reactos/dll/opengl/mesa/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 "enums.h"
  38 #include "formats.h"
  39 #include "macros.h"
  40 #include "mtypes.h"
  41 #include "fbobject.h"
  42 #include "framebuffer.h"
  43 #include "renderbuffer.h"
  44 #include "texobj.h"
  45
  46
  47
  48 /**
  49  * Compute/set the _DepthMax field for the given framebuffer.
  50  * This value depends on the Z buffer resolution.
  51  */
  52 static void
  53 compute_depth_max(struct gl_framebuffer *fb)
  54 {
  55    if (fb->Visual.depthBits == 0) {
  56       /* Special case.  Even if we don't have a depth buffer we need
  57        * good values for DepthMax for Z vertex transformation purposes
  58        * and for per-fragment fog computation.
  59        */
  60       fb->_DepthMax = (1 << 16) - 1;
  61    }
  62    else if (fb->Visual.depthBits < 32) {
  63       fb->_DepthMax = (1 << fb->Visual.depthBits) - 1;
  64    }
  65    else {
  66       /* Special case since shift values greater than or equal to the
  67        * number of bits in the left hand expression's type are undefined.
  68        */
  69       fb->_DepthMax = 0xffffffff;
  70    }
  71    fb->_DepthMaxF = (GLfloat) fb->_DepthMax;
  72
  73    /* Minimum resolvable depth value, for polygon offset */
  74    fb->_MRD = (GLfloat)1.0 / fb->_DepthMaxF;
  75 }
  76
  77 /**
  78  * Create and initialize a gl_framebuffer object.
  79  * This is intended for creating _window_system_ framebuffers, not generic
  80  * framebuffer objects ala GL_EXT_framebuffer_object.
  81  *
  82  * \sa _mesa_new_framebuffer
  83  */
  84 struct gl_framebuffer *
  85 _mesa_create_framebuffer(const struct gl_config *visual)
  86 {
  87    struct gl_framebuffer *fb = CALLOC_STRUCT(gl_framebuffer);
  88    assert(visual);
  89    if (fb) {
  90       _mesa_initialize_window_framebuffer(fb, visual);
  91    }
  92    return fb;
  93 }
  94
  95
  96 /**
  97  * Allocate a new gl_framebuffer object.
  98  * This is the default function for ctx->Driver.NewFramebuffer().
  99  * This is for allocating user-created framebuffers, not window-system
 100  * framebuffers!
 101  * \sa _mesa_create_framebuffer
 102  */
 103 struct gl_framebuffer *
 104 _mesa_new_framebuffer(struct gl_context *ctx, GLuint name)
 105 {
 106    struct gl_framebuffer *fb;
 107    (void) ctx;
 108    assert(name != 0);
 109    fb = CALLOC_STRUCT(gl_framebuffer);
 110    if (fb) {
 111       _mesa_initialize_user_framebuffer(fb, name);
 112    }
 113    return fb;
 114 }
 115
 116
 117 /**
 118  * Initialize a gl_framebuffer object.  Typically used to initialize
 119  * window system-created framebuffers, not user-created framebuffers.
 120  * \sa _mesa_initialize_user_framebuffer
 121  */
 122 void
 123 _mesa_initialize_window_framebuffer(struct gl_framebuffer *fb,
 124                                      const struct gl_config *visual)
 125 {
 126    assert(fb);
 127    assert(visual);
 128
 129    memset(fb, 0, sizeof(struct gl_framebuffer));
 130
 131    _glthread_INIT_MUTEX(fb->Mutex);
 132
 133    fb->RefCount = 1;
 134
 135    /* save the visual */
 136    fb->Visual = *visual;
 137
 138    /* Init read/draw renderbuffer state */
 139    if (visual->doubleBufferMode) {
 140       fb->ColorDrawBuffer = GL_BACK;
 141       fb->_ColorDrawBufferIndex = BUFFER_BACK_LEFT;
 142       fb->ColorReadBuffer = GL_BACK;
 143       fb->_ColorReadBufferIndex = BUFFER_BACK_LEFT;
 144    }
 145    else {
 146       fb->ColorDrawBuffer = GL_FRONT;
 147       fb->_ColorDrawBufferIndex = BUFFER_FRONT_LEFT;
 148       fb->ColorReadBuffer = GL_FRONT;
 149       fb->_ColorReadBufferIndex = BUFFER_FRONT_LEFT;
 150    }
 151
 152    fb->Delete = _mesa_destroy_framebuffer;
 153    fb->_Status = GL_FRAMEBUFFER_COMPLETE_EXT;
 154
 155    compute_depth_max(fb);
 156 }
 157
 158
 159 /**
 160  * Initialize a user-created gl_framebuffer object.
