libX11 mesa mkfontscale pixman xserver git update 29 Mar 2011

1 files changed, 542 insertions, 526 deletions

diff --git a/mesalib/src/mesa/main/buffers.c b/mesalib/src/mesa/main/buffers.c
index 928450f0f..63f53e2b0 100644
--- a/mesalib/src/mesa/main/buffers.c
+++ b/mesalib/src/mesa/main/buffers.c
@@ -1,526 +1,542 @@
-/*

- * Mesa 3-D graphics library

- * Version:  7.1

- *

- * Copyright (C) 1999-2007  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.

- */

-

-

-/**

- * \file buffers.c

- * glReadBuffer, DrawBuffer functions.

- */

-

-

-

-#include "glheader.h"

-#include "buffers.h"

-#include "colormac.h"

-#include "context.h"

-#include "enums.h"

-#include "mtypes.h"

-

-

-#define BAD_MASK ~0u

-

-

-/**

- * Return bitmask of BUFFER_BIT_* flags indicating which color buffers are

- * available to the rendering context (for drawing or reading).

- * This depends on the type of framebuffer.  For window system framebuffers

- * we look at the framebuffer's visual.  But for user-create framebuffers we

- * look at the number of supported color attachments.

- * \param fb  the framebuffer to draw to, or read from

- * \return  bitmask of BUFFER_BIT_* flags

- */

-static GLbitfield

-supported_buffer_bitmask(const struct gl_context *ctx, const struct gl_framebuffer *fb)

-{

-   GLbitfield mask = 0x0;

-

-   if (fb->Name > 0) {

-      /* A user-created renderbuffer */

-      GLuint i;

-      ASSERT(ctx->Extensions.EXT_framebuffer_object);

-      for (i = 0; i < ctx->Const.MaxColorAttachments; i++) {

-         mask |= (BUFFER_BIT_COLOR0 << i);

-      }

-   }

-   else {

-      /* A window system framebuffer */

-      GLint i;

-      mask = BUFFER_BIT_FRONT_LEFT; /* always have this */

-      if (fb->Visual.stereoMode) {

-         mask |= BUFFER_BIT_FRONT_RIGHT;

-         if (fb->Visual.doubleBufferMode) {

-            mask |= BUFFER_BIT_BACK_LEFT | BUFFER_BIT_BACK_RIGHT;

-         }

-      }

-      else if (fb->Visual.doubleBufferMode) {

-         mask |= BUFFER_BIT_BACK_LEFT;

-      }

-

-      for (i = 0; i < fb->Visual.numAuxBuffers; i++) {

-         mask |= (BUFFER_BIT_AUX0 << i);

-      }

-   }

-

-   return mask;

-}

-

-

-/**

- * Helper routine used by glDrawBuffer and glDrawBuffersARB.

- * Given a GLenum naming one or more color buffers (such as

- * GL_FRONT_AND_BACK), return the corresponding bitmask of BUFFER_BIT_* flags.

- */

-static GLbitfield

-draw_buffer_enum_to_bitmask(GLenum buffer)

-{

-   switch (buffer) {

-      case GL_NONE:

-         return 0;

-      case GL_FRONT:

-         return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT;

-      case GL_BACK:

-         return BUFFER_BIT_BACK_LEFT | BUFFER_BIT_BACK_RIGHT;

-      case GL_RIGHT:

-         return BUFFER_BIT_FRONT_RIGHT | BUFFER_BIT_BACK_RIGHT;

-      case GL_FRONT_RIGHT:

-         return BUFFER_BIT_FRONT_RIGHT;

-      case GL_BACK_RIGHT:

-         return BUFFER_BIT_BACK_RIGHT;

-      case GL_BACK_LEFT:

-         return BUFFER_BIT_BACK_LEFT;

-      case GL_FRONT_AND_BACK:

-         return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT

-              | BUFFER_BIT_FRONT_RIGHT | BUFFER_BIT_BACK_RIGHT;

-      case GL_LEFT:

-         return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT;

