xserver and mesa git update 28-12-2010

1 files changed, 1084 insertions, 1063 deletions

diff --git a/mesalib/src/mesa/main/framebuffer.c b/mesalib/src/mesa/main/framebuffer.c
index a98c09cfb..f8c0c6379 100644
--- a/mesalib/src/mesa/main/framebuffer.c
+++ b/mesalib/src/mesa/main/framebuffer.c
@@ -1,1063 +1,1084 @@
-/*
- * Mesa 3-D graphics library
- * Version:  7.2
- *
- * Copyright (C) 1999-2008  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 "buffers.h"
-#include "context.h"
-#include "depthstencil.h"
-#include "enums.h"
-#include "formats.h"
-#include "macros.h"
-#include "mtypes.h"
-#include "fbobject.h"
-#include "framebuffer.h"
-#include "renderbuffer.h"
-#include "texobj.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;
-
-   /* Minimum resolvable depth value, for polygon offset */
-   fb->_MRD = (GLfloat)1.0 / fb->_DepthMaxF;
-}
-
-/**
- * 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_window_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) {
-      _mesa_initialize_user_framebuffer(fb, name);
-   }
-   return fb;
-}
-
-
-/**
- * Initialize a gl_framebuffer object.  Typically used to initialize
- * window system-created framebuffers, not user-created framebuffers.
- * \sa _mesa_initialize_user_framebuffer
- */
-void
-_mesa_initialize_window_framebuffer(struct gl_framebuffer *fb,
-				     const GLvisual *visual)
-{
-   assert(fb);
-   assert(visual);
-
-   memset(fb, 0, sizeof(struct gl_framebuffer));
-
-   _glthread_INIT_MUTEX(fb->Mutex);
-
-   fb->RefCount = 1;
-
-   /* save the visual */
-   fb->Visual = *visual;
-
-   /* Init read/draw renderbuffer state */
-   if (visual->doubleBufferMode) {
-      fb->_NumColorDrawBuffers = 1;
-      fb->ColorDrawBuffer[0] = GL_BACK;
-      fb->_ColorDrawBufferIndexes[0] = BUFFER_BACK_LEFT;
-      fb->ColorReadBuffer = GL_BACK;
-      fb->_ColorReadBufferIndex = BUFFER_BACK_LEFT;
-   }
-   else {
-      fb->_NumColorDrawBuffers = 1;
-      fb->ColorDrawBuffer[0] = GL_FRONT;
-      fb->_ColorDrawBufferIndexes[0] = BUFFER_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);
-}
-
-
-/**
- * Initialize a user-created gl_framebuffer object.
- * \sa _mesa_initialize_window_framebuffer
- */
-void
-_mesa_initialize_user_framebuffer(struct gl_framebuffer *fb, GLuint name)
-{
-   assert(fb);
-   assert(name);
-
-   memset(fb, 0, sizeof(struct gl_framebuffer));
-
-   fb->Name = name;
-   fb->RefCount = 1;
-   fb->_NumColorDrawBuffers = 1;
-   fb->ColorDrawBuffer[0] = GL_COLOR_ATTACHMENT0_EXT;
-   fb->_ColorDrawBufferIndexes[0] = BUFFER_COLOR0;
-   fb->ColorReadBuffer = GL_COLOR_ATTACHMENT0_EXT;
-   fb->_ColorReadBufferIndex = BUFFER_COLOR0;
-   fb->Delete = _mesa_destroy_framebuffer;
-   _glthread_INIT_MUTEX(fb->Mutex);
-}
-
-
-/**
- * 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) {
-      _mesa_free_framebuffer_data(fb);
-      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);
-   assert(fb->RefCount == 0);
-
-   _glthread_DESTROY_MUTEX(fb->Mutex);
-
-   for (i = 0; i < BUFFER_COUNT; i++) {
-      struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
-      if (att->Renderbuffer) {
-         _mesa_reference_renderbuffer(&att->Renderbuffer, NULL);
-      }
-      if (att->Texture) {
-         _mesa_reference_texobj(&att->Texture, NULL);
-      }
-      ASSERT(!att->Renderbuffer);
-      ASSERT(!att->Texture);
-      att->Type = GL_NONE;
-   }
-
-   /* unbind _Depth/_StencilBuffer to decr ref counts */
-   _mesa_reference_renderbuffer(&fb->_DepthBuffer, NULL);
-   _mesa_reference_renderbuffer(&fb->_StencilBuffer, NULL);
-}
-
-
-/**
- * Set *ptr to point to fb, with refcounting and locking.
- */
-void
-_mesa_reference_framebuffer(struct gl_framebuffer **ptr,
-                            struct gl_framebuffer *fb)
-{
-   assert(ptr);
-   if (*ptr == fb) {
-      /* no change */
-      return;
-   }
-
-   if (*ptr) {
-      /* unreference old renderbuffer */
-      GLboolean deleteFlag = GL_FALSE;
-      struct gl_framebuffer *oldFb = *ptr;
-
-      _glthread_LOCK_MUTEX(oldFb->Mutex);
-      ASSERT(oldFb->RefCount > 0);
-      oldFb->RefCount--;
-      deleteFlag = (oldFb->RefCount == 0);
-      _glthread_UNLOCK_MUTEX(oldFb->Mutex);
-      
-      if (deleteFlag)
-         oldFb->Delete(oldFb);
-
-      *ptr = NULL;
-   }
-   assert(!*ptr);
-
-   if (fb) {
-      _glthread_LOCK_MUTEX(fb->Mutex);
-      fb->RefCount++;
-      _glthread_UNLOCK_MUTEX(fb->Mutex);
-      *ptr = fb;
-   }
-}
-
-
-/**
- * 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) {
-            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;
-
-   if (ctx) {
-      /* update scissor / window bounds */
-      _mesa_update_draw_buffer_bounds(ctx);
-      /* Signal new buffer state so that swrast will update its clipping
-       * info (the CLIP_BIT flag).
-       */
-      ctx->NewState |= _NEW_BUFFERS;
-   }
-}
-
-
-
-/**
- * XXX THIS IS OBSOLETE - drivers should take care of detecting window
- * size changes and act accordingly, likely calling _mesa_resize_framebuffer().
- *
- * GL_MESA_resize_buffers extension.
- *
- * When this function is called, we'll ask the window system how large
- * the current window is.  If it's a new size, we'll call the driver's
- * ResizeBuffers function.  The driver will then resize its color buffers
- * as needed, and maybe call the swrast's routine for reallocating
- * swrast-managed depth/stencil/accum/etc buffers.
- * \note This function should only be called through the GL API, not
- * from device drivers (as was done in the past).
- */
-void
-_mesa_resizebuffers( GLcontext *ctx )
-{
-   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx );
-
-   if (MESA_VERBOSE & VERBOSE_API)
-      _mesa_debug(ctx, "glResizeBuffersMESA\n");
-
-   if (!ctx->Driver.GetBufferSize) {
-      return;
-   }
-
-   if (ctx->WinSysDrawBuffer) {
-      GLuint newWidth, newHeight;
-      GLframebuffer *buffer = ctx->WinSysDrawBuffer;
-
-      assert(buffer->Name == 0);
-
-      /* ask device driver for size of output buffer */
-      ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight );
-
-      /* see if size of device driver's color buffer (window) has changed */
-      if (buffer->Width != newWidth || buffer->Height != newHeight) {
-         if (ctx->Driver.ResizeBuffers)
-            ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight );
-      }
-   }
-
-   if (ctx->WinSysReadBuffer
-       && ctx->WinSysReadBuffer != ctx->WinSysDrawBuffer) {
-      GLuint newWidth, newHeight;
-      GLframebuffer *buffer = ctx->WinSysReadBuffer;
-
-      assert(buffer->Name == 0);
-
-      /* ask device driver for size of read buffer */
-      ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight );
-
-      /* see if size of device driver's color buffer (window) has changed */
-      if (buffer->Width != newWidth || buffer->Height != newHeight) {
-         if (ctx->Driver.ResizeBuffers)
-            ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight );
-      }
-   }
-
-   ctx->NewState |= _NEW_BUFFERS;  /* to update scissor / window bounds */
-}
-
-
-/*
- * XXX THIS IS OBSOLETE
- */
-void GLAPIENTRY
-_mesa_ResizeBuffersMESA( void )
-{
-   GET_CURRENT_CONTEXT(ctx);
-
-   if (ctx->Extensions.MESA_resize_buffers)
-      _mesa_resizebuffers( 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 the min size.
- * Note: this is only intended for user-created framebuffers, not
- * window-system framebuffes.
- */
-static void
-update_framebuffer_size(GLcontext *ctx, struct gl_framebuffer *fb)
-{
-   GLuint minWidth = ~0, minHeight = ~0;
-   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) {
-         minWidth = MIN2(minWidth, rb->Width);
-         minHeight = MIN2(minHeight, rb->Height);
-      }
-   }
-
-   if (minWidth != ~0) {
-      fb->Width = minWidth;
-      fb->Height = minHeight;
-   }
-   else {
-      fb->Width = 0;
-      fb->Height = 0;
-   }
-}
-
-
-/**
- * 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(ctx, 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 may apply to user-created framebuffers or window system 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;
-
-   memset(&fb->Visual, 0, 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 renderbuffer */
-   for (i = 0; i < BUFFER_COUNT; i++) {
-      if (fb->Attachment[i].Renderbuffer) {
-         const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
-         const GLenum baseFormat = _mesa_get_format_base_format(rb->Format);
-         const gl_format fmt = rb->Format;
-         
-         if (baseFormat == GL_RGBA || baseFormat == GL_RGB ||
-	     baseFormat == GL_ALPHA) {
-            fb->Visual.redBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
-            fb->Visual.greenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
-            fb->Visual.blueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
-            fb->Visual.alphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
-            fb->Visual.rgbBits = fb->Visual.redBits
-               + fb->Visual.greenBits + fb->Visual.blueBits;
-            fb->Visual.floatMode = GL_FALSE;
-            fb->Visual.samples = rb->NumSamples;
-            break;
-         }
-      }
-   }
-
-   if (fb->Attachment[BUFFER_DEPTH].Renderbuffer) {
-      const struct gl_renderbuffer *rb =
-         fb->Attachment[BUFFER_DEPTH].Renderbuffer;
-      const gl_format fmt = rb->Format;
-      fb->Visual.haveDepthBuffer = GL_TRUE;
-      fb->Visual.depthBits = _mesa_get_format_bits(fmt, GL_DEPTH_BITS);
-   }
-
-   if (fb->Attachment[BUFFER_STENCIL].Renderbuffer) {
-      const struct gl_renderbuffer *rb =
-         fb->Attachment[BUFFER_STENCIL].Renderbuffer;
-      const gl_format fmt = rb->Format;
-      fb->Visual.haveStencilBuffer = GL_TRUE;
-      fb->Visual.stencilBits = _mesa_get_format_bits(fmt, GL_STENCIL_BITS);
-   }
-
-   if (fb->Attachment[BUFFER_ACCUM].Renderbuffer) {
-      const struct gl_renderbuffer *rb =
-         fb->Attachment[BUFFER_ACCUM].Renderbuffer;
-      const gl_format fmt = rb->Format;
-      fb->Visual.haveAccumBuffer = GL_TRUE;
-      fb->Visual.accumRedBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
-      fb->Visual.accumGreenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
-      fb->Visual.accumBlueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
-      fb->Visual.accumAlphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
-   }
-
-   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 && _mesa_is_format_packed_depth_stencil(depthRb->Format)) {
-      /* The attached depth buffer is a GL_DEPTH_STENCIL renderbuffer */
-      if (!fb->_DepthBuffer
-          || fb->_DepthBuffer->Wrapped != depthRb
-          || _mesa_get_format_base_format(fb->_DepthBuffer->Format) != GL_DEPTH_COMPONENT) {
-         /* need to update wrapper */
-         struct gl_renderbuffer *wrapper
-            = _mesa_new_z24_renderbuffer_wrapper(ctx, depthRb);
-         _mesa_reference_renderbuffer(&fb->_DepthBuffer, wrapper);
-         ASSERT(fb->_DepthBuffer->Wrapped == depthRb);
-      }
-   }
-   else {
-      /* depthRb may be null */
-      _mesa_reference_renderbuffer(&fb->_DepthBuffer, 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 && _mesa_is_format_packed_depth_stencil(stencilRb->Format)) {
-      /* The attached stencil buffer is a GL_DEPTH_STENCIL renderbuffer */
-      if (!fb->_StencilBuffer
-          || fb->_StencilBuffer->Wrapped != stencilRb
-          || _mesa_get_format_base_format(fb->_StencilBuffer->Format) != GL_STENCIL_INDEX) {
-         /* need to update wrapper */
-         struct gl_renderbuffer *wrapper
-            = _mesa_new_s8_renderbuffer_wrapper(ctx, stencilRb);
-         _mesa_reference_renderbuffer(&fb->_StencilBuffer, wrapper);
-         ASSERT(fb->_StencilBuffer->Wrapped == stencilRb);
-      }
-   }
-   else {
-      /* stencilRb may be null */
-      _mesa_reference_renderbuffer(&fb->_StencilBuffer, stencilRb);
-   }
-}
-
-
-/*
- * Example DrawBuffers scenarios:
- *
- * 1. glDrawBuffer(GL_FRONT_AND_BACK), fixed-func or shader writes to
- * "gl_FragColor" or program writes to the "result.color" register:
- *
- *   fragment color output   renderbuffer
- *   ---------------------   ---------------
- *   color[0]                Front, Back
- *
- *
- * 2. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]), shader writes to
- * gl_FragData[i] or program writes to result.color[i] registers:
- *
- *   fragment color output   renderbuffer
- *   ---------------------   ---------------
- *   color[0]                Front
- *   color[1]                Aux0
- *   color[3]                Aux1
- *
- *
- * 3. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]) and shader writes to
- * gl_FragColor, or fixed function:
- *
- *   fragment color output   renderbuffer
- *   ---------------------   ---------------
- *   color[0]                Front, Aux0, Aux1
- *
- *
- * In either case, the list of renderbuffers is stored in the
- * framebuffer->_ColorDrawBuffers[] array and
- * framebuffer->_NumColorDrawBuffers indicates the number of buffers.
- * The renderer (like swrast) has to look at the current fragment shader
- * to see if it writes to gl_FragColor vs. gl_FragData[i] to determine
- * how to map color outputs to renderbuffers.
- *
- * Note that these two calls are equivalent (for fixed function fragment
- * shading anyway):
