src/mesa/state_tracker/st_cb_fbo.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   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 TUNGSTEN GRAPHICS 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
  29 /**
  30  * Framebuffer/renderbuffer functions.
  31  *
  32  * \author Brian Paul
  33  */
  34
  35
  36 #include "main/imports.h"
  37 #include "main/context.h"
  38 #include "main/fbobject.h"
  39 #include "main/framebuffer.h"
  40 #include "main/macros.h"
  41 #include "main/renderbuffer.h"
  42
  43 #include "pipe/p_context.h"
  44 #include "pipe/p_defines.h"
  45 #include "pipe/p_screen.h"
  46 #include "st_context.h"
  47 #include "st_cb_fbo.h"
  48 #include "st_format.h"
  49 #include "st_public.h"
  50 #include "st_texture.h"
  51 #include "st_manager.h"
  52
  53 #include "util/u_format.h"
  54 #include "util/u_inlines.h"
  55
  56
  57 /**
  58  * gl_renderbuffer::AllocStorage()
  59  * This is called to allocate the original drawing surface, and
  60  * during window resize.
  61  */
  62 static GLboolean
  63 st_renderbuffer_alloc_storage(GLcontext * ctx, struct gl_renderbuffer *rb,
  64                               GLenum internalFormat,
  65                               GLuint width, GLuint height)
  66 {
  67    struct pipe_screen *screen = ctx->st->pipe->screen;
  68    struct st_renderbuffer *strb = st_renderbuffer(rb);
  69    enum pipe_format format;
  70
  71    if (strb->format != PIPE_FORMAT_NONE)
  72       format = strb->format;
  73    else
  74       format = st_choose_renderbuffer_format(screen, internalFormat);
  75
  76    /* init renderbuffer fields */
  77    strb->Base.Width  = width;
  78    strb->Base.Height = height;
  79    strb->Base.Format = st_pipe_format_to_mesa_format(format);
  80    strb->Base.DataType = st_format_datatype(format);
  81
  82    strb->defined = GL_FALSE;  /* undefined contents now */
  83
  84    if (strb->software) {
  85       size_t size;
  86
  87       free(strb->data);
  88
  89       assert(strb->format != PIPE_FORMAT_NONE);
  90
  91       strb->stride = util_format_get_stride(strb->format, width);
  92       size = util_format_get_2d_size(strb->format, strb->stride, height);
  93
  94       strb->data = malloc(size);
  95
  96       return strb->data != NULL;
  97    }
  98    else {
  99       struct pipe_texture template;
 100       unsigned surface_usage;
 101
 102       /* Free the old surface and texture
 103        */
 104       pipe_surface_reference( &strb->surface, NULL );
 105       pipe_texture_reference( &strb->texture, NULL );
 106       pipe_sampler_view_reference(&strb->sampler_view, NULL);
 107
 108       /* Setup new texture template.
 109        */
 110       memset(&template, 0, sizeof(template));
 111       template.target = PIPE_TEXTURE_2D;
 112       template.format = format;
 113       template.width0 = width;
 114       template.height0 = height;
 115       template.depth0 = 1;
 116       template.last_level = 0;
 117       template.nr_samples = rb->NumSamples;
 118       if (util_format_is_depth_or_stencil(format)) {
 119          template.tex_usage = PIPE_TEXTURE_USAGE_DEPTH_STENCIL;
 120       }
 121       else {
 122          template.tex_usage = (PIPE_TEXTURE_USAGE_DISPLAY_TARGET |
 123                                PIPE_TEXTURE_USAGE_RENDER_TARGET);
 124       }
 125
 126       /* Probably need dedicated flags for surface usage too:
 127        */
 128       surface_usage = (PIPE_BUFFER_USAGE_GPU_READ |
 129                        PIPE_BUFFER_USAGE_GPU_WRITE);
 130 #if 0
 131                        PIPE_BUFFER_USAGE_CPU_READ |
