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 #include <stdio.h>
  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 #include "state.h"
  48
  49
  50
  51 /**
  52  * Compute/set the _DepthMax field for the given framebuffer.
  53  * This value depends on the Z buffer resolution.
  54  */
  55 static void
  56 compute_depth_max(struct gl_framebuffer *fb)
  57 {
  58    if (fb->Visual.depthBits == 0) {
  59       /* Special case.  Even if we don't have a depth buffer we need
  60        * good values for DepthMax for Z vertex transformation purposes
  61        * and for per-fragment fog computation.
  62        */
  63       fb->_DepthMax = (1 << 16) - 1;
  64    }
  65    else if (fb->Visual.depthBits < 32) {
  66       fb->_DepthMax = (1 << fb->Visual.depthBits) - 1;
  67    }
  68    else {
  69       /* Special case since shift values greater than or equal to the
  70        * number of bits in the left hand expression's type are undefined.
  71        */
  72       fb->_DepthMax = 0xffffffff;
  73    }
  74    fb->_DepthMaxF = (GLfloat) fb->_DepthMax;
  75
  76    /* Minimum resolvable depth value, for polygon offset */
  77    fb->_MRD = (GLfloat)1.0 / fb->_DepthMaxF;
  78 }
  79
  80 /**
  81  * Create and initialize a gl_framebuffer object.
  82  * This is intended for creating _window_system_ framebuffers, not generic
  83  * framebuffer objects ala GL_EXT_framebuffer_object.
  84  *
  85  * \sa _mesa_new_framebuffer
  86  */
  87 struct gl_framebuffer *
  88 _mesa_create_framebuffer(const struct gl_config *visual)
  89 {
  90    struct gl_framebuffer *fb = CALLOC_STRUCT(gl_framebuffer);
  91    assert(visual);
  92    if (fb) {
  93       _mesa_initialize_window_framebuffer(fb, visual);
  94    }
  95    return fb;
  96 }
  97
  98
  99 /**
 100  * Allocate a new gl_framebuffer object.
 101  * This is the default function for ctx->Driver.NewFramebuffer().
 102  * This is for allocating user-created framebuffers, not window-system
 103  * framebuffers!
 104  * \sa _mesa_create_framebuffer
 105  */
 106 struct gl_framebuffer *
 107 _mesa_new_framebuffer(struct gl_context *ctx, GLuint name)
 108 {
 109    struct gl_framebuffer *fb;
 110    (void) ctx;
 111    assert(name != 0);
 112    fb = CALLOC_STRUCT(gl_framebuffer);
 113    if (fb) {
 114       _mesa_initialize_user_framebuffer(fb, name);
 115    }
 116    return fb;
 117 }
 118
 119
 120 /**
 121  * Initialize a gl_framebuffer object.  Typically used to initialize
 122  * window system-created framebuffers, not user-created framebuffers.
 123  * \sa _mesa_initialize_user_framebuffer
 124  */
 125 void
 126 _mesa_initialize_window_framebuffer(struct gl_framebuffer *fb,
 127                                      const struct gl_config *visual)
 128 {
 129    assert(fb);
 130    assert(visual);
 131
 132    memset(fb, 0, sizeof(struct gl_framebuffer));
 133
 134    simple_mtx_init(&fb->Mutex, mtx_plain);
 135
 136    fb->RefCount = 1;
 137
 138    /* save the visual */
 139    fb->Visual = *visual;
 140
 141    /* Init read/draw renderbuffer state */
 142    if (visual->doubleBufferMode) {
 143       fb->_NumColorDrawBuffers = 1;
 144       fb->ColorDrawBuffer[0] = GL_BACK;
 145       fb->_ColorDrawBufferIndexes[0] = BUFFER_BACK_LEFT;
 146       fb->ColorReadBuffer = GL_BACK;
 147       fb->_ColorReadBufferIndex = BUFFER_BACK_LEFT;
 148    }
 149    else {
 150       fb->_NumColorDrawBuffers = 1;
 151       fb->ColorDrawBuffer[0] = GL_FRONT;
 152       fb->_ColorDrawBufferIndexes[0] = BUFFER_FRONT_LEFT;
 153       fb->ColorReadBuffer = GL_FRONT;
 154       fb->_ColorReadBufferIndex = BUFFER_FRONT_LEFT;
 155    }
 156
 157    fb->Delete = _mesa_destroy_framebuffer;
 158    fb->_Status = GL_FRAMEBUFFER_COMPLETE_EXT;
 159    fb->_AllColorBuffersFixedPoint = !visual->floatMode;
 160    fb->_HasSNormOrFloatColorBuffer = visual->floatMode;
 161    fb->_HasAttachments = true;
 162
 163    compute_depth_max(fb);
 164 }
 165
 166
 167 /**
 168  * Initialize a user-created gl_framebuffer object.
