src/mesa/main/framebuffer.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * 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 "blend.h"
  36 #include "buffers.h"
  37 #include "context.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 #include "glformats.h"
  47
  48
  49
  50 /**
  51  * Compute/set the _DepthMax field for the given framebuffer.
  52  * This value depends on the Z buffer resolution.
  53  */
  54 static void
  55 compute_depth_max(struct gl_framebuffer *fb)
  56 {
  57    if (fb->Visual.depthBits == 0) {
  58       /* Special case.  Even if we don't have a depth buffer we need
  59        * good values for DepthMax for Z vertex transformation purposes
  60        * and for per-fragment fog computation.
  61        */
  62       fb->_DepthMax = (1 << 16) - 1;
  63    }
  64    else if (fb->Visual.depthBits < 32) {
  65       fb->_DepthMax = (1 << fb->Visual.depthBits) - 1;
  66    }
  67    else {
  68       /* Special case since shift values greater than or equal to the
  69        * number of bits in the left hand expression's type are undefined.
  70        */
  71       fb->_DepthMax = 0xffffffff;
  72    }
  73    fb->_DepthMaxF = (GLfloat) fb->_DepthMax;
  74
  75    /* Minimum resolvable depth value, for polygon offset */
  76    fb->_MRD = (GLfloat)1.0 / fb->_DepthMaxF;
  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 struct gl_config *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(struct gl_context *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 struct gl_config *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    fb->_AllColorBuffersFixedPoint = !visual->floatMode;
 159    fb->_HasSNormOrFloatColorBuffer = visual->floatMode;
 160
 161    compute_depth_max(fb);
 162 }
 163
 164
 165 /**
 166  * Initialize a user-created gl_framebuffer object.
 167  * \sa _mesa_initialize_window_framebuffer
 168  */
 169 void
 170 _mesa_initialize_user_framebuffer(struct gl_framebuffer *fb, GLuint name)
 171 {
 172    assert(fb);
 173    assert(name);
 174
 175    memset(fb, 0, sizeof(struct gl_framebuffer));
 176
 177    fb->Name = name;
 178    fb->RefCount = 1;
 179    fb->_NumColorDrawBuffers = 1;
 180    fb->ColorDrawBuffer[0] = GL_COLOR_ATTACHMENT0_EXT;
 181    fb->_ColorDrawBufferIndexes[0] = BUFFER_COLOR0;
 182    fb->ColorReadBuffer = GL_COLOR_ATTACHMENT0_EXT;
 183    fb->_ColorReadBufferIndex = BUFFER_COLOR0;
 184    fb->Delete = _mesa_destroy_framebuffer;
 185    _glthread_INIT_MUTEX(fb->Mutex);
 186 }
 187
 188
 189 /**
 190  * Deallocate buffer and everything attached to it.
 191  * Typically called via the gl_framebuffer->Delete() method.
 192  */
 193 void
 194 _mesa_destroy_framebuffer(struct gl_framebuffer *fb)
 195 {
 196    if (fb) {
 197       _mesa_free_framebuffer_data(fb);
 198       free(fb->Label);
 199       free(fb);
 200    }
 201 }
 202
 203
 204 /**
 205  * Free all the data hanging off the given gl_framebuffer, but don't free
 206  * the gl_framebuffer object itself.
 207  */
 208 void
 209 _mesa_free_framebuffer_data(struct gl_framebuffer *fb)
 210 {
 211    GLuint i;
 212
 213    assert(fb);
 214    assert(fb->RefCount == 0);
 215
 216    _glthread_DESTROY_MUTEX(fb->Mutex);
 217
 218    for (i = 0; i < BUFFER_COUNT; i++) {
 219       struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 220       if (att->Renderbuffer) {
 221          _mesa_reference_renderbuffer(&att->Renderbuffer, NULL);
 222       }
 223       if (att->Texture) {
 224          _mesa_reference_texobj(&att->Texture, NULL);
 225       }
 226       ASSERT(!att->Renderbuffer);
 227       ASSERT(!att->Texture);
 228       att->Type = GL_NONE;
 229    }
 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    /* Can only resize win-sys framebuffer objects */
 290    assert(_mesa_is_winsys_fbo(fb));
 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    fb->Width = width;
 311    fb->Height = height;
 312
 313    if (ctx) {
 314       /* update scissor / window bounds */
 315       _mesa_update_draw_buffer_bounds(ctx);
 316       /* Signal new buffer state so that swrast will update its clipping
 317        * info (the CLIP_BIT flag).
