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  * Create and initialize a gl_framebuffer object.
  80  * This is intended for creating _window_system_ framebuffers, not generic
  81  * framebuffer objects ala GL_EXT_framebuffer_object.
  82  *
  83  * \sa _mesa_new_framebuffer
  84  */
  85 struct gl_framebuffer *
  86 _mesa_create_framebuffer(const struct gl_config *visual)
  87 {
  88    struct gl_framebuffer *fb = CALLOC_STRUCT(gl_framebuffer);
  89    assert(visual);
  90    if (fb) {
  91       _mesa_initialize_window_framebuffer(fb, visual);
  92    }
  93    return fb;
  94 }
  95
  96
  97 /**
  98  * Allocate a new gl_framebuffer object.
  99  * This is the default function for ctx->Driver.NewFramebuffer().
 100  * This is for allocating user-created framebuffers, not window-system
 101  * framebuffers!
 102  * \sa _mesa_create_framebuffer
 103  */
 104 struct gl_framebuffer *
 105 _mesa_new_framebuffer(struct gl_context *ctx, GLuint name)
 106 {
 107    struct gl_framebuffer *fb;
 108    (void) ctx;
 109    assert(name != 0);
 110    fb = CALLOC_STRUCT(gl_framebuffer);
 111    if (fb) {
 112       _mesa_initialize_user_framebuffer(fb, name);
 113    }
 114    return fb;
 115 }
 116
 117
 118 /**
 119  * Initialize a gl_framebuffer object.  Typically used to initialize
 120  * window system-created framebuffers, not user-created framebuffers.
 121  * \sa _mesa_initialize_user_framebuffer
 122  */
 123 void
 124 _mesa_initialize_window_framebuffer(struct gl_framebuffer *fb,
 125                                      const struct gl_config *visual)
 126 {
 127    assert(fb);
 128    assert(visual);
 129
 130    memset(fb, 0, sizeof(struct gl_framebuffer));
 131
 132    _glthread_INIT_MUTEX(fb->Mutex);
 133
 134    fb->RefCount = 1;
 135
 136    /* save the visual */
 137    fb->Visual = *visual;
 138
 139    /* Init read/draw renderbuffer state */
 140    if (visual->doubleBufferMode) {
 141       fb->_NumColorDrawBuffers = 1;
 142       fb->ColorDrawBuffer[0] = GL_BACK;
 143       fb->_ColorDrawBufferIndexes[0] = BUFFER_BACK_LEFT;
 144       fb->ColorReadBuffer = GL_BACK;
 145       fb->_ColorReadBufferIndex = BUFFER_BACK_LEFT;
 146    }
 147    else {
 148       fb->_NumColorDrawBuffers = 1;
 149       fb->ColorDrawBuffer[0] = GL_FRONT;
 150       fb->_ColorDrawBufferIndexes[0] = BUFFER_FRONT_LEFT;
 151       fb->ColorReadBuffer = GL_FRONT;
 152       fb->_ColorReadBufferIndex = BUFFER_FRONT_LEFT;
 153    }
 154
 155    fb->Delete = _mesa_destroy_framebuffer;
 156    fb->_Status = GL_FRAMEBUFFER_COMPLETE_EXT;
 157
 158    compute_depth_max(fb);
 159 }
 160
 161
 162 /**
 163  * Initialize a user-created gl_framebuffer object.
 164  * \sa _mesa_initialize_window_framebuffer
 165  */
 166 void
 167 _mesa_initialize_user_framebuffer(struct gl_framebuffer *fb, GLuint name)
 168 {
 169    assert(fb);
 170    assert(name);
 171
 172    memset(fb, 0, sizeof(struct gl_framebuffer));
 173
 174    fb->Name = name;
 175    fb->RefCount = 1;
 176    fb->_NumColorDrawBuffers = 1;
 177    fb->ColorDrawBuffer[0] = GL_COLOR_ATTACHMENT0_EXT;
 178    fb->_ColorDrawBufferIndexes[0] = BUFFER_COLOR0;
 179    fb->ColorReadBuffer = GL_COLOR_ATTACHMENT0_EXT;
 180    fb->_ColorReadBufferIndex = BUFFER_COLOR0;
 181    fb->Delete = _mesa_destroy_framebuffer;
 182    _glthread_INIT_MUTEX(fb->Mutex);
 183 }
 184
 185
 186 /**
 187  * Deallocate buffer and everything attached to it.
 188  * Typically called via the gl_framebuffer->Delete() method.
 189  */
 190 void
 191 _mesa_destroy_framebuffer(struct gl_framebuffer *fb)
 192 {
 193    if (fb) {
 194       _mesa_free_framebuffer_data(fb);
 195       free(fb);
 196    }
 197 }
 198
 199
 200 /**
 201  * Free all the data hanging off the given gl_framebuffer, but don't free
 202  * the gl_framebuffer object itself.