 161  * \sa _mesa_initialize_window_framebuffer
 162  */
 163 void
 164 _mesa_initialize_user_framebuffer(struct gl_framebuffer *fb, GLuint name)
 165 {
 166    assert(fb);
 167    assert(name);
 168
 169    memset(fb, 0, sizeof(struct gl_framebuffer));
 170
 171    fb->Name = name;
 172    fb->RefCount = 1;
 173    fb->ColorDrawBuffer = GL_COLOR_ATTACHMENT0_EXT;
 174    fb->_ColorDrawBufferIndex = BUFFER_COLOR0;
 175    fb->ColorReadBuffer = GL_COLOR_ATTACHMENT0_EXT;
 176    fb->_ColorReadBufferIndex = BUFFER_COLOR0;
 177    fb->Delete = _mesa_destroy_framebuffer;
 178    _glthread_INIT_MUTEX(fb->Mutex);
 179 }
 180
 181
 182 /**
 183  * Deallocate buffer and everything attached to it.
 184  * Typically called via the gl_framebuffer->Delete() method.
 185  */
 186 void
 187 _mesa_destroy_framebuffer(struct gl_framebuffer *fb)
 188 {
 189    if (fb) {
 190       _mesa_free_framebuffer_data(fb);
 191       free(fb);
 192    }
 193 }
 194
 195
 196 /**
 197  * Free all the data hanging off the given gl_framebuffer, but don't free
 198  * the gl_framebuffer object itself.
 199  */
 200 void
 201 _mesa_free_framebuffer_data(struct gl_framebuffer *fb)
 202 {
 203    GLuint i;
 204
 205    assert(fb);
 206    assert(fb->RefCount == 0);
 207
 208    _glthread_DESTROY_MUTEX(fb->Mutex);
 209
 210    for (i = 0; i < BUFFER_COUNT; i++) {
 211       struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 212       if (att->Renderbuffer) {
 213          _mesa_reference_renderbuffer(&att->Renderbuffer, NULL);
 214       }
 215       if (att->Texture) {
 216          _mesa_reference_texobj(&att->Texture, NULL);
 217       }
 218       ASSERT(!att->Renderbuffer);
 219       ASSERT(!att->Texture);
 220       att->Type = GL_NONE;
 221    }
 222 }
 223
 224
 225 /**
 226  * Set *ptr to point to fb, with refcounting and locking.
 227  * This is normally only called from the _mesa_reference_framebuffer() macro
 228  * when there's a real pointer change.
 229  */
 230 void
 231 _mesa_reference_framebuffer_(struct gl_framebuffer **ptr,
 232                              struct gl_framebuffer *fb)
 233 {
 234    if (*ptr) {
 235       /* unreference old renderbuffer */
 236       GLboolean deleteFlag = GL_FALSE;
 237       struct gl_framebuffer *oldFb = *ptr;
 238
 239       _glthread_LOCK_MUTEX(oldFb->Mutex);
 240       ASSERT(oldFb->RefCount > 0);
 241       oldFb->RefCount--;
 242       deleteFlag = (oldFb->RefCount == 0);
 243       _glthread_UNLOCK_MUTEX(oldFb->Mutex);
 244
 245       if (deleteFlag)
 246          oldFb->Delete(oldFb);
 247
 248       *ptr = NULL;
 249    }
 250    assert(!*ptr);
 251
 252    if (fb) {
 253       _glthread_LOCK_MUTEX(fb->Mutex);
 254       fb->RefCount++;
 255       _glthread_UNLOCK_MUTEX(fb->Mutex);
 256       *ptr = fb;
 257    }
 258 }
 259
 260
 261 /**
 262  * Resize the given framebuffer's renderbuffers to the new width and height.
 263  * This should only be used for window-system framebuffers, not
 264  * user-created renderbuffers (i.e. made with GL_EXT_framebuffer_object).
