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-rw-r--r--src/mesa/main/framebuffer.c802
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diff --git a/src/mesa/main/framebuffer.c b/src/mesa/main/framebuffer.c
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+/*
+ * Mesa 3-D graphics library
+ * Version: 6.5.1
+ *
+ * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+/**
+ * Functions for allocating/managing framebuffers and renderbuffers.
+ * Also, routines for reading/writing renderbuffer data as ubytes,
+ * ushorts, uints, etc.
+ */
+
+
+#include "glheader.h"
+#include "imports.h"
+#include "context.h"
+#include "depthstencil.h"
+#include "mtypes.h"
+#include "fbobject.h"
+#include "framebuffer.h"
+#include "renderbuffer.h"
+
+
+
+/**
+ * Compute/set the _DepthMax field for the given framebuffer.
+ * This value depends on the Z buffer resolution.
+ */
+static void
+compute_depth_max(struct gl_framebuffer *fb)
+{
+ if (fb->Visual.depthBits == 0) {
+ /* Special case. Even if we don't have a depth buffer we need
+ * good values for DepthMax for Z vertex transformation purposes
+ * and for per-fragment fog computation.
+ */
+ fb->_DepthMax = (1 << 16) - 1;
+ }
+ else if (fb->Visual.depthBits < 32) {
+ fb->_DepthMax = (1 << fb->Visual.depthBits) - 1;
+ }
+ else {
+ /* Special case since shift values greater than or equal to the
+ * number of bits in the left hand expression's type are undefined.
+ */
+ fb->_DepthMax = 0xffffffff;
+ }
+ fb->_DepthMaxF = (GLfloat) fb->_DepthMax;
+ fb->_MRD = 1.0; /* Minimum resolvable depth value, for polygon offset */
+}
+
+
+/**
+ * Set the framebuffer's _DepthBuffer field, taking care of
+ * reference counts, etc.
+ */
+static void
+set_depth_renderbuffer(struct gl_framebuffer *fb,
+ struct gl_renderbuffer *rb)
+{
+ if (fb->_DepthBuffer) {
+ _mesa_dereference_renderbuffer(&fb->_DepthBuffer);
+ }
+ fb->_DepthBuffer = rb;
+ if (rb) {
+ rb->RefCount++;
+ }
+}
+
+
+/**
+ * Set the framebuffer's _StencilBuffer field, taking care of
+ * reference counts, etc.
+ */
+static void
+set_stencil_renderbuffer(struct gl_framebuffer *fb,
+ struct gl_renderbuffer *rb)
+{
+ if (fb->_StencilBuffer) {
+ _mesa_dereference_renderbuffer(&fb->_StencilBuffer);
+ }
+ fb->_StencilBuffer = rb;
+ if (rb) {
+ rb->RefCount++;
+ }
+}
+
+
+/**
+ * Create and initialize a gl_framebuffer object.
+ * This is intended for creating _window_system_ framebuffers, not generic
+ * framebuffer objects ala GL_EXT_framebuffer_object.
+ *
+ * \sa _mesa_new_framebuffer
+ */
+struct gl_framebuffer *
+_mesa_create_framebuffer(const GLvisual *visual)
+{
+ struct gl_framebuffer *fb = CALLOC_STRUCT(gl_framebuffer);
+ assert(visual);
+ if (fb) {
+ _mesa_initialize_framebuffer(fb, visual);
+ }
+ return fb;
+}
+
+
+/**
+ * Allocate a new gl_framebuffer object.
+ * This is the default function for ctx->Driver.NewFramebuffer().
+ * This is for allocating user-created framebuffers, not window-system
+ * framebuffers!