 203  */
 204 void
 205 _mesa_free_framebuffer_data(struct gl_framebuffer *fb)
 206 {
 207    GLuint i;
 208
 209    assert(fb);
 210    assert(fb->RefCount == 0);
 211
 212    _glthread_DESTROY_MUTEX(fb->Mutex);
 213
 214    for (i = 0; i < BUFFER_COUNT; i++) {
 215       struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 216       if (att->Renderbuffer) {
 217          _mesa_reference_renderbuffer(&att->Renderbuffer, NULL);
 218       }
 219       if (att->Texture) {
 220          _mesa_reference_texobj(&att->Texture, NULL);
 221       }
 222       ASSERT(!att->Renderbuffer);
 223       ASSERT(!att->Texture);
 224       att->Type = GL_NONE;
 225    }
 226
 227    /* unbind _Depth/_StencilBuffer to decr ref counts */
 228    _mesa_reference_renderbuffer(&fb->_DepthBuffer, NULL);
 229    _mesa_reference_renderbuffer(&fb->_StencilBuffer, NULL);
 230 }
 231
 232
 233 /**
 234  * Set *ptr to point to fb, with refcounting and locking.
 235  * This is normally only called from the _mesa_reference_framebuffer() macro
 236  * when there's a real pointer change.
 237  */
 238 void
 239 _mesa_reference_framebuffer_(struct gl_framebuffer **ptr,
 240                              struct gl_framebuffer *fb)
 241 {
 242    if (*ptr) {
 243       /* unreference old renderbuffer */
 244       GLboolean deleteFlag = GL_FALSE;
 245       struct gl_framebuffer *oldFb = *ptr;
 246
 247       _glthread_LOCK_MUTEX(oldFb->Mutex);
 248       ASSERT(oldFb->RefCount > 0);
 249       oldFb->RefCount--;
 250       deleteFlag = (oldFb->RefCount == 0);
 251       _glthread_UNLOCK_MUTEX(oldFb->Mutex);
 252
 253       if (deleteFlag)
 254          oldFb->Delete(oldFb);
 255
 256       *ptr = NULL;
 257    }
 258    assert(!*ptr);
 259
 260    if (fb) {
 261       _glthread_LOCK_MUTEX(fb->Mutex);
 262       fb->RefCount++;
 263       _glthread_UNLOCK_MUTEX(fb->Mutex);
 264       *ptr = fb;
 265    }
 266 }
 267
 268
 269 /**
 270  * Resize the given framebuffer's renderbuffers to the new width and height.
 271  * This should only be used for window-system framebuffers, not
 272  * user-created renderbuffers (i.e. made with GL_EXT_framebuffer_object).
 273  * This will typically be called via ctx->Driver.ResizeBuffers() or directly
 274  * from a device driver.
 275  *
 276  * \note it's possible for ctx to be null since a window can be resized
 277  * without a currently bound rendering context.
 278  */
 279 void
 280 _mesa_resize_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
 281                          GLuint width, GLuint height)
 282 {
 283    GLuint i;
 284
 285    /* XXX I think we could check if the size is not changing
 286     * and return early.
 287     */
 288
 289    /* For window system framebuffers, Name is zero */
 290    assert(fb->Name == 0);
 291
 292    for (i = 0; i < BUFFER_COUNT; i++) {
 293       struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 294       if (att->Type == GL_RENDERBUFFER_EXT && att->Renderbuffer) {
 295          struct gl_renderbuffer *rb = att->Renderbuffer;
 296          /* only resize if size is changing */
 297          if (rb->Width != width || rb->Height != height) {
 298             if (rb->AllocStorage(ctx, rb, rb->InternalFormat, width, height)) {
 299                ASSERT(rb->Width == width);
 300                ASSERT(rb->Height == height);
 301             }
 302             else {
 303                _mesa_error(ctx, GL_OUT_OF_MEMORY, "Resizing framebuffer");
 304                /* no return */
 305             }
 306          }
 307       }
 308    }
 309
 310    if (fb->_DepthBuffer) {
 311       struct gl_renderbuffer *rb = fb->_DepthBuffer;
 312       if (rb->Width != width || rb->Height != height) {
 313          if (!rb->AllocStorage(ctx, rb, rb->InternalFormat, width, height)) {
 314             _mesa_error(ctx, GL_OUT_OF_MEMORY, "Resizing framebuffer");
 315          }
 316       }
 317    }
 318
 319    if (fb->_StencilBuffer) {
 320       struct gl_renderbuffer *rb = fb->_StencilBuffer;
 321       if (rb->Width != width || rb->Height != height) {
 322          if (!rb->AllocStorage(ctx, rb, rb->InternalFormat, width, height)) {
 323             _mesa_error(ctx, GL_OUT_OF_MEMORY, "Resizing framebuffer");
 324          }
 325       }
 326    }
 327
 328    fb->Width = width;
 329    fb->Height = height;
 330
 331    if (ctx) {
 332       /* update scissor / window bounds */
 333       _mesa_update_draw_buffer_bounds(ctx);
 334       /* Signal new buffer state so that swrast will update its clipping
 335        * info (the CLIP_BIT flag).
 336        */
 337       ctx->NewState |= _NEW_BUFFERS;
 338    }
 339 }
 340
 341
 342
 343 /**
 344  * XXX THIS IS OBSOLETE - drivers should take care of detecting window
 345  * size changes and act accordingly, likely calling _mesa_resize_framebuffer().
