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/mfeatures.h"
  42 #include "main/renderbuffer.h"
  43
  44 #include "pipe/p_context.h"
  45 #include "pipe/p_defines.h"
  46 #include "pipe/p_screen.h"
  47 #include "st_context.h"
  48 #include "st_cb_fbo.h"
  49 #include "st_cb_flush.h"
  50 #include "st_cb_texture.h"
  51 #include "st_format.h"
  52 #include "st_texture.h"
  53 #include "st_manager.h"
  54
  55 #include "util/u_format.h"
  56 #include "util/u_inlines.h"
  57 #include "util/u_surface.h"
  58
  59
  60 /**
  61  * gl_renderbuffer::AllocStorage()
  62  * This is called to allocate the original drawing surface, and
  63  * during window resize.
  64  */
  65 static GLboolean
  66 st_renderbuffer_alloc_storage(struct gl_context * ctx,
  67                               struct gl_renderbuffer *rb,
  68                               GLenum internalFormat,
  69                               GLuint width, GLuint height)
  70 {
  71    struct st_context *st = st_context(ctx);
  72    struct pipe_context *pipe = st->pipe;
  73    struct pipe_screen *screen = st->pipe->screen;
  74    struct st_renderbuffer *strb = st_renderbuffer(rb);
  75    enum pipe_format format;
  76    struct pipe_surface surf_tmpl;
  77
  78    format = st_choose_renderbuffer_format(screen, internalFormat,
  79                                           rb->NumSamples);
  80
  81    if (format == PIPE_FORMAT_NONE) {
  82       return FALSE;
  83    }
  84
  85    /* init renderbuffer fields */
  86    strb->Base.Width  = width;
  87    strb->Base.Height = height;
  88    strb->Base.Format = st_pipe_format_to_mesa_format(format);
  89    strb->Base._BaseFormat = _mesa_base_fbo_format(ctx, internalFormat);
  90    strb->Base.DataType = st_format_datatype(format);
  91    strb->format = format;
  92
  93    strb->defined = GL_FALSE;  /* undefined contents now */
  94
  95    if (strb->software) {
  96       size_t size;
  97
  98       free(strb->data);
  99
 100       assert(strb->format != PIPE_FORMAT_NONE);
 101
 102       strb->stride = util_format_get_stride(strb->format, width);
 103       size = util_format_get_2d_size(strb->format, strb->stride, height);
 104
 105       strb->data = malloc(size);
 106
 107       return strb->data != NULL;
 108    }
 109    else {
 110       struct pipe_resource template;
 111
 112       /* Free the old surface and texture
 113        */
 114       pipe_surface_reference( &strb->surface, NULL );
 115       pipe_resource_reference( &strb->texture, NULL );
 116
 117       /* Setup new texture template.
 118        */
 119       memset(&template, 0, sizeof(template));
 120       template.target = st->internal_target;
 121       template.format = format;
 122       template.width0 = width;
 123       template.height0 = height;
 124       template.depth0 = 1;
 125       template.array_size = 1;
 126       template.last_level = 0;
 127       template.nr_samples = rb->NumSamples;
 128       if (util_format_is_depth_or_stencil(format)) {
 129          template.bind = PIPE_BIND_DEPTH_STENCIL;
 130       }
 131       else {
 132          template.bind = (PIPE_BIND_DISPLAY_TARGET |
 133                           PIPE_BIND_RENDER_TARGET);
 134       }
 135
 136       strb->texture = screen->resource_create(screen, &template);
 137
 138       if (!strb->texture)
 139          return FALSE;
 140
 141       memset(&surf_tmpl, 0, sizeof(surf_tmpl));
 142       u_surface_default_template(&surf_tmpl, strb->texture, template.bind);
 143       strb->surface = pipe->create_surface(pipe,
 144                                            strb->texture,
 145                                            &surf_tmpl);
 146       if (strb->surface) {
 147          assert(strb->surface->texture);
 148          assert(strb->surface->format);
 149          assert(strb->surface->width == width);
 150          assert(strb->surface->height == height);
 151       }
 152
 153       return strb->surface != NULL;
 154    }
 155 }
 156
 157
 158 /**
 159  * gl_renderbuffer::Delete()
 160  */
 161 static void
 162 st_renderbuffer_delete(struct gl_renderbuffer *rb)
 163 {
 164    struct st_renderbuffer *strb = st_renderbuffer(rb);
 165    ASSERT(strb);
 166    pipe_surface_reference(&strb->surface, NULL);
 167    pipe_resource_reference(&strb->texture, NULL);
 168    free(strb->data);
 169    free(strb);
 170 }
 171
 172
 173 /**
 174  * gl_renderbuffer::GetPointer()
 175  */
 176 static void *
 177 null_get_pointer(struct gl_context * ctx, struct gl_renderbuffer *rb,
 178                  GLint x, GLint y)
 179 {
 180    /* By returning NULL we force all software rendering to go through
 181     * the span routines.