+ * \sa _mesa_create_framebuffer
+ */
+struct gl_framebuffer *
+_mesa_new_framebuffer(GLcontext *ctx, GLuint name)
+{
+ struct gl_framebuffer *fb;
+ (void) ctx;
+ assert(name != 0);
+ fb = CALLOC_STRUCT(gl_framebuffer);
+ if (fb) {
+ fb->Name = name;
+ fb->RefCount = 1;
+ fb->ColorDrawBuffer[0] = GL_COLOR_ATTACHMENT0_EXT;
+ fb->_ColorDrawBufferMask[0] = BUFFER_BIT_COLOR0;
+ fb->ColorReadBuffer = GL_COLOR_ATTACHMENT0_EXT;
+ fb->_ColorReadBufferIndex = BUFFER_COLOR0;
+ fb->Delete = _mesa_destroy_framebuffer;
+ }
+ return fb;
+}
+
+
+/**
+ * Initialize a gl_framebuffer object. Typically used to initialize
+ * window system-created framebuffers, not user-created framebuffers.
+ * \sa _mesa_create_framebuffer
+ */
+void
+_mesa_initialize_framebuffer(struct gl_framebuffer *fb, const GLvisual *visual)
+{
+ assert(fb);
+ assert(visual);
+
+ _mesa_bzero(fb, sizeof(struct gl_framebuffer));
+
+ _glthread_INIT_MUTEX(fb->Mutex);
+
+ /* save the visual */
+ fb->Visual = *visual;
+
+ /* Init glRead/DrawBuffer state */
+ if (visual->doubleBufferMode) {
+ fb->ColorDrawBuffer[0] = GL_BACK;
+ fb->_ColorDrawBufferMask[0] = BUFFER_BIT_BACK_LEFT;
+ fb->ColorReadBuffer = GL_BACK;
+ fb->_ColorReadBufferIndex = BUFFER_BACK_LEFT;
+ }
+ else {
+ fb->ColorDrawBuffer[0] = GL_FRONT;
+ fb->_ColorDrawBufferMask[0] = BUFFER_BIT_FRONT_LEFT;
+ fb->ColorReadBuffer = GL_FRONT;
+ fb->_ColorReadBufferIndex = BUFFER_FRONT_LEFT;
+ }
+
+ fb->Delete = _mesa_destroy_framebuffer;
+ fb->_Status = GL_FRAMEBUFFER_COMPLETE_EXT;
+
+ compute_depth_max(fb);
+}
+
+
+/**
+ * Deallocate buffer and everything attached to it.
+ * Typically called via the gl_framebuffer->Delete() method.
+ */
+void
+_mesa_destroy_framebuffer(struct gl_framebuffer *fb)
+{
+ if (fb) {
+ _glthread_DESTROY_MUTEX(fb->Mutex);
+ _mesa_free_framebuffer_data(fb);
+ _mesa_free(fb);
+ }
+}
+
+
+/**
+ * Free all the data hanging off the given gl_framebuffer, but don't free
+ * the gl_framebuffer object itself.
+ */
+void
+_mesa_free_framebuffer_data(struct gl_framebuffer *fb)
+{
+ GLuint i;
+
+ assert(fb);
+
+ for (i = 0; i < BUFFER_COUNT; i++) {
+ struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
+ if (att->Renderbuffer) {
+ struct gl_renderbuffer *rb = att->Renderbuffer;
+ /* remove framebuffer's reference to renderbuffer */
+ _mesa_dereference_renderbuffer(&rb);
+ if (rb && rb->Name == 0) {
+ /* delete window system renderbuffer */
+ _mesa_dereference_renderbuffer(&rb);
+ }
+ }
+ att->Type = GL_NONE;
+ att->Renderbuffer = NULL;
+ }
+
+ /* unbind depth/stencil to decr ref counts */
+ set_depth_renderbuffer(fb, NULL);
+ set_stencil_renderbuffer(fb, NULL);
+}
+
+
+/**
+ * Decrement the reference count on a framebuffer and delete it when
+ * the refcount hits zero.
+ * Note: we pass the address of a pointer and set it to NULL if we delete it.
