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/renderbuffer.h"
  41
  42 #include "pipe/p_context.h"
  43 #include "pipe/p_defines.h"
  44 #include "pipe/p_screen.h"
  45 #include "st_context.h"
  46 #include "st_cb_fbo.h"
  47 #include "st_cb_texture.h"
  48 #include "st_format.h"
  49 #include "st_public.h"
  50 #include "st_texture.h"
  51
  52
  53
  54 /**
  55  * Compute the renderbuffer's Red/Green/EtcBit fields from the pipe format.
  56  */
  57 static int
  58 init_renderbuffer_bits(struct st_renderbuffer *strb,
  59                        enum pipe_format pipeFormat)
  60 {
  61    struct pipe_format_info info;
  62
  63    if (!st_get_format_info( pipeFormat, &info )) {
  64       assert( 0 );
  65    }
  66
  67    strb->Base._ActualFormat = info.base_format;
  68    strb->Base.RedBits = info.red_bits;
  69    strb->Base.GreenBits = info.green_bits;
  70    strb->Base.BlueBits = info.blue_bits;
  71    strb->Base.AlphaBits = info.alpha_bits;
  72    strb->Base.DepthBits = info.depth_bits;
  73    strb->Base.StencilBits = info.stencil_bits;
  74    strb->Base.DataType = st_format_datatype(pipeFormat);
  75
  76    return info.size;
  77 }
  78
  79 /**
  80  * gl_renderbuffer::AllocStorage()
  81  * This is called to allocate the original drawing surface, and
  82  * during window resize.
  83  */
  84 static GLboolean
  85 st_renderbuffer_alloc_storage(GLcontext * ctx, struct gl_renderbuffer *rb,
  86                               GLenum internalFormat,
  87                               GLuint width, GLuint height)
  88 {
  89    struct pipe_context *pipe = ctx->st->pipe;
  90    struct st_renderbuffer *strb = st_renderbuffer(rb);
  91    enum pipe_format format;
  92
  93    if (strb->format != PIPE_FORMAT_NONE)
  94       format = strb->format;
  95    else
  96       format = st_choose_renderbuffer_format(pipe, internalFormat);
  97
  98    /* init renderbuffer fields */
  99    strb->Base.Width  = width;
 100    strb->Base.Height = height;
 101    init_renderbuffer_bits(strb, format);
 102
 103    strb->defined = GL_FALSE;  /* undefined contents now */
 104
 105    if(strb->software) {
 106       struct pipe_format_block block;
 107       size_t size;
 108
 109       _mesa_free(strb->data);
 110
 111       assert(strb->format != PIPE_FORMAT_NONE);
 112       pf_get_block(strb->format, &block);
 113
 114       strb->stride = pf_get_stride(&block, width);
 115       size = pf_get_2d_size(&block, strb->stride, height);
 116
 117       strb->data = _mesa_malloc(size);
 118
 119       return strb->data != NULL;
 120    }
 121    else {
 122       struct pipe_texture template;
 123       unsigned surface_usage;
 124
 125       /* Free the old surface and texture
 126        */
 127       pipe_surface_reference( &strb->surface, NULL );
 128       pipe_texture_reference( &strb->texture, NULL );
 129
 130       /* Setup new texture template.
