src/mesa/main/framebuffer.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.2
   4  *
   5  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /**
  27  * Functions for allocating/managing framebuffers and renderbuffers.
  28  * Also, routines for reading/writing renderbuffer data as ubytes,
  29  * ushorts, uints, etc.
  30  */
  31
  32
  33 #include "glheader.h"
  34 #include "imports.h"
  35 #include "buffers.h"
  36 #include "context.h"
  37 #include "depthstencil.h"
  38 #include "enums.h"
  39 #include "formats.h"
  40 #include "macros.h"
  41 #include "mtypes.h"
  42 #include "fbobject.h"
  43 #include "framebuffer.h"
  44 #include "renderbuffer.h"
  45 #include "texobj.h"
  46
  47
  48
  49 /**
  50  * Compute/set the _DepthMax field for the given framebuffer.
  51  * This value depends on the Z buffer resolution.
  52  */
  53 static void
  54 compute_depth_max(struct gl_framebuffer *fb)
  55 {
  56    if (fb->Visual.depthBits == 0) {
  57       /* Special case.  Even if we don't have a depth buffer we need
  58        * good values for DepthMax for Z vertex transformation purposes
  59        * and for per-fragment fog computation.
  60        */
  61       fb->_DepthMax = (1 << 16) - 1;
  62    }
  63    else if (fb->Visual.depthBits < 32) {
  64       fb->_DepthMax = (1 << fb->Visual.depthBits) - 1;
  65    }
  66    else {
  67       /* Special case since shift values greater than or equal to the
  68        * number of bits in the left hand expression's type are undefined.
  69        */
  70       fb->_DepthMax = 0xffffffff;
  71    }
  72    fb->_DepthMaxF = (GLfloat) fb->_DepthMax;
  73
  74    /* Minimum resolvable depth value, for polygon offset */
  75    fb->_MRD = (GLfloat)1.0 / fb->_DepthMaxF;
  76 }
  77
  78
  79 /**
  80  * Create and initialize a gl_framebuffer object.
  81  * This is intended for creating _window_system_ framebuffers, not generic
  82  * framebuffer objects ala GL_EXT_framebuffer_object.
  83  *
  84  * \sa _mesa_new_framebuffer
  85  */
  86 struct gl_framebuffer *
  87 _mesa_create_framebuffer(const GLvisual *visual)
  88 {
  89    struct gl_framebuffer *fb = CALLOC_STRUCT(gl_framebuffer);
  90    assert(visual);
  91    if (fb) {
  92       _mesa_initialize_window_framebuffer(fb, visual);
  93    }
  94    return fb;
  95 }
  96
  97
  98 /**
  99  * Allocate a new gl_framebuffer object.
 100  * This is the default function for ctx->Driver.NewFramebuffer().
 101  * This is for allocating user-created framebuffers, not window-system
 102  * framebuffers!
 103  * \sa _mesa_create_framebuffer
 104  */
 105 struct gl_framebuffer *
 106 _mesa_new_framebuffer(GLcontext *ctx, GLuint name)
 107 {
 108    struct gl_framebuffer *fb;
 109    (void) ctx;
 110    assert(name != 0);
 111    fb = CALLOC_STRUCT(gl_framebuffer);
 112    if (fb) {
 113       _mesa_initialize_user_framebuffer(fb, name);
 114    }
 115    return fb;
 116 }
 117
 118
 119 /**
 120  * Initialize a gl_framebuffer object.  Typically used to initialize
 121  * window system-created framebuffers, not user-created framebuffers.
 122  * \sa _mesa_initialize_user_framebuffer
 123  */
 124 void
 125 _mesa_initialize_window_framebuffer(struct gl_framebuffer *fb,
 126                                      const GLvisual *visual)
 127 {
 128    assert(fb);
 129    assert(visual);
 130
 131    memset(fb, 0, sizeof(struct gl_framebuffer));
 132
 133    _glthread_INIT_MUTEX(fb->Mutex);
 134
 135    fb->RefCount = 1;
 136
 137    /* save the visual */
 138    fb->Visual = *visual;
 139
 140    /* Init read/draw renderbuffer state */
 141    if (visual->doubleBufferMode) {
 142       fb->_NumColorDrawBuffers = 1;
 143       fb->ColorDrawBuffer[0] = GL_BACK;
 144       fb->_ColorDrawBufferIndexes[0] = BUFFER_BACK_LEFT;
 145       fb->ColorReadBuffer = GL_BACK;
 146       fb->_ColorReadBufferIndex = BUFFER_BACK_LEFT;
 147    }
 148    else {
 149       fb->_NumColorDrawBuffers = 1;
 150       fb->ColorDrawBuffer[0] = GL_FRONT;
 151       fb->_ColorDrawBufferIndexes[0] = BUFFER_FRONT_LEFT;
 152       fb->ColorReadBuffer = GL_FRONT;
 153       fb->_ColorReadBufferIndex = BUFFER_FRONT_LEFT;
 154    }
 155
 156    fb->Delete = _mesa_destroy_framebuffer;
 157    fb->_Status = GL_FRAMEBUFFER_COMPLETE_EXT;
 158
 159    compute_depth_max(fb);
 160 }
 161
 162
 163 /**
 164  * Initialize a user-created gl_framebuffer object.