+ */
+void
+_mesa_dereference_framebuffer(struct gl_framebuffer **fb)
+{
+ GLboolean deleteFlag = GL_FALSE;
+
+ _glthread_LOCK_MUTEX((*fb)->Mutex);
+ {
+ ASSERT((*fb)->RefCount > 0);
+ (*fb)->RefCount--;
+ deleteFlag = ((*fb)->RefCount == 0);
+ }
+ _glthread_UNLOCK_MUTEX((*fb)->Mutex);
+
+ if (deleteFlag) {
+ (*fb)->Delete(*fb);
+ *fb = NULL;
+ }
+}
+
+
+
+
+/**
+ * Resize the given framebuffer's renderbuffers to the new width and height.
+ * This should only be used for window-system framebuffers, not
+ * user-created renderbuffers (i.e. made with GL_EXT_framebuffer_object).
+ * This will typically be called via ctx->Driver.ResizeBuffers() or directly
+ * from a device driver.
+ *
+ * \note it's possible for ctx to be null since a window can be resized
+ * without a currently bound rendering context.
+ */
+void
+_mesa_resize_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb,
+ GLuint width, GLuint height)
+{
+ GLuint i;
+
+ /* XXX I think we could check if the size is not changing
+ * and return early.
+ */
+
+ /* For window system framebuffers, Name is zero */
+ assert(fb->Name == 0);
+
+ for (i = 0; i < BUFFER_COUNT; i++) {
+ struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
+ if (att->Type == GL_RENDERBUFFER_EXT && att->Renderbuffer) {
+ struct gl_renderbuffer *rb = att->Renderbuffer;
+ /* only resize if size is changing */
+ if (rb->Width != width || rb->Height != height) {
+ /* could just as well pass rb->_ActualFormat here */
+ if (rb->AllocStorage(ctx, rb, rb->InternalFormat, width, height)) {
+ ASSERT(rb->Width == width);
+ ASSERT(rb->Height == height);
+ }
+ else {
+ _mesa_error(ctx, GL_OUT_OF_MEMORY, "Resizing framebuffer");
+ /* no return */
+ }
+ }
+ }
+ }
+
+ if (fb->_DepthBuffer) {
+ struct gl_renderbuffer *rb = fb->_DepthBuffer;
+ if (rb->Width != width || rb->Height != height) {
+ if (!rb->AllocStorage(ctx, rb, rb->InternalFormat, width, height)) {
+ _mesa_error(ctx, GL_OUT_OF_MEMORY, "Resizing framebuffer");
+ }
+ }
+ }
+
+ if (fb->_StencilBuffer) {
+ struct gl_renderbuffer *rb = fb->_StencilBuffer;
+ if (rb->Width != width || rb->Height != height) {
+ if (!rb->AllocStorage(ctx, rb, rb->InternalFormat, width, height)) {
+ _mesa_error(ctx, GL_OUT_OF_MEMORY, "Resizing framebuffer");
+ }
+ }
+ }
+
+ fb->Width = width;
+ fb->Height = height;
+
+ /* to update scissor / window bounds */
+ if (ctx)
+ _mesa_update_draw_buffer_bounds(ctx);
+}
+
+
+/**
+ * Examine all the framebuffer's renderbuffers to update the Width/Height
+ * fields of the framebuffer. If we have renderbuffers with different
+ * sizes, set the framebuffer's width and height to zero.
+ * Note: this is only intended for user-created framebuffers, not
+ * window-system framebuffes.
+ */
+static void
+update_framebuffer_size(struct gl_framebuffer *fb)
+{
+ GLboolean haveSize = GL_FALSE;
+ GLuint i;
+
+ /* user-created framebuffers only */
+ assert(fb->Name);
+
+ for (i = 0; i < BUFFER_COUNT; i++) {
+ struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
+ const struct gl_renderbuffer *rb = att->Renderbuffer;
+ if (rb) {
+ if (haveSize) {
+ if (rb->Width != fb->Width && rb->Height != fb->Height) {
+ /* size mismatch! */
+ fb->Width = 0;
+ fb->Height = 0;
+ return;
+ }
+ }
+ else {
+ fb->Width = rb->Width;
+ fb->Height = rb->Height;
+ haveSize = GL_TRUE;
+ }
+ }
+ }
+}
+
+
+/**
+ * Update the context's current drawing buffer's Xmin, Xmax, Ymin, Ymax fields.