 131        */
 132       memset(&template, 0, sizeof(template));
 133       template.target = PIPE_TEXTURE_2D;
 134       template.format = format;
 135       pf_get_block(format, &template.block);
 136       template.width[0] = width;
 137       template.height[0] = height;
 138       template.depth[0] = 1;
 139       template.last_level = 0;
 140       template.nr_samples = rb->NumSamples;
 141       if (pf_is_depth_stencil(format)) {
 142          template.tex_usage = PIPE_TEXTURE_USAGE_DEPTH_STENCIL;
 143       }
 144       else {
 145          template.tex_usage = (PIPE_TEXTURE_USAGE_DISPLAY_TARGET |
 146                                PIPE_TEXTURE_USAGE_RENDER_TARGET);
 147       }
 148
 149       /* Probably need dedicated flags for surface usage too:
 150        */
 151       surface_usage = (PIPE_BUFFER_USAGE_GPU_READ |
 152                        PIPE_BUFFER_USAGE_GPU_WRITE);
 153 #if 0
 154                        PIPE_BUFFER_USAGE_CPU_READ |
 155                        PIPE_BUFFER_USAGE_CPU_WRITE);
 156 #endif
 157
 158       strb->texture = pipe->screen->texture_create( pipe->screen,
 159                                                     &template );
 160
 161       if (!strb->texture)
 162          return FALSE;
 163
 164       strb->surface = pipe->screen->get_tex_surface( pipe->screen,
 165                                                      strb->texture,
 166                                                      0, 0, 0,
 167                                                      surface_usage );
 168
 169       assert(strb->surface->texture);
 170       assert(strb->surface->format);
 171       assert(strb->surface->width == width);
 172       assert(strb->surface->height == height);
 173
 174
 175       return strb->surface != NULL;
 176    }
 177 }
 178
 179
 180 /**
 181  * gl_renderbuffer::Delete()
 182  */
 183 static void
 184 st_renderbuffer_delete(struct gl_renderbuffer *rb)
 185 {
 186    struct st_renderbuffer *strb = st_renderbuffer(rb);
 187    ASSERT(strb);
 188    pipe_surface_reference(&strb->surface, NULL);
 189    pipe_texture_reference(&strb->texture, NULL);
 190    _mesa_free(strb->data);
 191    _mesa_free(strb);
 192 }
 193
 194
 195 /**
 196  * gl_renderbuffer::GetPointer()
 197  */
 198 static void *
 199 null_get_pointer(GLcontext * ctx, struct gl_renderbuffer *rb,
 200                  GLint x, GLint y)
 201 {
 202    /* By returning NULL we force all software rendering to go through
 203     * the span routines.
 204     */
 205 #if 0
 206    assert(0);  /* Should never get called with softpipe */
 207 #endif
 208    return NULL;
 209 }
 210
 211
 212 /**
 213  * Called via ctx->Driver.NewFramebuffer()
 214  */
 215 static struct gl_framebuffer *
 216 st_new_framebuffer(GLcontext *ctx, GLuint name)
 217 {
 218    /* XXX not sure we need to subclass gl_framebuffer for pipe */
 219    return _mesa_new_framebuffer(ctx, name);
 220 }
 221
 222
 223 /**
 224  * Called via ctx->Driver.NewRenderbuffer()
 225  */
 226 static struct gl_renderbuffer *
 227 st_new_renderbuffer(GLcontext *ctx, GLuint name)
 228 {
 229    struct st_renderbuffer *strb = ST_CALLOC_STRUCT(st_renderbuffer);
 230    if (strb) {
 231       _mesa_init_renderbuffer(&strb->Base, name);
 232       strb->Base.Delete = st_renderbuffer_delete;
 233       strb->Base.AllocStorage = st_renderbuffer_alloc_storage;
 234       strb->Base.GetPointer = null_get_pointer;
 235       strb->format = PIPE_FORMAT_NONE;
 236       return &strb->Base;
 237    }
 238    return NULL;
 239 }
 240
 241
 242 /**
 243  * Allocate a renderbuffer for a an on-screen window (not a user-created
 244  * renderbuffer).  The window system code determines the format.