 318        */
 319       ctx->NewState |= _NEW_BUFFERS;
 320    }
 321 }
 322
 323 /**
 324  * Examine all the framebuffer's renderbuffers to update the Width/Height
 325  * fields of the framebuffer.  If we have renderbuffers with different
 326  * sizes, set the framebuffer's width and height to the min size.
 327  * Note: this is only intended for user-created framebuffers, not
 328  * window-system framebuffes.
 329  */
 330 static void
 331 update_framebuffer_size(struct gl_context *ctx, struct gl_framebuffer *fb)
 332 {
 333    GLuint minWidth = ~0, minHeight = ~0;
 334    GLuint i;
 335
 336    /* user-created framebuffers only */
 337    assert(_mesa_is_user_fbo(fb));
 338
 339    for (i = 0; i < BUFFER_COUNT; i++) {
 340       struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 341       const struct gl_renderbuffer *rb = att->Renderbuffer;
 342       if (rb) {
 343          minWidth = MIN2(minWidth, rb->Width);
 344          minHeight = MIN2(minHeight, rb->Height);
 345       }
 346    }
 347
 348    if (minWidth != ~0) {
 349       fb->Width = minWidth;
 350       fb->Height = minHeight;
 351    }
 352    else {
 353       fb->Width = 0;
 354       fb->Height = 0;
 355    }
 356 }
 357
 358
 359 /**
 360  * Update the context's current drawing buffer's Xmin, Xmax, Ymin, Ymax fields.
 361  * These values are computed from the buffer's width and height and
 362  * the scissor box, if it's enabled.
 363  * \param ctx  the GL context.
 364  */
 365 void
 366 _mesa_update_draw_buffer_bounds(struct gl_context *ctx)
 367 {
 368    struct gl_framebuffer *buffer = ctx->DrawBuffer;
 369
 370    if (!buffer)
 371       return;
 372
 373    if (_mesa_is_user_fbo(buffer)) {
 374       /* user-created framebuffer size depends on the renderbuffers */
 375       update_framebuffer_size(ctx, buffer);
 376    }
 377
 378    buffer->_Xmin = 0;
 379    buffer->_Ymin = 0;
 380    buffer->_Xmax = buffer->Width;
 381    buffer->_Ymax = buffer->Height;
 382
 383    if (ctx->Scissor.Enabled) {
 384       if (ctx->Scissor.X > buffer->_Xmin) {
 385          buffer->_Xmin = ctx->Scissor.X;
 386       }
 387       if (ctx->Scissor.Y > buffer->_Ymin) {
 388          buffer->_Ymin = ctx->Scissor.Y;
 389       }
 390       if (ctx->Scissor.X + ctx->Scissor.Width < buffer->_Xmax) {
 391          buffer->_Xmax = ctx->Scissor.X + ctx->Scissor.Width;
 392       }
 393       if (ctx->Scissor.Y + ctx->Scissor.Height < buffer->_Ymax) {
 394          buffer->_Ymax = ctx->Scissor.Y + ctx->Scissor.Height;
 395       }
 396       /* finally, check for empty region */
 397       if (buffer->_Xmin > buffer->_Xmax) {
 398          buffer->_Xmin = buffer->_Xmax;
 399       }
 400       if (buffer->_Ymin > buffer->_Ymax) {
 401          buffer->_Ymin = buffer->_Ymax;
 402       }
 403    }
 404
 405    ASSERT(buffer->_Xmin <= buffer->_Xmax);
 406    ASSERT(buffer->_Ymin <= buffer->_Ymax);
 407 }
 408
 409
 410 /**
 411  * The glGet queries of the framebuffer red/green/blue size, stencil size,
 412  * etc. are satisfied by the fields of ctx->DrawBuffer->Visual.  These can
 413  * change depending on the renderbuffer bindings.  This function updates
 414  * the given framebuffer's Visual from the current renderbuffer bindings.
 415  *
 416  * This may apply to user-created framebuffers or window system framebuffers.