-      case GL_FRONT_LEFT:

-         return BUFFER_BIT_FRONT_LEFT;

-      case GL_AUX0:

-         return BUFFER_BIT_AUX0;

-      case GL_AUX1:

-      case GL_AUX2:

-      case GL_AUX3:

-         return 1 << BUFFER_COUNT; /* invalid, but not BAD_MASK */

-      case GL_COLOR_ATTACHMENT0_EXT:

-         return BUFFER_BIT_COLOR0;

-      case GL_COLOR_ATTACHMENT1_EXT:

-         return BUFFER_BIT_COLOR1;

-      case GL_COLOR_ATTACHMENT2_EXT:

-         return BUFFER_BIT_COLOR2;

-      case GL_COLOR_ATTACHMENT3_EXT:

-         return BUFFER_BIT_COLOR3;

-      case GL_COLOR_ATTACHMENT4_EXT:

-         return BUFFER_BIT_COLOR4;

-      case GL_COLOR_ATTACHMENT5_EXT:

-         return BUFFER_BIT_COLOR5;

-      case GL_COLOR_ATTACHMENT6_EXT:

-         return BUFFER_BIT_COLOR6;

-      case GL_COLOR_ATTACHMENT7_EXT:

-         return BUFFER_BIT_COLOR7;

-      default:

-         /* error */

-         return BAD_MASK;

-   }

-}

-

-

-/**

- * Helper routine used by glReadBuffer.

- * Given a GLenum naming a color buffer, return the index of the corresponding

- * renderbuffer (a BUFFER_* value).

- * return -1 for an invalid buffer.

- */

-static GLint

-read_buffer_enum_to_index(GLenum buffer)

-{

-   switch (buffer) {

-      case GL_FRONT:

-         return BUFFER_FRONT_LEFT;

-      case GL_BACK:

-         return BUFFER_BACK_LEFT;

-      case GL_RIGHT:

-         return BUFFER_FRONT_RIGHT;

-      case GL_FRONT_RIGHT:

-         return BUFFER_FRONT_RIGHT;

-      case GL_BACK_RIGHT:

-         return BUFFER_BACK_RIGHT;

-      case GL_BACK_LEFT:

-         return BUFFER_BACK_LEFT;

-      case GL_LEFT:

-         return BUFFER_FRONT_LEFT;

-      case GL_FRONT_LEFT:

-         return BUFFER_FRONT_LEFT;

-      case GL_AUX0:

-         return BUFFER_AUX0;

-      case GL_AUX1:

-      case GL_AUX2:

-      case GL_AUX3:

-         return BUFFER_COUNT; /* invalid, but not -1 */

-      case GL_COLOR_ATTACHMENT0_EXT:

-         return BUFFER_COLOR0;

-      case GL_COLOR_ATTACHMENT1_EXT:

-         return BUFFER_COLOR1;

-      case GL_COLOR_ATTACHMENT2_EXT:

-         return BUFFER_COLOR2;

-      case GL_COLOR_ATTACHMENT3_EXT:

-         return BUFFER_COLOR3;

-      case GL_COLOR_ATTACHMENT4_EXT:

-         return BUFFER_COLOR4;

-      case GL_COLOR_ATTACHMENT5_EXT:

-         return BUFFER_COLOR5;

-      case GL_COLOR_ATTACHMENT6_EXT:

-         return BUFFER_COLOR6;

-      case GL_COLOR_ATTACHMENT7_EXT:

-         return BUFFER_COLOR7;

-      default:

-         /* error */

-         return -1;

-   }

-}

-

-

-/**

- * Called by glDrawBuffer().

- * Specify which renderbuffer(s) to draw into for the first color output.

- * <buffer> can name zero, one, two or four renderbuffers!

- * \sa _mesa_DrawBuffersARB

- *

- * \param buffer  buffer token such as GL_LEFT or GL_FRONT_AND_BACK, etc.

- *

- * Note that the behaviour of this function depends on whether the

- * current ctx->DrawBuffer is a window-system framebuffer (Name=0) or

- * a user-created framebuffer object (Name!=0).