 265  * This will typically be called via ctx->Driver.ResizeBuffers() or directly
 266  * from a device driver.
 267  *
 268  * \note it's possible for ctx to be null since a window can be resized
 269  * without a currently bound rendering context.
 270  */
 271 void
 272 _mesa_resize_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
 273                          GLuint width, GLuint height)
 274 {
 275    GLuint i;
 276
 277    /* XXX I think we could check if the size is not changing
 278     * and return early.
 279     */
 280
 281    /* For window system framebuffers, Name is zero */
 282    assert(fb->Name == 0);
 283
 284    for (i = 0; i < BUFFER_COUNT; i++) {
 285       struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 286       if (att->Type == GL_RENDERBUFFER_EXT && att->Renderbuffer) {
 287          struct gl_renderbuffer *rb = att->Renderbuffer;
 288          /* only resize if size is changing */
 289          if (rb->Width != width || rb->Height != height) {
 290             if (rb->AllocStorage(ctx, rb, rb->InternalFormat, width, height)) {
 291                ASSERT(rb->Width == width);
 292                ASSERT(rb->Height == height);
 293             }
 294             else {
 295                _mesa_error(ctx, GL_OUT_OF_MEMORY, "Resizing framebuffer");
 296                /* no return */
 297             }
 298          }
 299       }
 300    }
 301
 302    fb->Width = width;
 303    fb->Height = height;
 304
 305    if (ctx) {
 306       /* update scissor / window bounds */
 307       _mesa_update_draw_buffer_bounds(ctx);
 308       /* Signal new buffer state so that swrast will update its clipping
 309        * info (the CLIP_BIT flag).
 310        */
 311       ctx->NewState |= _NEW_BUFFERS;
 312    }
 313 }
 314
 315
 316
 317 /**
 318  * XXX THIS IS OBSOLETE - drivers should take care of detecting window
 319  * size changes and act accordingly, likely calling _mesa_resize_framebuffer().
 320  *
 321  * GL_MESA_resize_buffers extension.
 322  *
 323  * When this function is called, we'll ask the window system how large
 324  * the current window is.  If it's a new size, we'll call the driver's
 325  * ResizeBuffers function.  The driver will then resize its color buffers
 326  * as needed, and maybe call the swrast's routine for reallocating
 327  * swrast-managed depth/stencil/accum/etc buffers.
 328  * \note This function should only be called through the GL API, not
 329  * from device drivers (as was done in the past).
 330  */
 331 void
 332 _mesa_resizebuffers( struct gl_context *ctx )
 333 {
 334    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx );
 335
 336    if (MESA_VERBOSE & VERBOSE_API)
 337       _mesa_debug(ctx, "glResizeBuffersMESA\n");
 338
 339    if (!ctx->Driver.GetBufferSize) {
 340       return;
 341    }
 342
 343    if (ctx->WinSysDrawBuffer) {
 344       GLuint newWidth, newHeight;
 345       struct gl_framebuffer *buffer = ctx->WinSysDrawBuffer;
 346
 347       assert(buffer->Name == 0);
 348
 349       /* ask device driver for size of output buffer */
 350       ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight );
 351
 352       /* see if size of device driver's color buffer (window) has changed */
 353       if (buffer->Width != newWidth || buffer->Height != newHeight) {
 354          if (ctx->Driver.ResizeBuffers)
 355             ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight );
 356       }
 357    }
 358
 359    if (ctx->WinSysReadBuffer
 360        && ctx->WinSysReadBuffer != ctx->WinSysDrawBuffer) {
 361       GLuint newWidth, newHeight;
 362       struct gl_framebuffer *buffer = ctx->WinSysReadBuffer;
 363
 364       assert(buffer->Name == 0);
 365
 366       /* ask device driver for size of read buffer */
 367       ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight );
 368
 369       /* see if size of device driver's color buffer (window) has changed */
 370       if (buffer->Width != newWidth || buffer->Height != newHeight) {
 371          if (ctx->Driver.ResizeBuffers)
 372             ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight );
 373       }
 374    }
 375
 376    ctx->NewState |= _NEW_BUFFERS;  /* to update scissor / window bounds */
 377 }
 378
 379
 380 /*
 381  * XXX THIS IS OBSOLETE
 382  */
 383 void GLAPIENTRY
 384 _mesa_ResizeBuffersMESA( void )
 385 {
 386    GET_CURRENT_CONTEXT(ctx);
 387
 388    if (ctx->Extensions.MESA_resize_buffers)
 389       _mesa_resizebuffers( ctx );
 390 }
 391
 392
 393
 394 /**
 395  * Examine all the framebuffer's renderbuffers to update the Width/Height
 396  * fields of the framebuffer.  If we have renderbuffers with different
 397  * sizes, set the framebuffer's width and height to the min size.