 417  *
 418  * Also note: ctx->DrawBuffer->Visual.depthBits might not equal
 419  * ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer.DepthBits.
 420  * The former one is used to convert floating point depth values into
 421  * integer Z values.
 422  */
 423 void
 424 _mesa_update_framebuffer_visual(struct gl_context *ctx,
 425                                 struct gl_framebuffer *fb)
 426 {
 427    GLuint i;
 428
 429    memset(&fb->Visual, 0, sizeof(fb->Visual));
 430    fb->Visual.rgbMode = GL_TRUE; /* assume this */
 431
 432 #if 0 /* this _might_ be needed */
 433    if (fb->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 434       /* leave visual fields zero'd */
 435       return;
 436    }
 437 #endif
 438
 439    /* find first RGB renderbuffer */
 440    for (i = 0; i < BUFFER_COUNT; i++) {
 441       if (fb->Attachment[i].Renderbuffer) {
 442          const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
 443          const GLenum baseFormat = _mesa_get_format_base_format(rb->Format);
 444          const gl_format fmt = rb->Format;
 445
 446          /* Grab samples and sampleBuffers from any attachment point (assuming
 447           * the framebuffer is complete, we'll get the same answer from all
 448           * attachments).
 449           */
 450          fb->Visual.samples = rb->NumSamples;
 451          fb->Visual.sampleBuffers = rb->NumSamples > 0 ? 1 : 0;
 452
 453          if (_mesa_is_legal_color_format(ctx, baseFormat)) {
 454             fb->Visual.redBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
 455             fb->Visual.greenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
 456             fb->Visual.blueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
 457             fb->Visual.alphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
 458             fb->Visual.rgbBits = fb->Visual.redBits
 459                + fb->Visual.greenBits + fb->Visual.blueBits;
 460             if (_mesa_get_format_color_encoding(fmt) == GL_SRGB)
 461                 fb->Visual.sRGBCapable = ctx->Extensions.EXT_framebuffer_sRGB;
 462             break;
 463          }
 464       }
 465    }
 466
 467    fb->Visual.floatMode = GL_FALSE;
 468    for (i = 0; i < BUFFER_COUNT; i++) {
 469       if (fb->Attachment[i].Renderbuffer) {
 470          const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
 471          const gl_format fmt = rb->Format;
 472
 473          if (_mesa_get_format_datatype(fmt) == GL_FLOAT) {
 474             fb->Visual.floatMode = GL_TRUE;
 475             break;
 476          }
 477       }
 478    }
 479
 480    if (fb->Attachment[BUFFER_DEPTH].Renderbuffer) {
 481       const struct gl_renderbuffer *rb =
 482          fb->Attachment[BUFFER_DEPTH].Renderbuffer;
 483       const gl_format fmt = rb->Format;
 484       fb->Visual.haveDepthBuffer = GL_TRUE;
 485       fb->Visual.depthBits = _mesa_get_format_bits(fmt, GL_DEPTH_BITS);
 486    }
 487
 488    if (fb->Attachment[BUFFER_STENCIL].Renderbuffer) {
 489       const struct gl_renderbuffer *rb =
 490          fb->Attachment[BUFFER_STENCIL].Renderbuffer;
 491       const gl_format fmt = rb->Format;
 492       fb->Visual.haveStencilBuffer = GL_TRUE;
 493       fb->Visual.stencilBits = _mesa_get_format_bits(fmt, GL_STENCIL_BITS);
 494    }
 495
 496    if (fb->Attachment[BUFFER_ACCUM].Renderbuffer) {
 497       const struct gl_renderbuffer *rb =
 498          fb->Attachment[BUFFER_ACCUM].Renderbuffer;
 499       const gl_format fmt = rb->Format;
 500       fb->Visual.haveAccumBuffer = GL_TRUE;
 501       fb->Visual.accumRedBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
 502       fb->Visual.accumGreenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
 503       fb->Visual.accumBlueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
 504       fb->Visual.accumAlphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
 505    }
 506
 507    compute_depth_max(fb);
 508 }
 509
 510
 511 /*
 512  * Example DrawBuffers scenarios:
 513  *
 514  * 1. glDrawBuffer(GL_FRONT_AND_BACK), fixed-func or shader writes to
 515  * "gl_FragColor" or program writes to the "result.color" register:
 516  *
 517  *   fragment color output   renderbuffer
 518  *   ---------------------   ---------------
 519  *   color[0]                Front, Back
 520  *
 521  *
 522  * 2. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]), shader writes to
 523  * gl_FragData[i] or program writes to result.color[i] registers:
 524  *
 525  *   fragment color output   renderbuffer
 526  *   ---------------------   ---------------
 527  *   color[0]                Front
 528  *   color[1]                Aux0
 529  *   color[3]                Aux1
 530  *
 531  *
 532  * 3. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]) and shader writes to
 533  * gl_FragColor, or fixed function:
 534  *
 535  *   fragment color output   renderbuffer
 536  *   ---------------------   ---------------
 537  *   color[0]                Front, Aux0, Aux1
 538  *
 539  *
 540  * In either case, the list of renderbuffers is stored in the
 541  * framebuffer->_ColorDrawBuffers[] array and
 542  * framebuffer->_NumColorDrawBuffers indicates the number of buffers.