- *   In the former case, we update the per-context ctx->Color.DrawBuffer

- *   state var _and_ the FB's ColorDrawBuffer state.

- *   In the later case, we update the FB's ColorDrawBuffer state only.

- *

- * Furthermore, upon a MakeCurrent() or BindFramebuffer() call, if the

- * new FB is a window system FB, we need to re-update the FB's

- * ColorDrawBuffer state to match the context.  This is handled in

- * _mesa_update_framebuffer().

- *

- * See the GL_EXT_framebuffer_object spec for more info.

- */

-void GLAPIENTRY

-_mesa_DrawBuffer(GLenum buffer)

-{

-   GLbitfield destMask;

-   GET_CURRENT_CONTEXT(ctx);

-   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); /* too complex... */

-

-   if (MESA_VERBOSE & VERBOSE_API) {

-      _mesa_debug(ctx, "glDrawBuffer %s\n", _mesa_lookup_enum_by_nr(buffer));

-   }

-

-   if (buffer == GL_NONE) {

-      destMask = 0x0;

-   }

-   else {

-      const GLbitfield supportedMask

-         = supported_buffer_bitmask(ctx, ctx->DrawBuffer);

-      destMask = draw_buffer_enum_to_bitmask(buffer);

-      if (destMask == BAD_MASK) {

-         /* totally bogus buffer */

-         _mesa_error(ctx, GL_INVALID_ENUM, "glDrawBuffer(buffer=0x%x)", buffer);

-         return;

-      }

-      destMask &= supportedMask;

-      if (destMask == 0x0) {

-         /* none of the named color buffers exist! */

-         _mesa_error(ctx, GL_INVALID_OPERATION,

-                     "glDrawBuffer(buffer=0x%x)", buffer);

-         return;

-      }

-   }

-

-   /* if we get here, there's no error so set new state */

-   _mesa_drawbuffers(ctx, 1, &buffer, &destMask);

-

-   /*

-    * Call device driver function.

-    */

-   if (ctx->Driver.DrawBuffers)

-      ctx->Driver.DrawBuffers(ctx, 1, &buffer);

-   else if (ctx->Driver.DrawBuffer)

-      ctx->Driver.DrawBuffer(ctx, buffer);

-}

-

-

-/**

- * Called by glDrawBuffersARB; specifies the destination color renderbuffers

- * for N fragment program color outputs.

- * \sa _mesa_DrawBuffer

- * \param n  number of outputs

- * \param buffers  array [n] of renderbuffer names.  Unlike glDrawBuffer, the

- *                 names cannot specify more than one buffer.  For example,

- *                 GL_FRONT_AND_BACK is illegal.

- */

-void GLAPIENTRY

-_mesa_DrawBuffersARB(GLsizei n, const GLenum *buffers)

-{

-   GLint output;

-   GLbitfield usedBufferMask, supportedMask;

-   GLbitfield destMask[MAX_DRAW_BUFFERS];

-   GET_CURRENT_CONTEXT(ctx);

-   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

-

-   /* Turns out n==0 is a valid input that should not produce an error.

-    * The remaining code below correctly handles the n==0 case.

-    */

-   if (n < 0 || n > (GLsizei) ctx->Const.MaxDrawBuffers) {

-      _mesa_error(ctx, GL_INVALID_VALUE, "glDrawBuffersARB(n)");

-      return;

-   }

-

-   supportedMask = supported_buffer_bitmask(ctx, ctx->DrawBuffer);

-   usedBufferMask = 0x0;

-

-   /* complicated error checking... */

-   for (output = 0; output < n; output++) {

-      if (buffers[output] == GL_NONE) {

-         destMask[output] = 0x0;

-      }

-      else {

-         destMask[output] = draw_buffer_enum_to_bitmask(buffers[output]);

-         if (destMask[output] == BAD_MASK

-             || _mesa_bitcount(destMask[output]) > 1) {

-            _mesa_error(ctx, GL_INVALID_ENUM, "glDrawBuffersARB(buffer)");