+ * These values are computed from the buffer's width and height and
+ * the scissor box, if it's enabled.
+ * \param ctx the GL context.
+ */
+void
+_mesa_update_draw_buffer_bounds(GLcontext *ctx)
+{
+ struct gl_framebuffer *buffer = ctx->DrawBuffer;
+
+ if (!buffer)
+ return;
+
+ if (buffer->Name) {
+ /* user-created framebuffer size depends on the renderbuffers */
+ update_framebuffer_size(buffer);
+ }
+
+ buffer->_Xmin = 0;
+ buffer->_Ymin = 0;
+ buffer->_Xmax = buffer->Width;
+ buffer->_Ymax = buffer->Height;
+
+ if (ctx->Scissor.Enabled) {
+ if (ctx->Scissor.X > buffer->_Xmin) {
+ buffer->_Xmin = ctx->Scissor.X;
+ }
+ if (ctx->Scissor.Y > buffer->_Ymin) {
+ buffer->_Ymin = ctx->Scissor.Y;
+ }
+ if (ctx->Scissor.X + ctx->Scissor.Width < buffer->_Xmax) {
+ buffer->_Xmax = ctx->Scissor.X + ctx->Scissor.Width;
+ }
+ if (ctx->Scissor.Y + ctx->Scissor.Height < buffer->_Ymax) {
+ buffer->_Ymax = ctx->Scissor.Y + ctx->Scissor.Height;
+ }
+ /* finally, check for empty region */
+ if (buffer->_Xmin > buffer->_Xmax) {
+ buffer->_Xmin = buffer->_Xmax;
+ }
+ if (buffer->_Ymin > buffer->_Ymax) {
+ buffer->_Ymin = buffer->_Ymax;
+ }
+ }
+
+ ASSERT(buffer->_Xmin <= buffer->_Xmax);
+ ASSERT(buffer->_Ymin <= buffer->_Ymax);
+}
+
+
+/**
+ * The glGet queries of the framebuffer red/green/blue size, stencil size,
+ * etc. are satisfied by the fields of ctx->DrawBuffer->Visual. These can
+ * change depending on the renderbuffer bindings. This function updates
+ * the given framebuffer's Visual from the current renderbuffer bindings.
+ * This is only intended for user-created framebuffers.
+ *
+ * Also note: ctx->DrawBuffer->Visual.depthBits might not equal
+ * ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer.DepthBits.
+ * The former one is used to convert floating point depth values into
+ * integer Z values.
+ */
+void
+_mesa_update_framebuffer_visual(struct gl_framebuffer *fb)
+{
+ GLuint i;
+
+ _mesa_bzero(&fb->Visual, sizeof(fb->Visual));
+ fb->Visual.rgbMode = GL_TRUE; /* assume this */
+
+#if 0 /* this _might_ be needed */
+ if (fb->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+ /* leave visual fields zero'd */
+ return;
+ }
+#endif
+
+ /* find first RGB or CI renderbuffer */
+ for (i = 0; i < BUFFER_COUNT; i++) {
+ if (fb->Attachment[i].Renderbuffer) {
+ const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
+ if (rb->_BaseFormat == GL_RGBA || rb->_BaseFormat == GL_RGB) {
+ fb->Visual.redBits = rb->RedBits;
+ fb->Visual.greenBits = rb->GreenBits;
+ fb->Visual.blueBits = rb->BlueBits;
+ fb->Visual.alphaBits = rb->AlphaBits;
+ fb->Visual.rgbBits = fb->Visual.redBits
+ + fb->Visual.greenBits + fb->Visual.blueBits;
+ fb->Visual.floatMode = GL_FALSE;
+ break;
+ }
+ else if (rb->_BaseFormat == GL_COLOR_INDEX) {
+ fb->Visual.indexBits = rb->IndexBits;
+ fb->Visual.rgbMode = GL_FALSE;
+ break;
+ }
+ }
+ }
+
+ if (fb->Attachment[BUFFER_DEPTH].Renderbuffer) {
+ fb->Visual.haveDepthBuffer = GL_TRUE;
+ fb->Visual.depthBits
+ = fb->Attachment[BUFFER_DEPTH].Renderbuffer->DepthBits;
+ }
+
+ if (fb->Attachment[BUFFER_STENCIL].Renderbuffer) {
+ fb->Visual.haveStencilBuffer = GL_TRUE;
+ fb->Visual.stencilBits
+ = fb->Attachment[BUFFER_STENCIL].Renderbuffer->StencilBits;
+ }
+
+ compute_depth_max(fb);
+}
+
+
+/**
+ * Update the framebuffer's _DepthBuffer field using the renderbuffer
+ * found at the given attachment index.