 245  */
 246 struct gl_renderbuffer *
 247 st_new_renderbuffer_fb(enum pipe_format format, int samples, boolean sw)
 248 {
 249    struct st_renderbuffer *strb;
 250
 251    strb = ST_CALLOC_STRUCT(st_renderbuffer);
 252    if (!strb) {
 253       _mesa_error(NULL, GL_OUT_OF_MEMORY, "creating renderbuffer");
 254       return NULL;
 255    }
 256
 257    _mesa_init_renderbuffer(&strb->Base, 0);
 258    strb->Base.ClassID = 0x4242; /* just a unique value */
 259    strb->Base.NumSamples = samples;
 260    strb->format = format;
 261    init_renderbuffer_bits(strb, format);
 262    strb->software = sw;
 263
 264    switch (format) {
 265    case PIPE_FORMAT_A8R8G8B8_UNORM:
 266    case PIPE_FORMAT_B8G8R8A8_UNORM:
 267    case PIPE_FORMAT_X8R8G8B8_UNORM:
 268    case PIPE_FORMAT_B8G8R8X8_UNORM:
 269    case PIPE_FORMAT_A1R5G5B5_UNORM:
 270    case PIPE_FORMAT_A4R4G4B4_UNORM:
 271    case PIPE_FORMAT_R5G6B5_UNORM:
 272       strb->Base.InternalFormat = GL_RGBA;
 273       strb->Base._BaseFormat = GL_RGBA;
 274       break;
 275    case PIPE_FORMAT_Z16_UNORM:
 276       strb->Base.InternalFormat = GL_DEPTH_COMPONENT16;
 277       strb->Base._BaseFormat = GL_DEPTH_COMPONENT;
 278       break;
 279    case PIPE_FORMAT_Z32_UNORM:
 280       strb->Base.InternalFormat = GL_DEPTH_COMPONENT32;
 281       strb->Base._BaseFormat = GL_DEPTH_COMPONENT;
 282       break;
 283    case PIPE_FORMAT_S8Z24_UNORM:
 284    case PIPE_FORMAT_Z24S8_UNORM:
 285    case PIPE_FORMAT_X8Z24_UNORM:
 286    case PIPE_FORMAT_Z24X8_UNORM:
 287       strb->Base.InternalFormat = GL_DEPTH24_STENCIL8_EXT;
 288       strb->Base._BaseFormat = GL_DEPTH_STENCIL_EXT;
 289       break;
 290    case PIPE_FORMAT_S8_UNORM:
 291       strb->Base.InternalFormat = GL_STENCIL_INDEX8_EXT;
 292       strb->Base._BaseFormat = GL_STENCIL_INDEX;
 293       break;
 294    case PIPE_FORMAT_R16G16B16A16_SNORM:
 295       strb->Base.InternalFormat = GL_RGBA16;
 296       strb->Base._BaseFormat = GL_RGBA;
 297       break;
 298    default:
 299       _mesa_problem(NULL,
 300                     "Unexpected format in st_new_renderbuffer_fb");
 301       return NULL;
 302    }
 303
 304    /* st-specific methods */
 305    strb->Base.Delete = st_renderbuffer_delete;
 306    strb->Base.AllocStorage = st_renderbuffer_alloc_storage;
 307    strb->Base.GetPointer = null_get_pointer;
 308
 309    /* surface is allocated in st_renderbuffer_alloc_storage() */
 310    strb->surface = NULL;
 311
 312    return &strb->Base;
 313 }
 314
 315
 316
 317
 318 /**
 319  * Called via ctx->Driver.BindFramebufferEXT().