 398  * Note: this is only intended for user-created framebuffers, not
 399  * window-system framebuffes.
 400  */
 401 static void
 402 update_framebuffer_size(struct gl_context *ctx, struct gl_framebuffer *fb)
 403 {
 404    GLuint minWidth = ~0, minHeight = ~0;
 405    GLuint i;
 406
 407    /* user-created framebuffers only */
 408    assert(fb->Name);
 409
 410    for (i = 0; i < BUFFER_COUNT; i++) {
 411       struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 412       const struct gl_renderbuffer *rb = att->Renderbuffer;
 413       if (rb) {
 414          minWidth = MIN2(minWidth, rb->Width);
 415          minHeight = MIN2(minHeight, rb->Height);
 416       }
 417    }
 418
 419    if (minWidth != ~0) {
 420       fb->Width = minWidth;
 421       fb->Height = minHeight;
 422    }
 423    else {
 424       fb->Width = 0;
 425       fb->Height = 0;
 426    }
 427 }
 428
 429
 430 /**
 431  * Update the context's current drawing buffer's Xmin, Xmax, Ymin, Ymax fields.
 432  * These values are computed from the buffer's width and height and
 433  * the scissor box, if it's enabled.
 434  * \param ctx  the GL context.
 435  */
 436 void
 437 _mesa_update_draw_buffer_bounds(struct gl_context *ctx)
 438 {
 439    struct gl_framebuffer *buffer = ctx->DrawBuffer;
 440
 441    if (!buffer)
 442       return;
 443
 444    if (buffer->Name) {
 445       /* user-created framebuffer size depends on the renderbuffers */
 446       update_framebuffer_size(ctx, buffer);
 447    }
 448
 449    buffer->_Xmin = 0;
 450    buffer->_Ymin = 0;
 451    buffer->_Xmax = buffer->Width;
 452    buffer->_Ymax = buffer->Height;
 453
 454    if (ctx->Scissor.Enabled) {
 455       if (ctx->Scissor.X > buffer->_Xmin) {
 456          buffer->_Xmin = ctx->Scissor.X;
 457       }
 458       if (ctx->Scissor.Y > buffer->_Ymin) {
 459          buffer->_Ymin = ctx->Scissor.Y;
 460       }
 461       if (ctx->Scissor.X + ctx->Scissor.Width < buffer->_Xmax) {
 462          buffer->_Xmax = ctx->Scissor.X + ctx->Scissor.Width;
 463       }
 464       if (ctx->Scissor.Y + ctx->Scissor.Height < buffer->_Ymax) {
 465          buffer->_Ymax = ctx->Scissor.Y + ctx->Scissor.Height;
 466       }
 467       /* finally, check for empty region */
 468       if (buffer->_Xmin > buffer->_Xmax) {
 469          buffer->_Xmin = buffer->_Xmax;
 470       }
 471       if (buffer->_Ymin > buffer->_Ymax) {
 472          buffer->_Ymin = buffer->_Ymax;
 473       }
 474    }
 475
 476    ASSERT(buffer->_Xmin <= buffer->_Xmax);
 477    ASSERT(buffer->_Ymin <= buffer->_Ymax);
 478 }
 479
 480
 481 /**
 482  * The glGet queries of the framebuffer red/green/blue size, stencil size,
 483  * etc. are satisfied by the fields of ctx->DrawBuffer->Visual.  These can
 484  * change depending on the renderbuffer bindings.  This function updates
 485  * the given framebuffer's Visual from the current renderbuffer bindings.
 486  *
 487  * This may apply to user-created framebuffers or window system framebuffers.
 488  *
 489  * Also note: ctx->DrawBuffer->Visual.depthBits might not equal
 490  * ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer.DepthBits.
 491  * The former one is used to convert floating point depth values into
 492  * integer Z values.