 165  * \sa _mesa_initialize_window_framebuffer
 166  */
 167 void
 168 _mesa_initialize_user_framebuffer(struct gl_framebuffer *fb, GLuint name)
 169 {
 170    assert(fb);
 171    assert(name);
 172
 173    memset(fb, 0, sizeof(struct gl_framebuffer));
 174
 175    fb->Name = name;
 176    fb->RefCount = 1;
 177    fb->_NumColorDrawBuffers = 1;
 178    fb->ColorDrawBuffer[0] = GL_COLOR_ATTACHMENT0_EXT;
 179    fb->_ColorDrawBufferIndexes[0] = BUFFER_COLOR0;
 180    fb->ColorReadBuffer = GL_COLOR_ATTACHMENT0_EXT;
 181    fb->_ColorReadBufferIndex = BUFFER_COLOR0;
 182    fb->Delete = _mesa_destroy_framebuffer;
 183    _glthread_INIT_MUTEX(fb->Mutex);
 184 }
 185
 186
 187 /**
 188  * Deallocate buffer and everything attached to it.
 189  * Typically called via the gl_framebuffer->Delete() method.
 190  */
 191 void
 192 _mesa_destroy_framebuffer(struct gl_framebuffer *fb)
 193 {
 194    if (fb) {
 195       _mesa_free_framebuffer_data(fb);
 196       free(fb);
 197    }
 198 }
 199
 200
 201 /**
 202  * Free all the data hanging off the given gl_framebuffer, but don't free
 203  * the gl_framebuffer object itself.
 204  */
 205 void
 206 _mesa_free_framebuffer_data(struct gl_framebuffer *fb)
 207 {
 208    GLuint i;
 209
 210    assert(fb);
 211    assert(fb->RefCount == 0);
 212
 213    _glthread_DESTROY_MUTEX(fb->Mutex);
 214
 215    for (i = 0; i < BUFFER_COUNT; i++) {
 216       struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 217       if (att->Renderbuffer) {
 218          _mesa_reference_renderbuffer(&att->Renderbuffer, NULL);
 219       }
 220       if (att->Texture) {
 221          _mesa_reference_texobj(&att->Texture, NULL);
 222       }
 223       ASSERT(!att->Renderbuffer);
 224       ASSERT(!att->Texture);
 225       att->Type = GL_NONE;
 226    }
 227
 228    /* unbind _Depth/_StencilBuffer to decr ref counts */
 229    _mesa_reference_renderbuffer(&fb->_DepthBuffer, NULL);
 230    _mesa_reference_renderbuffer(&fb->_StencilBuffer, NULL);
 231 }
 232
 233
 234 /**
 235  * Set *ptr to point to fb, with refcounting and locking.
 236  */
 237 void
 238 _mesa_reference_framebuffer(struct gl_framebuffer **ptr,
 239                             struct gl_framebuffer *fb)
 240 {
 241    assert(ptr);
 242    if (*ptr == fb) {
 243       /* no change */
 244       return;
 245    }
 246
 247    if (*ptr) {
 248       /* unreference old renderbuffer */
 249       GLboolean deleteFlag = GL_FALSE;
 250       struct gl_framebuffer *oldFb = *ptr;
 251
 252       _glthread_LOCK_MUTEX(oldFb->Mutex);
 253       ASSERT(oldFb->RefCount > 0);
 254       oldFb->RefCount--;
 255       deleteFlag = (oldFb->RefCount == 0);
 256       _glthread_UNLOCK_MUTEX(oldFb->Mutex);
 257
 258       if (deleteFlag)
 259          oldFb->Delete(oldFb);
 260
 261       *ptr = NULL;
 262    }
 263    assert(!*ptr);
 264
 265    if (fb) {
 266       _glthread_LOCK_MUTEX(fb->Mutex);
 267       fb->RefCount++;
 268       _glthread_UNLOCK_MUTEX(fb->Mutex);
 269       *ptr = fb;
 270    }
 271 }
 272
 273
 274 /**
 275  * Resize the given framebuffer's renderbuffers to the new width and height.
 276  * This should only be used for window-system framebuffers, not
 277  * user-created renderbuffers (i.e. made with GL_EXT_framebuffer_object).
 278  * This will typically be called via ctx->Driver.ResizeBuffers() or directly
 279  * from a device driver.
 280  *
 281  * \note it's possible for ctx to be null since a window can be resized
 282  * without a currently bound rendering context.
 283  */
 284 void
 285 _mesa_resize_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb,
 286                          GLuint width, GLuint height)
 287 {
 288    GLuint i;
 289
 290    /* XXX I think we could check if the size is not changing
 291     * and return early.