 132                        PIPE_BUFFER_USAGE_CPU_WRITE);
 133 #endif
 134
 135       strb->texture = screen->texture_create(screen, &template);
 136
 137       if (!strb->texture)
 138          return FALSE;
 139
 140       strb->surface = screen->get_tex_surface(screen,
 141                                               strb->texture,
 142                                               0, 0, 0,
 143                                               surface_usage);
 144       if (strb->surface) {
 145          assert(strb->surface->texture);
 146          assert(strb->surface->format);
 147          assert(strb->surface->width == width);
 148          assert(strb->surface->height == height);
 149       }
 150
 151       return strb->surface != NULL;
 152    }
 153 }
 154
 155
 156 /**
 157  * gl_renderbuffer::Delete()
 158  */
 159 static void
 160 st_renderbuffer_delete(struct gl_renderbuffer *rb)
 161 {
 162    struct st_renderbuffer *strb = st_renderbuffer(rb);
 163    ASSERT(strb);
 164    pipe_surface_reference(&strb->surface, NULL);
 165    pipe_texture_reference(&strb->texture, NULL);
 166    pipe_sampler_view_reference(&strb->sampler_view, NULL);
 167    free(strb->data);
 168    free(strb);
 169 }
 170
 171
 172 /**
 173  * gl_renderbuffer::GetPointer()
 174  */
 175 static void *
 176 null_get_pointer(GLcontext * ctx, struct gl_renderbuffer *rb,
 177                  GLint x, GLint y)
 178 {
 179    /* By returning NULL we force all software rendering to go through
 180     * the span routines.
 181     */
 182 #if 0
 183    assert(0);  /* Should never get called with softpipe */
 184 #endif
 185    return NULL;
 186 }
 187
 188
 189 /**
 190  * Called via ctx->Driver.NewFramebuffer()
 191  */
 192 static struct gl_framebuffer *
 193 st_new_framebuffer(GLcontext *ctx, GLuint name)
 194 {
 195    /* XXX not sure we need to subclass gl_framebuffer for pipe */
 196    return _mesa_new_framebuffer(ctx, name);
 197 }
 198
 199
 200 /**
 201  * Called via ctx->Driver.NewRenderbuffer()
 202  */
 203 static struct gl_renderbuffer *
 204 st_new_renderbuffer(GLcontext *ctx, GLuint name)
 205 {
 206    struct st_renderbuffer *strb = ST_CALLOC_STRUCT(st_renderbuffer);
 207    if (strb) {
 208       _mesa_init_renderbuffer(&strb->Base, name);
 209       strb->Base.Delete = st_renderbuffer_delete;
 210       strb->Base.AllocStorage = st_renderbuffer_alloc_storage;
 211       strb->Base.GetPointer = null_get_pointer;
 212       strb->format = PIPE_FORMAT_NONE;
 213       return &strb->Base;
 214    }
 215    return NULL;
 216 }
 217
 218
 219 /**
 220  * Allocate a renderbuffer for a an on-screen window (not a user-created
 221  * renderbuffer).  The window system code determines the format.
 222  */
 223 struct gl_renderbuffer *
 224 st_new_renderbuffer_fb(enum pipe_format format, int samples, boolean sw)
 225 {
 226    struct st_renderbuffer *strb;
 227
 228    strb = ST_CALLOC_STRUCT(st_renderbuffer);
 229    if (!strb) {
 230       _mesa_error(NULL, GL_OUT_OF_MEMORY, "creating renderbuffer");
 231       return NULL;
 232    }
 233
 234    _mesa_init_renderbuffer(&strb->Base, 0);
 235    strb->Base.ClassID = 0x4242; /* just a unique value */
 236    strb->Base.NumSamples = samples;
 237    strb->Base.Format = st_pipe_format_to_mesa_format(format);
 238    strb->Base.DataType = st_format_datatype(format);
 239    strb->format = format;
 240    strb->software = sw;
 241
 242    switch (format) {
 243    case PIPE_FORMAT_B8G8R8A8_UNORM:
 244    case PIPE_FORMAT_A8R8G8B8_UNORM:
 245    case PIPE_FORMAT_B8G8R8X8_UNORM:
 246    case PIPE_FORMAT_X8R8G8B8_UNORM:
 247    case PIPE_FORMAT_B5G5R5A1_UNORM:
 248    case PIPE_FORMAT_B4G4R4A4_UNORM:
 249    case PIPE_FORMAT_B5G6R5_UNORM:
 250       strb->Base.InternalFormat = GL_RGBA;
 251       break;
 252    case PIPE_FORMAT_Z16_UNORM:
 253       strb->Base.InternalFormat = GL_DEPTH_COMPONENT16;
 254       break;
 255    case PIPE_FORMAT_Z32_UNORM:
 256       strb->Base.InternalFormat = GL_DEPTH_COMPONENT32;
 257       break;
 258    case PIPE_FORMAT_Z24_UNORM_S8_USCALED:
 259    case PIPE_FORMAT_S8_USCALED_Z24_UNORM:
 260    case PIPE_FORMAT_Z24X8_UNORM:
 261    case PIPE_FORMAT_X8Z24_UNORM:
 262       strb->Base.InternalFormat = GL_DEPTH24_STENCIL8_EXT;
 263       break;
 264    case PIPE_FORMAT_S8_USCALED:
 265       strb->Base.InternalFormat = GL_STENCIL_INDEX8_EXT;
 266       break;
 267    case PIPE_FORMAT_R16G16B16A16_SNORM:
 268       strb->Base.InternalFormat = GL_RGBA16;
 269       break;
 270    default:
 271       _mesa_problem(NULL,
 272                     "Unexpected format in st_new_renderbuffer_fb");
 273       free(strb);
 274       return NULL;
 275    }
 276
 277    /* st-specific methods */
 278    strb->Base.Delete = st_renderbuffer_delete;
 279    strb->Base.AllocStorage = st_renderbuffer_alloc_storage;
 280    strb->Base.GetPointer = null_get_pointer;
 281
 282    /* surface is allocated in st_renderbuffer_alloc_storage() */
 283    strb->surface = NULL;
 284
 285    return &strb->Base;
 286 }
 287
 288
 289
 290
 291 /**
 292  * Called via ctx->Driver.BindFramebufferEXT().
 293  */
 294 static void
 295 st_bind_framebuffer(GLcontext *ctx, GLenum target,
 296                     struct gl_framebuffer *fb, struct gl_framebuffer *fbread)
 297 {
 298
 299 }
 300
 301 /**
 302  * Called by ctx->Driver.FramebufferRenderbuffer
 303  */
 304 static void
 305 st_framebuffer_renderbuffer(GLcontext *ctx,
 306                             struct gl_framebuffer *fb,
 307                             GLenum attachment,
 308                             struct gl_renderbuffer *rb)
 309 {
 310    /* XXX no need for derivation? */
 311    _mesa_framebuffer_renderbuffer(ctx, fb, attachment, rb);
 312 }
 313
 314
 315 /**
 316  * Called by ctx->Driver.RenderTexture
 317  */
 318 static void
 319 st_render_texture(GLcontext *ctx,
 320                   struct gl_framebuffer *fb,
 321                   struct gl_renderbuffer_attachment *att)
 322 {
 323    struct pipe_screen *screen = ctx->st->pipe->screen;
 324    struct st_renderbuffer *strb;
 325    struct gl_renderbuffer *rb;
 326    struct pipe_texture *pt = st_get_texobj_texture(att->Texture);
 327    struct st_texture_object *stObj;
 328    const struct gl_texture_image *texImage;
 329    GLint pt_level;
 330
 331    /* When would this fail?  Perhaps assert? */
 332    if (!pt)
 333       return;
 334
 335    /* The first gallium texture level = Mesa BaseLevel */
 336    pt_level = MAX2(0, (GLint) att->TextureLevel - att->Texture->BaseLevel);
 337    texImage = att->Texture->Image[att->CubeMapFace][pt_level];
 338
 339    /* create new renderbuffer which wraps the texture image */
 340    rb = st_new_renderbuffer(ctx, 0);
 341    if (!rb) {
 342       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glFramebufferTexture()");
 343       return;
 344    }
 345
 346    _mesa_reference_renderbuffer(&att->Renderbuffer, rb);
 347    assert(rb->RefCount == 1);
 348    rb->AllocStorage = NULL; /* should not get called */
 349    strb = st_renderbuffer(rb);
 350
 351    assert(strb->Base.RefCount > 0);
 352
 353    /* get the texture for the texture object */
 354    stObj = st_texture_object(att->Texture);
 355