 493  */
 494 void
 495 _mesa_update_framebuffer_visual(struct gl_context *ctx,
 496                                 struct gl_framebuffer *fb)
 497 {
 498    GLuint i;
 499
 500    memset(&fb->Visual, 0, sizeof(fb->Visual));
 501    fb->Visual.rgbMode = GL_TRUE; /* assume this */
 502
 503 #if 0 /* this _might_ be needed */
 504    if (fb->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 505       /* leave visual fields zero'd */
 506       return;
 507    }
 508 #endif
 509
 510    /* find first RGB renderbuffer */
 511    for (i = 0; i < BUFFER_COUNT; i++) {
 512       if (fb->Attachment[i].Renderbuffer) {
 513          const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
 514          const GLenum baseFormat = _mesa_get_format_base_format(rb->Format);
 515          const gl_format fmt = rb->Format;
 516
 517          if (_mesa_is_legal_color_format(ctx, baseFormat)) {
 518             fb->Visual.redBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
 519             fb->Visual.greenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
 520             fb->Visual.blueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
 521             fb->Visual.alphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
 522             fb->Visual.rgbBits = fb->Visual.redBits
 523                + fb->Visual.greenBits + fb->Visual.blueBits;
 524             fb->Visual.samples = rb->NumSamples;
 525             fb->Visual.sampleBuffers = rb->NumSamples > 0 ? 1 : 0;
 526             break;
 527          }
 528       }
 529    }
 530
 531    fb->Visual.floatMode = GL_FALSE;
 532    for (i = 0; i < BUFFER_COUNT; i++) {
 533       if (fb->Attachment[i].Renderbuffer) {
 534          const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
 535          const gl_format fmt = rb->Format;
 536
 537          if (_mesa_get_format_datatype(fmt) == GL_FLOAT) {
 538             fb->Visual.floatMode = GL_TRUE;
 539             break;
 540          }
 541       }
 542    }
 543
 544    if (fb->Attachment[BUFFER_DEPTH].Renderbuffer) {
 545       const struct gl_renderbuffer *rb =
 546          fb->Attachment[BUFFER_DEPTH].Renderbuffer;
 547       const gl_format fmt = rb->Format;
 548       fb->Visual.haveDepthBuffer = GL_TRUE;
 549       fb->Visual.depthBits = _mesa_get_format_bits(fmt, GL_DEPTH_BITS);
 550    }
 551
 552    if (fb->Attachment[BUFFER_STENCIL].Renderbuffer) {
 553       const struct gl_renderbuffer *rb =
 554          fb->Attachment[BUFFER_STENCIL].Renderbuffer;
 555       const gl_format fmt = rb->Format;
 556       fb->Visual.haveStencilBuffer = GL_TRUE;
 557       fb->Visual.stencilBits = _mesa_get_format_bits(fmt, GL_STENCIL_BITS);
 558    }
 559
 560    if (fb->Attachment[BUFFER_ACCUM].Renderbuffer) {
 561       const struct gl_renderbuffer *rb =
 562          fb->Attachment[BUFFER_ACCUM].Renderbuffer;
 563       const gl_format fmt = rb->Format;
 564       fb->Visual.haveAccumBuffer = GL_TRUE;
 565       fb->Visual.accumRedBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
 566       fb->Visual.accumGreenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
 567       fb->Visual.accumBlueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
 568       fb->Visual.accumAlphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
 569    }
 570
 571    compute_depth_max(fb);
 572 }
 573
 574
 575 /*
 576  * Example DrawBuffers scenarios:
 577  *
 578  * 1. glDrawBuffer(GL_FRONT_AND_BACK), fixed-func or shader writes to
 579  * "gl_FragColor" or program writes to the "result.color" register:
 580  *
 581  *   fragment color output   renderbuffer
 582  *   ---------------------   ---------------
 583  *   color[0]                Front, Back
 584  *
 585  *
 586  * 2. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]), shader writes to
 587  * gl_FragData[i] or program writes to result.color[i] registers:
 588  *
 589  *   fragment color output   renderbuffer
 590  *   ---------------------   ---------------
 591  *   color[0]                Front
 592  *   color[1]                Aux0
 593  *   color[3]                Aux1
 594  *
 595  *
 596  * 3. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]) and shader writes to
 597  * gl_FragColor, or fixed function:
 598  *
 599  *   fragment color output   renderbuffer
 600  *   ---------------------   ---------------
 601  *   color[0]                Front, Aux0, Aux1
 602  *
 603  *
 604  * In either case, the list of renderbuffers is stored in the
 605  * framebuffer->_ColorDrawBuffers[] array and
 606  * framebuffer->_NumColorDrawBuffers indicates the number of buffers.