 169  * \sa _mesa_initialize_window_framebuffer
 170  */
 171 void
 172 _mesa_initialize_user_framebuffer(struct gl_framebuffer *fb, GLuint name)
 173 {
 174    assert(fb);
 175    assert(name);
 176
 177    memset(fb, 0, sizeof(struct gl_framebuffer));
 178
 179    fb->Name = name;
 180    fb->RefCount = 1;
 181    fb->_NumColorDrawBuffers = 1;
 182    fb->ColorDrawBuffer[0] = GL_COLOR_ATTACHMENT0_EXT;
 183    fb->_ColorDrawBufferIndexes[0] = BUFFER_COLOR0;
 184    fb->ColorReadBuffer = GL_COLOR_ATTACHMENT0_EXT;
 185    fb->_ColorReadBufferIndex = BUFFER_COLOR0;
 186    fb->Delete = _mesa_destroy_framebuffer;
 187    simple_mtx_init(&fb->Mutex, mtx_plain);
 188 }
 189
 190
 191 /**
 192  * Deallocate buffer and everything attached to it.
 193  * Typically called via the gl_framebuffer->Delete() method.
 194  */
 195 void
 196 _mesa_destroy_framebuffer(struct gl_framebuffer *fb)
 197 {
 198    if (fb) {
 199       _mesa_free_framebuffer_data(fb);
 200       free(fb->Label);
 201       free(fb);
 202    }
 203 }
 204
 205
 206 /**
 207  * Free all the data hanging off the given gl_framebuffer, but don't free
 208  * the gl_framebuffer object itself.
 209  */
 210 void
 211 _mesa_free_framebuffer_data(struct gl_framebuffer *fb)
 212 {
 213    assert(fb);
 214    assert(fb->RefCount == 0);
 215
 216    simple_mtx_destroy(&fb->Mutex);
 217
 218    for (unsigned 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       simple_mtx_lock(&oldFb->Mutex);
 248       assert(oldFb->RefCount > 0);
 249       oldFb->RefCount--;
 250       deleteFlag = (oldFb->RefCount == 0);
 251       simple_mtx_unlock(&oldFb->Mutex);
 252
 253       if (deleteFlag)
 254          oldFb->Delete(oldFb);
 255
 256       *ptr = NULL;
 257    }
 258
 259    if (fb) {
 260       simple_mtx_lock(&fb->Mutex);
 261       fb->RefCount++;
 262       simple_mtx_unlock(&fb->Mutex);
 263       *ptr = fb;
 264    }
 265 }
 266
 267
 268 /**
 269  * Resize the given framebuffer's renderbuffers to the new width and height.
 270  * This should only be used for window-system framebuffers, not
 271  * user-created renderbuffers (i.e. made with GL_EXT_framebuffer_object).
 272  * This will typically be called directly from a device driver.
 273  *
 274  * \note it's possible for ctx to be null since a window can be resized
 275  * without a currently bound rendering context.
 276  */
 277 void
 278 _mesa_resize_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
 279                          GLuint width, GLuint height)
 280 {
 281    /* XXX I think we could check if the size is not changing
 282     * and return early.
 283     */
 284
 285    /* Can only resize win-sys framebuffer objects */
 286    assert(_mesa_is_winsys_fbo(fb));
 287
 288    for (unsigned i = 0; i < BUFFER_COUNT; i++) {
 289       struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 290       if (att->Type == GL_RENDERBUFFER_EXT && att->Renderbuffer) {
 291          struct gl_renderbuffer *rb = att->Renderbuffer;
 292          /* only resize if size is changing */
 293          if (rb->Width != width || rb->Height != height) {
 294             if (rb->AllocStorage(ctx, rb, rb->InternalFormat, width, height)) {
 295                assert(rb->Width == width);
 296                assert(rb->Height == height);
 297             }
 298             else {
 299                _mesa_error(ctx, GL_OUT_OF_MEMORY, "Resizing framebuffer");
 300                /* no return */
 301             }
 302          }
 303       }
 304    }
 305
 306    fb->Width = width;
 307    fb->Height = height;
 308
 309    if (ctx) {
 310       /* update scissor / window bounds */
 311       _mesa_update_draw_buffer_bounds(ctx, ctx->DrawBuffer);
 312       /* Signal new buffer state so that swrast will update its clipping
 313        * info (the CLIP_BIT flag).
 314        */
 315       ctx->NewState |= _NEW_BUFFERS;
 316    }
 317 }
 318
 319 /**
 320  * Given a bounding box, intersect the bounding box with the scissor of
 321  * a specified vieport.
 322  *
 323  * \param ctx     GL context.
 324  * \param idx     Index of the desired viewport
 325  * \param bbox    Bounding box for the scissored viewport.  Stored as xmin,
 326  *                xmax, ymin, ymax.