 320  */
 321 static void
 322 st_bind_framebuffer(GLcontext *ctx, GLenum target,
 323                     struct gl_framebuffer *fb, struct gl_framebuffer *fbread)
 324 {
 325
 326 }
 327
 328 /**
 329  * Called by ctx->Driver.FramebufferRenderbuffer
 330  */
 331 static void
 332 st_framebuffer_renderbuffer(GLcontext *ctx,
 333                             struct gl_framebuffer *fb,
 334                             GLenum attachment,
 335                             struct gl_renderbuffer *rb)
 336 {
 337    /* XXX no need for derivation? */
 338    _mesa_framebuffer_renderbuffer(ctx, fb, attachment, rb);
 339 }
 340
 341
 342 /**
 343  * Called by ctx->Driver.RenderTexture
 344  */
 345 static void
 346 st_render_texture(GLcontext *ctx,
 347                   struct gl_framebuffer *fb,
 348                   struct gl_renderbuffer_attachment *att)
 349 {
 350    struct pipe_screen *screen = ctx->st->pipe->screen;
 351    struct st_renderbuffer *strb;
 352    struct gl_renderbuffer *rb;
 353    struct pipe_texture *pt = st_get_texobj_texture(att->Texture);
 354    struct st_texture_object *stObj;
 355    const struct gl_texture_image *texImage =
 356       att->Texture->Image[att->CubeMapFace][att->TextureLevel];
 357
 358    if (!pt)
 359       return;
 360
 361    /* create new renderbuffer which wraps the texture image */
 362    rb = st_new_renderbuffer(ctx, 0);
 363    if (!rb) {
 364       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glFramebufferTexture()");
 365       return;
 366    }
 367
 368    _mesa_reference_renderbuffer(&att->Renderbuffer, rb);
 369    assert(rb->RefCount == 1);
 370    rb->AllocStorage = NULL; /* should not get called */
 371    strb = st_renderbuffer(rb);
 372
 373    assert(strb->Base.RefCount > 0);
 374
 375    /* get the texture for the texture object */
 376    stObj = st_texture_object(att->Texture);
 377
 378    /* point renderbuffer at texobject */
 379    strb->rtt = stObj;
 380    strb->rtt_level = att->TextureLevel;
 381    strb->rtt_face = att->CubeMapFace;
 382    strb->rtt_slice = att->Zoffset;
 383
 384    rb->Width = texImage->Width2;
 385    rb->Height = texImage->Height2;
 386    /*printf("***** render to texture level %d: %d x %d\n", att->TextureLevel, rb->Width, rb->Height);*/
 387
 388    /*printf("***** pipe texture %d x %d\n", pt->width[0], pt->height[0]);*/
 389
 390    pipe_texture_reference( &strb->texture, pt );
 391
 392    pipe_surface_reference(&strb->surface, NULL);
 393
 394    /* new surface for rendering into the texture */
 395    strb->surface = screen->get_tex_surface(screen,
 396                                            strb->texture,
 397                                            strb->rtt_face,
 398                                            strb->rtt_level,
 399                                            strb->rtt_slice,
 400                                            PIPE_BUFFER_USAGE_GPU_READ |
 401                                            PIPE_BUFFER_USAGE_GPU_WRITE);
 402
 403    init_renderbuffer_bits(strb, pt->format);
 404
 405    /*
 406    printf("RENDER TO TEXTURE obj=%p pt=%p surf=%p  %d x %d\n",
 407           att->Texture, pt, strb->surface, rb->Width, rb->Height);
 408    */
 409
 410    /* Invalidate buffer state so that the pipe's framebuffer state
 411     * gets updated.
 412     * That's where the new renderbuffer (which we just created) gets
 413     * passed to the pipe as a (color/depth) render target.
 414     */
 415    st_invalidate_state(ctx, _NEW_BUFFERS);
 416 }
 417
 418
 419 /**
 420  * Called via ctx->Driver.FinishRenderTexture.
 421  */
 422 static void
 423 st_finish_render_texture(GLcontext *ctx,
 424                          struct gl_renderbuffer_attachment *att)
 425 {
 426    struct st_renderbuffer *strb = st_renderbuffer(att->Renderbuffer);
 427
 428    if (!strb)
 429       return;
 430
 431    st_flush( ctx->st, PIPE_FLUSH_RENDER_CACHE, NULL );
 432
 433    if (strb->surface)
 434       pipe_surface_reference( &strb->surface, NULL );
 435
 436    strb->rtt = NULL;
 437
 438    /*
 439    printf("FINISH RENDER TO TEXTURE surf=%p\n", strb->surface);
 440    */
 441
 442    _mesa_reference_renderbuffer(&att->Renderbuffer, NULL);
 443
 444    /* restore previous framebuffer state */
 445    st_invalidate_state(ctx, _NEW_BUFFERS);
 446 }
 447
 448
 449 /**
 450  * Validate a renderbuffer attachment for a particular usage.