 607  * The renderer (like swrast) has to look at the current fragment shader
 608  * to see if it writes to gl_FragColor vs. gl_FragData[i] to determine
 609  * how to map color outputs to renderbuffers.
 610  *
 611  * Note that these two calls are equivalent (for fixed function fragment
 612  * shading anyway):
 613  *   a)  glDrawBuffer(GL_FRONT_AND_BACK);  (assuming non-stereo framebuffer)
 614  *   b)  glDrawBuffers(2, [GL_FRONT_LEFT, GL_BACK_LEFT]);
 615  */
 616
 617
 618
 619
 620 /**
 621  * Update the (derived) list of color drawing renderbuffer pointers.
 622  * Later, when we're rendering we'll loop from 0 to _NumColorDrawBuffers
 623  * writing colors.
 624  */
 625 static void
 626 update_color_draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb)
 627 {
 628    GLint buf = fb->_ColorDrawBufferIndex;
 629    if (buf >= 0) {
 630       fb->_ColorDrawBuffer = fb->Attachment[buf].Renderbuffer;
 631    }
 632    else {
 633       fb->_ColorDrawBuffer = NULL;
 634    }
 635 }
 636
 637
 638 /**
 639  * Update the (derived) color read renderbuffer pointer.
 640  * Unlike the DrawBuffer, we can only read from one (or zero) color buffers.
 641  */
 642 static void
 643 update_color_read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 644 {
 645    (void) ctx;
 646    if (fb->_ColorReadBufferIndex == -1 ||
 647        fb->DeletePending ||
 648        fb->Width == 0 ||
 649        fb->Height == 0) {
 650       fb->_ColorReadBuffer = NULL; /* legal! */
 651    }
 652    else {
 653       ASSERT(fb->_ColorReadBufferIndex >= 0);
 654       ASSERT(fb->_ColorReadBufferIndex < BUFFER_COUNT);
 655       fb->_ColorReadBuffer
 656          = fb->Attachment[fb->_ColorReadBufferIndex].Renderbuffer;
 657    }
 658 }
 659
 660
 661 /**
 662  * Update a gl_framebuffer's derived state.
 663  *
 664  * Specifically, update these framebuffer fields:
 665  *    _ColorDrawBuffers
 666  *    _NumColorDrawBuffers
 667  *    _ColorReadBuffer
 668  *
 669  * If the framebuffer is user-created, make sure it's complete.
 670  *
 671  * The following functions (at least) can effect framebuffer state:
 672  * glReadBuffer, glDrawBuffer, glDrawBuffersARB, glFramebufferRenderbufferEXT,
 673  * glRenderbufferStorageEXT.
 674  */
 675 static void
 676 update_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 677 {
 678    if (fb->Name == 0) {
 679       /* This is a window-system framebuffer */
 680       /* Need to update the FB's GL_DRAW_BUFFER state to match the
 681        * context state (GL_READ_BUFFER too).
 682        */
 683       _mesa_drawbuffer(ctx, ctx->Color.DrawBuffer, 0);
 684    }
 685    else {
 686       /* This is a user-created framebuffer.
 687        * Completeness only matters for user-created framebuffers.
 688        */
 689       if (fb->_Status != GL_FRAMEBUFFER_COMPLETE) {
 690          _mesa_test_framebuffer_completeness(ctx, fb);
 691       }
 692    }
 693
 694    /* Strictly speaking, we don't need to update the draw-state
 695     * if this FB is bound as ctx->ReadBuffer (and conversely, the
 696     * read-state if this FB is bound as ctx->DrawBuffer), but no
 697     * harm.
 698     */
 699    update_color_draw_buffers(ctx, fb);
 700    update_color_read_buffer(ctx, fb);
 701
 702    compute_depth_max(fb);
 703 }
 704
 705
 706 /**
 707  * Update state related to the current draw/read framebuffers.