 327  */
 328 void
 329 _mesa_intersect_scissor_bounding_box(const struct gl_context *ctx,
 330                                      unsigned idx, int *bbox)
 331 {
 332    if (ctx->Scissor.EnableFlags & (1u << idx)) {
 333       if (ctx->Scissor.ScissorArray[idx].X > bbox[0]) {
 334          bbox[0] = ctx->Scissor.ScissorArray[idx].X;
 335       }
 336       if (ctx->Scissor.ScissorArray[idx].Y > bbox[2]) {
 337          bbox[2] = ctx->Scissor.ScissorArray[idx].Y;
 338       }
 339       if (ctx->Scissor.ScissorArray[idx].X + ctx->Scissor.ScissorArray[idx].Width < bbox[1]) {
 340          bbox[1] = ctx->Scissor.ScissorArray[idx].X + ctx->Scissor.ScissorArray[idx].Width;
 341       }
 342       if (ctx->Scissor.ScissorArray[idx].Y + ctx->Scissor.ScissorArray[idx].Height < bbox[3]) {
 343          bbox[3] = ctx->Scissor.ScissorArray[idx].Y + ctx->Scissor.ScissorArray[idx].Height;
 344       }
 345       /* finally, check for empty region */
 346       if (bbox[0] > bbox[1]) {
 347          bbox[0] = bbox[1];
 348       }
 349       if (bbox[2] > bbox[3]) {
 350          bbox[2] = bbox[3];
 351       }
 352    }
 353 }
 354
 355 /**
 356  * Calculate the inclusive bounding box for the scissor of a specific viewport
 357  *
 358  * \param ctx     GL context.
 359  * \param buffer  Framebuffer to be checked against
 360  * \param idx     Index of the desired viewport
 361  * \param bbox    Bounding box for the scissored viewport.  Stored as xmin,
 362  *                xmax, ymin, ymax.
 363  *
 364  * \warning This function assumes that the framebuffer dimensions are up to
 365  * date.
 366  *
 367  * \sa _mesa_clip_to_region
 368  */
 369 static void
 370 scissor_bounding_box(const struct gl_context *ctx,
 371                      const struct gl_framebuffer *buffer,
 372                      unsigned idx, int *bbox)
 373 {
 374    bbox[0] = 0;
 375    bbox[2] = 0;
 376    bbox[1] = buffer->Width;
 377    bbox[3] = buffer->Height;
 378
 379    _mesa_intersect_scissor_bounding_box(ctx, idx, bbox);
 380
 381    assert(bbox[0] <= bbox[1]);
 382    assert(bbox[2] <= bbox[3]);
 383 }
 384
 385 /**
 386  * Update the context's current drawing buffer's Xmin, Xmax, Ymin, Ymax fields.
 387  * These values are computed from the buffer's width and height and
 388  * the scissor box, if it's enabled.
 389  * \param ctx  the GL context.
 390  */
 391 void
 392 _mesa_update_draw_buffer_bounds(struct gl_context *ctx,
 393                                 struct gl_framebuffer *buffer)
 394 {
 395    int bbox[4];
 396
 397    if (!buffer)
 398       return;
 399
 400    /* Default to the first scissor as that's always valid */
 401    scissor_bounding_box(ctx, buffer, 0, bbox);
 402    buffer->_Xmin = bbox[0];
 403    buffer->_Ymin = bbox[2];
 404    buffer->_Xmax = bbox[1];
 405    buffer->_Ymax = bbox[3];
 406 }
 407
 408
 409 /**
 410  * The glGet queries of the framebuffer red/green/blue size, stencil size,
 411  * etc. are satisfied by the fields of ctx->DrawBuffer->Visual.  These can
 412  * change depending on the renderbuffer bindings.  This function updates
 413  * the given framebuffer's Visual from the current renderbuffer bindings.
 414  *
 415  * This may apply to user-created framebuffers or window system framebuffers.
 416  *
 417  * Also note: ctx->DrawBuffer->Visual.depthBits might not equal
 418  * ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer.DepthBits.
 419  * The former one is used to convert floating point depth values into
 420  * integer Z values.
 421  */
 422 void
 423 _mesa_update_framebuffer_visual(struct gl_context *ctx,
 424                                 struct gl_framebuffer *fb)
 425 {
 426    memset(&fb->Visual, 0, sizeof(fb->Visual));
 427    fb->Visual.rgbMode = GL_TRUE; /* assume this */
 428
 429    /* find first RGB renderbuffer */
 430    for (unsigned i = 0; i < BUFFER_COUNT; i++) {
 431       if (fb->Attachment[i].Renderbuffer) {
 432          const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
 433          const GLenum baseFormat = _mesa_get_format_base_format(rb->Format);
 434          const mesa_format fmt = rb->Format;
 435
 436          /* Grab samples and sampleBuffers from any attachment point (assuming
 437           * the framebuffer is complete, we'll get the same answer from all
 438           * attachments).