 292     */
 293
 294    /* For window system framebuffers, Name is zero */
 295    assert(fb->Name == 0);
 296
 297    for (i = 0; i < BUFFER_COUNT; i++) {
 298       struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 299       if (att->Type == GL_RENDERBUFFER_EXT && att->Renderbuffer) {
 300          struct gl_renderbuffer *rb = att->Renderbuffer;
 301          /* only resize if size is changing */
 302          if (rb->Width != width || rb->Height != height) {
 303             if (rb->AllocStorage(ctx, rb, rb->InternalFormat, width, height)) {
 304                ASSERT(rb->Width == width);
 305                ASSERT(rb->Height == height);
 306             }
 307             else {
 308                _mesa_error(ctx, GL_OUT_OF_MEMORY, "Resizing framebuffer");
 309                /* no return */
 310             }
 311          }
 312       }
 313    }
 314
 315    if (fb->_DepthBuffer) {
 316       struct gl_renderbuffer *rb = fb->_DepthBuffer;
 317       if (rb->Width != width || rb->Height != height) {
 318          if (!rb->AllocStorage(ctx, rb, rb->InternalFormat, width, height)) {
 319             _mesa_error(ctx, GL_OUT_OF_MEMORY, "Resizing framebuffer");
 320          }
 321       }
 322    }
 323
 324    if (fb->_StencilBuffer) {
 325       struct gl_renderbuffer *rb = fb->_StencilBuffer;
 326       if (rb->Width != width || rb->Height != height) {
 327          if (!rb->AllocStorage(ctx, rb, rb->InternalFormat, width, height)) {
 328             _mesa_error(ctx, GL_OUT_OF_MEMORY, "Resizing framebuffer");
 329          }
 330       }
 331    }
 332
 333    fb->Width = width;
 334    fb->Height = height;
 335
 336    if (ctx) {
 337       /* update scissor / window bounds */
 338       _mesa_update_draw_buffer_bounds(ctx);
 339       /* Signal new buffer state so that swrast will update its clipping
 340        * info (the CLIP_BIT flag).
 341        */
 342       ctx->NewState |= _NEW_BUFFERS;
 343    }
 344 }
 345
 346
 347
 348 /**
 349  * XXX THIS IS OBSOLETE - drivers should take care of detecting window
 350  * size changes and act accordingly, likely calling _mesa_resize_framebuffer().
 351  *
 352  * GL_MESA_resize_buffers extension.
 353  *
 354  * When this function is called, we'll ask the window system how large
 355  * the current window is.  If it's a new size, we'll call the driver's
 356  * ResizeBuffers function.  The driver will then resize its color buffers
 357  * as needed, and maybe call the swrast's routine for reallocating
 358  * swrast-managed depth/stencil/accum/etc buffers.
 359  * \note This function should only be called through the GL API, not
 360  * from device drivers (as was done in the past).
 361  */
 362 void
 363 _mesa_resizebuffers( GLcontext *ctx )
 364 {
 365    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx );
 366
 367    if (MESA_VERBOSE & VERBOSE_API)
 368       _mesa_debug(ctx, "glResizeBuffersMESA\n");
 369
 370    if (!ctx->Driver.GetBufferSize) {
 371       return;
 372    }
 373
 374    if (ctx->WinSysDrawBuffer) {
 375       GLuint newWidth, newHeight;
 376       GLframebuffer *buffer = ctx->WinSysDrawBuffer;
 377
 378       assert(buffer->Name == 0);
 379
 380       /* ask device driver for size of output buffer */
 381       ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight );
 382
 383       /* see if size of device driver's color buffer (window) has changed */
 384       if (buffer->Width != newWidth || buffer->Height != newHeight) {
 385          if (ctx->Driver.ResizeBuffers)
 386             ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight );
 387       }
 388    }
 389
 390    if (ctx->WinSysReadBuffer
 391        && ctx->WinSysReadBuffer != ctx->WinSysDrawBuffer) {
 392       GLuint newWidth, newHeight;
 393       GLframebuffer *buffer = ctx->WinSysReadBuffer;
 394
 395       assert(buffer->Name == 0);
 396
 397       /* ask device driver for size of read buffer */
 398       ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight );
 399
 400       /* see if size of device driver's color buffer (window) has changed */
 401       if (buffer->Width != newWidth || buffer->Height != newHeight) {
 402          if (ctx->Driver.ResizeBuffers)
 403             ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight );
 404       }
 405    }
 406
 407    ctx->NewState |= _NEW_BUFFERS;  /* to update scissor / window bounds */
 408 }
 409
 410
 411 /*
 412  * XXX THIS IS OBSOLETE
 413  */
 414 void GLAPIENTRY
 415 _mesa_ResizeBuffersMESA( void )
 416 {
 417    GET_CURRENT_CONTEXT(ctx);
 418
 419    if (ctx->Extensions.MESA_resize_buffers)
 420       _mesa_resizebuffers( ctx );
 421 }
 422
 423
 424
 425 /**
 426  * Examine all the framebuffer's renderbuffers to update the Width/Height
 427  * fields of the framebuffer.  If we have renderbuffers with different
 428  * sizes, set the framebuffer's width and height to the min size.
 429  * Note: this is only intended for user-created framebuffers, not
 430  * window-system framebuffes.