 543  * The renderer (like swrast) has to look at the current fragment shader
 544  * to see if it writes to gl_FragColor vs. gl_FragData[i] to determine
 545  * how to map color outputs to renderbuffers.
 546  *
 547  * Note that these two calls are equivalent (for fixed function fragment
 548  * shading anyway):
 549  *   a)  glDrawBuffer(GL_FRONT_AND_BACK);  (assuming non-stereo framebuffer)
 550  *   b)  glDrawBuffers(2, [GL_FRONT_LEFT, GL_BACK_LEFT]);
 551  */
 552
 553
 554
 555
 556 /**
 557  * Update the (derived) list of color drawing renderbuffer pointers.
 558  * Later, when we're rendering we'll loop from 0 to _NumColorDrawBuffers
 559  * writing colors.
 560  */
 561 static void
 562 update_color_draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb)
 563 {
 564    GLuint output;
 565
 566    /* set 0th buffer to NULL now in case _NumColorDrawBuffers is zero */
 567    fb->_ColorDrawBuffers[0] = NULL;
 568
 569    for (output = 0; output < fb->_NumColorDrawBuffers; output++) {
 570       GLint buf = fb->_ColorDrawBufferIndexes[output];
 571       if (buf >= 0) {
 572          fb->_ColorDrawBuffers[output] = fb->Attachment[buf].Renderbuffer;
 573       }
 574       else {
 575          fb->_ColorDrawBuffers[output] = NULL;
 576       }
 577    }
 578 }
 579
 580
 581 /**
 582  * Update the (derived) color read renderbuffer pointer.
 583  * Unlike the DrawBuffer, we can only read from one (or zero) color buffers.
 584  */
 585 static void
 586 update_color_read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 587 {
 588    (void) ctx;
 589    if (fb->_ColorReadBufferIndex == -1 ||
 590        fb->DeletePending ||
 591        fb->Width == 0 ||
 592        fb->Height == 0) {
 593       fb->_ColorReadBuffer = NULL; /* legal! */
 594    }
 595    else {
 596       ASSERT(fb->_ColorReadBufferIndex >= 0);
 597       ASSERT(fb->_ColorReadBufferIndex < BUFFER_COUNT);
 598       fb->_ColorReadBuffer
 599          = fb->Attachment[fb->_ColorReadBufferIndex].Renderbuffer;
 600    }
 601 }
 602
 603
 604 /**
 605  * Update a gl_framebuffer's derived state.
 606  *
 607  * Specifically, update these framebuffer fields:
 608  *    _ColorDrawBuffers
 609  *    _NumColorDrawBuffers
 610  *    _ColorReadBuffer
 611  *
 612  * If the framebuffer is user-created, make sure it's complete.
 613  *
 614  * The following functions (at least) can effect framebuffer state:
 615  * glReadBuffer, glDrawBuffer, glDrawBuffersARB, glFramebufferRenderbufferEXT,
 616  * glRenderbufferStorageEXT.
 617  */
 618 static void
 619 update_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 620 {
 621    if (_mesa_is_winsys_fbo(fb)) {
 622       /* This is a window-system framebuffer */
 623       /* Need to update the FB's GL_DRAW_BUFFER state to match the
 624        * context state (GL_READ_BUFFER too).