 439           */
 440          fb->Visual.samples = rb->NumSamples;
 441          fb->Visual.sampleBuffers = rb->NumSamples > 0 ? 1 : 0;
 442
 443          if (_mesa_is_legal_color_format(ctx, baseFormat)) {
 444             fb->Visual.redBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
 445             fb->Visual.greenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
 446             fb->Visual.blueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
 447             fb->Visual.alphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
 448             fb->Visual.rgbBits = fb->Visual.redBits
 449                + fb->Visual.greenBits + fb->Visual.blueBits;
 450             if (_mesa_get_format_color_encoding(fmt) == GL_SRGB)
 451                 fb->Visual.sRGBCapable = ctx->Extensions.EXT_framebuffer_sRGB;
 452             break;
 453          }
 454       }
 455    }
 456
 457    fb->Visual.floatMode = GL_FALSE;
 458    for (unsigned i = 0; i < BUFFER_COUNT; i++) {
 459       if (fb->Attachment[i].Renderbuffer) {
 460          const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
 461          const mesa_format fmt = rb->Format;
 462
 463          if (_mesa_get_format_datatype(fmt) == GL_FLOAT) {
 464             fb->Visual.floatMode = GL_TRUE;
 465             break;
 466          }
 467       }
 468    }
 469
 470    if (fb->Attachment[BUFFER_DEPTH].Renderbuffer) {
 471       const struct gl_renderbuffer *rb =
 472          fb->Attachment[BUFFER_DEPTH].Renderbuffer;
 473       const mesa_format fmt = rb->Format;
 474       fb->Visual.haveDepthBuffer = GL_TRUE;
 475       fb->Visual.depthBits = _mesa_get_format_bits(fmt, GL_DEPTH_BITS);
 476    }
 477
 478    if (fb->Attachment[BUFFER_STENCIL].Renderbuffer) {
 479       const struct gl_renderbuffer *rb =
 480          fb->Attachment[BUFFER_STENCIL].Renderbuffer;
 481       const mesa_format fmt = rb->Format;
 482       fb->Visual.haveStencilBuffer = GL_TRUE;
 483       fb->Visual.stencilBits = _mesa_get_format_bits(fmt, GL_STENCIL_BITS);
 484    }
 485
 486    if (fb->Attachment[BUFFER_ACCUM].Renderbuffer) {
 487       const struct gl_renderbuffer *rb =
 488          fb->Attachment[BUFFER_ACCUM].Renderbuffer;
 489       const mesa_format fmt = rb->Format;
 490       fb->Visual.haveAccumBuffer = GL_TRUE;
 491       fb->Visual.accumRedBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
 492       fb->Visual.accumGreenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
 493       fb->Visual.accumBlueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
 494       fb->Visual.accumAlphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
 495    }
 496
 497    compute_depth_max(fb);
 498 }
 499
 500
 501 /*
 502  * Example DrawBuffers scenarios:
 503  *
 504  * 1. glDrawBuffer(GL_FRONT_AND_BACK), fixed-func or shader writes to
 505  * "gl_FragColor" or program writes to the "result.color" register:
 506  *
 507  *   fragment color output   renderbuffer
 508  *   ---------------------   ---------------
 509  *   color[0]                Front, Back
 510  *
 511  *
 512  * 2. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]), shader writes to
 513  * gl_FragData[i] or program writes to result.color[i] registers:
 514  *
 515  *   fragment color output   renderbuffer
 516  *   ---------------------   ---------------
 517  *   color[0]                Front
 518  *   color[1]                Aux0
 519  *   color[3]                Aux1
 520  *
 521  *
 522  * 3. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]) and shader writes to
 523  * gl_FragColor, or fixed function:
 524  *
 525  *   fragment color output   renderbuffer
 526  *   ---------------------   ---------------
 527  *   color[0]                Front, Aux0, Aux1
 528  *
 529  *
 530  * In either case, the list of renderbuffers is stored in the
 531  * framebuffer->_ColorDrawBuffers[] array and
 532  * framebuffer->_NumColorDrawBuffers indicates the number of buffers.
 533  * The renderer (like swrast) has to look at the current fragment shader
 534  * to see if it writes to gl_FragColor vs. gl_FragData[i] to determine
 535  * how to map color outputs to renderbuffers.
 536  *
 537  * Note that these two calls are equivalent (for fixed function fragment
 538  * shading anyway):
 539  *   a)  glDrawBuffer(GL_FRONT_AND_BACK);  (assuming non-stereo framebuffer)
 540  *   b)  glDrawBuffers(2, [GL_FRONT_LEFT, GL_BACK_LEFT]);
 541  */
 542
 543
 544
 545
 546 /**
 547  * Update the (derived) list of color drawing renderbuffer pointers.
 548  * Later, when we're rendering we'll loop from 0 to _NumColorDrawBuffers
 549  * writing colors.