 431  */
 432 static void
 433 update_framebuffer_size(GLcontext *ctx, struct gl_framebuffer *fb)
 434 {
 435    GLuint minWidth = ~0, minHeight = ~0;
 436    GLuint i;
 437
 438    /* user-created framebuffers only */
 439    assert(fb->Name);
 440
 441    for (i = 0; i < BUFFER_COUNT; i++) {
 442       struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 443       const struct gl_renderbuffer *rb = att->Renderbuffer;
 444       if (rb) {
 445          minWidth = MIN2(minWidth, rb->Width);
 446          minHeight = MIN2(minHeight, rb->Height);
 447       }
 448    }
 449
 450    if (minWidth != ~0) {
 451       fb->Width = minWidth;
 452       fb->Height = minHeight;
 453    }
 454    else {
 455       fb->Width = 0;
 456       fb->Height = 0;
 457    }
 458 }
 459
 460
 461 /**
 462  * Update the context's current drawing buffer's Xmin, Xmax, Ymin, Ymax fields.
 463  * These values are computed from the buffer's width and height and
 464  * the scissor box, if it's enabled.
 465  * \param ctx  the GL context.
 466  */
 467 void
 468 _mesa_update_draw_buffer_bounds(GLcontext *ctx)
 469 {
 470    struct gl_framebuffer *buffer = ctx->DrawBuffer;
 471
 472    if (!buffer)
 473       return;
 474
 475    if (buffer->Name) {
 476       /* user-created framebuffer size depends on the renderbuffers */
 477       update_framebuffer_size(ctx, buffer);
 478    }
 479
 480    buffer->_Xmin = 0;
 481    buffer->_Ymin = 0;
 482    buffer->_Xmax = buffer->Width;
 483    buffer->_Ymax = buffer->Height;
 484
 485    if (ctx->Scissor.Enabled) {
 486       if (ctx->Scissor.X > buffer->_Xmin) {
 487          buffer->_Xmin = ctx->Scissor.X;
 488       }
 489       if (ctx->Scissor.Y > buffer->_Ymin) {
 490          buffer->_Ymin = ctx->Scissor.Y;
 491       }
 492       if (ctx->Scissor.X + ctx->Scissor.Width < buffer->_Xmax) {
 493          buffer->_Xmax = ctx->Scissor.X + ctx->Scissor.Width;
 494       }
 495       if (ctx->Scissor.Y + ctx->Scissor.Height < buffer->_Ymax) {
 496          buffer->_Ymax = ctx->Scissor.Y + ctx->Scissor.Height;
 497       }
 498       /* finally, check for empty region */
 499       if (buffer->_Xmin > buffer->_Xmax) {
 500          buffer->_Xmin = buffer->_Xmax;
 501       }
 502       if (buffer->_Ymin > buffer->_Ymax) {
 503          buffer->_Ymin = buffer->_Ymax;
 504       }
 505    }
 506
 507    ASSERT(buffer->_Xmin <= buffer->_Xmax);
 508    ASSERT(buffer->_Ymin <= buffer->_Ymax);
 509 }
 510
 511
 512 /**
 513  * The glGet queries of the framebuffer red/green/blue size, stencil size,
 514  * etc. are satisfied by the fields of ctx->DrawBuffer->Visual.  These can
 515  * change depending on the renderbuffer bindings.  This function updates
 516  * the given framebuffer's Visual from the current renderbuffer bindings.
 517  *
 518  * This may apply to user-created framebuffers or window system framebuffers.
 519  *
 520  * Also note: ctx->DrawBuffer->Visual.depthBits might not equal
 521  * ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer.DepthBits.
 522  * The former one is used to convert floating point depth values into
 523  * integer Z values.
 524  */
 525 void
 526 _mesa_update_framebuffer_visual(struct gl_framebuffer *fb)
 527 {
 528    GLuint i;
 529
 530    memset(&fb->Visual, 0, sizeof(fb->Visual));
 531    fb->Visual.rgbMode = GL_TRUE; /* assume this */
 532
 533 #if 0 /* this _might_ be needed */
 534    if (fb->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 535       /* leave visual fields zero'd */
 536       return;
 537    }
 538 #endif
 539
 540    /* find first RGB renderbuffer */
 541    for (i = 0; i < BUFFER_COUNT; i++) {
 542       if (fb->Attachment[i].Renderbuffer) {
 543          const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
 544          const GLenum baseFormat = _mesa_get_format_base_format(rb->Format);
 545          const gl_format fmt = rb->Format;
 546
 547          if (baseFormat == GL_RGBA || baseFormat == GL_RGB ||
 548              baseFormat == GL_ALPHA) {
 549             fb->Visual.redBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
 550             fb->Visual.greenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
 551             fb->Visual.blueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
 552             fb->Visual.alphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
 553             fb->Visual.rgbBits = fb->Visual.redBits
 554                + fb->Visual.greenBits + fb->Visual.blueBits;
 555             fb->Visual.floatMode = GL_FALSE;
 556             fb->Visual.samples = rb->NumSamples;
 557             break;
 558          }
 559       }
 560    }
 561
 562    if (fb->Attachment[BUFFER_DEPTH].Renderbuffer) {
 563       const struct gl_renderbuffer *rb =
 564          fb->Attachment[BUFFER_DEPTH].Renderbuffer;
 565       const gl_format fmt = rb->Format;
 566       fb->Visual.haveDepthBuffer = GL_TRUE;
 567       fb->Visual.depthBits = _mesa_get_format_bits(fmt, GL_DEPTH_BITS);
 568    }
 569
 570    if (fb->Attachment[BUFFER_STENCIL].Renderbuffer) {
 571       const struct gl_renderbuffer *rb =
 572          fb->Attachment[BUFFER_STENCIL].Renderbuffer;
 573       const gl_format fmt = rb->Format;
 574       fb->Visual.haveStencilBuffer = GL_TRUE;
 575       fb->Visual.stencilBits = _mesa_get_format_bits(fmt, GL_STENCIL_BITS);
 576    }
 577
 578    if (fb->Attachment[BUFFER_ACCUM].Renderbuffer) {
 579       const struct gl_renderbuffer *rb =
 580          fb->Attachment[BUFFER_ACCUM].Renderbuffer;
 581       const gl_format fmt = rb->Format;
 582       fb->Visual.haveAccumBuffer = GL_TRUE;
 583       fb->Visual.accumRedBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
 584       fb->Visual.accumGreenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
 585       fb->Visual.accumBlueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
 586       fb->Visual.accumAlphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
 587    }
 588
 589    compute_depth_max(fb);
 590 }
 591
 592
 593 /**
 594  * Update the framebuffer's _DepthBuffer field using the renderbuffer
 595  * found at the given attachment index.