 346  *
 347  * GL_MESA_resize_buffers extension.
 348  *
 349  * When this function is called, we'll ask the window system how large
 350  * the current window is.  If it's a new size, we'll call the driver's
 351  * ResizeBuffers function.  The driver will then resize its color buffers
 352  * as needed, and maybe call the swrast's routine for reallocating
 353  * swrast-managed depth/stencil/accum/etc buffers.
 354  * \note This function should only be called through the GL API, not
 355  * from device drivers (as was done in the past).
 356  */
 357 void
 358 _mesa_resizebuffers( struct gl_context *ctx )
 359 {
 360    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx );
 361
 362    if (MESA_VERBOSE & VERBOSE_API)
 363       _mesa_debug(ctx, "glResizeBuffersMESA\n");
 364
 365    if (!ctx->Driver.GetBufferSize) {
 366       return;
 367    }
 368
 369    if (ctx->WinSysDrawBuffer) {
 370       GLuint newWidth, newHeight;
 371       struct gl_framebuffer *buffer = ctx->WinSysDrawBuffer;
 372
 373       assert(buffer->Name == 0);
 374
 375       /* ask device driver for size of output buffer */
 376       ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight );
 377
 378       /* see if size of device driver's color buffer (window) has changed */
 379       if (buffer->Width != newWidth || buffer->Height != newHeight) {
 380          if (ctx->Driver.ResizeBuffers)
 381             ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight );
 382       }
 383    }
 384
 385    if (ctx->WinSysReadBuffer
 386        && ctx->WinSysReadBuffer != ctx->WinSysDrawBuffer) {
 387       GLuint newWidth, newHeight;
 388       struct gl_framebuffer *buffer = ctx->WinSysReadBuffer;
 389
 390       assert(buffer->Name == 0);
 391
 392       /* ask device driver for size of read buffer */
 393       ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight );
 394
 395       /* see if size of device driver's color buffer (window) has changed */
 396       if (buffer->Width != newWidth || buffer->Height != newHeight) {
 397          if (ctx->Driver.ResizeBuffers)
 398             ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight );
 399       }
 400    }
 401
 402    ctx->NewState |= _NEW_BUFFERS;  /* to update scissor / window bounds */
 403 }
 404
 405
 406 /*
 407  * XXX THIS IS OBSOLETE
 408  */
 409 void GLAPIENTRY
 410 _mesa_ResizeBuffersMESA( void )
 411 {
 412    GET_CURRENT_CONTEXT(ctx);
 413
 414    if (ctx->Extensions.MESA_resize_buffers)
 415       _mesa_resizebuffers( ctx );
 416 }
 417
 418
 419
 420 /**
 421  * Examine all the framebuffer's renderbuffers to update the Width/Height
 422  * fields of the framebuffer.  If we have renderbuffers with different
 423  * sizes, set the framebuffer's width and height to the min size.
 424  * Note: this is only intended for user-created framebuffers, not
 425  * window-system framebuffes.
 426  */
 427 static void
 428 update_framebuffer_size(struct gl_context *ctx, struct gl_framebuffer *fb)
 429 {
 430    GLuint minWidth = ~0, minHeight = ~0;
 431    GLuint i;
 432
 433    /* user-created framebuffers only */
 434    assert(fb->Name);
 435
 436    for (i = 0; i < BUFFER_COUNT; i++) {
 437       struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 438       const struct gl_renderbuffer *rb = att->Renderbuffer;
 439       if (rb) {
 440          minWidth = MIN2(minWidth, rb->Width);
 441          minHeight = MIN2(minHeight, rb->Height);
 442       }
 443    }
 444
 445    if (minWidth != ~0) {
 446       fb->Width = minWidth;
 447       fb->Height = minHeight;
 448    }
 449    else {
 450       fb->Width = 0;
 451       fb->Height = 0;
 452    }
 453 }
 454
 455
 456 /**
 457  * Update the context's current drawing buffer's Xmin, Xmax, Ymin, Ymax fields.
 458  * These values are computed from the buffer's width and height and
 459  * the scissor box, if it's enabled.
 460  * \param ctx  the GL context.