+ *
+ * If that attachment points to a combined GL_DEPTH_STENCIL renderbuffer,
+ * create and install a depth wrapper/adaptor.
+ *
+ * \param fb the framebuffer whose _DepthBuffer field to update
+ * \param attIndex indicates the renderbuffer to possibly wrap
+ */
+void
+_mesa_update_depth_buffer(GLcontext *ctx,
+ struct gl_framebuffer *fb,
+ GLuint attIndex)
+{
+ struct gl_renderbuffer *depthRb;
+
+ /* only one possiblity for now */
+ ASSERT(attIndex == BUFFER_DEPTH);
+
+ depthRb = fb->Attachment[attIndex].Renderbuffer;
+
+ if (depthRb && depthRb->_ActualFormat == GL_DEPTH24_STENCIL8_EXT) {
+ /* The attached depth buffer is a GL_DEPTH_STENCIL renderbuffer */
+ if (!fb->_DepthBuffer
+ || fb->_DepthBuffer->Wrapped != depthRb
+ || fb->_DepthBuffer->_BaseFormat != GL_DEPTH_COMPONENT) {
+ /* need to update wrapper */
+ struct gl_renderbuffer *wrapper
+ = _mesa_new_z24_renderbuffer_wrapper(ctx, depthRb);
+ set_depth_renderbuffer(fb, wrapper);
+ ASSERT(fb->_DepthBuffer->Wrapped == depthRb);
+ }
+ }
+ else {
+ /* depthRb may be null */
+ set_depth_renderbuffer(fb, depthRb);
+ }
+}
+
+
+/**
+ * Update the framebuffer's _StencilBuffer field using the renderbuffer
+ * found at the given attachment index.
+ *
+ * If that attachment points to a combined GL_DEPTH_STENCIL renderbuffer,
+ * create and install a stencil wrapper/adaptor.
+ *
+ * \param fb the framebuffer whose _StencilBuffer field to update
+ * \param attIndex indicates the renderbuffer to possibly wrap
+ */
+void
+_mesa_update_stencil_buffer(GLcontext *ctx,
+ struct gl_framebuffer *fb,
+ GLuint attIndex)
+{
+ struct gl_renderbuffer *stencilRb;
+
+ ASSERT(attIndex == BUFFER_DEPTH ||
+ attIndex == BUFFER_STENCIL);
+
+ stencilRb = fb->Attachment[attIndex].Renderbuffer;
+
+ if (stencilRb && stencilRb->_ActualFormat == GL_DEPTH24_STENCIL8_EXT) {
+ /* The attached stencil buffer is a GL_DEPTH_STENCIL renderbuffer */
+ if (!fb->_StencilBuffer
+ || fb->_StencilBuffer->Wrapped != stencilRb
+ || fb->_StencilBuffer->_BaseFormat != GL_STENCIL_INDEX) {
+ /* need to update wrapper */
+ struct gl_renderbuffer *wrapper
+ = _mesa_new_s8_renderbuffer_wrapper(ctx, stencilRb);
+ set_stencil_renderbuffer(fb, wrapper);
+ ASSERT(fb->_StencilBuffer->Wrapped == stencilRb);
+ }
+ }
+ else {
+ /* stencilRb may be null */
+ set_stencil_renderbuffer(fb, stencilRb);
+ }
+}
+
+
+/**
+ * Update the list of color drawing renderbuffer pointers.