 182     */
 183 #if 0
 184    assert(0);  /* Should never get called with softpipe */
 185 #endif
 186    return NULL;
 187 }
 188
 189
 190 /**
 191  * Called via ctx->Driver.NewFramebuffer()
 192  */
 193 static struct gl_framebuffer *
 194 st_new_framebuffer(struct gl_context *ctx, GLuint name)
 195 {
 196    /* XXX not sure we need to subclass gl_framebuffer for pipe */
 197    return _mesa_new_framebuffer(ctx, name);
 198 }
 199
 200
 201 /**
 202  * Called via ctx->Driver.NewRenderbuffer()
 203  */
 204 static struct gl_renderbuffer *
 205 st_new_renderbuffer(struct gl_context *ctx, GLuint name)
 206 {
 207    struct st_renderbuffer *strb = ST_CALLOC_STRUCT(st_renderbuffer);
 208    if (strb) {
 209       _mesa_init_renderbuffer(&strb->Base, name);
 210       strb->Base.Delete = st_renderbuffer_delete;
 211       strb->Base.AllocStorage = st_renderbuffer_alloc_storage;
 212       strb->Base.GetPointer = null_get_pointer;
 213       strb->format = PIPE_FORMAT_NONE;
 214       return &strb->Base;
 215    }
 216    return NULL;
 217 }
 218
 219
 220 /**
 221  * Allocate a renderbuffer for a an on-screen window (not a user-created
 222  * renderbuffer).  The window system code determines the format.
 223  */
 224 struct gl_renderbuffer *
 225 st_new_renderbuffer_fb(enum pipe_format format, int samples, boolean sw)
 226 {
 227    struct st_renderbuffer *strb;
 228
 229    strb = ST_CALLOC_STRUCT(st_renderbuffer);
 230    if (!strb) {
 231       _mesa_error(NULL, GL_OUT_OF_MEMORY, "creating renderbuffer");
 232       return NULL;
 233    }
 234
 235    _mesa_init_renderbuffer(&strb->Base, 0);
 236    strb->Base.ClassID = 0x4242; /* just a unique value */
 237    strb->Base.NumSamples = samples;
 238    strb->Base.Format = st_pipe_format_to_mesa_format(format);
 239    strb->Base._BaseFormat = _mesa_get_format_base_format(strb->Base.Format);
 240    strb->Base.DataType = st_format_datatype(format);
 241    strb->format = format;
 242    strb->software = sw;
 243
 244    switch (format) {
 245    case PIPE_FORMAT_R8G8B8A8_UNORM:
 246    case PIPE_FORMAT_B8G8R8A8_UNORM:
 247    case PIPE_FORMAT_A8R8G8B8_UNORM:
 248    case PIPE_FORMAT_R8G8B8X8_UNORM:
 249    case PIPE_FORMAT_B8G8R8X8_UNORM:
 250    case PIPE_FORMAT_X8R8G8B8_UNORM:
 251    case PIPE_FORMAT_B5G5R5A1_UNORM:
 252    case PIPE_FORMAT_B4G4R4A4_UNORM:
 253    case PIPE_FORMAT_B5G6R5_UNORM:
 254       strb->Base.InternalFormat = GL_RGBA;
 255       break;
 256    case PIPE_FORMAT_Z16_UNORM:
 257       strb->Base.InternalFormat = GL_DEPTH_COMPONENT16;
 258       break;
 259    case PIPE_FORMAT_Z32_UNORM:
 260       strb->Base.InternalFormat = GL_DEPTH_COMPONENT32;
 261       break;
 262    case PIPE_FORMAT_Z24_UNORM_S8_USCALED:
 263    case PIPE_FORMAT_S8_USCALED_Z24_UNORM:
 264    case PIPE_FORMAT_Z24X8_UNORM:
 265    case PIPE_FORMAT_X8Z24_UNORM:
 266       strb->Base.InternalFormat = GL_DEPTH24_STENCIL8_EXT;
 267       break;
 268    case PIPE_FORMAT_S8_USCALED:
 269       strb->Base.InternalFormat = GL_STENCIL_INDEX8_EXT;
 270       break;
 271    case PIPE_FORMAT_R16G16B16A16_SNORM:
 272       /* accum buffer */
 273       strb->Base.InternalFormat = GL_RGBA16_SNORM;
 274       break;
 275    case PIPE_FORMAT_R8_UNORM:
 276       strb->Base.InternalFormat = GL_R8;
 277       break;
 278    case PIPE_FORMAT_R8G8_UNORM:
 279       strb->Base.InternalFormat = GL_RG8;
 280       break;
 281    case PIPE_FORMAT_R16_UNORM:
 282       strb->Base.InternalFormat = GL_R16;
 283       break;
 284    case PIPE_FORMAT_R16G16_UNORM:
 285       strb->Base.InternalFormat = GL_RG16;
 286       break;
 287    default:
 288       _mesa_problem(NULL,
 289                     "Unexpected format in st_new_renderbuffer_fb");
 290       free(strb);
 291       return NULL;
 292    }
 293
 294    /* st-specific methods */
 295    strb->Base.Delete = st_renderbuffer_delete;
 296    strb->Base.AllocStorage = st_renderbuffer_alloc_storage;
 297    strb->Base.GetPointer = null_get_pointer;
 298
 299    /* surface is allocated in st_renderbuffer_alloc_storage() */
 300    strb->surface = NULL;
 301
 302    return &strb->Base;
 303 }
 304
 305
 306
 307
 308 /**
 309  * Called via ctx->Driver.BindFramebufferEXT().
 310  */
 311 static void
 312 st_bind_framebuffer(struct gl_context *ctx, GLenum target,
 313                     struct gl_framebuffer *fb, struct gl_framebuffer *fbread)
 314 {
 315
 316 }
 317
 318 /**
 319  * Called by ctx->Driver.FramebufferRenderbuffer
 320  */
 321 static void
 322 st_framebuffer_renderbuffer(struct gl_context *ctx,
 323                             struct gl_framebuffer *fb,
 324                             GLenum attachment,
 325                             struct gl_renderbuffer *rb)
 326 {
 327    /* XXX no need for derivation? */
 328    _mesa_framebuffer_renderbuffer(ctx, fb, attachment, rb);
 329 }
 330
 331
 332 /**
 333  * Called by ctx->Driver.RenderTexture
 334  */
 335 static void
 336 st_render_texture(struct gl_context *ctx,
 337                   struct gl_framebuffer *fb,
 338                   struct gl_renderbuffer_attachment *att)
 339 {
 340    struct st_context *st = st_context(ctx);
 341    struct pipe_context *pipe = st->pipe;
 342    struct st_renderbuffer *strb;
 343    struct gl_renderbuffer *rb;
 344    struct pipe_resource *pt;
 345    struct st_texture_object *stObj;
 346    const struct gl_texture_image *texImage;
 347    struct pipe_surface surf_tmpl;
 348
 349    if (!st_finalize_texture(ctx, pipe, att->Texture))
 350       return;
 351
 352    pt = st_get_texobj_resource(att->Texture);
 353    assert(pt);
 354
 355    /* get pointer to texture image we're rendeing to */