 461  */
 462 void
 463 _mesa_update_draw_buffer_bounds(struct gl_context *ctx)
 464 {
 465    struct gl_framebuffer *buffer = ctx->DrawBuffer;
 466
 467    if (!buffer)
 468       return;
 469
 470    if (buffer->Name) {
 471       /* user-created framebuffer size depends on the renderbuffers */
 472       update_framebuffer_size(ctx, buffer);
 473    }
 474
 475    buffer->_Xmin = 0;
 476    buffer->_Ymin = 0;
 477    buffer->_Xmax = buffer->Width;
 478    buffer->_Ymax = buffer->Height;
 479
 480    if (ctx->Scissor.Enabled) {
 481       if (ctx->Scissor.X > buffer->_Xmin) {
 482          buffer->_Xmin = ctx->Scissor.X;
 483       }
 484       if (ctx->Scissor.Y > buffer->_Ymin) {
 485          buffer->_Ymin = ctx->Scissor.Y;
 486       }
 487       if (ctx->Scissor.X + ctx->Scissor.Width < buffer->_Xmax) {
 488          buffer->_Xmax = ctx->Scissor.X + ctx->Scissor.Width;
 489       }
 490       if (ctx->Scissor.Y + ctx->Scissor.Height < buffer->_Ymax) {
 491          buffer->_Ymax = ctx->Scissor.Y + ctx->Scissor.Height;
 492       }
 493       /* finally, check for empty region */
 494       if (buffer->_Xmin > buffer->_Xmax) {
 495          buffer->_Xmin = buffer->_Xmax;
 496       }
 497       if (buffer->_Ymin > buffer->_Ymax) {
 498          buffer->_Ymin = buffer->_Ymax;
 499       }
 500    }
 501
 502    ASSERT(buffer->_Xmin <= buffer->_Xmax);
 503    ASSERT(buffer->_Ymin <= buffer->_Ymax);
 504 }
 505
 506
 507 /**
 508  * The glGet queries of the framebuffer red/green/blue size, stencil size,
 509  * etc. are satisfied by the fields of ctx->DrawBuffer->Visual.  These can
 510  * change depending on the renderbuffer bindings.  This function updates
 511  * the given framebuffer's Visual from the current renderbuffer bindings.
 512  *
 513  * This may apply to user-created framebuffers or window system framebuffers.
 514  *
 515  * Also note: ctx->DrawBuffer->Visual.depthBits might not equal
 516  * ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer.DepthBits.
 517  * The former one is used to convert floating point depth values into
 518  * integer Z values.
 519  */
 520 void
 521 _mesa_update_framebuffer_visual(struct gl_context *ctx,
 522                                 struct gl_framebuffer *fb)
 523 {
 524    GLuint i;
 525
 526    memset(&fb->Visual, 0, sizeof(fb->Visual));
 527    fb->Visual.rgbMode = GL_TRUE; /* assume this */
 528
 529 #if 0 /* this _might_ be needed */
 530    if (fb->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 531       /* leave visual fields zero'd */
 532       return;
 533    }
 534 #endif
 535
 536    /* find first RGB renderbuffer */
 537    for (i = 0; i < BUFFER_COUNT; i++) {
 538       if (fb->Attachment[i].Renderbuffer) {
 539          const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
 540          const GLenum baseFormat = _mesa_get_format_base_format(rb->Format);
 541          const gl_format fmt = rb->Format;
 542
 543          if (_mesa_is_legal_color_format(ctx, baseFormat)) {
 544             fb->Visual.redBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
 545             fb->Visual.greenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
 546             fb->Visual.blueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
 547             fb->Visual.alphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
 548             fb->Visual.rgbBits = fb->Visual.redBits
 549                + fb->Visual.greenBits + fb->Visual.blueBits;
 550             fb->Visual.samples = rb->NumSamples;
 551             if (_mesa_get_format_color_encoding(fmt) == GL_SRGB)
 552                 fb->Visual.sRGBCapable = ctx->Const.sRGBCapable;
 553             break;
 554          }
 555       }
 556    }
 557
 558    fb->Visual.floatMode = GL_FALSE;
 559    for (i = 0; i < BUFFER_COUNT; i++) {
 560       if (fb->Attachment[i].Renderbuffer) {
 561          const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
 562          const gl_format fmt = rb->Format;
 563
 564          if (_mesa_get_format_datatype(fmt) == GL_FLOAT) {
 565             fb->Visual.floatMode = GL_TRUE;
 566             break;
 567          }
 568       }
 569    }
 570
 571    if (fb->Attachment[BUFFER_DEPTH].Renderbuffer) {
 572       const struct gl_renderbuffer *rb =
 573          fb->Attachment[BUFFER_DEPTH].Renderbuffer;
 574       const gl_format fmt = rb->Format;
 575       fb->Visual.haveDepthBuffer = GL_TRUE;
 576       fb->Visual.depthBits = _mesa_get_format_bits(fmt, GL_DEPTH_BITS);
 577    }
 578
 579    if (fb->Attachment[BUFFER_STENCIL].Renderbuffer) {
 580       const struct gl_renderbuffer *rb =
 581          fb->Attachment[BUFFER_STENCIL].Renderbuffer;
 582       const gl_format fmt = rb->Format;
 583       fb->Visual.haveStencilBuffer = GL_TRUE;
 584       fb->Visual.stencilBits = _mesa_get_format_bits(fmt, GL_STENCIL_BITS);
 585    }
 586
 587    if (fb->Attachment[BUFFER_ACCUM].Renderbuffer) {
 588       const struct gl_renderbuffer *rb =
 589          fb->Attachment[BUFFER_ACCUM].Renderbuffer;
 590       const gl_format fmt = rb->Format;
 591       fb->Visual.haveAccumBuffer = GL_TRUE;
 592       fb->Visual.accumRedBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
 593       fb->Visual.accumGreenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
 594       fb->Visual.accumBlueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
 595       fb->Visual.accumAlphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
 596    }
 597
 598    compute_depth_max(fb);
 599 }
 600
 601
 602 /**
 603  * Update the framebuffer's _DepthBuffer field using the renderbuffer
 604  * found at the given attachment index.