 550  */
 551 static void
 552 update_color_draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb)
 553 {
 554    GLuint output;
 555
 556    /* set 0th buffer to NULL now in case _NumColorDrawBuffers is zero */
 557    fb->_ColorDrawBuffers[0] = NULL;
 558
 559    for (output = 0; output < fb->_NumColorDrawBuffers; output++) {
 560       gl_buffer_index buf = fb->_ColorDrawBufferIndexes[output];
 561       if (buf != BUFFER_NONE) {
 562          fb->_ColorDrawBuffers[output] = fb->Attachment[buf].Renderbuffer;
 563       }
 564       else {
 565          fb->_ColorDrawBuffers[output] = NULL;
 566       }
 567    }
 568 }
 569
 570
 571 /**
 572  * Update the (derived) color read renderbuffer pointer.
 573  * Unlike the DrawBuffer, we can only read from one (or zero) color buffers.
 574  */
 575 static void
 576 update_color_read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 577 {
 578    (void) ctx;
 579    if (fb->_ColorReadBufferIndex == BUFFER_NONE ||
 580        fb->DeletePending ||
 581        fb->Width == 0 ||
 582        fb->Height == 0) {
 583       fb->_ColorReadBuffer = NULL; /* legal! */
 584    }
 585    else {
 586       assert(fb->_ColorReadBufferIndex >= 0);
 587       assert(fb->_ColorReadBufferIndex < BUFFER_COUNT);
 588       fb->_ColorReadBuffer
 589          = fb->Attachment[fb->_ColorReadBufferIndex].Renderbuffer;
 590    }
 591 }
 592
 593
 594 /**
 595  * Update a gl_framebuffer's derived state.
 596  *
 597  * Specifically, update these framebuffer fields:
 598  *    _ColorDrawBuffers
 599  *    _NumColorDrawBuffers
 600  *    _ColorReadBuffer
 601  *
 602  * If the framebuffer is user-created, make sure it's complete.
 603  *
 604  * The following functions (at least) can effect framebuffer state:
 605  * glReadBuffer, glDrawBuffer, glDrawBuffersARB, glFramebufferRenderbufferEXT,
 606  * glRenderbufferStorageEXT.
 607  */
 608 static void
 609 update_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 610 {
 611    if (_mesa_is_winsys_fbo(fb)) {
 612       /* This is a window-system framebuffer */
 613       /* Need to update the FB's GL_DRAW_BUFFER state to match the
 614        * context state (GL_READ_BUFFER too).
 615        */
 616       if (fb->ColorDrawBuffer[0] != ctx->Color.DrawBuffer[0]) {
 617          _mesa_drawbuffers(ctx, fb, ctx->Const.MaxDrawBuffers,
 618                            ctx->Color.DrawBuffer, NULL);
 619       }
 620
 621       /* Call device driver function if fb is the bound draw buffer. */
 622       if (fb == ctx->DrawBuffer) {
 623          if (ctx->Driver.DrawBufferAllocate)
 624             ctx->Driver.DrawBufferAllocate(ctx);
 625       }
 626    }
 627    else {
 628       /* This is a user-created framebuffer.
 629        * Completeness only matters for user-created framebuffers.
 630        */
 631       if (fb->_Status != GL_FRAMEBUFFER_COMPLETE) {
 632          _mesa_test_framebuffer_completeness(ctx, fb);
 633       }
 634    }
 635
 636    /* Strictly speaking, we don't need to update the draw-state
 637     * if this FB is bound as ctx->ReadBuffer (and conversely, the
 638     * read-state if this FB is bound as ctx->DrawBuffer), but no
 639     * harm.
 640     */
 641    update_color_draw_buffers(ctx, fb);
 642    update_color_read_buffer(ctx, fb);
 643
 644    compute_depth_max(fb);
 645 }
 646
 647
 648 /**
 649  * Update state related to the draw/read framebuffers.
 650  */
 651 void
 652 _mesa_update_framebuffer(struct gl_context *ctx,
 653                          struct gl_framebuffer *readFb,
 654                          struct gl_framebuffer *drawFb)
 655 {
 656    assert(ctx);
 657
 658    update_framebuffer(ctx, drawFb);
 659    if (readFb != drawFb)
 660       update_framebuffer(ctx, readFb);
 661
 662    _mesa_update_clamp_vertex_color(ctx, drawFb);
 663    _mesa_update_clamp_fragment_color(ctx, drawFb);
 664 }
 665
 666
 667 /**
 668  * Check if the renderbuffer for a read/draw operation exists.
 669  * \param format  a basic image format such as GL_RGB, GL_RGBA, GL_ALPHA,
 670  *                GL_DEPTH_COMPONENT, etc. or GL_COLOR, GL_DEPTH, GL_STENCIL.
 671  * \param reading  if TRUE, we're going to read from the buffer,
 672                    if FALSE, we're going to write to the buffer.