 356    texImage = _mesa_get_attachment_teximage(att);
 357
 358    /* create new renderbuffer which wraps the texture image */
 359    rb = st_new_renderbuffer(ctx, 0);
 360    if (!rb) {
 361       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glFramebufferTexture()");
 362       return;
 363    }
 364
 365    _mesa_reference_renderbuffer(&att->Renderbuffer, rb);
 366    assert(rb->RefCount == 1);
 367    rb->AllocStorage = NULL; /* should not get called */
 368    strb = st_renderbuffer(rb);
 369
 370    assert(strb->Base.RefCount > 0);
 371
 372    /* get the texture for the texture object */
 373    stObj = st_texture_object(att->Texture);
 374
 375    /* point renderbuffer at texobject */
 376    strb->rtt = stObj;
 377    strb->rtt_level = att->TextureLevel;
 378    strb->rtt_face = att->CubeMapFace;
 379    strb->rtt_slice = att->Zoffset;
 380
 381    rb->Width = texImage->Width2;
 382    rb->Height = texImage->Height2;
 383    rb->_BaseFormat = texImage->_BaseFormat;
 384    rb->InternalFormat = texImage->InternalFormat;
 385    /*printf("***** render to texture level %d: %d x %d\n", att->TextureLevel, rb->Width, rb->Height);*/
 386
 387    /*printf("***** pipe texture %d x %d\n", pt->width0, pt->height0);*/
 388
 389    pipe_resource_reference( &strb->texture, pt );
 390
 391    pipe_surface_reference(&strb->surface, NULL);
 392
 393    assert(strb->rtt_level <= strb->texture->last_level);
 394
 395    /* new surface for rendering into the texture */
 396    memset(&surf_tmpl, 0, sizeof(surf_tmpl));
 397    surf_tmpl.format = ctx->Color.sRGBEnabled ? strb->texture->format : util_format_linear(strb->texture->format);
 398    surf_tmpl.usage = PIPE_BIND_RENDER_TARGET;
 399    surf_tmpl.u.tex.level = strb->rtt_level;
 400    surf_tmpl.u.tex.first_layer = strb->rtt_face + strb->rtt_slice;
 401    surf_tmpl.u.tex.last_layer = strb->rtt_face + strb->rtt_slice;
 402    strb->surface = pipe->create_surface(pipe,
 403                                         strb->texture,
 404                                         &surf_tmpl);
 405
 406    strb->format = pt->format;
 407
 408    strb->Base.Format = st_pipe_format_to_mesa_format(pt->format);
 409    strb->Base.DataType = st_format_datatype(pt->format);
 410
 411    /*
 412    printf("RENDER TO TEXTURE obj=%p pt=%p surf=%p  %d x %d\n",
 413           att->Texture, pt, strb->surface, rb->Width, rb->Height);
 414    */
 415
 416    /* Invalidate buffer state so that the pipe's framebuffer state
 417     * gets updated.
 418     * That's where the new renderbuffer (which we just created) gets
 419     * passed to the pipe as a (color/depth) render target.
 420     */
 421    st_invalidate_state(ctx, _NEW_BUFFERS);
 422 }
 423
 424
 425 /**
 426  * Called via ctx->Driver.FinishRenderTexture.