- *   a)  glDrawBuffer(GL_FRONT_AND_BACK);  (assuming non-stereo framebuffer)
- *   b)  glDrawBuffers(2, [GL_FRONT_LEFT, GL_BACK_LEFT]);
- */
-
-
-
-
-/**
- * Update the (derived) 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;
-
-   /* set 0th buffer to NULL now in case _NumColorDrawBuffers is zero */
-   fb->_ColorDrawBuffers[0] = NULL;
-
-   for (output = 0; output < fb->_NumColorDrawBuffers; output++) {
-      GLint buf = fb->_ColorDrawBufferIndexes[output];
-      if (buf >= 0) {
-         fb->_ColorDrawBuffers[output] = fb->Attachment[buf].Renderbuffer;
-      }
-      else {
-         fb->_ColorDrawBuffers[output] = NULL;
-      }
-   }
-}
-
-
-/**
- * Update the (derived) 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->DeletePending ||
-       fb->Width == 0 ||
-       fb->Height == 0) {
-      fb->_ColorReadBuffer = NULL; /* legal! */
-   }
-   else {
-      ASSERT(fb->_ColorReadBufferIndex >= 0);
-      ASSERT(fb->_ColorReadBufferIndex < BUFFER_COUNT);
-      fb->_ColorReadBuffer
-         = fb->Attachment[fb->_ColorReadBufferIndex].Renderbuffer;
-   }
-}
-
-
-/**
- * Update a gl_framebuffer's derived state.
- *
- * Specifically, update these framebuffer fields:
- *    _ColorDrawBuffers
- *    _NumColorDrawBuffers
- *    _ColorReadBuffer
- *    _DepthBuffer
- *    _StencilBuffer
- *
- * If the framebuffer is user-created, make sure it's complete.
- *
- * The following functions (at least) can effect framebuffer state:
- * glReadBuffer, glDrawBuffer, glDrawBuffersARB, glFramebufferRenderbufferEXT,
- * glRenderbufferStorageEXT.
- */
-static void
-update_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb)
-{
-   if (fb->Name == 0) {
-      /* This is a window-system framebuffer */
-      /* Need to update the FB's GL_DRAW_BUFFER state to match the
-       * context state (GL_READ_BUFFER too).
-       */
-      if (fb->ColorDrawBuffer[0] != ctx->Color.DrawBuffer[0]) {
-         _mesa_drawbuffers(ctx, ctx->Const.MaxDrawBuffers,
-                           ctx->Color.DrawBuffer, NULL);
-      }
-      if (fb->ColorReadBuffer != ctx->Pixel.ReadBuffer) {
-         
-      }
-   }
-   else {
-      /* This is a user-created framebuffer.
-       * Completeness only matters for user-created framebuffers.
-       */
-      if (fb->_Status != GL_FRAMEBUFFER_COMPLETE) {
-         _mesa_test_framebuffer_completeness(ctx, fb);
-      }
-   }
-
-   /* Strictly speaking, we don't need to update the draw-state
-    * if this FB is bound as ctx->ReadBuffer (and conversely, the
-    * read-state if this FB is bound as ctx->DrawBuffer), but no
-    * harm.
-    */
-   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);
-}
-
-
-/**
- * Update state related to the current draw/read framebuffers.
- */
-void
-_mesa_update_framebuffer(GLcontext *ctx)
-{
-   struct gl_framebuffer *drawFb;
-   struct gl_framebuffer *readFb;
-
-   assert(ctx);
-   drawFb = ctx->DrawBuffer;
-   readFb = ctx->ReadBuffer;
-
-   update_framebuffer(ctx, drawFb);
-   if (readFb != drawFb)
-      update_framebuffer(ctx, readFb);
-}
-
-
-/**
- * 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 we don't know the framebuffer status, update it now */
-   if (ctx->ReadBuffer->_Status == 0) {
-      _mesa_test_framebuffer_completeness(ctx, ctx->ReadBuffer);
-   }
-
-   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;
-      }
-      ASSERT(_mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_RED_BITS) > 0 ||
-             _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_ALPHA_BITS) > 0 ||
-             _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_INDEX_BITS) > 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 could do some code merging w/ above function.
- */
-GLboolean
-_mesa_dest_buffer_exists(GLcontext *ctx, GLenum format)
-{
-   const struct gl_renderbuffer_attachment *att = ctx->DrawBuffer->Attachment;
-
-   /* If we don't know the framebuffer status, update it now */
-   if (ctx->DrawBuffer->_Status == 0) {
-      _mesa_test_framebuffer_completeness(ctx, ctx->DrawBuffer);
-   }
-
-   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 since GL_DRAW_BUFFER could be GL_NONE. */
-      /* 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_dest_buffer_exists",
-                    format);
-      return GL_FALSE;
-   }
-
-   /* OK */
-   return GL_TRUE;
-}
-
-
-/**
- * Used to answer the GL_IMPLEMENTATION_COLOR_READ_FORMAT_OES query.
- */
-GLenum
-_mesa_get_color_read_format(GLcontext *ctx)
-{
-   switch (ctx->ReadBuffer->_ColorReadBuffer->Format) {
-   case MESA_FORMAT_ARGB8888:
-      return GL_BGRA;
-   case MESA_FORMAT_RGB565:
-      return GL_BGR;
-   default:
-      return GL_RGBA;
-   }
-}
-
-
-/**
- * Used to answer the GL_IMPLEMENTATION_COLOR_READ_TYPE_OES query.
- */
-GLenum
-_mesa_get_color_read_type(GLcontext *ctx)
-{
-   switch (ctx->ReadBuffer->_ColorReadBuffer->Format) {
-   case MESA_FORMAT_ARGB8888:
-      return GL_UNSIGNED_BYTE;
-   case MESA_FORMAT_RGB565:
-      return GL_UNSIGNED_SHORT_5_6_5_REV;
-   default:
-      return GL_UNSIGNED_BYTE;
-   }
-}
-
-
-/**
- * Print framebuffer info to stderr, for debugging.
- */
-void
-_mesa_print_framebuffer(const struct gl_framebuffer *fb)
-{
-   GLuint i;
-
-   fprintf(stderr, "Mesa Framebuffer %u at %p\n", fb->Name, (void *) fb);
-   fprintf(stderr, "  Size: %u x %u  Status: %s\n", fb->Width, fb->Height,
-           _mesa_lookup_enum_by_nr(fb->_Status));
-   fprintf(stderr, "  Attachments:\n");
-
-   for (i = 0; i < BUFFER_COUNT; i++) {
-      const struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
-      if (att->Type == GL_TEXTURE) {
-         const struct gl_texture_image *texImage;
-         fprintf(stderr,
-                 "  %2d: Texture %u, level %u, face %u, slice %u, complete %d\n",
-                 i, att->Texture->Name, att->TextureLevel, att->CubeMapFace,
-                 att->Zoffset, att->Complete);
-         texImage = att->Texture->Image[att->CubeMapFace][att->TextureLevel];
-         fprintf(stderr, "       Size: %u x %u x %u  Format %s\n",
-                 texImage->Width, texImage->Height, texImage->Depth,
-                 _mesa_get_format_name(texImage->TexFormat));
-      }
-      else if (att->Type == GL_RENDERBUFFER) {
-         fprintf(stderr, "  %2d: Renderbuffer %u, complete %d\n",
-                 i, att->Renderbuffer->Name, att->Complete);
-         fprintf(stderr, "       Size: %u x %u  Format %s\n",
-                 att->Renderbuffer->Width, att->Renderbuffer->Height,
-                 _mesa_get_format_name(att->Renderbuffer->Format));
-      }
-      else {
-         fprintf(stderr, "  %2d: none\n", i);
-      }
-   }
-}
+/*