 708  */
 709 void
 710 _mesa_update_framebuffer(struct gl_context *ctx)
 711 {
 712    struct gl_framebuffer *drawFb;
 713    struct gl_framebuffer *readFb;
 714
 715    assert(ctx);
 716    drawFb = ctx->DrawBuffer;
 717    readFb = ctx->ReadBuffer;
 718
 719    update_framebuffer(ctx, drawFb);
 720    if (readFb != drawFb)
 721       update_framebuffer(ctx, readFb);
 722 }
 723
 724
 725 /**
 726  * Check if the renderbuffer for a read/draw operation exists.
 727  * \param format  a basic image format such as GL_RGB, GL_RGBA, GL_ALPHA,
 728  *                GL_DEPTH_COMPONENT, etc. or GL_COLOR, GL_DEPTH, GL_STENCIL.
 729  * \param reading  if TRUE, we're going to read from the buffer,
 730                    if FALSE, we're going to write to the buffer.
 731  * \return GL_TRUE if buffer exists, GL_FALSE otherwise
 732  */
 733 static GLboolean
 734 renderbuffer_exists(struct gl_context *ctx,
 735                     struct gl_framebuffer *fb,
 736                     GLenum format,
 737                     GLboolean reading)
 738 {
 739    const struct gl_renderbuffer_attachment *att = fb->Attachment;
 740
 741    /* If we don't know the framebuffer status, update it now */
 742    if (fb->_Status == 0) {
 743       _mesa_test_framebuffer_completeness(ctx, fb);
 744    }
 745
 746    if (fb->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 747       return GL_FALSE;
 748    }
 749
 750    switch (format) {
 751    case GL_COLOR:
 752    case GL_RED:
 753    case GL_GREEN:
 754    case GL_BLUE:
 755    case GL_ALPHA:
 756    case GL_LUMINANCE:
 757    case GL_LUMINANCE_ALPHA:
 758    case GL_INTENSITY:
 759    case GL_RG:
 760    case GL_RGB:
 761    case GL_BGR:
 762    case GL_RGBA:
 763    case GL_BGRA:
 764    case GL_ABGR_EXT:
 765    case GL_RED_INTEGER_EXT:
 766    case GL_RG_INTEGER:
 767    case GL_GREEN_INTEGER_EXT:
 768    case GL_BLUE_INTEGER_EXT:
 769    case GL_ALPHA_INTEGER_EXT:
 770    case GL_RGB_INTEGER_EXT:
 771    case GL_RGBA_INTEGER_EXT:
 772    case GL_BGR_INTEGER_EXT:
 773    case GL_BGRA_INTEGER_EXT:
 774    case GL_LUMINANCE_INTEGER_EXT:
 775    case GL_LUMINANCE_ALPHA_INTEGER_EXT:
 776       if (reading) {
 777          /* about to read from a color buffer */
 778          const struct gl_renderbuffer *readBuf = fb->_ColorReadBuffer;
 779          if (!readBuf) {
 780             return GL_FALSE;
 781          }
 782          ASSERT(_mesa_get_format_bits(readBuf->Format, GL_RED_BITS) > 0 ||
 783                 _mesa_get_format_bits(readBuf->Format, GL_ALPHA_BITS) > 0 ||
 784                 _mesa_get_format_bits(readBuf->Format, GL_TEXTURE_LUMINANCE_SIZE) > 0 ||
 785                 _mesa_get_format_bits(readBuf->Format, GL_TEXTURE_INTENSITY_SIZE) > 0 ||
 786                 _mesa_get_format_bits(readBuf->Format, GL_INDEX_BITS) > 0);
 787       }
 788       else {
 789          /* about to draw to zero or more color buffers (none is OK) */
 790          return GL_TRUE;
 791       }
 792       break;
 793    case GL_DEPTH:
 794    case GL_DEPTH_COMPONENT:
 795       if (att[BUFFER_DEPTH].Type == GL_NONE) {
 796          return GL_FALSE;
 797       }
 798       break;
 799    case GL_STENCIL:
 800    case GL_STENCIL_INDEX:
 801       if (att[BUFFER_STENCIL].Type == GL_NONE) {
 802          return GL_FALSE;
 803       }
 804       break;
 805    default:
 806       _mesa_problem(ctx,
 807                     "Unexpected format 0x%x in renderbuffer_exists",
 808                     format);
 809       return GL_FALSE;
 810    }
 811
 812    /* OK */
 813    return GL_TRUE;
 814 }
 815
 816
 817 /**
 818  * Check if the renderbuffer for a read operation (glReadPixels, glCopyPixels,
 819  * glCopyTex[Sub]Image, etc) exists.