 596  *
 597  * If that attachment points to a combined GL_DEPTH_STENCIL renderbuffer,
 598  * create and install a depth wrapper/adaptor.
 599  *
 600  * \param fb  the framebuffer whose _DepthBuffer field to update
 601  * \param attIndex  indicates the renderbuffer to possibly wrap
 602  */
 603 void
 604 _mesa_update_depth_buffer(GLcontext *ctx,
 605                           struct gl_framebuffer *fb,
 606                           GLuint attIndex)
 607 {
 608    struct gl_renderbuffer *depthRb;
 609
 610    /* only one possiblity for now */
 611    ASSERT(attIndex == BUFFER_DEPTH);
 612
 613    depthRb = fb->Attachment[attIndex].Renderbuffer;
 614
 615    if (depthRb && depthRb->_BaseFormat == GL_DEPTH_STENCIL) {
 616       /* The attached depth buffer is a GL_DEPTH_STENCIL renderbuffer */
 617       if (!fb->_DepthBuffer
 618           || fb->_DepthBuffer->Wrapped != depthRb
 619           || _mesa_get_format_base_format(fb->_DepthBuffer->Format) != GL_DEPTH_COMPONENT) {
 620          /* need to update wrapper */
 621          struct gl_renderbuffer *wrapper
 622             = _mesa_new_z24_renderbuffer_wrapper(ctx, depthRb);
 623          _mesa_reference_renderbuffer(&fb->_DepthBuffer, wrapper);
 624          ASSERT(fb->_DepthBuffer->Wrapped == depthRb);
 625       }
 626    }
 627    else {
 628       /* depthRb may be null */
 629       _mesa_reference_renderbuffer(&fb->_DepthBuffer, depthRb);
 630    }
 631 }
 632
 633
 634 /**
 635  * Update the framebuffer's _StencilBuffer field using the renderbuffer
 636  * found at the given attachment index.
 637  *
 638  * If that attachment points to a combined GL_DEPTH_STENCIL renderbuffer,
 639  * create and install a stencil wrapper/adaptor.
 640  *
 641  * \param fb  the framebuffer whose _StencilBuffer field to update
 642  * \param attIndex  indicates the renderbuffer to possibly wrap
 643  */
 644 void
 645 _mesa_update_stencil_buffer(GLcontext *ctx,
 646                             struct gl_framebuffer *fb,
 647                             GLuint attIndex)
 648 {
 649    struct gl_renderbuffer *stencilRb;
 650
 651    ASSERT(attIndex == BUFFER_DEPTH ||
 652           attIndex == BUFFER_STENCIL);
 653
 654    stencilRb = fb->Attachment[attIndex].Renderbuffer;
 655
 656    if (stencilRb && stencilRb->_BaseFormat == GL_DEPTH_STENCIL) {
 657       /* The attached stencil buffer is a GL_DEPTH_STENCIL renderbuffer */
 658       if (!fb->_StencilBuffer
 659           || fb->_StencilBuffer->Wrapped != stencilRb
 660           || _mesa_get_format_base_format(fb->_StencilBuffer->Format) != GL_STENCIL_INDEX) {
 661          /* need to update wrapper */
 662          struct gl_renderbuffer *wrapper
 663             = _mesa_new_s8_renderbuffer_wrapper(ctx, stencilRb);
 664          _mesa_reference_renderbuffer(&fb->_StencilBuffer, wrapper);
 665          ASSERT(fb->_StencilBuffer->Wrapped == stencilRb);
 666       }
 667    }
 668    else {
 669       /* stencilRb may be null */
 670       _mesa_reference_renderbuffer(&fb->_StencilBuffer, stencilRb);
 671    }
 672 }
 673
 674
 675 /*
 676  * Example DrawBuffers scenarios:
 677  *
 678  * 1. glDrawBuffer(GL_FRONT_AND_BACK), fixed-func or shader writes to
 679  * "gl_FragColor" or program writes to the "result.color" register:
 680  *
 681  *   fragment color output   renderbuffer
 682  *   ---------------------   ---------------
 683  *   color[0]                Front, Back
 684  *
 685  *
 686  * 2. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]), shader writes to
 687  * gl_FragData[i] or program writes to result.color[i] registers:
 688  *
 689  *   fragment color output   renderbuffer
 690  *   ---------------------   ---------------
 691  *   color[0]                Front
 692  *   color[1]                Aux0
 693  *   color[3]                Aux1
 694  *
 695  *
 696  * 3. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]) and shader writes to
 697  * gl_FragColor, or fixed function:
 698  *
 699  *   fragment color output   renderbuffer
 700  *   ---------------------   ---------------
 701  *   color[0]                Front, Aux0, Aux1
 702  *
 703  *
 704  * In either case, the list of renderbuffers is stored in the
 705  * framebuffer->_ColorDrawBuffers[] array and
 706  * framebuffer->_NumColorDrawBuffers indicates the number of buffers.