 451  */
 452
 453 static GLboolean
 454 st_validate_attachment(struct pipe_screen *screen,
 455                        const struct gl_renderbuffer_attachment *att,
 456                        GLuint usage)
 457 {
 458    const struct st_texture_object *stObj =
 459       st_texture_object(att->Texture);
 460
 461    /**
 462     * Only validate texture attachments for now, since
 463     * st_renderbuffer_alloc_storage makes sure that
 464     * the format is supported.
 465     */
 466
 467    if (att->Type != GL_TEXTURE)
 468       return GL_TRUE;
 469
 470    if (!stObj)
 471       return GL_FALSE;
 472
 473    return screen->is_format_supported(screen, stObj->pt->format,
 474                                       PIPE_TEXTURE_2D,
 475                                       usage, 0);
 476 }
 477
 478 /**
 479  * Check that the framebuffer configuration is valid in terms of what
 480  * the driver can support.
 481  *
 482  * For Gallium we only supports combined Z+stencil, not separate buffers.
 483  */
 484 static void
 485 st_validate_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb)
 486 {
 487    struct pipe_screen *screen = ctx->st->pipe->screen;
 488    const struct gl_renderbuffer *depthRb =
 489       fb->Attachment[BUFFER_DEPTH].Renderbuffer;
 490    const struct gl_renderbuffer *stencilRb =
 491       fb->Attachment[BUFFER_STENCIL].Renderbuffer;
 492    GLuint i;
 493
 494    if (stencilRb && depthRb && stencilRb != depthRb) {
 495       fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 496       return;
 497    }
 498
 499    if (!st_validate_attachment(screen,
 500                                &fb->Attachment[BUFFER_DEPTH],
 501                                PIPE_TEXTURE_USAGE_DEPTH_STENCIL)) {
 502       fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 503       return;
 504    }
 505    if (!st_validate_attachment(screen,
 506                                &fb->Attachment[BUFFER_STENCIL],
 507                                PIPE_TEXTURE_USAGE_DEPTH_STENCIL)) {
 508       fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 509       return;
 510    }
 511    for (i = 0; i < ctx->Const.MaxColorAttachments; i++) {
 512       if (!st_validate_attachment(screen,
 513                                   &fb->Attachment[BUFFER_COLOR0 + i],
 514                                   PIPE_TEXTURE_USAGE_RENDER_TARGET)) {
 515          fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 516          return;
 517       }
 518    }
 519 }
 520
 521
 522 /**
 523  * Copy back color buffer to front color buffer.
 524  */
 525 static void
 526 copy_back_to_front(struct st_context *st,
 527                    struct gl_framebuffer *fb,
 528                    gl_buffer_index frontIndex,
 529                    gl_buffer_index backIndex)
 530
 531 {
 532    struct st_framebuffer *stfb = (struct st_framebuffer *) fb;
 533    struct pipe_surface *surf_front, *surf_back;
 534
 535    (void) st_get_framebuffer_surface(stfb, frontIndex, &surf_front);
 536    (void) st_get_framebuffer_surface(stfb, backIndex, &surf_back);
 537
 538    if (surf_front && surf_back) {
 539       st->pipe->surface_copy(st->pipe,
 540                              surf_front, 0, 0,  /* dest */
 541                              surf_back, 0, 0,   /* src */
 542                              fb->Width, fb->Height);
 543    }
 544 }
 545
 546
 547 /**
 548  * Check if we're drawing into, or read from, a front color buffer.  If the
 549  * front buffer is missing, create it now.
 550  *
 551  * The back color buffer must exist since we'll use its format/samples info
 552  * for creating the front buffer.