+ * Mesa 3-D graphics library

+ * Version:  7.2

+ *

+ * Copyright (C) 1999-2008  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 "buffers.h"

+#include "context.h"

+#include "depthstencil.h"

+#include "enums.h"

+#include "formats.h"

+#include "macros.h"

+#include "mtypes.h"

+#include "fbobject.h"

+#include "framebuffer.h"

+#include "renderbuffer.h"

+#include "texobj.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;

+

+   /* Minimum resolvable depth value, for polygon offset */

+   fb->_MRD = (GLfloat)1.0 / fb->_DepthMaxF;

+}

+

+/**

+ * 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 struct gl_config *visual)

+{

+   struct gl_framebuffer *fb = CALLOC_STRUCT(gl_framebuffer);

+   assert(visual);

+   if (fb) {

+      _mesa_initialize_window_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(struct gl_context *ctx, GLuint name)

+{

+   struct gl_framebuffer *fb;

+   (void) ctx;

+   assert(name != 0);

+   fb = CALLOC_STRUCT(gl_framebuffer);

+   if (fb) {

+      _mesa_initialize_user_framebuffer(fb, name);

+   }

+   return fb;

+}

+

+

+/**

+ * Initialize a gl_framebuffer object.  Typically used to initialize

+ * window system-created framebuffers, not user-created framebuffers.