 707  * The renderer (like swrast) has to look at the current fragment shader
 708  * to see if it writes to gl_FragColor vs. gl_FragData[i] to determine
 709  * how to map color outputs to renderbuffers.
 710  *
 711  * Note that these two calls are equivalent (for fixed function fragment
 712  * shading anyway):
 713  *   a)  glDrawBuffer(GL_FRONT_AND_BACK);  (assuming non-stereo framebuffer)
 714  *   b)  glDrawBuffers(2, [GL_FRONT_LEFT, GL_BACK_LEFT]);
 715  */
 716
 717
 718
 719
 720 /**
 721  * Update the (derived) list of color drawing renderbuffer pointers.
 722  * Later, when we're rendering we'll loop from 0 to _NumColorDrawBuffers
 723  * writing colors.
 724  */
 725 static void
 726 update_color_draw_buffers(GLcontext *ctx, struct gl_framebuffer *fb)
 727 {
 728    GLuint output;
 729
 730    /* set 0th buffer to NULL now in case _NumColorDrawBuffers is zero */
 731    fb->_ColorDrawBuffers[0] = NULL;
 732
 733    for (output = 0; output < fb->_NumColorDrawBuffers; output++) {
 734       GLint buf = fb->_ColorDrawBufferIndexes[output];
 735       if (buf >= 0) {
 736          fb->_ColorDrawBuffers[output] = fb->Attachment[buf].Renderbuffer;
 737       }
 738       else {
 739          fb->_ColorDrawBuffers[output] = NULL;
 740       }
 741    }
 742 }
 743
 744
 745 /**
 746  * Update the (derived) color read renderbuffer pointer.
 747  * Unlike the DrawBuffer, we can only read from one (or zero) color buffers.
 748  */
 749 static void
 750 update_color_read_buffer(GLcontext *ctx, struct gl_framebuffer *fb)
 751 {
 752    (void) ctx;
 753    if (fb->_ColorReadBufferIndex == -1 ||
 754        fb->DeletePending ||
 755        fb->Width == 0 ||
 756        fb->Height == 0) {
 757       fb->_ColorReadBuffer = NULL; /* legal! */
 758    }
 759    else {
 760       ASSERT(fb->_ColorReadBufferIndex >= 0);
 761       ASSERT(fb->_ColorReadBufferIndex < BUFFER_COUNT);
 762       fb->_ColorReadBuffer
 763          = fb->Attachment[fb->_ColorReadBufferIndex].Renderbuffer;
 764    }
 765 }
 766
 767
 768 /**
 769  * Update a gl_framebuffer's derived state.
 770  *
 771  * Specifically, update these framebuffer fields:
 772  *    _ColorDrawBuffers
 773  *    _NumColorDrawBuffers
 774  *    _ColorReadBuffer
 775  *    _DepthBuffer
 776  *    _StencilBuffer
 777  *
 778  * If the framebuffer is user-created, make sure it's complete.
 779  *
 780  * The following functions (at least) can effect framebuffer state:
 781  * glReadBuffer, glDrawBuffer, glDrawBuffersARB, glFramebufferRenderbufferEXT,
 782  * glRenderbufferStorageEXT.
 783  */
 784 static void
 785 update_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb)
 786 {
 787    if (fb->Name == 0) {
 788       /* This is a window-system framebuffer */
 789       /* Need to update the FB's GL_DRAW_BUFFER state to match the
 790        * context state (GL_READ_BUFFER too).
 791        */
 792       if (fb->ColorDrawBuffer[0] != ctx->Color.DrawBuffer[0]) {
 793          _mesa_drawbuffers(ctx, ctx->Const.MaxDrawBuffers,
 794                            ctx->Color.DrawBuffer, NULL);
 795       }
 796       if (fb->ColorReadBuffer != ctx->Pixel.ReadBuffer) {
 797
 798       }
 799    }
 800    else {
 801       /* This is a user-created framebuffer.