-            return;

-         }         

-         destMask[output] &= supportedMask;

-         if (destMask[output] == 0) {

-            _mesa_error(ctx, GL_INVALID_OPERATION,

-                        "glDrawBuffersARB(unsupported buffer)");

-            return;

-         }

-         if (destMask[output] & usedBufferMask) {

-            /* can't specify a dest buffer more than once! */

-            _mesa_error(ctx, GL_INVALID_OPERATION,

-                        "glDrawBuffersARB(duplicated buffer)");

-            return;

-         }

-

-         /* update bitmask */

-         usedBufferMask |= destMask[output];

-      }

-   }

-

-   /* OK, if we get here, there were no errors so set the new state */

-   _mesa_drawbuffers(ctx, n, buffers, destMask);

-

-   /*

-    * Call device driver function.  Note that n can be equal to 0,

-    * in which case we don't want to reference buffers[0], which

-    * may not be valid.

-    */

-   if (ctx->Driver.DrawBuffers)

-      ctx->Driver.DrawBuffers(ctx, n, buffers);

-   else if (ctx->Driver.DrawBuffer)

-      ctx->Driver.DrawBuffer(ctx, n > 0 ? buffers[0] : GL_NONE);

-}

-

-

-/**

- * Helper function to set the GL_DRAW_BUFFER state in the context and

- * current FBO.  Called via glDrawBuffer(), glDrawBuffersARB()

- *

- * All error checking will have been done prior to calling this function

- * so nothing should go wrong at this point.

- *

- * \param ctx  current context

- * \param n    number of color outputs to set

- * \param buffers  array[n] of colorbuffer names, like GL_LEFT.

- * \param destMask  array[n] of BUFFER_BIT_* bitmasks which correspond to the

- *                  colorbuffer names.  (i.e. GL_FRONT_AND_BACK =>

- *                  BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT).

- */

-void

-_mesa_drawbuffers(struct gl_context *ctx, GLuint n, const GLenum *buffers,

-                  const GLbitfield *destMask)

-{

-   struct gl_framebuffer *fb = ctx->DrawBuffer;

-   GLbitfield mask[MAX_DRAW_BUFFERS];

-   GLboolean newState = GL_FALSE;

-

-   if (!destMask) {

-      /* compute destMask values now */

-      const GLbitfield supportedMask = supported_buffer_bitmask(ctx, fb);

-      GLuint output;

-      for (output = 0; output < n; output++) {

-         mask[output] = draw_buffer_enum_to_bitmask(buffers[output]);

-         ASSERT(mask[output] != BAD_MASK);

-         mask[output] &= supportedMask;

-      }

-      destMask = mask;

-   }

-

-   /*

-    * If n==1, destMask[0] may have up to four bits set.

-    * Otherwise, destMask[x] can only have one bit set.

-    */

-   if (n == 1) {

-      GLuint count = 0, destMask0 = destMask[0];

-      while (destMask0) {

-         GLint bufIndex = _mesa_ffs(destMask0) - 1;

-         if (fb->_ColorDrawBufferIndexes[count] != bufIndex) {

-            fb->_ColorDrawBufferIndexes[count] = bufIndex;

-            newState = GL_TRUE;

-         }

-         count++;

-         destMask0 &= ~(1 << bufIndex);

-      }

-      fb->ColorDrawBuffer[0] = buffers[0];

-      if (fb->_NumColorDrawBuffers != count) {

-         fb->_NumColorDrawBuffers = count;

-         newState = GL_TRUE;

-      }

-   }

-   else {

-      GLuint buf, count = 0;

-      for (buf = 0; buf < n; buf++ ) {

-         if (destMask[buf]) {

-            GLint bufIndex = _mesa_ffs(destMask[buf]) - 1;

-            /* only one bit should be set in the destMask[buf] field */

-            ASSERT(_mesa_bitcount(destMask[buf]) == 1);