 625        */
 626       if (fb->ColorDrawBuffer[0] != ctx->Color.DrawBuffer[0]) {
 627          _mesa_drawbuffers(ctx, ctx->Const.MaxDrawBuffers,
 628                            ctx->Color.DrawBuffer, NULL);
 629       }
 630    }
 631    else {
 632       /* This is a user-created framebuffer.
 633        * Completeness only matters for user-created framebuffers.
 634        */
 635       if (fb->_Status != GL_FRAMEBUFFER_COMPLETE) {
 636          _mesa_test_framebuffer_completeness(ctx, fb);
 637       }
 638    }
 639
 640    /* Strictly speaking, we don't need to update the draw-state
 641     * if this FB is bound as ctx->ReadBuffer (and conversely, the
 642     * read-state if this FB is bound as ctx->DrawBuffer), but no
 643     * harm.
 644     */
 645    update_color_draw_buffers(ctx, fb);
 646    update_color_read_buffer(ctx, fb);
 647
 648    compute_depth_max(fb);
 649 }
 650
 651
 652 /**
 653  * Update state related to the current draw/read framebuffers.
 654  */
 655 void
 656 _mesa_update_framebuffer(struct gl_context *ctx)
 657 {
 658    struct gl_framebuffer *drawFb;
 659    struct gl_framebuffer *readFb;
 660
 661    assert(ctx);
 662    drawFb = ctx->DrawBuffer;
 663    readFb = ctx->ReadBuffer;
 664
 665    update_framebuffer(ctx, drawFb);
 666    if (readFb != drawFb)
 667       update_framebuffer(ctx, readFb);
 668
 669    _mesa_update_clamp_vertex_color(ctx);
 670    _mesa_update_clamp_fragment_color(ctx);
 671 }
 672
 673
 674 /**
 675  * Check if the renderbuffer for a read/draw operation exists.
 676  * \param format  a basic image format such as GL_RGB, GL_RGBA, GL_ALPHA,
 677  *                GL_DEPTH_COMPONENT, etc. or GL_COLOR, GL_DEPTH, GL_STENCIL.
 678  * \param reading  if TRUE, we're going to read from the buffer,
 679                    if FALSE, we're going to write to the buffer.
 680  * \return GL_TRUE if buffer exists, GL_FALSE otherwise
 681  */
 682 static GLboolean
 683 renderbuffer_exists(struct gl_context *ctx,
 684                     struct gl_framebuffer *fb,
 685                     GLenum format,
 686                     GLboolean reading)
 687 {
 688    const struct gl_renderbuffer_attachment *att = fb->Attachment;
 689
 690    /* If we don't know the framebuffer status, update it now */
 691    if (fb->_Status == 0) {
 692       _mesa_test_framebuffer_completeness(ctx, fb);
 693    }
 694
 695    if (fb->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 696       return GL_FALSE;
 697    }
 698
 699    switch (format) {
 700    case GL_COLOR:
 701    case GL_RED:
 702    case GL_GREEN:
 703    case GL_BLUE:
 704    case GL_ALPHA:
 705    case GL_LUMINANCE:
 706    case GL_LUMINANCE_ALPHA:
 707    case GL_INTENSITY:
 708    case GL_RG:
 709    case GL_RGB:
 710    case GL_BGR:
 711    case GL_RGBA:
 712    case GL_BGRA:
 713    case GL_ABGR_EXT:
 714    case GL_RED_INTEGER_EXT:
 715    case GL_RG_INTEGER:
 716    case GL_GREEN_INTEGER_EXT:
 717    case GL_BLUE_INTEGER_EXT:
 718    case GL_ALPHA_INTEGER_EXT:
 719    case GL_RGB_INTEGER_EXT:
 720    case GL_RGBA_INTEGER_EXT:
 721    case GL_BGR_INTEGER_EXT:
 722    case GL_BGRA_INTEGER_EXT:
 723    case GL_LUMINANCE_INTEGER_EXT:
 724    case GL_LUMINANCE_ALPHA_INTEGER_EXT:
 725       if (reading) {
 726          /* about to read from a color buffer */
 727          const struct gl_renderbuffer *readBuf = fb->_ColorReadBuffer;
 728          if (!readBuf) {
 729             return GL_FALSE;