 802        * Completeness only matters for user-created framebuffers.
 803        */
 804       if (fb->_Status != GL_FRAMEBUFFER_COMPLETE) {
 805          _mesa_test_framebuffer_completeness(ctx, fb);
 806       }
 807    }
 808
 809    /* Strictly speaking, we don't need to update the draw-state
 810     * if this FB is bound as ctx->ReadBuffer (and conversely, the
 811     * read-state if this FB is bound as ctx->DrawBuffer), but no
 812     * harm.
 813     */
 814    update_color_draw_buffers(ctx, fb);
 815    update_color_read_buffer(ctx, fb);
 816    _mesa_update_depth_buffer(ctx, fb, BUFFER_DEPTH);
 817    _mesa_update_stencil_buffer(ctx, fb, BUFFER_STENCIL);
 818
 819    compute_depth_max(fb);
 820 }
 821
 822
 823 /**
 824  * Update state related to the current draw/read framebuffers.
 825  */
 826 void
 827 _mesa_update_framebuffer(GLcontext *ctx)
 828 {
 829    struct gl_framebuffer *drawFb;
 830    struct gl_framebuffer *readFb;
 831
 832    assert(ctx);
 833    drawFb = ctx->DrawBuffer;
 834    readFb = ctx->ReadBuffer;
 835
 836    update_framebuffer(ctx, drawFb);
 837    if (readFb != drawFb)
 838       update_framebuffer(ctx, readFb);
 839 }
 840
 841
 842 /**
 843  * Check if the renderbuffer for a read operation (glReadPixels, glCopyPixels,
 844  * glCopyTex[Sub]Image, etc) exists.
 845  * \param format  a basic image format such as GL_RGB, GL_RGBA, GL_ALPHA,
 846  *                GL_DEPTH_COMPONENT, etc. or GL_COLOR, GL_DEPTH, GL_STENCIL.
 847  * \return GL_TRUE if buffer exists, GL_FALSE otherwise
 848  */
 849 GLboolean
 850 _mesa_source_buffer_exists(GLcontext *ctx, GLenum format)
 851 {
 852    const struct gl_renderbuffer_attachment *att = ctx->ReadBuffer->Attachment;
 853
 854    /* If we don't know the framebuffer status, update it now */
 855    if (ctx->ReadBuffer->_Status == 0) {
 856       _mesa_test_framebuffer_completeness(ctx, ctx->ReadBuffer);
 857    }
 858
 859    if (ctx->ReadBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 860       return GL_FALSE;
 861    }
 862
 863    switch (format) {
 864    case GL_COLOR:
 865    case GL_RED:
 866    case GL_GREEN:
 867    case GL_BLUE:
 868    case GL_ALPHA:
 869    case GL_LUMINANCE:
 870    case GL_LUMINANCE_ALPHA:
 871    case GL_INTENSITY:
 872    case GL_RGB:
 873    case GL_BGR:
 874    case GL_RGBA:
 875    case GL_BGRA:
 876    case GL_ABGR_EXT:
 877    case GL_COLOR_INDEX:
 878       if (ctx->ReadBuffer->_ColorReadBuffer == NULL) {
 879          return GL_FALSE;
 880       }
 881       ASSERT(_mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_RED_BITS) > 0 ||
 882              _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_ALPHA_BITS) > 0 ||
 883              _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_INDEX_BITS) > 0);
 884       break;
 885    case GL_DEPTH:
 886    case GL_DEPTH_COMPONENT:
 887       if (!att[BUFFER_DEPTH].Renderbuffer) {
 888          return GL_FALSE;
 889       }
 890       /*ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);*/
 891       break;
 892    case GL_STENCIL:
 893    case GL_STENCIL_INDEX:
 894       if (!att[BUFFER_STENCIL].Renderbuffer) {
 895          return GL_FALSE;
 896       }
 897       /*ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);*/
 898       break;
 899    case GL_DEPTH_STENCIL_EXT:
 900       if (!att[BUFFER_DEPTH].Renderbuffer ||
 901           !att[BUFFER_STENCIL].Renderbuffer) {
 902          return GL_FALSE;
 903       }
 904       /*
 905       ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);
 906       ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);
 907       */
 908       break;
 909    default:
 910       _mesa_problem(ctx,
 911                     "Unexpected format 0x%x in _mesa_source_buffer_exists",
 912                     format);
 913       return GL_FALSE;
 914    }
 915
 916    /* OK */
 917    return GL_TRUE;
 918 }
 919
 920
 921 /**
 922  * As above, but for drawing operations.
 923  * XXX could do some code merging w/ above function.