 673  * \return GL_TRUE if buffer exists, GL_FALSE otherwise
 674  */
 675 static GLboolean
 676 renderbuffer_exists(struct gl_context *ctx,
 677                     struct gl_framebuffer *fb,
 678                     GLenum format,
 679                     GLboolean reading)
 680 {
 681    const struct gl_renderbuffer_attachment *att = fb->Attachment;
 682
 683    /* If we don't know the framebuffer status, update it now */
 684    if (fb->_Status == 0) {
 685       _mesa_test_framebuffer_completeness(ctx, fb);
 686    }
 687
 688    if (fb->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 689       return GL_FALSE;
 690    }
 691
 692    switch (format) {
 693    case GL_COLOR:
 694    case GL_RED:
 695    case GL_GREEN:
 696    case GL_BLUE:
 697    case GL_ALPHA:
 698    case GL_LUMINANCE:
 699    case GL_LUMINANCE_ALPHA:
 700    case GL_INTENSITY:
 701    case GL_RG:
 702    case GL_RGB:
 703    case GL_BGR:
 704    case GL_RGBA:
 705    case GL_BGRA:
 706    case GL_ABGR_EXT:
 707    case GL_RED_INTEGER_EXT:
 708    case GL_RG_INTEGER:
 709    case GL_GREEN_INTEGER_EXT:
 710    case GL_BLUE_INTEGER_EXT:
 711    case GL_ALPHA_INTEGER_EXT:
 712    case GL_RGB_INTEGER_EXT:
 713    case GL_RGBA_INTEGER_EXT:
 714    case GL_BGR_INTEGER_EXT:
 715    case GL_BGRA_INTEGER_EXT:
 716    case GL_LUMINANCE_INTEGER_EXT:
 717    case GL_LUMINANCE_ALPHA_INTEGER_EXT:
 718       if (reading) {
 719          /* about to read from a color buffer */
 720          const struct gl_renderbuffer *readBuf = fb->_ColorReadBuffer;
 721          if (!readBuf) {
 722             return GL_FALSE;
 723          }
 724          assert(_mesa_get_format_bits(readBuf->Format, GL_RED_BITS) > 0 ||
 725                 _mesa_get_format_bits(readBuf->Format, GL_ALPHA_BITS) > 0 ||
 726                 _mesa_get_format_bits(readBuf->Format, GL_TEXTURE_LUMINANCE_SIZE) > 0 ||
 727                 _mesa_get_format_bits(readBuf->Format, GL_TEXTURE_INTENSITY_SIZE) > 0 ||
 728                 _mesa_get_format_bits(readBuf->Format, GL_INDEX_BITS) > 0);
 729       }
 730       else {
 731          /* about to draw to zero or more color buffers (none is OK) */
 732          return GL_TRUE;
 733       }
 734       break;
 735    case GL_DEPTH:
 736    case GL_DEPTH_COMPONENT:
 737       if (att[BUFFER_DEPTH].Type == GL_NONE) {
 738          return GL_FALSE;
 739       }
 740       break;
 741    case GL_STENCIL:
 742    case GL_STENCIL_INDEX:
 743       if (att[BUFFER_STENCIL].Type == GL_NONE) {
 744          return GL_FALSE;
 745       }
 746       break;
 747    case GL_DEPTH_STENCIL_EXT:
 748       if (att[BUFFER_DEPTH].Type == GL_NONE ||
 749           att[BUFFER_STENCIL].Type == GL_NONE) {
 750          return GL_FALSE;
 751       }
 752       break;
 753    default:
 754       _mesa_problem(ctx,
 755                     "Unexpected format 0x%x in renderbuffer_exists",
 756                     format);
 757       return GL_FALSE;
 758    }
 759
 760    /* OK */
 761    return GL_TRUE;
 762 }
 763
 764
 765 /**
 766  * Check if the renderbuffer for a read operation (glReadPixels, glCopyPixels,
 767  * glCopyTex[Sub]Image, etc) exists.
 768  * \param format  a basic image format such as GL_RGB, GL_RGBA, GL_ALPHA,
 769  *                GL_DEPTH_COMPONENT, etc. or GL_COLOR, GL_DEPTH, GL_STENCIL.
 770  * \return GL_TRUE if buffer exists, GL_FALSE otherwise
 771  */
 772 GLboolean
 773 _mesa_source_buffer_exists(struct gl_context *ctx, GLenum format)
 774 {
 775    return renderbuffer_exists(ctx, ctx->ReadBuffer, format, GL_TRUE);
 776 }
 777
 778
 779 /**
 780  * As above, but for drawing operations.
 781  */
 782 GLboolean
 783 _mesa_dest_buffer_exists(struct gl_context *ctx, GLenum format)
 784 {
 785    return renderbuffer_exists(ctx, ctx->DrawBuffer, format, GL_FALSE);
 786 }
 787
 788
 789 /**
 790  * Used to answer the GL_IMPLEMENTATION_COLOR_READ_FORMAT_OES queries (using
 791  * GetIntegerv, GetFramebufferParameteriv, etc)
 792  *
 793  * If @fb is NULL, the method returns the value for the current bound
 794  * framebuffer.