-            if (fb->_ColorDrawBufferIndexes[buf] != bufIndex) {

-               fb->_ColorDrawBufferIndexes[buf] = bufIndex;

-               newState = GL_TRUE;

-            }

-            count = buf + 1;

-         }

-         else {

-            if (fb->_ColorDrawBufferIndexes[buf] != -1) {

-               fb->_ColorDrawBufferIndexes[buf] = -1;

-               newState = GL_TRUE;

-            }

-         }

-         fb->ColorDrawBuffer[buf] = buffers[buf];

-      }

-      /* set remaining outputs to -1 (GL_NONE) */

-      while (buf < ctx->Const.MaxDrawBuffers) {

-         if (fb->_ColorDrawBufferIndexes[buf] != -1) {

-            fb->_ColorDrawBufferIndexes[buf] = -1;

-            newState = GL_TRUE;

-         }

-         fb->ColorDrawBuffer[buf] = GL_NONE;

-         buf++;

-      }

-      fb->_NumColorDrawBuffers = count;

-   }

-

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

-      /* also set context drawbuffer state */

-      GLuint buf;

-      for (buf = 0; buf < ctx->Const.MaxDrawBuffers; buf++) {

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

-            ctx->Color.DrawBuffer[buf] = fb->ColorDrawBuffer[buf];

-            newState = GL_TRUE;

-         }

-      }

-   }

-

-   if (newState)

-      FLUSH_VERTICES(ctx, _NEW_BUFFERS);

-}

-

-

-/**

- * Like \sa _mesa_drawbuffers(), this is a helper function for setting

- * GL_READ_BUFFER state in the context and current FBO.

- * \param ctx  the rendering context

- * \param buffer  GL_FRONT, GL_BACK, GL_COLOR_ATTACHMENT0, etc.

- * \param bufferIndex  the numerical index corresponding to 'buffer'

- */

-void

-_mesa_readbuffer(struct gl_context *ctx, GLenum buffer, GLint bufferIndex)

-{

-   struct gl_framebuffer *fb = ctx->ReadBuffer;

-

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

-      /* Only update the per-context READ_BUFFER state if we're bound to

-       * a window-system framebuffer.

-       */

-      ctx->Pixel.ReadBuffer = buffer;

-   }

-

-   fb->ColorReadBuffer = buffer;

-   fb->_ColorReadBufferIndex = bufferIndex;

-

-   ctx->NewState |= _NEW_BUFFERS;

-}

-

-

-

-/**

- * Called by glReadBuffer to set the source renderbuffer for reading pixels.

- * \param mode color buffer such as GL_FRONT, GL_BACK, etc.

- */

-void GLAPIENTRY

-_mesa_ReadBuffer(GLenum buffer)

-{

-   struct gl_framebuffer *fb;

-   GLbitfield supportedMask;

-   GLint srcBuffer;

-   GET_CURRENT_CONTEXT(ctx);

-   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

-

-   if (MESA_VERBOSE & VERBOSE_API)

-      _mesa_debug(ctx, "glReadBuffer %s\n", _mesa_lookup_enum_by_nr(buffer));

-

-   fb = ctx->ReadBuffer;

-

-   if (MESA_VERBOSE & VERBOSE_API)

-      _mesa_debug(ctx, "glReadBuffer %s\n", _mesa_lookup_enum_by_nr(buffer));

-

-   if (fb->Name > 0 && buffer == GL_NONE) {

-      /* This is legal for user-created framebuffer objects */

-      srcBuffer = -1;

-   }

-   else {

-      /* general case / window-system framebuffer */

-      srcBuffer = read_buffer_enum_to_index(buffer);

-      if (srcBuffer == -1) {

-         _mesa_error(ctx, GL_INVALID_ENUM,

-                     "glReadBuffer(buffer=0x%x)", buffer);

-         return;

-      }

-      supportedMask = supported_buffer_bitmask(ctx, fb);

-      if (((1 << srcBuffer) & supportedMask) == 0) {

-         _mesa_error(ctx, GL_INVALID_OPERATION,

-                     "glReadBuffer(buffer=0x%x)", buffer);

-         return;

-      }

-   }

-

-   /* OK, all error checking has been completed now */

-

-   _mesa_readbuffer(ctx, buffer, srcBuffer);

-   ctx->NewState |= _NEW_BUFFERS;

-

-   /*

-    * Call device driver function.