 605  *
 606  * If that attachment points to a combined GL_DEPTH_STENCIL renderbuffer,
 607  * create and install a depth wrapper/adaptor.
 608  *
 609  * \param fb  the framebuffer whose _DepthBuffer field to update
 610  * \param attIndex  indicates the renderbuffer to possibly wrap
 611  */
 612 void
 613 _mesa_update_depth_buffer(struct gl_context *ctx,
 614                           struct gl_framebuffer *fb,
 615                           GLuint attIndex)
 616 {
 617    struct gl_renderbuffer *depthRb;
 618
 619    /* only one possiblity for now */
 620    ASSERT(attIndex == BUFFER_DEPTH);
 621
 622    depthRb = fb->Attachment[attIndex].Renderbuffer;
 623
 624    if (depthRb && _mesa_is_format_packed_depth_stencil(depthRb->Format)) {
 625       /* The attached depth buffer is a GL_DEPTH_STENCIL renderbuffer */
 626       if (!fb->_DepthBuffer
 627           || fb->_DepthBuffer->Wrapped != depthRb
 628           || _mesa_get_format_base_format(fb->_DepthBuffer->Format) != GL_DEPTH_COMPONENT) {
 629          /* need to update wrapper */
 630          struct gl_renderbuffer *wrapper;
 631
 632          if (depthRb->Format == MESA_FORMAT_Z32_FLOAT_X24S8) {
 633             wrapper = _mesa_new_z32f_renderbuffer_wrapper(ctx, depthRb);
 634          }
 635          else {
 636             wrapper = _mesa_new_z24_renderbuffer_wrapper(ctx, depthRb);
 637          }
 638          _mesa_reference_renderbuffer(&fb->_DepthBuffer, wrapper);
 639          ASSERT(fb->_DepthBuffer->Wrapped == depthRb);
 640       }
 641    }
 642    else {
 643       /* depthRb may be null */
 644       _mesa_reference_renderbuffer(&fb->_DepthBuffer, depthRb);
 645    }
 646 }
 647
 648
 649 /**
 650  * Update the framebuffer's _StencilBuffer field using the renderbuffer
 651  * found at the given attachment index.
 652  *
 653  * If that attachment points to a combined GL_DEPTH_STENCIL renderbuffer,
 654  * create and install a stencil wrapper/adaptor.
 655  *
 656  * \param fb  the framebuffer whose _StencilBuffer field to update
 657  * \param attIndex  indicates the renderbuffer to possibly wrap
 658  */
 659 void
 660 _mesa_update_stencil_buffer(struct gl_context *ctx,
 661                             struct gl_framebuffer *fb,
 662                             GLuint attIndex)
 663 {
 664    struct gl_renderbuffer *stencilRb;
 665
 666    ASSERT(attIndex == BUFFER_DEPTH ||
 667           attIndex == BUFFER_STENCIL);
 668
 669    stencilRb = fb->Attachment[attIndex].Renderbuffer;
 670
 671    if (stencilRb && _mesa_is_format_packed_depth_stencil(stencilRb->Format)) {
 672       /* The attached stencil buffer is a GL_DEPTH_STENCIL renderbuffer */
 673       if (!fb->_StencilBuffer
 674           || fb->_StencilBuffer->Wrapped != stencilRb
 675           || _mesa_get_format_base_format(fb->_StencilBuffer->Format) != GL_STENCIL_INDEX) {
 676          /* need to update wrapper */
 677          struct gl_renderbuffer *wrapper
 678             = _mesa_new_s8_renderbuffer_wrapper(ctx, stencilRb);
 679          _mesa_reference_renderbuffer(&fb->_StencilBuffer, wrapper);
 680          ASSERT(fb->_StencilBuffer->Wrapped == stencilRb);
 681       }
 682    }
 683    else {
 684       /* stencilRb may be null */
 685       _mesa_reference_renderbuffer(&fb->_StencilBuffer, stencilRb);
 686    }
 687 }
 688
 689
 690 /*
 691  * Example DrawBuffers scenarios:
 692  *
 693  * 1. glDrawBuffer(GL_FRONT_AND_BACK), fixed-func or shader writes to
 694  * "gl_FragColor" or program writes to the "result.color" register:
 695  *
 696  *   fragment color output   renderbuffer
 697  *   ---------------------   ---------------
 698  *   color[0]                Front, Back
 699  *
 700  *
 701  * 2. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]), shader writes to
 702  * gl_FragData[i] or program writes to result.color[i] registers:
 703  *
 704  *   fragment color output   renderbuffer
 705  *   ---------------------   ---------------
 706  *   color[0]                Front
 707  *   color[1]                Aux0
 708  *   color[3]                Aux1
 709  *
 710  *
 711  * 3. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]) and shader writes to
 712  * gl_FragColor, or fixed function:
 713  *
 714  *   fragment color output   renderbuffer
 715  *   ---------------------   ---------------
 716  *   color[0]                Front, Aux0, Aux1
 717  *
 718  *
 719  * In either case, the list of renderbuffers is stored in the
 720  * framebuffer->_ColorDrawBuffers[] array and
 721  * framebuffer->_NumColorDrawBuffers indicates the number of buffers.