+ * \sa _mesa_initialize_user_framebuffer

+ */

+void

+_mesa_initialize_window_framebuffer(struct gl_framebuffer *fb,

+				     const struct gl_config *visual)

+{

+   assert(fb);

+   assert(visual);

+

+   memset(fb, 0, sizeof(struct gl_framebuffer));

+

+   _glthread_INIT_MUTEX(fb->Mutex);

+

+   fb->RefCount = 1;

+

+   /* save the visual */

+   fb->Visual = *visual;

+

+   /* Init read/draw renderbuffer state */

+   if (visual->doubleBufferMode) {

+      fb->_NumColorDrawBuffers = 1;

+      fb->ColorDrawBuffer[0] = GL_BACK;

+      fb->_ColorDrawBufferIndexes[0] = BUFFER_BACK_LEFT;

+      fb->ColorReadBuffer = GL_BACK;

+      fb->_ColorReadBufferIndex = BUFFER_BACK_LEFT;

+   }

+   else {

+      fb->_NumColorDrawBuffers = 1;

+      fb->ColorDrawBuffer[0] = GL_FRONT;

+      fb->_ColorDrawBufferIndexes[0] = BUFFER_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);

+}

+

+

+/**

+ * Initialize a user-created gl_framebuffer object.

+ * \sa _mesa_initialize_window_framebuffer

+ */

+void

+_mesa_initialize_user_framebuffer(struct gl_framebuffer *fb, GLuint name)

+{

+   assert(fb);

+   assert(name);

+

+   memset(fb, 0, sizeof(struct gl_framebuffer));

+

+   fb->Name = name;

+   fb->RefCount = 1;

+   fb->_NumColorDrawBuffers = 1;

+   fb->ColorDrawBuffer[0] = GL_COLOR_ATTACHMENT0_EXT;

+   fb->_ColorDrawBufferIndexes[0] = BUFFER_COLOR0;

+   fb->ColorReadBuffer = GL_COLOR_ATTACHMENT0_EXT;

+   fb->_ColorReadBufferIndex = BUFFER_COLOR0;

+   fb->Delete = _mesa_destroy_framebuffer;

+   _glthread_INIT_MUTEX(fb->Mutex);

+}

+

+

+/**

+ * 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) {

+      _mesa_free_framebuffer_data(fb);

+      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);

+   assert(fb->RefCount == 0);

+

+   _glthread_DESTROY_MUTEX(fb->Mutex);

+

+   for (i = 0; i < BUFFER_COUNT; i++) {

+      struct gl_renderbuffer_attachment *att = &fb->Attachment[i];

+      if (att->Renderbuffer) {

+         _mesa_reference_renderbuffer(&att->Renderbuffer, NULL);

+      }

+      if (att->Texture) {

+         _mesa_reference_texobj(&att->Texture, NULL);

+      }

+      ASSERT(!att->Renderbuffer);

+      ASSERT(!att->Texture);

+      att->Type = GL_NONE;

+   }

+

+   /* unbind _Depth/_StencilBuffer to decr ref counts */

+   _mesa_reference_renderbuffer(&fb->_DepthBuffer, NULL);

+   _mesa_reference_renderbuffer(&fb->_StencilBuffer, NULL);

+}

+

+

+/**

+ * Set *ptr to point to fb, with refcounting and locking.

+ */

+void

+_mesa_reference_framebuffer(struct gl_framebuffer **ptr,

+                            struct gl_framebuffer *fb)

+{

+   assert(ptr);

+   if (*ptr == fb) {

+      /* no change */

+      return;

+   }

+

+   if (*ptr) {

+      /* unreference old renderbuffer */

+      GLboolean deleteFlag = GL_FALSE;

+      struct gl_framebuffer *oldFb = *ptr;

+

+      _glthread_LOCK_MUTEX(oldFb->Mutex);

+      ASSERT(oldFb->RefCount > 0);

+      oldFb->RefCount--;

+      deleteFlag = (oldFb->RefCount == 0);

+      _glthread_UNLOCK_MUTEX(oldFb->Mutex);

+      

+      if (deleteFlag)

+         oldFb->Delete(oldFb);

+

+      *ptr = NULL;

+   }

+   assert(!*ptr);

+

+   if (fb) {

+      _glthread_LOCK_MUTEX(fb->Mutex);

+      fb->RefCount++;

+      _glthread_UNLOCK_MUTEX(fb->Mutex);

+      *ptr = fb;

+   }

+}

+

+

+/**

+ * 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(struct gl_context *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) {

+            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;

+

+   if (ctx) {

+      /* update scissor / window bounds */

+      _mesa_update_draw_buffer_bounds(ctx);

+      /* Signal new buffer state so that swrast will update its clipping

+       * info (the CLIP_BIT flag).

+       */

+      ctx->NewState |= _NEW_BUFFERS;

+   }

+}

+

+

+

+/**

+ * XXX THIS IS OBSOLETE - drivers should take care of detecting window

+ * size changes and act accordingly, likely calling _mesa_resize_framebuffer().

+ *

+ * GL_MESA_resize_buffers extension.

+ *

+ * When this function is called, we'll ask the window system how large

+ * the current window is.  If it's a new size, we'll call the driver's

+ * ResizeBuffers function.  The driver will then resize its color buffers

+ * as needed, and maybe call the swrast's routine for reallocating

+ * swrast-managed depth/stencil/accum/etc buffers.

+ * \note This function should only be called through the GL API, not

+ * from device drivers (as was done in the past).