+ * Later, when we're rendering we'll loop from 0 to _NumColorDrawBuffers
+ * writing colors.
+ */
+static void
+update_color_draw_buffers(GLcontext *ctx, struct gl_framebuffer *fb)
+{
+ GLuint output;
+
+ /*
+ * Fragment programs can write to multiple colorbuffers with
+ * the GL_ARB_draw_buffers extension.
+ */
+ for (output = 0; output < ctx->Const.MaxDrawBuffers; output++) {
+ GLbitfield bufferMask = fb->_ColorDrawBufferMask[output];
+ GLuint count = 0;
+ GLuint i;
+ /* We need the inner loop here because glDrawBuffer(GL_FRONT_AND_BACK)
+ * can specify writing to two or four color buffers (for example).
+ */
+ for (i = 0; bufferMask && i < BUFFER_COUNT; i++) {
+ const GLuint bufferBit = 1 << i;
+ if (bufferBit & bufferMask) {
+ struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
+ if (rb) {
+ fb->_ColorDrawBuffers[output][count] = rb;
+ count++;
+ }
+ else {
+ /*_mesa_warning(ctx, "DrawBuffer names a missing buffer!\n");*/
+ }
+ bufferMask &= ~bufferBit;
+ }
+ }
+ fb->_NumColorDrawBuffers[output] = count;
+ }
+}
+
+
+/**
+ * Update the color read renderbuffer pointer.
+ * Unlike the DrawBuffer, we can only read from one (or zero) color buffers.
+ */
+static void
+update_color_read_buffer(GLcontext *ctx, struct gl_framebuffer *fb)
+{
+ (void) ctx;
+ if (fb->_ColorReadBufferIndex == -1) {
+ fb->_ColorReadBuffer = NULL; /* legal! */
+ }
+ else {
+ ASSERT(fb->_ColorReadBufferIndex >= 0);
+ ASSERT(fb->_ColorReadBufferIndex < BUFFER_COUNT);
+ fb->_ColorReadBuffer
+ = fb->Attachment[fb->_ColorReadBufferIndex].Renderbuffer;
+ }
+}
+
+
+/**
+ * Update state related to the current draw/read framebuffers.
+ * Specifically, update these framebuffer fields:
+ * _ColorDrawBuffers
+ * _NumColorDrawBuffers
+ * _ColorReadBuffer
+ * _DepthBuffer
+ * _StencilBuffer
+ * If the current framebuffer is user-created, make sure it's complete.
+ * The following functions can effect this state: glReadBuffer,
+ * glDrawBuffer, glDrawBuffersARB, glFramebufferRenderbufferEXT,
+ * glRenderbufferStorageEXT.
+ */
+void
+_mesa_update_framebuffer(GLcontext *ctx)
+{
+ struct gl_framebuffer *fb = ctx->DrawBuffer;
+
+ /* Completeness only matters for user-created framebuffers */
+ if (fb->Name != 0) {
+ _mesa_test_framebuffer_completeness(ctx, fb);
+ _mesa_update_framebuffer_visual(fb);
+ }
+
+ update_color_draw_buffers(ctx, fb);
+ update_color_read_buffer(ctx, fb);
+ _mesa_update_depth_buffer(ctx, fb, BUFFER_DEPTH);
+ _mesa_update_stencil_buffer(ctx, fb, BUFFER_STENCIL);
+
+ compute_depth_max(fb);
+}
+
+
+/**
+ * Check if the renderbuffer for a read operation (glReadPixels, glCopyPixels,
+ * glCopyTex[Sub]Image, etc. exists.
+ * \param format a basic image format such as GL_RGB, GL_RGBA, GL_ALPHA,
+ * GL_DEPTH_COMPONENT, etc. or GL_COLOR, GL_DEPTH, GL_STENCIL.