 820  * \param format  a basic image format such as GL_RGB, GL_RGBA, GL_ALPHA,
 821  *                GL_DEPTH_COMPONENT, etc. or GL_COLOR, GL_DEPTH, GL_STENCIL.
 822  * \return GL_TRUE if buffer exists, GL_FALSE otherwise
 823  */
 824 GLboolean
 825 _mesa_source_buffer_exists(struct gl_context *ctx, GLenum format)
 826 {
 827    return renderbuffer_exists(ctx, ctx->ReadBuffer, format, GL_TRUE);
 828 }
 829
 830
 831 /**
 832  * As above, but for drawing operations.
 833  * XXX could do some code merging w/ above function.
 834  */
 835 GLboolean
 836 _mesa_dest_buffer_exists(struct gl_context *ctx, GLenum format)
 837 {
 838    return renderbuffer_exists(ctx, ctx->DrawBuffer, format, GL_FALSE);
 839 }
 840
 841
 842 /**
 843  * Used to answer the GL_IMPLEMENTATION_COLOR_READ_FORMAT_OES query.
 844  */
 845 GLenum
 846 _mesa_get_color_read_format(struct gl_context *ctx)
 847 {
 848    switch (ctx->ReadBuffer->_ColorReadBuffer->Format) {
 849    case MESA_FORMAT_ARGB8888:
 850       return GL_BGRA;
 851    case MESA_FORMAT_RGB565:
 852       return GL_BGR;
 853    default:
 854       return GL_RGBA;
 855    }
 856 }
 857
 858
 859 /**
 860  * Used to answer the GL_IMPLEMENTATION_COLOR_READ_TYPE_OES query.
 861  */
 862 GLenum
 863 _mesa_get_color_read_type(struct gl_context *ctx)
 864 {
 865    switch (ctx->ReadBuffer->_ColorReadBuffer->Format) {
 866    case MESA_FORMAT_ARGB8888:
 867       return GL_UNSIGNED_BYTE;
 868    case MESA_FORMAT_RGB565:
 869       return GL_UNSIGNED_SHORT_5_6_5_REV;
 870    default:
 871       return GL_UNSIGNED_BYTE;
 872    }
 873 }
 874
 875
 876 /**
 877  * Print framebuffer info to stderr, for debugging.
 878  */
 879 void
 880 _mesa_print_framebuffer(const struct gl_framebuffer *fb)
 881 {
 882    GLuint i;
 883
 884    fprintf(stderr, "Mesa Framebuffer %u at %p\n", fb->Name, (void *) fb);
 885    fprintf(stderr, "  Size: %u x %u  Status: %s\n", fb->Width, fb->Height,
 886            _mesa_lookup_enum_by_nr(fb->_Status));
 887    fprintf(stderr, "  Attachments:\n");
 888
 889    for (i = 0; i < BUFFER_COUNT; i++) {
 890       const struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 891       if (att->Type == GL_TEXTURE) {
 892          const struct gl_texture_image *texImage =
 893             _mesa_get_attachment_teximage_const(att);
 894          fprintf(stderr,
 895                  "  %2d: Texture %u, level %u, face %u, slice %u, complete %d\n",
 896                  i, att->Texture->Name, att->TextureLevel, att->CubeMapFace,
 897                  att->Zoffset, att->Complete);
 898          fprintf(stderr, "       Size: %u x %u x %u  Format %s\n",
 899                  texImage->Width, texImage->Height, texImage->Depth,
 900                  _mesa_get_format_name(texImage->TexFormat));
 901       }
 902       else if (att->Type == GL_RENDERBUFFER) {
 903          fprintf(stderr, "  %2d: Renderbuffer %u, complete %d\n",
 904                  i, att->Renderbuffer->Name, att->Complete);
 905          fprintf(stderr, "       Size: %u x %u  Format %s\n",
 906                  att->Renderbuffer->Width, att->Renderbuffer->Height,
 907                  _mesa_get_format_name(att->Renderbuffer->Format));
 908       }
 909       else {
 910          fprintf(stderr, "  %2d: none\n", i);
 911       }
 912    }
 913 }