+ */

+void

+_mesa_resizebuffers( struct gl_context *ctx )

+{

+   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx );

+

+   if (MESA_VERBOSE & VERBOSE_API)

+      _mesa_debug(ctx, "glResizeBuffersMESA\n");

+

+   if (!ctx->Driver.GetBufferSize) {

+      return;

+   }

+

+   if (ctx->WinSysDrawBuffer) {

+      GLuint newWidth, newHeight;

+      struct gl_framebuffer *buffer = ctx->WinSysDrawBuffer;

+

+      assert(buffer->Name == 0);

+

+      /* ask device driver for size of output buffer */

+      ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight );

+

+      /* see if size of device driver's color buffer (window) has changed */

+      if (buffer->Width != newWidth || buffer->Height != newHeight) {

+         if (ctx->Driver.ResizeBuffers)

+            ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight );

+      }

+   }

+

+   if (ctx->WinSysReadBuffer

+       && ctx->WinSysReadBuffer != ctx->WinSysDrawBuffer) {

+      GLuint newWidth, newHeight;

+      struct gl_framebuffer *buffer = ctx->WinSysReadBuffer;

+

+      assert(buffer->Name == 0);

+

+      /* ask device driver for size of read buffer */

+      ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight );

+

+      /* see if size of device driver's color buffer (window) has changed */

+      if (buffer->Width != newWidth || buffer->Height != newHeight) {

+         if (ctx->Driver.ResizeBuffers)

+            ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight );

+      }

+   }

+

+   ctx->NewState |= _NEW_BUFFERS;  /* to update scissor / window bounds */

+}

+

+

+/*

+ * XXX THIS IS OBSOLETE

+ */

+void GLAPIENTRY

+_mesa_ResizeBuffersMESA( void )

+{

+   GET_CURRENT_CONTEXT(ctx);

+

+   if (ctx->Extensions.MESA_resize_buffers)

+      _mesa_resizebuffers( 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 the min size.

+ * Note: this is only intended for user-created framebuffers, not

+ * window-system framebuffes.

+ */

+static void

+update_framebuffer_size(struct gl_context *ctx, struct gl_framebuffer *fb)

+{

+   GLuint minWidth = ~0, minHeight = ~0;

+   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) {

+         minWidth = MIN2(minWidth, rb->Width);

+         minHeight = MIN2(minHeight, rb->Height);

+      }

+   }

+

+   if (minWidth != ~0) {

+      fb->Width = minWidth;

+      fb->Height = minHeight;

+   }

+   else {

+      fb->Width = 0;

+      fb->Height = 0;

+   }

+}

+

+

+/**

+ * 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(struct gl_context *ctx)

+{

+   struct gl_framebuffer *buffer = ctx->DrawBuffer;

+

+   if (!buffer)

+      return;

+

+   if (buffer->Name) {

+      /* user-created framebuffer size depends on the renderbuffers */

+      update_framebuffer_size(ctx, 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 may apply to user-created framebuffers or window system 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;

+

+   memset(&fb->Visual, 0, 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 renderbuffer */

+   for (i = 0; i < BUFFER_COUNT; i++) {

+      if (fb->Attachment[i].Renderbuffer) {

+         const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;

+         const GLenum baseFormat = _mesa_get_format_base_format(rb->Format);

+         const gl_format fmt = rb->Format;

+         

+         if (baseFormat == GL_RGBA || baseFormat == GL_RGB ||

+	     baseFormat == GL_ALPHA) {

+            fb->Visual.redBits = _mesa_get_format_bits(fmt, GL_RED_BITS);

+            fb->Visual.greenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);

+            fb->Visual.blueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);

+            fb->Visual.alphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);

+            fb->Visual.rgbBits = fb->Visual.redBits

+               + fb->Visual.greenBits + fb->Visual.blueBits;

+            fb->Visual.floatMode = GL_FALSE;

+            fb->Visual.samples = rb->NumSamples;

+            break;

+         }

+      }

+   }

+

+   if (fb->Attachment[BUFFER_DEPTH].Renderbuffer) {

+      const struct gl_renderbuffer *rb =

+         fb->Attachment[BUFFER_DEPTH].Renderbuffer;

+      const gl_format fmt = rb->Format;

+      fb->Visual.haveDepthBuffer = GL_TRUE;

+      fb->Visual.depthBits = _mesa_get_format_bits(fmt, GL_DEPTH_BITS);

+   }

+

+   if (fb->Attachment[BUFFER_STENCIL].Renderbuffer) {

+      const struct gl_renderbuffer *rb =

+         fb->Attachment[BUFFER_STENCIL].Renderbuffer;

+      const gl_format fmt = rb->Format;

+      fb->Visual.haveStencilBuffer = GL_TRUE;

+      fb->Visual.stencilBits = _mesa_get_format_bits(fmt, GL_STENCIL_BITS);

+   }

+

+   if (fb->Attachment[BUFFER_ACCUM].Renderbuffer) {

+      const struct gl_renderbuffer *rb =

+         fb->Attachment[BUFFER_ACCUM].Renderbuffer;

+      const gl_format fmt = rb->Format;

+      fb->Visual.haveAccumBuffer = GL_TRUE;

+      fb->Visual.accumRedBits = _mesa_get_format_bits(fmt, GL_RED_BITS);

+      fb->Visual.accumGreenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);

+      fb->Visual.accumBlueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);

+      fb->Visual.accumAlphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);

+   }

+

+   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(struct gl_context *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 && _mesa_is_format_packed_depth_stencil(depthRb->Format)) {

+      /* The attached depth buffer is a GL_DEPTH_STENCIL renderbuffer */

+      if (!fb->_DepthBuffer

+          || fb->_DepthBuffer->Wrapped != depthRb

+          || _mesa_get_format_base_format(fb->_DepthBuffer->Format) != GL_DEPTH_COMPONENT) {

+         /* need to update wrapper */

+         struct gl_renderbuffer *wrapper

+            = _mesa_new_z24_renderbuffer_wrapper(ctx, depthRb);

+         _mesa_reference_renderbuffer(&fb->_DepthBuffer, wrapper);

+         ASSERT(fb->_DepthBuffer->Wrapped == depthRb);

+      }

+   }

+   else {

+      /* depthRb may be null */

+      _mesa_reference_renderbuffer(&fb->_DepthBuffer, 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(struct gl_context *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 && _mesa_is_format_packed_depth_stencil(stencilRb->Format)) {

+      /* The attached stencil buffer is a GL_DEPTH_STENCIL renderbuffer */

+      if (!fb->_StencilBuffer

+          || fb->_StencilBuffer->Wrapped != stencilRb

+          || _mesa_get_format_base_format(fb->_StencilBuffer->Format) != GL_STENCIL_INDEX) {