 795  */
 796 GLenum
 797 _mesa_get_color_read_format(struct gl_context *ctx,
 798                             struct gl_framebuffer *fb,
 799                             const char *caller)
 800 {
 801    if (ctx->NewState)
 802       _mesa_update_state(ctx);
 803
 804    if (fb == NULL)
 805       fb = ctx->ReadBuffer;
 806
 807    if (!fb || !fb->_ColorReadBuffer) {
 808       /*
 809        * From OpenGL 4.5 spec, section 18.2.2 "ReadPixels":
 810        *
 811        *    "An INVALID_OPERATION error is generated by GetIntegerv if pname
 812        *     is IMPLEMENTATION_COLOR_READ_FORMAT or IMPLEMENTATION_COLOR_-
 813        *     READ_TYPE and any of:
 814        *      * the read framebuffer is not framebuffer complete.
 815        *      * the read framebuffer is a framebuffer object, and the selected
 816        *        read buffer (see section 18.2.1) has no image attached.
 817        *      * the selected read buffer is NONE."
 818        *
 819        * There is not equivalent quote for GetFramebufferParameteriv or
 820        * GetNamedFramebufferParameteriv, but from section 9.2.3 "Framebuffer
 821        * Object Queries":
 822        *
 823        *    "Values of framebuffer-dependent state are identical to those that
 824        *     would be obtained were the framebuffer object bound and queried
 825        *     using the simple state queries in that table."
 826        *
 827        * Where "using the simple state queries" refer to use GetIntegerv. So
 828        * we will assume that on that situation the same error should be
 829        * triggered too.
 830        */
 831       _mesa_error(ctx, GL_INVALID_OPERATION,
 832                   "%s(GL_IMPLEMENTATION_COLOR_READ_FORMAT: no GL_READ_BUFFER)",
 833                   caller);
 834       return GL_NONE;
 835    }
 836    else {
 837       const mesa_format format = fb->_ColorReadBuffer->Format;
 838       const GLenum data_type = _mesa_get_format_datatype(format);
 839
 840       if (format == MESA_FORMAT_B8G8R8A8_UNORM)
 841          return GL_BGRA;
 842       else if (format == MESA_FORMAT_B5G6R5_UNORM)
 843          return GL_RGB;
 844       else if (format == MESA_FORMAT_R_UNORM8)
 845          return GL_RED;
 846
 847       switch (data_type) {
 848       case GL_UNSIGNED_INT:
 849       case GL_INT:
 850          return GL_RGBA_INTEGER;
 851       default:
 852          return GL_RGBA;
 853       }
 854    }
 855 }
 856
 857
 858 /**
 859  * Used to answer the GL_IMPLEMENTATION_COLOR_READ_TYPE_OES queries (using
 860  * GetIntegerv, GetFramebufferParameteriv, etc)
 861  *
 862  * If @fb is NULL, the method returns the value for the current bound
 863  * framebuffer.
 864  */
 865 GLenum
 866 _mesa_get_color_read_type(struct gl_context *ctx,
 867                           struct gl_framebuffer *fb,
 868                           const char *caller)
 869 {
 870    if (ctx->NewState)
 871       _mesa_update_state(ctx);
 872
 873    if (fb == NULL)
 874       fb = ctx->ReadBuffer;
 875
 876    if (!fb || !fb->_ColorReadBuffer) {
 877       /*
 878        * See comment on _mesa_get_color_read_format
 879        */
 880       _mesa_error(ctx, GL_INVALID_OPERATION,
 881                   "%s(GL_IMPLEMENTATION_COLOR_READ_TYPE: no GL_READ_BUFFER)",
 882                   caller);
 883       return GL_NONE;
 884    }
 885    else {
 886       const GLenum format = fb->_ColorReadBuffer->Format;
 887       const GLenum data_type = _mesa_get_format_datatype(format);
 888
 889       if (format == MESA_FORMAT_B5G6R5_UNORM)
 890          return GL_UNSIGNED_SHORT_5_6_5;
 891
 892       if (format == MESA_FORMAT_B10G10R10A2_UNORM ||
 893           format == MESA_FORMAT_B10G10R10X2_UNORM ||
 894           format == MESA_FORMAT_R10G10B10A2_UNORM ||
 895           format == MESA_FORMAT_R10G10B10X2_UNORM)
 896          return GL_UNSIGNED_INT_2_10_10_10_REV;
 897
 898       switch (data_type) {
 899       case GL_SIGNED_NORMALIZED:
 900          return GL_BYTE;
 901       case GL_UNSIGNED_INT:
 902       case GL_INT:
 903       case GL_FLOAT:
 904          return data_type;
 905       case GL_UNSIGNED_NORMALIZED:
 906       default:
 907          return GL_UNSIGNED_BYTE;
 908       }
 909    }
 910 }
 911
 912
 913 /**
 914  * Returns the read renderbuffer for the specified format.