-    */

-   if (ctx->Driver.ReadBuffer)

-      (*ctx->Driver.ReadBuffer)(ctx, buffer);

-}

+/*
+ * Mesa 3-D graphics library
+ * Version:  7.1
+ *
+ * Copyright (C) 1999-2007  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.
+ */
+
+
+/**
+ * \file buffers.c
+ * glReadBuffer, DrawBuffer functions.
+ */
+
+
+
+#include "glheader.h"
+#include "buffers.h"
+#include "colormac.h"
+#include "context.h"
+#include "enums.h"
+#include "mtypes.h"
+
+
+#define BAD_MASK ~0u
+
+
+/**
+ * Return bitmask of BUFFER_BIT_* flags indicating which color buffers are
+ * available to the rendering context (for drawing or reading).
+ * This depends on the type of framebuffer.  For window system framebuffers
+ * we look at the framebuffer's visual.  But for user-create framebuffers we
+ * look at the number of supported color attachments.
+ * \param fb  the framebuffer to draw to, or read from
+ * \return  bitmask of BUFFER_BIT_* flags
+ */
+static GLbitfield
+supported_buffer_bitmask(const struct gl_context *ctx, const struct gl_framebuffer *fb)
+{
+   GLbitfield mask = 0x0;
+
+   if (fb->Name > 0) {
+      /* A user-created renderbuffer */
+      GLuint i;
+      ASSERT(ctx->Extensions.EXT_framebuffer_object);
+      for (i = 0; i < ctx->Const.MaxColorAttachments; i++) {
+         mask |= (BUFFER_BIT_COLOR0 << i);
+      }
+   }
+   else {
+      /* A window system framebuffer */
+      GLint i;
+      mask = BUFFER_BIT_FRONT_LEFT; /* always have this */
+      if (fb->Visual.stereoMode) {
+         mask |= BUFFER_BIT_FRONT_RIGHT;
+         if (fb->Visual.doubleBufferMode) {
+            mask |= BUFFER_BIT_BACK_LEFT | BUFFER_BIT_BACK_RIGHT;
+         }
+      }
+      else if (fb->Visual.doubleBufferMode) {
+         mask |= BUFFER_BIT_BACK_LEFT;
+      }
+
+      for (i = 0; i < fb->Visual.numAuxBuffers; i++) {
+         mask |= (BUFFER_BIT_AUX0 << i);
+      }
+   }
+
+   return mask;
+}
+
+
+/**
+ * Helper routine used by glDrawBuffer and glDrawBuffersARB.
+ * Given a GLenum naming one or more color buffers (such as
+ * GL_FRONT_AND_BACK), return the corresponding bitmask of BUFFER_BIT_* flags.
+ */
+static GLbitfield
+draw_buffer_enum_to_bitmask(GLenum buffer)
+{
+   switch (buffer) {
+      case GL_NONE:
+         return 0;
+      case GL_FRONT:
+         return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT;
+      case GL_BACK:
+         return BUFFER_BIT_BACK_LEFT | BUFFER_BIT_BACK_RIGHT;
+      case GL_RIGHT:
+         return BUFFER_BIT_FRONT_RIGHT | BUFFER_BIT_BACK_RIGHT;
+      case GL_FRONT_RIGHT:
+         return BUFFER_BIT_FRONT_RIGHT;
+      case GL_BACK_RIGHT:
+         return BUFFER_BIT_BACK_RIGHT;
+      case GL_BACK_LEFT:
+         return BUFFER_BIT_BACK_LEFT;
+      case GL_FRONT_AND_BACK:
+         return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT
+              | BUFFER_BIT_FRONT_RIGHT | BUFFER_BIT_BACK_RIGHT;
+      case GL_LEFT:
+         return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT;
+      case GL_FRONT_LEFT:
+         return BUFFER_BIT_FRONT_LEFT;