+         /* need to update wrapper */

+         struct gl_renderbuffer *wrapper

+            = _mesa_new_s8_renderbuffer_wrapper(ctx, stencilRb);

+         _mesa_reference_renderbuffer(&fb->_StencilBuffer, wrapper);

+         ASSERT(fb->_StencilBuffer->Wrapped == stencilRb);

+      }

+   }

+   else {

+      /* stencilRb may be null */

+      _mesa_reference_renderbuffer(&fb->_StencilBuffer, stencilRb);

+   }

+}

+

+

+/*

+ * Example DrawBuffers scenarios:

+ *

+ * 1. glDrawBuffer(GL_FRONT_AND_BACK), fixed-func or shader writes to

+ * "gl_FragColor" or program writes to the "result.color" register:

+ *

+ *   fragment color output   renderbuffer

+ *   ---------------------   ---------------

+ *   color[0]                Front, Back

+ *

+ *

+ * 2. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]), shader writes to

+ * gl_FragData[i] or program writes to result.color[i] registers:

+ *

+ *   fragment color output   renderbuffer

+ *   ---------------------   ---------------

+ *   color[0]                Front

+ *   color[1]                Aux0

+ *   color[3]                Aux1

+ *

+ *

+ * 3. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]) and shader writes to

+ * gl_FragColor, or fixed function:

+ *

+ *   fragment color output   renderbuffer

+ *   ---------------------   ---------------

+ *   color[0]                Front, Aux0, Aux1

+ *

+ *

+ * In either case, the list of renderbuffers is stored in the

+ * framebuffer->_ColorDrawBuffers[] array and

+ * framebuffer->_NumColorDrawBuffers indicates the number of buffers.

+ * The renderer (like swrast) has to look at the current fragment shader

+ * to see if it writes to gl_FragColor vs. gl_FragData[i] to determine

+ * how to map color outputs to renderbuffers.

+ *

+ * Note that these two calls are equivalent (for fixed function fragment

+ * shading anyway):

+ *   a)  glDrawBuffer(GL_FRONT_AND_BACK);  (assuming non-stereo framebuffer)

+ *   b)  glDrawBuffers(2, [GL_FRONT_LEFT, GL_BACK_LEFT]);

+ */

+

+

+

+

+/**

+ * Update the (derived) 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(struct gl_context *ctx, struct gl_framebuffer *fb)

+{

+   GLuint output;

+

+   /* set 0th buffer to NULL now in case _NumColorDrawBuffers is zero */

+   fb->_ColorDrawBuffers[0] = NULL;

+

+   for (output = 0; output < fb->_NumColorDrawBuffers; output++) {

+      GLint buf = fb->_ColorDrawBufferIndexes[output];

+      if (buf >= 0) {

+         fb->_ColorDrawBuffers[output] = fb->Attachment[buf].Renderbuffer;

+      }

+      else {

+         fb->_ColorDrawBuffers[output] = NULL;

+      }

+   }

+}

+

+

+/**

+ * Update the (derived) color read renderbuffer pointer.

+ * Unlike the DrawBuffer, we can only read from one (or zero) color buffers.

+ */

+static void

+update_color_read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb)

+{

+   (void) ctx;

+   if (fb->_ColorReadBufferIndex == -1 ||

+       fb->DeletePending ||

+       fb->Width == 0 ||

+       fb->Height == 0) {

+      fb->_ColorReadBuffer = NULL; /* legal! */

+   }

+   else {

+      ASSERT(fb->_ColorReadBufferIndex >= 0);

+      ASSERT(fb->_ColorReadBufferIndex < BUFFER_COUNT);

+      fb->_ColorReadBuffer

+         = fb->Attachment[fb->_ColorReadBufferIndex].Renderbuffer;

+   }

+}

+

+

+/**

+ * Update a gl_framebuffer's derived state.

+ *

+ * Specifically, update these framebuffer fields:

+ *    _ColorDrawBuffers

+ *    _NumColorDrawBuffers

+ *    _ColorReadBuffer

+ *    _DepthBuffer

+ *    _StencilBuffer

+ *

+ * If the framebuffer is user-created, make sure it's complete.

+ *

+ * The following functions (at least) can effect framebuffer state:

+ * glReadBuffer, glDrawBuffer, glDrawBuffersARB, glFramebufferRenderbufferEXT,

+ * glRenderbufferStorageEXT.

+ */

+static void

+update_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)

+{

+   if (fb->Name == 0) {

+      /* This is a window-system framebuffer */

+      /* Need to update the FB's GL_DRAW_BUFFER state to match the

+       * context state (GL_READ_BUFFER too).

+       */

+      if (fb->ColorDrawBuffer[0] != ctx->Color.DrawBuffer[0]) {

+         _mesa_drawbuffers(ctx, ctx->Const.MaxDrawBuffers,

+                           ctx->Color.DrawBuffer, NULL);

+      }

+      if (fb->ColorReadBuffer != ctx->Pixel.ReadBuffer) {

+         

+      }

+   }

+   else {

+      /* This is a user-created framebuffer.

+       * Completeness only matters for user-created framebuffers.

+       */

+      if (fb->_Status != GL_FRAMEBUFFER_COMPLETE) {

+         _mesa_test_framebuffer_completeness(ctx, fb);

+      }

+   }

+

+   /* Strictly speaking, we don't need to update the draw-state

+    * if this FB is bound as ctx->ReadBuffer (and conversely, the

+    * read-state if this FB is bound as ctx->DrawBuffer), but no

+    * harm.

+    */

+   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);

+}

+

+

+/**

+ * Update state related to the current draw/read framebuffers.