 722  * The renderer (like swrast) has to look at the current fragment shader
 723  * to see if it writes to gl_FragColor vs. gl_FragData[i] to determine
 724  * how to map color outputs to renderbuffers.
 725  *
 726  * Note that these two calls are equivalent (for fixed function fragment
 727  * shading anyway):
 728  *   a)  glDrawBuffer(GL_FRONT_AND_BACK);  (assuming non-stereo framebuffer)
 729  *   b)  glDrawBuffers(2, [GL_FRONT_LEFT, GL_BACK_LEFT]);
 730  */
 731
 732
 733
 734
 735 /**
 736  * Update the (derived) list of color drawing renderbuffer pointers.
 737  * Later, when we're rendering we'll loop from 0 to _NumColorDrawBuffers
 738  * writing colors.
 739  */
 740 static void
 741 update_color_draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb)
 742 {
 743    GLuint output;
 744
 745    /* set 0th buffer to NULL now in case _NumColorDrawBuffers is zero */
 746    fb->_ColorDrawBuffers[0] = NULL;
 747
 748    for (output = 0; output < fb->_NumColorDrawBuffers; output++) {
 749       GLint buf = fb->_ColorDrawBufferIndexes[output];
 750       if (buf >= 0) {
 751          fb->_ColorDrawBuffers[output] = fb->Attachment[buf].Renderbuffer;
 752       }
 753       else {
 754          fb->_ColorDrawBuffers[output] = NULL;
 755       }
 756    }
 757 }
 758
 759
 760 /**
 761  * Update the (derived) color read renderbuffer pointer.
 762  * Unlike the DrawBuffer, we can only read from one (or zero) color buffers.
 763  */
 764 static void
 765 update_color_read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 766 {
 767    (void) ctx;
 768    if (fb->_ColorReadBufferIndex == -1 ||
 769        fb->DeletePending ||
 770        fb->Width == 0 ||
 771        fb->Height == 0) {
 772       fb->_ColorReadBuffer = NULL; /* legal! */
 773    }
 774    else {
 775       ASSERT(fb->_ColorReadBufferIndex >= 0);
 776       ASSERT(fb->_ColorReadBufferIndex < BUFFER_COUNT);
 777       fb->_ColorReadBuffer
 778          = fb->Attachment[fb->_ColorReadBufferIndex].Renderbuffer;
 779    }
 780 }
 781
 782
 783 /**
 784  * Update a gl_framebuffer's derived state.
 785  *
 786  * Specifically, update these framebuffer fields:
 787  *    _ColorDrawBuffers
 788  *    _NumColorDrawBuffers
 789  *    _ColorReadBuffer
 790  *    _DepthBuffer
 791  *    _StencilBuffer
 792  *
 793  * If the framebuffer is user-created, make sure it's complete.
 794  *
 795  * The following functions (at least) can effect framebuffer state:
 796  * glReadBuffer, glDrawBuffer, glDrawBuffersARB, glFramebufferRenderbufferEXT,
 797  * glRenderbufferStorageEXT.
 798  */
 799 static void
 800 update_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 801 {
 802    if (fb->Name == 0) {
 803       /* This is a window-system framebuffer */
 804       /* Need to update the FB's GL_DRAW_BUFFER state to match the
 805        * context state (GL_READ_BUFFER too).
 806        */
 807       if (fb->ColorDrawBuffer[0] != ctx->Color.DrawBuffer[0]) {
 808          _mesa_drawbuffers(ctx, ctx->Const.MaxDrawBuffers,
 809                            ctx->Color.DrawBuffer, NULL);
 810       }
 811    }
 812    else {
 813       /* This is a user-created framebuffer.
 814        * Completeness only matters for user-created framebuffers.
 815        */
 816       if (fb->_Status != GL_FRAMEBUFFER_COMPLETE) {
 817          _mesa_test_framebuffer_completeness(ctx, fb);
 818       }
 819    }
 820
 821    /* Strictly speaking, we don't need to update the draw-state
 822     * if this FB is bound as ctx->ReadBuffer (and conversely, the
 823     * read-state if this FB is bound as ctx->DrawBuffer), but no
 824     * harm.
 825     */
 826    update_color_draw_buffers(ctx, fb);
 827    update_color_read_buffer(ctx, fb);
 828    _mesa_update_depth_buffer(ctx, fb, BUFFER_DEPTH);
 829    _mesa_update_stencil_buffer(ctx, fb, BUFFER_STENCIL);
 830
 831    compute_depth_max(fb);
 832 }
 833
 834
 835 /**
 836  * Update state related to the current draw/read framebuffers.