 356    /* point renderbuffer at texobject */
 357    strb->rtt = stObj;
 358    strb->rtt_level = pt_level;
 359    strb->rtt_face = att->CubeMapFace;
 360    strb->rtt_slice = att->Zoffset;
 361
 362    rb->Width = texImage->Width2;
 363    rb->Height = texImage->Height2;
 364    rb->_BaseFormat = texImage->_BaseFormat;
 365    /*printf("***** render to texture level %d: %d x %d\n", att->TextureLevel, rb->Width, rb->Height);*/
 366
 367    /*printf("***** pipe texture %d x %d\n", pt->width0, pt->height0);*/
 368
 369    pipe_texture_reference( &strb->texture, pt );
 370
 371    pipe_surface_reference(&strb->surface, NULL);
 372
 373    pipe_sampler_view_reference(&strb->sampler_view, st_get_stobj_sampler_view(stObj));
 374
 375    assert(strb->rtt_level <= strb->texture->last_level);
 376
 377    /* new surface for rendering into the texture */
 378    strb->surface = screen->get_tex_surface(screen,
 379                                            strb->texture,
 380                                            strb->rtt_face,
 381                                            strb->rtt_level,
 382                                            strb->rtt_slice,
 383                                            PIPE_BUFFER_USAGE_GPU_READ |
 384                                            PIPE_BUFFER_USAGE_GPU_WRITE);
 385
 386    strb->format = pt->format;
 387
 388    strb->Base.Format = st_pipe_format_to_mesa_format(pt->format);
 389    strb->Base.DataType = st_format_datatype(pt->format);
 390
 391    /*
 392    printf("RENDER TO TEXTURE obj=%p pt=%p surf=%p  %d x %d\n",
 393           att->Texture, pt, strb->surface, rb->Width, rb->Height);
 394    */
 395
 396    /* Invalidate buffer state so that the pipe's framebuffer state
 397     * gets updated.
 398     * That's where the new renderbuffer (which we just created) gets
 399     * passed to the pipe as a (color/depth) render target.
 400     */
 401    st_invalidate_state(ctx, _NEW_BUFFERS);
 402 }
 403
 404
 405 /**
 406  * Called via ctx->Driver.FinishRenderTexture.
 407  */
 408 static void
 409 st_finish_render_texture(GLcontext *ctx,
 410                          struct gl_renderbuffer_attachment *att)
 411 {
 412    struct st_renderbuffer *strb = st_renderbuffer(att->Renderbuffer);
 413
 414    if (!strb)
 415       return;
 416
 417    st_flush( ctx->st, PIPE_FLUSH_RENDER_CACHE, NULL );
 418
 419    strb->rtt = NULL;
 420
 421    /*
 422    printf("FINISH RENDER TO TEXTURE surf=%p\n", strb->surface);
 423    */
 424
 425    /* restore previous framebuffer state */
 426    st_invalidate_state(ctx, _NEW_BUFFERS);
 427 }
 428
 429
 430 /**
 431  * Validate a renderbuffer attachment for a particular usage.
 432  */
 433
 434 static GLboolean
 435 st_validate_attachment(struct pipe_screen *screen,
 436                        const struct gl_renderbuffer_attachment *att,
 437                        GLuint usage)
 438 {
 439    const struct st_texture_object *stObj =
 440       st_texture_object(att->Texture);
 441
 442    /**
 443     * Only validate texture attachments for now, since
 444     * st_renderbuffer_alloc_storage makes sure that
 445     * the format is supported.
 446     */
 447
 448    if (att->Type != GL_TEXTURE)
 449       return GL_TRUE;
 450
 451    if (!stObj)
 452       return GL_FALSE;
 453
 454    return screen->is_format_supported(screen, stObj->pt->format,
 455                                       PIPE_TEXTURE_2D,
 456                                       usage, 0);
 457 }
 458
 459 /**
 460  * Check that the framebuffer configuration is valid in terms of what
 461  * the driver can support.
