VALIDATE_TWO_DRAWABLES_INFO(ctx->sPriv, driDrawPriv,
 373                                          driReadPriv);
 374    }
 375 }
 376
 377 /**
 378  * This ensures all contexts which bind to a drawable pick up the
 379  * drawable change and signal new buffer state.
 380  * Calling st_resize_framebuffer for each context may seem like overkill,
 381  * but no new buffers will actually be allocated if the dimensions don't
 382  * change.
 383  */
 384
 385 static void
 386 dri1_propagate_drawable_change(struct dri_context *ctx)
 387 {
 388    __DRIdrawablePrivate *dPriv = ctx->dPriv;
 389    __DRIdrawablePrivate *rPriv = ctx->rPriv;
 390    boolean flushed = FALSE;
 391
 392    if (dPriv && ctx->d_stamp != dPriv->lastStamp) {
 393
 394       st_flush(ctx->st, PIPE_FLUSH_RENDER_CACHE, NULL);
 395       flushed = TRUE;
 396       ctx->d_stamp = dPriv->lastStamp;
 397       st_resize_framebuffer(dri_drawable(dPriv)->stfb, dPriv->w, dPriv->h);
 398
 399    }
 400
 401    if (rPriv && dPriv != rPriv && ctx->r_stamp != rPriv->lastStamp) {
 402
 403       if (!flushed)
 404          st_flush(ctx->st, PIPE_FLUSH_RENDER_CACHE, NULL);
 405       ctx->r_stamp = rPriv->lastStamp;
 406       st_resize_framebuffer(dri_drawable(rPriv)->stfb, rPriv->w, rPriv->h);
 407
 408    } else if (rPriv && dPriv == rPriv) {
 409
 410       ctx->r_stamp = ctx->d_stamp;
 411
 412    }
 413 }
 414
 415 void
 416 dri1_update_drawables(struct dri_context *ctx,
 417                       struct dri_drawable *draw, struct dri_drawable *read)
 418 {
 419    dri_lock(ctx);
 420    dri1_update_drawables_locked(ctx, draw->dPriv, read->dPriv);
 421    dri_unlock(ctx);
 422
 423    dri1_propagate_drawable_change(ctx);
 424 }
 425
 426 static INLINE boolean
 427 dri1_intersect_src_bbox(struct drm_clip_rect *dst,
 428                         int dst_x,
 429                         int dst_y,
 430                         const struct drm_clip_rect *src,
 431                         const struct drm_clip_rect *bbox)
 432 {
 433    int xy1;
 434    int xy2;
 435
 436    xy1 = ((int)src->x1 > (int)bbox->x1 + dst_x) ? src->x1 :
 437       (int)bbox->x1 + dst_x;
 438    xy2 = ((int)src->x2 < (int)bbox->x2 + dst_x) ? src->x2 :
 439       (int)bbox->x2 + dst_x;
 440    if (xy1 >= xy2 || xy1 < 0)
 441       return FALSE;
 442
 443    dst->x1 = xy1;
 444    dst->x2 = xy2;
 445
 446    xy1 = ((int)src->y1 > (int)bbox->y1 + dst_y) ? src->y1 :
 447       (int)bbox->y1 + dst_y;
 448    xy2 = ((int)src->y2 < (int)bbox->y2 + dst_y) ? src->y2 :
 449       (int)bbox->y2 + dst_y;
 450    if (xy1 >= xy2 || xy1 < 0)
 451       return FALSE;
 452
 453    dst->y1 = xy1;
 454    dst->y2 = xy2;
 455    return TRUE;
 456 }
 457
 458 static void
 459 dri1_swap_copy(struct dri_context *ctx,
 460                struct pipe_surface *dst,
 461                struct pipe_surface *src,
 462                __DRIdrawablePrivate * dPriv, const struct drm_clip_rect *bbox)
 463 {
 464    struct pipe_context *pipe = ctx->pipe;
 465    struct drm_clip_rect clip;
 466    struct drm_clip_rect *cur;
 467    int i;
 468
 469    cur = dPriv->pClipRects;
 470
 471    for (i = 0; i < dPriv->numClipRects; ++i) {
 472       if (dri1_intersect_src_bbox(&clip, dPriv->x, dPriv->y, cur++, bbox))
 473          pipe->surface_copy(pipe, dst, clip.x1, clip.y1,
 474                             src,
 475                             (int)clip.x1 - dPriv->x,
 476                             (int)clip.y1 - dPriv->y,
 477                             clip.x2 - clip.x1, clip.y2 - clip.y1);
 478    }
 479 }
 480
 481 static void
 482 dri1_copy_to_front(struct dri_context *ctx,
 483                    struct pipe_surface *surf,
 484                    __DRIdrawablePrivate * dPriv,
 485                    const struct drm_clip_rect *sub_box,
 486                    struct pipe_fence_handle **fence)
 487 {
 488    struct pipe_context *pipe = ctx->pipe;
 489    boolean save_lost_lock;
 490    uint cur_w;
 491    uint cur_h;
 492    struct drm_clip_rect bbox;
 493    boolean visible = TRUE;
 494
 495    *fence = NULL;
 496
 497    dri_lock(ctx);
 498    save_lost_lock = ctx->stLostLock;
 499    dri1_update_drawables_locked(ctx, dPriv, dPriv);
 500    st_get_framebuffer_dimensions(dri_drawable(dPriv)->stfb, &cur_w, &cur_h);
 501
 502    bbox.x1 = 0;
 503    bbox.x2 = cur_w;
 504    bbox.y1 = 0;
 505    bbox.y2 = cur_h;
 506
 507    if (sub_box)
 508       visible = dri1_intersect_src_bbox(&bbox, 0, 0, &bbox, sub_box);
 509
 510    if (visible && __dri1_api_hooks->present_locked) {
 511
 512       __dri1_api_hooks->present_locked(pipe,
 513                                        surf,
 514                                        dPriv->pClipRects,
 515                                        dPriv->numClipRects,
 516                                        dPriv->x, dPriv->y, &bbox, fence);
 517
 518    } else if (visible && __dri1_api_hooks->front_srf_locked) {
 519
 520       struct pipe_surface *front = __dri1_api_hooks->front_srf_locked(pipe);
 521
 522       if (front)
 523          dri1_swap_copy(ctx, front, surf, dPriv, &bbox);
 524
 525       st_flush(ctx->st, PIPE_FLUSH_RENDER_CACHE, fence);
 526    }
 527
 528    ctx->stLostLock = save_lost_lock;
 529
 530    /**
 531     * FIXME: Revisit this: Update drawables on copy_sub_buffer ?