 837  */
 838 void
 839 _mesa_update_framebuffer(struct gl_context *ctx)
 840 {
 841    struct gl_framebuffer *drawFb;
 842    struct gl_framebuffer *readFb;
 843
 844    assert(ctx);
 845    drawFb = ctx->DrawBuffer;
 846    readFb = ctx->ReadBuffer;
 847
 848    update_framebuffer(ctx, drawFb);
 849    if (readFb != drawFb)
 850       update_framebuffer(ctx, readFb);
 851 }
 852
 853
 854 /**
 855  * Check if the renderbuffer for a read operation (glReadPixels, glCopyPixels,
 856  * glCopyTex[Sub]Image, etc) exists.
 857  * \param format  a basic image format such as GL_RGB, GL_RGBA, GL_ALPHA,
 858  *                GL_DEPTH_COMPONENT, etc. or GL_COLOR, GL_DEPTH, GL_STENCIL.
 859  * \return GL_TRUE if buffer exists, GL_FALSE otherwise
 860  */
 861 GLboolean
 862 _mesa_source_buffer_exists(struct gl_context *ctx, GLenum format)
 863 {
 864    const struct gl_renderbuffer_attachment *att = ctx->ReadBuffer->Attachment;
 865
 866    /* If we don't know the framebuffer status, update it now */
 867    if (ctx->ReadBuffer->_Status == 0) {
 868       _mesa_test_framebuffer_completeness(ctx, ctx->ReadBuffer);
 869    }
 870
 871    if (ctx->ReadBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 872       return GL_FALSE;
 873    }
 874
 875    switch (format) {
 876    case GL_COLOR:
 877    case GL_RED:
 878    case GL_GREEN:
 879    case GL_BLUE:
 880    case GL_ALPHA:
 881    case GL_LUMINANCE:
 882    case GL_LUMINANCE_ALPHA:
 883    case GL_INTENSITY:
 884    case GL_RG:
 885    case GL_RGB:
 886    case GL_BGR:
 887    case GL_RGBA:
 888    case GL_BGRA:
 889    case GL_ABGR_EXT:
 890    case GL_COLOR_INDEX:
 891    case GL_RED_INTEGER_EXT:
 892    case GL_GREEN_INTEGER_EXT:
 893    case GL_BLUE_INTEGER_EXT:
 894    case GL_ALPHA_INTEGER_EXT:
 895    case GL_RGB_INTEGER_EXT:
 896    case GL_RGBA_INTEGER_EXT:
 897    case GL_BGR_INTEGER_EXT:
 898    case GL_BGRA_INTEGER_EXT:
 899    case GL_LUMINANCE_INTEGER_EXT:
 900    case GL_LUMINANCE_ALPHA_INTEGER_EXT:
 901       if (ctx->ReadBuffer->_ColorReadBuffer == NULL) {
 902          return GL_FALSE;
 903       }
 904       ASSERT(_mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_RED_BITS) > 0 ||
 905              _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_ALPHA_BITS) > 0 ||
 906              _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_TEXTURE_LUMINANCE_SIZE) > 0 ||
 907              _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_TEXTURE_INTENSITY_SIZE) > 0 ||
 908              _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_INDEX_BITS) > 0);
 909       break;
 910    case GL_DEPTH:
 911    case GL_DEPTH_COMPONENT:
 912       if (!att[BUFFER_DEPTH].Renderbuffer) {
 913          return GL_FALSE;
 914       }
 915       /*ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);*/
 916       break;
 917    case GL_STENCIL:
 918    case GL_STENCIL_INDEX:
 919       if (!att[BUFFER_STENCIL].Renderbuffer) {
 920          return GL_FALSE;
 921       }
 922       /*ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);*/
 923       break;
 924    case GL_DEPTH_STENCIL_EXT:
 925       if (!att[BUFFER_DEPTH].Renderbuffer ||
 926           !att[BUFFER_STENCIL].Renderbuffer) {
 927          return GL_FALSE;
 928       }
 929       /*
 930       ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);
 931       ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);
 932       */
 933       break;
 934    default:
 935       _mesa_problem(ctx,
 936                     "Unexpected format 0x%x in _mesa_source_buffer_exists",
 937                     format);
 938       return GL_FALSE;
 939    }
 940
 941    /* OK */
 942    return GL_TRUE;
 943 }
 944
 945
 946 /**
 947  * As above, but for drawing operations.
 948  * XXX could do some code merging w/ above function.