 462  *
 463  * For Gallium we only supports combined Z+stencil, not separate buffers.
 464  */
 465 static void
 466 st_validate_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb)
 467 {
 468    struct pipe_screen *screen = ctx->st->pipe->screen;
 469    const struct gl_renderbuffer *depthRb =
 470       fb->Attachment[BUFFER_DEPTH].Renderbuffer;
 471    const struct gl_renderbuffer *stencilRb =
 472       fb->Attachment[BUFFER_STENCIL].Renderbuffer;
 473    GLuint i;
 474
 475    if (stencilRb && depthRb && stencilRb != depthRb) {
 476       fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 477       return;
 478    }
 479
 480    if (!st_validate_attachment(screen,
 481                                &fb->Attachment[BUFFER_DEPTH],
 482                                PIPE_TEXTURE_USAGE_DEPTH_STENCIL)) {
 483       fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 484       return;
 485    }
 486    if (!st_validate_attachment(screen,
 487                                &fb->Attachment[BUFFER_STENCIL],
 488                                PIPE_TEXTURE_USAGE_DEPTH_STENCIL)) {
 489       fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 490       return;
 491    }
 492    for (i = 0; i < ctx->Const.MaxColorAttachments; i++) {
 493       if (!st_validate_attachment(screen,
 494                                   &fb->Attachment[BUFFER_COLOR0 + i],
 495                                   PIPE_TEXTURE_USAGE_RENDER_TARGET)) {
 496          fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 497          return;
 498       }
 499    }
 500 }
 501
 502
 503 /**
 504  * Copy back color buffer to front color buffer.
 505  */
 506 static void
 507 copy_back_to_front(struct st_context *st,
 508                    struct gl_framebuffer *fb,
 509                    gl_buffer_index frontIndex,
 510                    gl_buffer_index backIndex)
 511
 512 {
 513    struct st_framebuffer *stfb = (struct st_framebuffer *) fb;
 514    struct pipe_surface *surf_front, *surf_back;
 515
 516    (void) st_get_framebuffer_surface(stfb, frontIndex, &surf_front);
 517    (void) st_get_framebuffer_surface(stfb, backIndex, &surf_back);
 518
 519    if (surf_front && surf_back) {
 520       st->pipe->surface_copy(st->pipe,
 521                              surf_front, 0, 0,  /* dest */
 522                              surf_back, 0, 0,   /* src */
 523                              fb->Width, fb->Height);
 524    }
 525 }
 526
 527
 528 /**
 529  * Check if we're drawing into, or read from, a front color buffer.  If the
 530  * front buffer is missing, create it now.
 531  *
 532  * The back color buffer must exist since we'll use its format/samples info
 533  * for creating the front buffer.
 534  *
 535  * \param frontIndex  either BUFFER_FRONT_LEFT or BUFFER_FRONT_RIGHT
 536  * \param backIndex  either BUFFER_BACK_LEFT or BUFFER_BACK_RIGHT
 537  */
 538 static void
 539 check_create_front_buffer(GLcontext *ctx, struct gl_framebuffer *fb,
 540                           gl_buffer_index frontIndex,
 541                           gl_buffer_index backIndex)
 542 {
 543    if (fb->Attachment[frontIndex].Renderbuffer == NULL) {
 544       GLboolean create = GL_FALSE;
 545
 546       /* check if drawing to or reading from front buffer */
 547       if (fb->_ColorReadBufferIndex == frontIndex) {
 548          create = GL_TRUE;
 549       }
 550       else {
 551          GLuint b;
 552          for (b = 0; b < fb->_NumColorDrawBuffers; b++) {
 553             if (fb->_ColorDrawBufferIndexes[b] == frontIndex) {
 554                create = GL_TRUE;
 555                break;
 556             }
 557          }
 558       }
 559
 560       if (create) {
 561          struct st_renderbuffer *back;
 562          struct gl_renderbuffer *front;
 563          enum pipe_format colorFormat;
 564          uint samples;
 565
 566          if (0)
 567             _mesa_debug(ctx, "Allocate new front buffer\n");
 568
 569          /* get back renderbuffer info */
 570          back = st_renderbuffer(fb->Attachment[backIndex].Renderbuffer);
 571          colorFormat = back->format;
 572          samples = back->Base.NumSamples;
 573
 574          /* create front renderbuffer */
 575          front = st_new_renderbuffer_fb(colorFormat, samples, FALSE);
 576          _mesa_add_renderbuffer(fb, frontIndex, front);
 577
 578          /* alloc texture/surface for new front buffer */
 579          front->AllocStorage(ctx, front, front->InternalFormat,
 580                              fb->Width, fb->Height);
 581
 582          /* initialize the front color buffer contents by copying
 583           * the back buffer.