 924  */
 925 GLboolean
 926 _mesa_dest_buffer_exists(GLcontext *ctx, GLenum format)
 927 {
 928    const struct gl_renderbuffer_attachment *att = ctx->DrawBuffer->Attachment;
 929
 930    /* If we don't know the framebuffer status, update it now */
 931    if (ctx->DrawBuffer->_Status == 0) {
 932       _mesa_test_framebuffer_completeness(ctx, ctx->DrawBuffer);
 933    }
 934
 935    if (ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 936       return GL_FALSE;
 937    }
 938
 939    switch (format) {
 940    case GL_COLOR:
 941    case GL_RED:
 942    case GL_GREEN:
 943    case GL_BLUE:
 944    case GL_ALPHA:
 945    case GL_LUMINANCE:
 946    case GL_LUMINANCE_ALPHA:
 947    case GL_INTENSITY:
 948    case GL_RGB:
 949    case GL_BGR:
 950    case GL_RGBA:
 951    case GL_BGRA:
 952    case GL_ABGR_EXT:
 953    case GL_COLOR_INDEX:
 954       /* Nothing special since GL_DRAW_BUFFER could be GL_NONE. */
 955       /* Could assert that colorbuffer has RedBits > 0 */
 956       break;
 957    case GL_DEPTH:
 958    case GL_DEPTH_COMPONENT:
 959       if (!att[BUFFER_DEPTH].Renderbuffer) {
 960          return GL_FALSE;
 961       }
 962       /*ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);*/
 963       break;
 964    case GL_STENCIL:
 965    case GL_STENCIL_INDEX:
 966       if (!att[BUFFER_STENCIL].Renderbuffer) {
 967          return GL_FALSE;
 968       }
 969       /*ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);*/
 970       break;
 971    case GL_DEPTH_STENCIL_EXT:
 972       if (!att[BUFFER_DEPTH].Renderbuffer ||
 973           !att[BUFFER_STENCIL].Renderbuffer) {
 974          return GL_FALSE;
 975       }
 976       /*
 977       ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);
 978       ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);
 979       */
 980       break;
 981    default:
 982       _mesa_problem(ctx,
 983                     "Unexpected format 0x%x in _mesa_dest_buffer_exists",
 984                     format);
 985       return GL_FALSE;
 986    }
 987
 988    /* OK */
 989    return GL_TRUE;
 990 }
 991
 992
 993 /**
 994  * Used to answer the GL_IMPLEMENTATION_COLOR_READ_FORMAT_OES query.
 995  */
 996 GLenum
 997 _mesa_get_color_read_format(GLcontext *ctx)
 998 {
 999    switch (ctx->ReadBuffer->_ColorReadBuffer->Format) {
1000    case MESA_FORMAT_ARGB8888:
1001       return GL_BGRA;
1002    case MESA_FORMAT_RGB565:
1003       return GL_BGR;
1004    default:
1005       return GL_RGBA;
1006    }
1007 }
1008
1009
1010 /**
1011  * Used to answer the GL_IMPLEMENTATION_COLOR_READ_TYPE_OES query.
1012  */
1013 GLenum
1014 _mesa_get_color_read_type(GLcontext *ctx)
1015 {
1016    switch (ctx->ReadBuffer->_ColorReadBuffer->Format) {
1017    case MESA_FORMAT_ARGB8888:
1018       return GL_UNSIGNED_BYTE;
1019    case MESA_FORMAT_RGB565:
1020       return GL_UNSIGNED_SHORT_5_6_5_REV;
1021    default:
1022       return GL_UNSIGNED_BYTE;
1023    }
1024 }
1025
1026
1027 /**
1028  * Print framebuffer info to stderr, for debugging.
1029  */
1030 void
1031 _mesa_print_framebuffer(const struct gl_framebuffer *fb)
1032 {
1033    GLuint i;
1034
1035    fprintf(stderr, "Mesa Framebuffer %u at %p\n", fb->Name, (void *) fb);
1036    fprintf(stderr, "  Size: %u x %u  Status: %s\n", fb->Width, fb->Height,
1037            _mesa_lookup_enum_by_nr(fb->_Status));
1038    fprintf(stderr, "  Attachments:\n");
1039
1040    for (i = 0; i < BUFFER_COUNT; i++) {
1041       const struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
1042       if (att->Type == GL_TEXTURE) {
1043          const struct gl_texture_image *texImage;
1044          fprintf(stderr,
1045                  "  %2d: Texture %u, level %u, face %u, slice %u, complete %d\n",
1046                  i, att->Texture->Name, att->TextureLevel, att->CubeMapFace,
1047                  att->Zoffset, att->Complete);
1048          texImage = att->Texture->Image[att->CubeMapFace][att->TextureLevel];
1049          fprintf(stderr, "       Size: %u x %u x %u  Format %s\n",
1050                  texImage->Width, texImage->Height, texImage->Depth,
1051                  _mesa_get_format_name(texImage->TexFormat));
1052       }
1053       else if (att->Type == GL_RENDERBUFFER) {
1054          fprintf(stderr, "  %2d: Renderbuffer %u, complete %d\n",
1055                  i, att->Renderbuffer->Name, att->Complete);
1056          fprintf(stderr, "       Size: %u x %u  Format %s\n",
1057                  att->Renderbuffer->Width, att->Renderbuffer->Height,
1058                  _mesa_get_format_name(att->Renderbuffer->Format));
1059       }
1060       else {
1061          fprintf(stderr, "  %2d: none\n", i);
1062       }
1063    }
1064 }