 915  */
 916 struct gl_renderbuffer *
 917 _mesa_get_read_renderbuffer_for_format(const struct gl_context *ctx,
 918                                        GLenum format)
 919 {
 920    const struct gl_framebuffer *rfb = ctx->ReadBuffer;
 921
 922    if (_mesa_is_color_format(format)) {
 923       return rfb->Attachment[rfb->_ColorReadBufferIndex].Renderbuffer;
 924    } else if (_mesa_is_depth_format(format) ||
 925               _mesa_is_depthstencil_format(format)) {
 926       return rfb->Attachment[BUFFER_DEPTH].Renderbuffer;
 927    } else {
 928       return rfb->Attachment[BUFFER_STENCIL].Renderbuffer;
 929    }
 930 }
 931
 932
 933 /**
 934  * Print framebuffer info to stderr, for debugging.
 935  */
 936 void
 937 _mesa_print_framebuffer(const struct gl_framebuffer *fb)
 938 {
 939    fprintf(stderr, "Mesa Framebuffer %u at %p\n", fb->Name, (void *) fb);
 940    fprintf(stderr, "  Size: %u x %u  Status: %s\n", fb->Width, fb->Height,
 941            _mesa_enum_to_string(fb->_Status));
 942    fprintf(stderr, "  Attachments:\n");
 943
 944    for (unsigned i = 0; i < BUFFER_COUNT; i++) {
 945       const struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
 946       if (att->Type == GL_TEXTURE) {
 947          const struct gl_texture_image *texImage = att->Renderbuffer->TexImage;
 948          fprintf(stderr,
 949                  "  %2d: Texture %u, level %u, face %u, slice %u, complete %d\n",
 950                  i, att->Texture->Name, att->TextureLevel, att->CubeMapFace,
 951                  att->Zoffset, att->Complete);
 952          fprintf(stderr, "       Size: %u x %u x %u  Format %s\n",
 953                  texImage->Width, texImage->Height, texImage->Depth,
 954                  _mesa_get_format_name(texImage->TexFormat));
 955       }
 956       else if (att->Type == GL_RENDERBUFFER) {
 957          fprintf(stderr, "  %2d: Renderbuffer %u, complete %d\n",
 958                  i, att->Renderbuffer->Name, att->Complete);
 959          fprintf(stderr, "       Size: %u x %u  Format %s\n",
 960                  att->Renderbuffer->Width, att->Renderbuffer->Height,
 961                  _mesa_get_format_name(att->Renderbuffer->Format));
 962       }
 963       else {
 964          fprintf(stderr, "  %2d: none\n", i);
 965       }
 966    }
 967 }
 968
 969 bool
 970 _mesa_is_front_buffer_reading(const struct gl_framebuffer *fb)
 971 {
 972    if (!fb || _mesa_is_user_fbo(fb))
 973       return false;
 974
 975    return fb->_ColorReadBufferIndex == BUFFER_FRONT_LEFT;
 976 }
 977
 978 bool
 979 _mesa_is_front_buffer_drawing(const struct gl_framebuffer *fb)
 980 {
 981    if (!fb || _mesa_is_user_fbo(fb))
 982       return false;
 983
 984    return (fb->_NumColorDrawBuffers >= 1 &&
 985            fb->_ColorDrawBufferIndexes[0] == BUFFER_FRONT_LEFT);
 986 }
 987
 988 static inline GLuint
 989 _mesa_geometric_nonvalidated_samples(const struct gl_framebuffer *buffer)
 990 {
 991    return buffer->_HasAttachments ?
 992       buffer->Visual.samples :
 993       buffer->DefaultGeometry.NumSamples;
 994 }
 995
 996 bool
 997 _mesa_is_multisample_enabled(const struct gl_context *ctx)
 998 {
 999    /* The sample count may not be validated by the driver, but when it is set,
1000     * we know that is in a valid range and no driver should ever validate a
1001     * multisampled framebuffer to non-multisampled and vice-versa.
1002     */
1003    return ctx->Multisample.Enabled &&
1004           ctx->DrawBuffer &&
1005           _mesa_geometric_nonvalidated_samples(ctx->DrawBuffer) >= 1;
1006 }
1007
1008 /**
1009  * Is alpha testing enabled and applicable to the currently bound
1010  * framebuffer?
1011  */
1012 bool
1013 _mesa_is_alpha_test_enabled(const struct gl_context *ctx)
1014 {
1015    bool buffer0_is_integer = ctx->DrawBuffer->_IntegerBuffers & 0x1;
1016    return (ctx->Color.AlphaEnabled && !buffer0_is_integer);
1017 }
1018
1019 /**
1020  * Is alpha to coverage enabled and applicable to the currently bound
1021  * framebuffer?
1022  */
1023 bool
1024 _mesa_is_alpha_to_coverage_enabled(const struct gl_context *ctx)
1025 {
1026    bool buffer0_is_integer = ctx->DrawBuffer->_IntegerBuffers & 0x1;
1027    return (ctx->Multisample.SampleAlphaToCoverage &&
1028            _mesa_is_multisample_enabled(ctx) &&
1029            !buffer0_is_integer);
1030 }