 730          }
 731          ASSERT(_mesa_get_format_bits(readBuf->Format, GL_RED_BITS) > 0 ||
 732                 _mesa_get_format_bits(readBuf->Format, GL_ALPHA_BITS) > 0 ||
 733                 _mesa_get_format_bits(readBuf->Format, GL_TEXTURE_LUMINANCE_SIZE) > 0 ||
 734                 _mesa_get_format_bits(readBuf->Format, GL_TEXTURE_INTENSITY_SIZE) > 0 ||
 735                 _mesa_get_format_bits(readBuf->Format, GL_INDEX_BITS) > 0);
 736       }
 737       else {
 738          /* about to draw to zero or more color buffers (none is OK) */
 739          return GL_TRUE;
 740       }
 741       break;
 742    case GL_DEPTH:
 743    case GL_DEPTH_COMPONENT:
 744       if (att[BUFFER_DEPTH].Type == GL_NONE) {
 745          return GL_FALSE;
 746       }
 747       break;
 748    case GL_STENCIL:
 749    case GL_STENCIL_INDEX:
 750       if (att[BUFFER_STENCIL].Type == GL_NONE) {
 751          return GL_FALSE;
 752       }
 753       break;
 754    case GL_DEPTH_STENCIL_EXT:
 755       if (att[BUFFER_DEPTH].Type == GL_NONE ||
 756           att[BUFFER_STENCIL].Type == GL_NONE) {
 757          return GL_FALSE;
 758       }
 759       break;
 760    default:
 761       _mesa_problem(ctx,
 762                     "Unexpected format 0x%x in renderbuffer_exists",
 763                     format);
 764       return GL_FALSE;
 765    }
 766
 767    /* OK */
 768    return GL_TRUE;
 769 }
 770
 771
 772 /**
 773  * Check if the renderbuffer for a read operation (glReadPixels, glCopyPixels,
 774  * glCopyTex[Sub]Image, etc) exists.
 775  * \param format  a basic image format such as GL_RGB, GL_RGBA, GL_ALPHA,
 776  *                GL_DEPTH_COMPONENT, etc. or GL_COLOR, GL_DEPTH, GL_STENCIL.
 777  * \return GL_TRUE if buffer exists, GL_FALSE otherwise
 778  */
 779 GLboolean
 780 _mesa_source_buffer_exists(struct gl_context *ctx, GLenum format)
 781 {
 782    return renderbuffer_exists(ctx, ctx->ReadBuffer, format, GL_TRUE);
 783 }
 784
 785
 786 /**
 787  * As above, but for drawing operations.
 788  */
 789 GLboolean
 790 _mesa_dest_buffer_exists(struct gl_context *ctx, GLenum format)
 791 {
 792    return renderbuffer_exists(ctx, ctx->DrawBuffer, format, GL_FALSE);
 793 }
 794
 795
 796 /**
 797  * Used to answer the GL_IMPLEMENTATION_COLOR_READ_FORMAT_OES query.
 798  */
 799 GLenum
 800 _mesa_get_color_read_format(struct gl_context *ctx)
 801 {
 802    if (!ctx->ReadBuffer || !ctx->ReadBuffer->_ColorReadBuffer) {
 803       /* The spec is unclear how to handle this case, but NVIDIA's
 804        * driver generates GL_INVALID_OPERATION.
 805        */
 806       _mesa_error(ctx, GL_INVALID_OPERATION,
 807                   "glGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_FORMAT: "
 808                   "no GL_READ_BUFFER)");
 809       return GL_NONE;
 810    }
 811    else {
 812       const GLenum format = ctx->ReadBuffer->_ColorReadBuffer->Format;
 813       const GLenum data_type = _mesa_get_format_datatype(format);
 814
 815       if (format == MESA_FORMAT_ARGB8888)
 816          return GL_BGRA;
 817       else if (format == MESA_FORMAT_RGB565)
 818          return GL_BGR;
 819
 820       switch (data_type) {
 821       case GL_UNSIGNED_INT:
 822       case GL_INT:
 823          return GL_RGBA_INTEGER;
 824       default:
 825          return GL_RGBA;
 826       }
 827    }
 828 }
 829
 830
 831 /**
 832  * Used to answer the GL_IMPLEMENTATION_COLOR_READ_TYPE_OES query.