+ * \return GL_TRUE if buffer exists, GL_FALSE otherwise
+ */
+GLboolean
+_mesa_source_buffer_exists(GLcontext *ctx, GLenum format)
+{
+ const struct gl_renderbuffer_attachment *att
+ = ctx->ReadBuffer->Attachment;
+
+ if (ctx->ReadBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+ return GL_FALSE;
+ }
+
+ switch (format) {
+ case GL_COLOR:
+ case GL_RED:
+ case GL_GREEN:
+ case GL_BLUE:
+ case GL_ALPHA:
+ case GL_LUMINANCE:
+ case GL_LUMINANCE_ALPHA:
+ case GL_INTENSITY:
+ case GL_RGB:
+ case GL_BGR:
+ case GL_RGBA:
+ case GL_BGRA:
+ case GL_ABGR_EXT:
+ case GL_COLOR_INDEX:
+ if (ctx->ReadBuffer->_ColorReadBuffer == NULL) {
+ return GL_FALSE;
+ }
+ /* XXX enable this post 6.5 release:
+ ASSERT(ctx->ReadBuffer->_ColorReadBuffer->RedBits > 0 ||
+ ctx->ReadBuffer->_ColorReadBuffer->IndexBits > 0);
+ */
+ break;
+ case GL_DEPTH:
+ case GL_DEPTH_COMPONENT:
+ if (!att[BUFFER_DEPTH].Renderbuffer) {
+ return GL_FALSE;
+ }
+ ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);
+ break;
+ case GL_STENCIL:
+ case GL_STENCIL_INDEX:
+ if (!att[BUFFER_STENCIL].Renderbuffer) {
+ return GL_FALSE;
+ }
+ ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);
+ break;
+ case GL_DEPTH_STENCIL_EXT:
+ if (!att[BUFFER_DEPTH].Renderbuffer ||
+ !att[BUFFER_STENCIL].Renderbuffer) {
+ return GL_FALSE;
+ }
+ ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);
+ ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);
+ break;
+ default:
+ _mesa_problem(ctx,
+ "Unexpected format 0x%x in _mesa_source_buffer_exists",
+ format);
+ return GL_FALSE;
+ }
+
+ /* OK */
+ return GL_TRUE;
+}
+
+
+/**
+ * As above, but for drawing operations.
+ * XXX code do some code merging w/ above function.
+ */
+GLboolean
+_mesa_dest_buffer_exists(GLcontext *ctx, GLenum format)
+{
+ const struct gl_renderbuffer_attachment *att
+ = ctx->ReadBuffer->Attachment;
+
+ if (ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+ return GL_FALSE;
+ }
+
+ switch (format) {
+ case GL_COLOR:
+ case GL_RED:
+ case GL_GREEN:
+ case GL_BLUE:
+ case GL_ALPHA:
+ case GL_LUMINANCE:
+ case GL_LUMINANCE_ALPHA:
+ case GL_INTENSITY:
+ case GL_RGB:
+ case GL_BGR:
+ case GL_RGBA:
+ case GL_BGRA:
+ case GL_ABGR_EXT:
+ case GL_COLOR_INDEX:
+ /* nothing special */
+ /* Could assert that colorbuffer has RedBits > 0 */
+ break;
+ case GL_DEPTH:
+ case GL_DEPTH_COMPONENT:
+ if (!att[BUFFER_DEPTH].Renderbuffer) {
+ return GL_FALSE;
+ }
+ ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);
+ break;
+ case GL_STENCIL:
+ case GL_STENCIL_INDEX:
+ if (!att[BUFFER_STENCIL].Renderbuffer) {
+ return GL_FALSE;
+ }
+ ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);
+ break;
+ case GL_DEPTH_STENCIL_EXT:
+ if (!att[BUFFER_DEPTH].Renderbuffer ||
+ !att[BUFFER_STENCIL].Renderbuffer) {
+ return GL_FALSE;
+ }
+ ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);
+ ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);
+ break;
+ default:
+ _mesa_problem(ctx,
+ "Unexpected format 0x%x in _mesa_source_buffer_exists",
+ format);
+ return GL_FALSE;
+ }
+
+ /* OK */
+ return GL_TRUE;
+}