 532     */
 533
 534    if (!sub_box)
 535       dri1_update_drawables_locked(ctx, ctx->dPriv, ctx->rPriv);
 536
 537    dri_unlock(ctx);
 538    dri1_propagate_drawable_change(ctx);
 539 }
 540
 541 void
 542 dri1_flush_frontbuffer(struct pipe_screen *screen,
 543                        struct pipe_surface *surf, void *context_private)
 544 {
 545    struct dri_context *ctx = (struct dri_context *)context_private;
 546    struct pipe_fence_handle *dummy_fence;
 547
 548    dri1_copy_to_front(ctx, surf, ctx->dPriv, NULL, &dummy_fence);
 549    screen->fence_reference(screen, &dummy_fence, NULL);
 550
 551    /**
 552     * FIXME: Do we need swap throttling here?
 553     */
 554 }
 555
 556 void
 557 dri_swap_buffers(__DRIdrawablePrivate * dPriv)
 558 {
 559    struct dri_context *ctx;
 560    struct pipe_surface *back_surf;
 561    struct dri_drawable *draw = dri_drawable(dPriv);
 562    struct pipe_screen *screen = dri_screen(draw->sPriv)->pipe_screen;
 563    struct pipe_fence_handle *fence;
 564    struct st_context *st = st_get_current();
 565
 566    assert(__dri1_api_hooks != NULL);
 567
 568    if (!st)
 569       return;                          /* For now */
 570
 571    ctx = (struct dri_context *)st->pipe->priv;
 572
 573    st_get_framebuffer_surface(draw->stfb, ST_SURFACE_BACK_LEFT, &back_surf);
 574    if (back_surf) {
 575       st_notify_swapbuffers(draw->stfb);
 576       st_flush(ctx->st, PIPE_FLUSH_RENDER_CACHE, NULL);
 577       fence = dri_swap_fences_pop_front(draw);
 578       if (fence) {
 579          (void)screen->fence_finish(screen, fence, 0);
 580          screen->fence_reference(screen, &fence, NULL);
 581       }
 582       dri1_copy_to_front(ctx, back_surf, dPriv, NULL, &fence);
 583       dri_swap_fences_push_back(draw, fence);
 584       screen->fence_reference(screen, &fence, NULL);
 585    }
 586 }
 587
 588 void
 589 dri_copy_sub_buffer(__DRIdrawablePrivate * dPriv, int x, int y, int w, int h)
 590 {
 591    struct pipe_screen *screen = dri_screen(dPriv->driScreenPriv)->pipe_screen;
 592    struct drm_clip_rect sub_bbox;
 593    struct dri_context *ctx;
 594    struct pipe_surface *back_surf;
 595    struct dri_drawable *draw = dri_drawable(dPriv);
 596    struct pipe_fence_handle *dummy_fence;
 597    struct st_context *st = st_get_current();
 598
 599    assert(__dri1_api_hooks != NULL);
 600
 601    if (!st)
 602       return;
 603
 604    ctx = (struct dri_context *)st->pipe->priv;
 605
 606    sub_bbox.x1 = x;
 607    sub_bbox.x2 = x + w;
 608    sub_bbox.y1 = y;
 609    sub_bbox.y2 = y + h;
 610
 611    st_get_framebuffer_surface(draw->stfb, ST_SURFACE_BACK_LEFT, &back_surf);
 612    if (back_surf) {
 613       st_flush(ctx->st, PIPE_FLUSH_RENDER_CACHE, NULL);
 614       dri1_copy_to_front(ctx, back_surf, dPriv, &sub_bbox, &dummy_fence);
 615       screen->fence_reference(screen, &dummy_fence, NULL);
 616    }
 617 }
 618
 619 /* vim: set sw=3 ts=8 sts=3 expandtab: */