+      case GL_AUX0:
+         return BUFFER_BIT_AUX0;
+      case GL_AUX1:
+      case GL_AUX2:
+      case GL_AUX3:
+         return 1 << BUFFER_COUNT; /* invalid, but not BAD_MASK */
+      case GL_COLOR_ATTACHMENT0_EXT:
+         return BUFFER_BIT_COLOR0;
+      case GL_COLOR_ATTACHMENT1_EXT:
+         return BUFFER_BIT_COLOR1;
+      case GL_COLOR_ATTACHMENT2_EXT:
+         return BUFFER_BIT_COLOR2;
+      case GL_COLOR_ATTACHMENT3_EXT:
+         return BUFFER_BIT_COLOR3;
+      case GL_COLOR_ATTACHMENT4_EXT:
+         return BUFFER_BIT_COLOR4;
+      case GL_COLOR_ATTACHMENT5_EXT:
+         return BUFFER_BIT_COLOR5;
+      case GL_COLOR_ATTACHMENT6_EXT:
+         return BUFFER_BIT_COLOR6;
+      case GL_COLOR_ATTACHMENT7_EXT:
+         return BUFFER_BIT_COLOR7;
+      default:
+         /* error */
+         return BAD_MASK;
+   }
+}
+
+
+/**
+ * Helper routine used by glReadBuffer.
+ * Given a GLenum naming a color buffer, return the index of the corresponding
+ * renderbuffer (a BUFFER_* value).
+ * return -1 for an invalid buffer.
+ */
+static GLint
+read_buffer_enum_to_index(GLenum buffer)
+{
+   switch (buffer) {
+      case GL_FRONT:
+         return BUFFER_FRONT_LEFT;
+      case GL_BACK:
+         return BUFFER_BACK_LEFT;
+      case GL_RIGHT:
+         return BUFFER_FRONT_RIGHT;
+      case GL_FRONT_RIGHT:
+         return BUFFER_FRONT_RIGHT;
+      case GL_BACK_RIGHT:
+         return BUFFER_BACK_RIGHT;
+      case GL_BACK_LEFT:
+         return BUFFER_BACK_LEFT;
+      case GL_LEFT:
+         return BUFFER_FRONT_LEFT;
+      case GL_FRONT_LEFT:
+         return BUFFER_FRONT_LEFT;
+      case GL_AUX0:
+         return BUFFER_AUX0;
+      case GL_AUX1:
+      case GL_AUX2:
+      case GL_AUX3:
+         return BUFFER_COUNT; /* invalid, but not -1 */
+      case GL_COLOR_ATTACHMENT0_EXT:
+         return BUFFER_COLOR0;
+      case GL_COLOR_ATTACHMENT1_EXT:
+         return BUFFER_COLOR1;
+      case GL_COLOR_ATTACHMENT2_EXT:
+         return BUFFER_COLOR2;
+      case GL_COLOR_ATTACHMENT3_EXT:
+         return BUFFER_COLOR3;
+      case GL_COLOR_ATTACHMENT4_EXT:
+         return BUFFER_COLOR4;
+      case GL_COLOR_ATTACHMENT5_EXT:
+         return BUFFER_COLOR5;
+      case GL_COLOR_ATTACHMENT6_EXT:
+         return BUFFER_COLOR6;
+      case GL_COLOR_ATTACHMENT7_EXT:
+         return BUFFER_COLOR7;
+      default:
+         /* error */
+         return -1;
+   }
+}
+
+
+/**
+ * Called by glDrawBuffer().
+ * Specify which renderbuffer(s) to draw into for the first color output.
+ * <buffer> can name zero, one, two or four renderbuffers!
+ * \sa _mesa_DrawBuffersARB
+ *
+ * \param buffer  buffer token such as GL_LEFT or GL_FRONT_AND_BACK, etc.
+ *
+ * Note that the behaviour of this function depends on whether the
+ * current ctx->DrawBuffer is a window-system framebuffer (Name=0) or
+ * a user-created framebuffer object (Name!=0).
+ *   In the former case, we update the per-context ctx->Color.DrawBuffer
+ *   state var _and_ the FB's ColorDrawBuffer state.