 584           */
 585          copy_back_to_front(ctx->st, fb, frontIndex, backIndex);
 586       }
 587    }
 588 }
 589
 590
 591 /**
 592  * If front left/right color buffers are missing, create them now.
 593  */
 594 static void
 595 check_create_front_buffers(GLcontext *ctx, struct gl_framebuffer *fb)
 596 {
 597    /* check if we need to create the front left buffer now */
 598    check_create_front_buffer(ctx, fb, BUFFER_FRONT_LEFT, BUFFER_BACK_LEFT);
 599
 600    if (fb->Visual.stereoMode) {
 601       check_create_front_buffer(ctx, fb, BUFFER_FRONT_RIGHT, BUFFER_BACK_RIGHT);
 602    }
 603
 604    st_invalidate_state(ctx, _NEW_BUFFERS);
 605 }
 606
 607
 608 /**
 609  * Called via glDrawBuffer.
 610  */
 611 static void
 612 st_DrawBuffers(GLcontext *ctx, GLsizei count, const GLenum *buffers)
 613 {
 614    GLframebuffer *fb = ctx->DrawBuffer;
 615    GLuint i;
 616
 617    (void) count;
 618    (void) buffers;
 619
 620    /* add the renderbuffers on demand */
 621    for (i = 0; i < fb->_NumColorDrawBuffers; i++) {
 622       gl_buffer_index idx = fb->_ColorDrawBufferIndexes[i];
 623       st_manager_add_color_renderbuffer(ctx->st, fb, idx);
 624    }
 625
 626    check_create_front_buffers(ctx, ctx->DrawBuffer);
 627 }
 628
 629
 630 /**
 631  * Called via glReadBuffer.
 632  */
 633 static void
 634 st_ReadBuffer(GLcontext *ctx, GLenum buffer)
 635 {
 636    GLframebuffer *fb = ctx->ReadBuffer;
 637
 638    (void) buffer;
 639
 640    /* add the renderbuffer on demand */
 641    st_manager_add_color_renderbuffer(ctx->st, fb, fb->_ColorReadBufferIndex);
 642    check_create_front_buffers(ctx, fb);
 643 }
 644
 645
 646 void st_init_fbo_functions(struct dd_function_table *functions)
 647 {
 648    functions->NewFramebuffer = st_new_framebuffer;
 649    functions->NewRenderbuffer = st_new_renderbuffer;
 650    functions->BindFramebuffer = st_bind_framebuffer;
 651    functions->FramebufferRenderbuffer = st_framebuffer_renderbuffer;
 652    functions->RenderTexture = st_render_texture;
 653    functions->FinishRenderTexture = st_finish_render_texture;
 654    functions->ValidateFramebuffer = st_validate_framebuffer;
 655    /* no longer needed by core Mesa, drivers handle resizes...
 656    functions->ResizeBuffers = st_resize_buffers;
 657    */
 658
 659    functions->DrawBuffers = st_DrawBuffers;
 660    functions->ReadBuffer = st_ReadBuffer;
 661 }
 662
 663 struct pipe_sampler_view *
 664 st_renderbuffer_get_sampler_view(struct st_renderbuffer *rb,
 665                                  struct pipe_context *pipe)
 666 {
 667    if (!rb->sampler_view) {
 668       rb->sampler_view = st_sampler_view_from_texture(pipe, rb->texture);
 669    }
 670
 671    return rb->sampler_view;
 672 }