 833  */
 834 GLenum
 835 _mesa_get_color_read_type(struct gl_context *ctx)
 836 {
 837    if (!ctx->ReadBuffer || !ctx->ReadBuffer->_ColorReadBuffer) {
 838       /* The spec is unclear how to handle this case, but NVIDIA's
 839        * driver generates GL_INVALID_OPERATION.
 840        */
 841       _mesa_error(ctx, GL_INVALID_OPERATION,
 842                   "glGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_TYPE: "
 843                   "no GL_READ_BUFFER)");
 844       return GL_NONE;
 845    }
 846    else {
 847       const GLenum format = ctx->ReadBuffer->_ColorReadBuffer->Format;
 848       const GLenum data_type = _mesa_get_format_datatype(format);
 849
 850       if (format == MESA_FORMAT_RGB565)
 851          return GL_UNSIGNED_SHORT_5_6_5_REV;
 852
 853       switch (data_type) {
 854       case GL_SIGNED_NORMALIZED:
 855          return GL_BYTE;
 856       case GL_UNSIGNED_INT:
 857       case GL_INT:
 858       case GL_FLOAT:
 859          return data_type;
 860       case GL_UNSIGNED_NORMALIZED:
 861       default:
 862          return GL_UNSIGNED_BYTE;
 863       }
 864    }
 865 }
 866
 867
 868 /**
 869  * Returns the read renderbuffer for the specified format.
 870  */
 871 struct gl_renderbuffer *
 872 _mesa_get_read_renderbuffer_for_format(const struct gl_context *ctx,
 873                                        GLenum format)
 874 {
 875    const struct gl_framebuffer *rfb = ctx->ReadBuffer;
 876
 877    if (_mesa_is_color_format(format)) {
 878       return rfb->Attachment[rfb->_ColorReadBufferIndex].Renderbuffer;
 879    } else if (_mesa_is_depth_format(format) ||
 880               _mesa_is_depthstencil_format(format)) {
 881       return rfb->Attachment[BUFFER_DEPTH].Renderbuffer;
 882    } else {
 883       return rfb->Attachment[BUFFER_STENCIL].Renderbuffer;
 884    }
 885 }
 886
 887
 888 /**
 889  * Print framebuffer info to stderr, for debugging.
 890  */
 891 void
 892 _mesa_print_framebuffer(const struct gl_framebuffer *fb)
 893 {
 894    GLuint i;
 895
 896    fprintf(stderr, "Mesa Framebuffer %u at %p\n", fb->Name, (void *) fb);
 897    fprintf(stderr, "  Size: %u x %u  Status: %s\n", fb->Width, fb->Height,
 898            _mesa_lookup_enum_by_nr(fb->_Status));
 899    fprintf(stderr, "  Attachments:\n");
 900
 901    for (i = 0; i < BUFFER_COUNT; i++) {
 902       const struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 903       if (att->Type == GL_TEXTURE) {
 904          const struct gl_texture_image *texImage = att->Renderbuffer->TexImage;
 905          fprintf(stderr,
 906                  "  %2d: Texture %u, level %u, face %u, slice %u, complete %d\n",
 907                  i, att->Texture->Name, att->TextureLevel, att->CubeMapFace,
 908                  att->Zoffset, att->Complete);
 909          fprintf(stderr, "       Size: %u x %u x %u  Format %s\n",
 910                  texImage->Width, texImage->Height, texImage->Depth,
 911                  _mesa_get_format_name(texImage->TexFormat));
 912       }
 913       else if (att->Type == GL_RENDERBUFFER) {
 914          fprintf(stderr, "  %2d: Renderbuffer %u, complete %d\n",
 915                  i, att->Renderbuffer->Name, att->Complete);
 916          fprintf(stderr, "       Size: %u x %u  Format %s\n",
 917                  att->Renderbuffer->Width, att->Renderbuffer->Height,
 918                  _mesa_get_format_name(att->Renderbuffer->Format));
 919       }
 920       else {
 921          fprintf(stderr, "  %2d: none\n", i);
 922       }
 923    }
 924 }