 427  */
 428 static void
 429 st_finish_render_texture(struct gl_context *ctx,
 430                          struct gl_renderbuffer_attachment *att)
 431 {
 432    struct st_renderbuffer *strb = st_renderbuffer(att->Renderbuffer);
 433
 434    if (!strb)
 435       return;
 436
 437    strb->rtt = NULL;
 438
 439    /*
 440    printf("FINISH RENDER TO TEXTURE surf=%p\n", strb->surface);
 441    */
 442
 443    /* restore previous framebuffer state */
 444    st_invalidate_state(ctx, _NEW_BUFFERS);
 445 }
 446
 447
 448 /**
 449  * Validate a renderbuffer attachment for a particular set of bindings.
 450  */
 451 static GLboolean
 452 st_validate_attachment(struct gl_context *ctx,
 453                        struct pipe_screen *screen,
 454                        const struct gl_renderbuffer_attachment *att,
 455                        unsigned bindings)
 456 {
 457    const struct st_texture_object *stObj = st_texture_object(att->Texture);
 458    enum pipe_format format;
 459    gl_format texFormat;
 460
 461    /* Only validate texture attachments for now, since
 462     * st_renderbuffer_alloc_storage makes sure that
 463     * the format is supported.
 464     */
 465    if (att->Type != GL_TEXTURE)
 466       return GL_TRUE;
 467
 468    if (!stObj)
 469       return GL_FALSE;
 470
 471    format = stObj->pt->format;
 472    texFormat = _mesa_get_attachment_teximage_const(att)->TexFormat;
 473
 474    /* If the encoding is sRGB and sRGB rendering cannot be enabled,
 475     * check for linear format support instead.
 476     * Later when we create a surface, we change the format to a linear one. */
 477    if (!ctx->Const.sRGBCapable &&
 478        _mesa_get_format_color_encoding(texFormat) == GL_SRGB) {
 479       const gl_format linearFormat = _mesa_get_srgb_format_linear(texFormat);
 480       format = st_mesa_format_to_pipe_format(linearFormat);
 481    }
 482
 483    return screen->is_format_supported(screen, format,
 484                                       PIPE_TEXTURE_2D,
 485                                       stObj->pt->nr_samples, bindings);
 486 }
 487
 488
 489 /**
 490  * Check if two renderbuffer attachments name a combined depth/stencil
 491  * renderbuffer.
 492  */
 493 GLboolean
 494 st_is_depth_stencil_combined(const struct gl_renderbuffer_attachment *depth,
 495                              const struct gl_renderbuffer_attachment *stencil)
 496 {
 497    assert(depth && stencil);
 498
 499    if (depth->Type == stencil->Type) {
 500       if (depth->Type == GL_RENDERBUFFER_EXT &&
 501           depth->Renderbuffer == stencil->Renderbuffer)
 502          return GL_TRUE;
 503
 504       if (depth->Type == GL_TEXTURE &&
 505           depth->Texture == stencil->Texture)
 506          return GL_TRUE;
 507    }
 508
 509    return GL_FALSE;
 510 }
 511
 512
 513 /**
 514  * Check that the framebuffer configuration is valid in terms of what
 515  * the driver can support.
 516  *
 517  * For Gallium we only supports combined Z+stencil, not separate buffers.