 949  */
 950 GLboolean
 951 _mesa_dest_buffer_exists(struct gl_context *ctx, GLenum format)
 952 {
 953    const struct gl_renderbuffer_attachment *att = ctx->DrawBuffer->Attachment;
 954
 955    /* If we don't know the framebuffer status, update it now */
 956    if (ctx->DrawBuffer->_Status == 0) {
 957       _mesa_test_framebuffer_completeness(ctx, ctx->DrawBuffer);
 958    }
 959
 960    if (ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 961       return GL_FALSE;
 962    }
 963
 964    switch (format) {
 965    case GL_COLOR:
 966    case GL_RED:
 967    case GL_GREEN:
 968    case GL_BLUE:
 969    case GL_ALPHA:
 970    case GL_LUMINANCE:
 971    case GL_LUMINANCE_ALPHA:
 972    case GL_INTENSITY:
 973    case GL_RGB:
 974    case GL_BGR:
 975    case GL_RGBA:
 976    case GL_BGRA:
 977    case GL_ABGR_EXT:
 978    case GL_COLOR_INDEX:
 979    case GL_RED_INTEGER_EXT:
 980    case GL_GREEN_INTEGER_EXT:
 981    case GL_BLUE_INTEGER_EXT:
 982    case GL_ALPHA_INTEGER_EXT:
 983    case GL_RGB_INTEGER_EXT:
 984    case GL_RGBA_INTEGER_EXT:
 985    case GL_BGR_INTEGER_EXT:
 986    case GL_BGRA_INTEGER_EXT:
 987    case GL_LUMINANCE_INTEGER_EXT:
 988    case GL_LUMINANCE_ALPHA_INTEGER_EXT:
 989       /* Nothing special since GL_DRAW_BUFFER could be GL_NONE. */
 990       /* Could assert that colorbuffer has RedBits > 0 */
 991       break;
 992    case GL_DEPTH:
 993    case GL_DEPTH_COMPONENT:
 994       if (!att[BUFFER_DEPTH].Renderbuffer) {
 995          return GL_FALSE;
 996       }
 997       /*ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);*/
 998       break;
 999    case GL_STENCIL:
1000    case GL_STENCIL_INDEX:
1001       if (!att[BUFFER_STENCIL].Renderbuffer) {
1002          return GL_FALSE;
1003       }
1004       /*ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);*/
1005       break;
1006    case GL_DEPTH_STENCIL_EXT:
1007       if (!att[BUFFER_DEPTH].Renderbuffer ||
1008           !att[BUFFER_STENCIL].Renderbuffer) {
1009          return GL_FALSE;
1010       }
1011       /*
1012       ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);
1013       ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);
1014       */
1015       break;
1016    default:
1017       _mesa_problem(ctx,
1018                     "Unexpected format 0x%x in _mesa_dest_buffer_exists",
1019                     format);
1020       return GL_FALSE;
1021    }
1022
1023    /* OK */
1024    return GL_TRUE;
1025 }
1026
1027
1028 /**
1029  * Used to answer the GL_IMPLEMENTATION_COLOR_READ_FORMAT_OES query.
1030  */
1031 GLenum
1032 _mesa_get_color_read_format(struct gl_context *ctx)
1033 {
1034    switch (ctx->ReadBuffer->_ColorReadBuffer->Format) {
1035    case MESA_FORMAT_ARGB8888:
1036       return GL_BGRA;
1037    case MESA_FORMAT_RGB565:
1038       return GL_BGR;
1039    default:
1040       return GL_RGBA;
1041    }
1042 }
1043
1044
1045 /**
1046  * Used to answer the GL_IMPLEMENTATION_COLOR_READ_TYPE_OES query.
1047  */
1048 GLenum
1049 _mesa_get_color_read_type(struct gl_context *ctx)
1050 {
1051    switch (ctx->ReadBuffer->_ColorReadBuffer->Format) {
1052    case MESA_FORMAT_ARGB8888:
1053       return GL_UNSIGNED_BYTE;
1054    case MESA_FORMAT_RGB565:
1055       return GL_UNSIGNED_SHORT_5_6_5_REV;
1056    default:
1057       return GL_UNSIGNED_BYTE;
1058    }
1059 }
1060
1061
1062 /**
1063  * Print framebuffer info to stderr, for debugging.
1064  */
1065 void
1066 _mesa_print_framebuffer(const struct gl_framebuffer *fb)
1067 {
1068    GLuint i;
1069
1070    fprintf(stderr, "Mesa Framebuffer %u at %p\n", fb->Name, (void *) fb);
1071    fprintf(stderr, "  Size: %u x %u  Status: %s\n", fb->Width, fb->Height,
1072            _mesa_lookup_enum_by_nr(fb->_Status));
1073    fprintf(stderr, "  Attachments:\n");
1074
1075    for (i = 0; i < BUFFER_COUNT; i++) {
1076       const struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
1077       if (att->Type == GL_TEXTURE) {
1078          const struct gl_texture_image *texImage =
1079             _mesa_get_attachment_teximage_const(att);
1080          fprintf(stderr,
1081                  "  %2d: Texture %u, level %u, face %u, slice %u, complete %d\n",
1082                  i, att->Texture->Name, att->TextureLevel, att->CubeMapFace,
1083                  att->Zoffset, att->Complete);
1084          fprintf(stderr, "       Size: %u x %u x %u  Format %s\n",
1085                  texImage->Width, texImage->Height, texImage->Depth,
1086                  _mesa_get_format_name(texImage->TexFormat));
1087       }
1088       else if (att->Type == GL_RENDERBUFFER) {
1089          fprintf(stderr, "  %2d: Renderbuffer %u, complete %d\n",
1090                  i, att->Renderbuffer->Name, att->Complete);
1091          fprintf(stderr, "       Size: %u x %u  Format %s\n",
1092                  att->Renderbuffer->Width, att->Renderbuffer->Height,
1093                  _mesa_get_format_name(att->Renderbuffer->Format));
1094       }
1095       else {
1096          fprintf(stderr, "  %2d: none\n", i);
1097       }
1098    }
1099 }