 553  *
 554  * \param frontIndex  either BUFFER_FRONT_LEFT or BUFFER_FRONT_RIGHT
 555  * \param backIndex  either BUFFER_BACK_LEFT or BUFFER_BACK_RIGHT
 556  */
 557 static void
 558 check_create_front_buffer(GLcontext *ctx, struct gl_framebuffer *fb,
 559                           gl_buffer_index frontIndex,
 560                           gl_buffer_index backIndex)
 561 {
 562    if (fb->Attachment[frontIndex].Renderbuffer == NULL) {
 563       GLboolean create = GL_FALSE;
 564
 565       /* check if drawing to or reading from front buffer */
 566       if (fb->_ColorReadBufferIndex == frontIndex) {
 567          create = GL_TRUE;
 568       }
 569       else {
 570          GLuint b;
 571          for (b = 0; b < fb->_NumColorDrawBuffers; b++) {
 572             if (fb->_ColorDrawBufferIndexes[b] == frontIndex) {
 573                create = GL_TRUE;
 574                break;
 575             }
 576          }
 577       }
 578
 579       if (create) {
 580          struct st_renderbuffer *back;
 581          struct gl_renderbuffer *front;
 582          enum pipe_format colorFormat;
 583          uint samples;
 584
 585          if (0)
 586             _mesa_debug(ctx, "Allocate new front buffer\n");
 587
 588          /* get back renderbuffer info */
 589          back = st_renderbuffer(fb->Attachment[backIndex].Renderbuffer);
 590          colorFormat = back->format;
 591          samples = back->Base.NumSamples;
 592
 593          /* create front renderbuffer */
 594          front = st_new_renderbuffer_fb(colorFormat, samples, FALSE);
 595          _mesa_add_renderbuffer(fb, frontIndex, front);
 596
 597          /* alloc texture/surface for new front buffer */
 598          front->AllocStorage(ctx, front, front->InternalFormat,
 599                              fb->Width, fb->Height);
 600
 601          /* initialize the front color buffer contents by copying
 602           * the back buffer.
 603           */
 604          copy_back_to_front(ctx->st, fb, frontIndex, backIndex);
 605       }
 606    }
 607 }
 608
 609
 610 /**
 611  * If front left/right color buffers are missing, create them now.
 612  */
 613 static void
 614 check_create_front_buffers(GLcontext *ctx, struct gl_framebuffer *fb)
 615 {
 616    /* check if we need to create the front left buffer now */
 617    check_create_front_buffer(ctx, fb, BUFFER_FRONT_LEFT, BUFFER_BACK_LEFT);
 618
 619    if (fb->Visual.stereoMode) {
 620       check_create_front_buffer(ctx, fb, BUFFER_FRONT_RIGHT, BUFFER_BACK_RIGHT);
 621    }
 622
 623    st_invalidate_state(ctx, _NEW_BUFFERS);
 624 }
 625
 626
 627 /**
 628  * Called via glDrawBuffer.
 629  */
 630 static void
 631 st_DrawBuffers(GLcontext *ctx, GLsizei count, const GLenum *buffers)
 632 {
 633    (void) count;
 634    (void) buffers;
 635    check_create_front_buffers(ctx, ctx->DrawBuffer);
 636 }
 637
 638
 639 /**
 640  * Called via glReadBuffer.
 641  */
 642 static void
 643 st_ReadBuffer(GLcontext *ctx, GLenum buffer)
 644 {
 645    (void) buffer;
 646    check_create_front_buffers(ctx, ctx->ReadBuffer);
 647 }
 648
 649
 650 void st_init_fbo_functions(struct dd_function_table *functions)
 651 {
 652    functions->NewFramebuffer = st_new_framebuffer;
 653    functions->NewRenderbuffer = st_new_renderbuffer;
 654    functions->BindFramebuffer = st_bind_framebuffer;
 655    functions->FramebufferRenderbuffer = st_framebuffer_renderbuffer;
 656    functions->RenderTexture = st_render_texture;
 657    functions->FinishRenderTexture = st_finish_render_texture;
 658    functions->ValidateFramebuffer = st_validate_framebuffer;
 659    /* no longer needed by core Mesa, drivers handle resizes...
 660    functions->ResizeBuffers = st_resize_buffers;
 661    */
 662
 663    functions->DrawBuffers = st_DrawBuffers;
 664    functions->ReadBuffer = st_ReadBuffer;
 665 }