 518  */
 519 static void
 520 st_validate_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 521 {
 522    struct st_context *st = st_context(ctx);
 523    struct pipe_screen *screen = st->pipe->screen;
 524    const struct gl_renderbuffer_attachment *depth =
 525          &fb->Attachment[BUFFER_DEPTH];
 526    const struct gl_renderbuffer_attachment *stencil =
 527          &fb->Attachment[BUFFER_STENCIL];
 528    GLuint i;
 529    enum pipe_format first_format = PIPE_FORMAT_NONE;
 530    boolean mixed_formats =
 531          screen->get_param(screen, PIPE_CAP_MIXED_COLORBUFFER_FORMATS) != 0;
 532
 533    if (depth->Type && stencil->Type && depth->Type != stencil->Type) {
 534       fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 535       return;
 536    }
 537    if (depth->Type == GL_RENDERBUFFER_EXT &&
 538        stencil->Type == GL_RENDERBUFFER_EXT &&
 539        depth->Renderbuffer != stencil->Renderbuffer) {
 540       fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 541       return;
 542    }
 543    if (depth->Type == GL_TEXTURE &&
 544        stencil->Type == GL_TEXTURE &&
 545        depth->Texture != stencil->Texture) {
 546       fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 547       return;
 548    }
 549
 550    if (!st_validate_attachment(ctx,
 551                                screen,
 552                                depth,
 553                                PIPE_BIND_DEPTH_STENCIL)) {
 554       fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 555       return;
 556    }
 557    if (!st_validate_attachment(ctx,
 558                                screen,
 559                                stencil,
 560                                PIPE_BIND_DEPTH_STENCIL)) {
 561       fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 562       return;
 563    }
 564    for (i = 0; i < ctx->Const.MaxColorAttachments; i++) {
 565       struct gl_renderbuffer_attachment *att =
 566             &fb->Attachment[BUFFER_COLOR0 + i];
 567       enum pipe_format format;
 568
 569       if (!st_validate_attachment(ctx,
 570                                   screen,
 571                                   att,
 572                                   PIPE_BIND_RENDER_TARGET)) {
 573          fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 574          return;
 575       }
 576
 577       if (!mixed_formats) {
 578          /* Disallow mixed formats. */
 579          if (att->Type != GL_NONE) {
 580             format = st_renderbuffer(att->Renderbuffer)->surface->format;
 581          } else {
 582             continue;
 583          }
 584
 585          if (first_format == PIPE_FORMAT_NONE) {
 586             first_format = format;
 587          } else if (format != first_format) {
 588             fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 589             return;
 590          }
 591       }
 592    }
 593 }
 594
 595
 596 /**
 597  * Called via glDrawBuffer.
 598  */
 599 static void
 600 st_DrawBuffers(struct gl_context *ctx, GLsizei count, const GLenum *buffers)
 601 {
 602    struct st_context *st = st_context(ctx);
 603    struct gl_framebuffer *fb = ctx->DrawBuffer;
 604    GLuint i;
 605
 606    (void) count;
 607    (void) buffers;
 608
 609    /* add the renderbuffers on demand */
 610    for (i = 0; i < fb->_NumColorDrawBuffers; i++) {
 611       gl_buffer_index idx = fb->_ColorDrawBufferIndexes[i];
 612       st_manager_add_color_renderbuffer(st, fb, idx);
 613    }
 614 }
 615
 616
 617 /**
 618  * Called via glReadBuffer.
 619  */
 620 static void
 621 st_ReadBuffer(struct gl_context *ctx, GLenum buffer)
 622 {
 623    struct st_context *st = st_context(ctx);
 624    struct gl_framebuffer *fb = ctx->ReadBuffer;
 625
 626    (void) buffer;
 627
 628    /* add the renderbuffer on demand */
 629    st_manager_add_color_renderbuffer(st, fb, fb->_ColorReadBufferIndex);
 630 }
 631
 632
 633 void st_init_fbo_functions(struct dd_function_table *functions)
 634 {
 635 #if FEATURE_EXT_framebuffer_object
 636    functions->NewFramebuffer = st_new_framebuffer;
 637    functions->NewRenderbuffer = st_new_renderbuffer;
 638    functions->BindFramebuffer = st_bind_framebuffer;
 639    functions->FramebufferRenderbuffer = st_framebuffer_renderbuffer;
 640    functions->RenderTexture = st_render_texture;
 641    functions->FinishRenderTexture = st_finish_render_texture;
 642    functions->ValidateFramebuffer = st_validate_framebuffer;
 643 #endif
 644    /* no longer needed by core Mesa, drivers handle resizes...
 645    functions->ResizeBuffers = st_resize_buffers;
 646    */
 647
 648    functions->DrawBuffers = st_DrawBuffers;
 649    functions->ReadBuffer = st_ReadBuffer;
 650 }
 651
 652