+ */

+void

+_mesa_update_framebuffer(struct gl_context *ctx)

+{

+   struct gl_framebuffer *drawFb;

+   struct gl_framebuffer *readFb;

+

+   assert(ctx);

+   drawFb = ctx->DrawBuffer;

+   readFb = ctx->ReadBuffer;

+

+   update_framebuffer(ctx, drawFb);

+   if (readFb != drawFb)

+      update_framebuffer(ctx, readFb);

+}

+

+

+/**

+ * 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(struct gl_context *ctx, GLenum format)

+{

+   const struct gl_renderbuffer_attachment *att = ctx->ReadBuffer->Attachment;

+

+   /* If we don't know the framebuffer status, update it now */

+   if (ctx->ReadBuffer->_Status == 0) {

+      _mesa_test_framebuffer_completeness(ctx, ctx->ReadBuffer);

+   }

+

+   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_RG:

+   case GL_RGB:

+   case GL_BGR:

+   case GL_RGBA:

+   case GL_BGRA:

+   case GL_ABGR_EXT:

+   case GL_COLOR_INDEX:

+   case GL_RED_INTEGER_EXT:

+   case GL_GREEN_INTEGER_EXT:

+   case GL_BLUE_INTEGER_EXT:

+   case GL_ALPHA_INTEGER_EXT:

+   case GL_RGB_INTEGER_EXT:

+   case GL_RGBA_INTEGER_EXT:

+   case GL_BGR_INTEGER_EXT:

+   case GL_BGRA_INTEGER_EXT:

+   case GL_LUMINANCE_INTEGER_EXT:

+   case GL_LUMINANCE_ALPHA_INTEGER_EXT:

+      if (ctx->ReadBuffer->_ColorReadBuffer == NULL) {

+         return GL_FALSE;

+      }

+      ASSERT(_mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_RED_BITS) > 0 ||

+             _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_ALPHA_BITS) > 0 ||

+             _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_INDEX_BITS) > 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 could do some code merging w/ above function.

+ */

+GLboolean

+_mesa_dest_buffer_exists(struct gl_context *ctx, GLenum format)

+{

+   const struct gl_renderbuffer_attachment *att = ctx->DrawBuffer->Attachment;

+

+   /* If we don't know the framebuffer status, update it now */

+   if (ctx->DrawBuffer->_Status == 0) {

+      _mesa_test_framebuffer_completeness(ctx, ctx->DrawBuffer);

+   }

+

+   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:

+   case GL_RED_INTEGER_EXT:

+   case GL_GREEN_INTEGER_EXT:

+   case GL_BLUE_INTEGER_EXT:

+   case GL_ALPHA_INTEGER_EXT:

+   case GL_RGB_INTEGER_EXT:

+   case GL_RGBA_INTEGER_EXT:

+   case GL_BGR_INTEGER_EXT:

+   case GL_BGRA_INTEGER_EXT:

+   case GL_LUMINANCE_INTEGER_EXT:

+   case GL_LUMINANCE_ALPHA_INTEGER_EXT:

+      /* Nothing special since GL_DRAW_BUFFER could be GL_NONE. */

+      /* 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_dest_buffer_exists",

+                    format);

+      return GL_FALSE;

+   }

+

+   /* OK */

+   return GL_TRUE;

+}

+

+

+/**

+ * Used to answer the GL_IMPLEMENTATION_COLOR_READ_FORMAT_OES query.

+ */

+GLenum

+_mesa_get_color_read_format(struct gl_context *ctx)

+{

+   switch (ctx->ReadBuffer->_ColorReadBuffer->Format) {

+   case MESA_FORMAT_ARGB8888:

+      return GL_BGRA;

+   case MESA_FORMAT_RGB565:

+      return GL_BGR;

+   default:

+      return GL_RGBA;

+   }

+}

+

+

+/**

+ * Used to answer the GL_IMPLEMENTATION_COLOR_READ_TYPE_OES query.

+ */

+GLenum

+_mesa_get_color_read_type(struct gl_context *ctx)

+{

+   switch (ctx->ReadBuffer->_ColorReadBuffer->Format) {

+   case MESA_FORMAT_ARGB8888:

+      return GL_UNSIGNED_BYTE;

+   case MESA_FORMAT_RGB565:

+      return GL_UNSIGNED_SHORT_5_6_5_REV;

+   default:

+      return GL_UNSIGNED_BYTE;

+   }

+}

+

+

+/**

+ * Print framebuffer info to stderr, for debugging.

+ */

+void

+_mesa_print_framebuffer(const struct gl_framebuffer *fb)

+{

+   GLuint i;

+

+   fprintf(stderr, "Mesa Framebuffer %u at %p\n", fb->Name, (void *) fb);

+   fprintf(stderr, "  Size: %u x %u  Status: %s\n", fb->Width, fb->Height,

+           _mesa_lookup_enum_by_nr(fb->_Status));

+   fprintf(stderr, "  Attachments:\n");

+

+   for (i = 0; i < BUFFER_COUNT; i++) {

+      const struct gl_renderbuffer_attachment *att = &fb->Attachment[i];

+      if (att->Type == GL_TEXTURE) {

+         const struct gl_texture_image *texImage;

+         fprintf(stderr,

+                 "  %2d: Texture %u, level %u, face %u, slice %u, complete %d\n",

+                 i, att->Texture->Name, att->TextureLevel, att->CubeMapFace,

+                 att->Zoffset, att->Complete);

+         texImage = att->Texture->Image[att->CubeMapFace][att->TextureLevel];

+         fprintf(stderr, "       Size: %u x %u x %u  Format %s\n",

+                 texImage->Width, texImage->Height, texImage->Depth,

+                 _mesa_get_format_name(texImage->TexFormat));

+      }

+      else if (att->Type == GL_RENDERBUFFER) {

+         fprintf(stderr, "  %2d: Renderbuffer %u, complete %d\n",

+                 i, att->Renderbuffer->Name, att->Complete);

+         fprintf(stderr, "       Size: %u x %u  Format %s\n",

+                 att->Renderbuffer->Width, att->Renderbuffer->Height,

+                 _mesa_get_format_name(att->Renderbuffer->Format));

+      }

+      else {

+         fprintf(stderr, "  %2d: none\n", i);

+      }

+   }

+}