+ *   In the later case, we update the FB's ColorDrawBuffer state only.
+ *
+ * Furthermore, upon a MakeCurrent() or BindFramebuffer() call, if the
+ * new FB is a window system FB, we need to re-update the FB's
+ * ColorDrawBuffer state to match the context.  This is handled in
+ * _mesa_update_framebuffer().
+ *
+ * See the GL_EXT_framebuffer_object spec for more info.
+ */
+void GLAPIENTRY
+_mesa_DrawBuffer(GLenum buffer)
+{
+   GLbitfield destMask;
+   GET_CURRENT_CONTEXT(ctx);
+   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); /* too complex... */
+
+   if (MESA_VERBOSE & VERBOSE_API) {
+      _mesa_debug(ctx, "glDrawBuffer %s\n", _mesa_lookup_enum_by_nr(buffer));
+   }
+
+   if (buffer == GL_NONE) {
+      destMask = 0x0;
+   }
+   else {
+      const GLbitfield supportedMask
+         = supported_buffer_bitmask(ctx, ctx->DrawBuffer);
+      destMask = draw_buffer_enum_to_bitmask(buffer);
+      if (destMask == BAD_MASK) {
+         /* totally bogus buffer */
+         _mesa_error(ctx, GL_INVALID_ENUM, "glDrawBuffer(buffer=0x%x)", buffer);
+         return;
+      }
+      destMask &= supportedMask;
+      if (destMask == 0x0) {
+         /* none of the named color buffers exist! */
+         _mesa_error(ctx, GL_INVALID_OPERATION,
+                     "glDrawBuffer(buffer=0x%x)", buffer);
+         return;
+      }
+   }
+
+   /* if we get here, there's no error so set new state */
+   _mesa_drawbuffers(ctx, 1, &buffer, &destMask);
+
+   /*
+    * Call device driver function.
+    */
+   if (ctx->Driver.DrawBuffers)
+      ctx->Driver.DrawBuffers(ctx, 1, &buffer);
+   else if (ctx->Driver.DrawBuffer)
+      ctx->Driver.DrawBuffer(ctx, buffer);
+}
+
+
+/**
+ * Called by glDrawBuffersARB; specifies the destination color renderbuffers
+ * for N fragment program color outputs.
+ * \sa _mesa_DrawBuffer
+ * \param n  number of outputs
+ * \param buffers  array [n] of renderbuffer names.  Unlike glDrawBuffer, the
+ *                 names cannot specify more than one buffer.  For example,
+ *                 GL_FRONT_AND_BACK is illegal.
+ */
+void GLAPIENTRY
+_mesa_DrawBuffersARB(GLsizei n, const GLenum *buffers)
+{
+   GLint output;
+   GLbitfield usedBufferMask, supportedMask;
+   GLbitfield destMask[MAX_DRAW_BUFFERS];
+   GET_CURRENT_CONTEXT(ctx);
+   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
+
+   /* Turns out n==0 is a valid input that should not produce an error.
+    * The remaining code below correctly handles the n==0 case.
+    */
+   if (n < 0 || n > (GLsizei) ctx->Const.MaxDrawBuffers) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glDrawBuffersARB(n)");
+      return;
+   }
+
+   supportedMask = supported_buffer_bitmask(ctx, ctx->DrawBuffer);
+   usedBufferMask = 0x0;
+
+   /* complicated error checking... */
+   for (output = 0; output < n; output++) {
+      if (buffers[output] == GL_NONE) {
+         destMask[output] = 0x0;
+      }
+      else {
+         destMask[output] = draw_buffer_enum_to_bitmask(buffers[output]);
+         if (destMask[output] == BAD_MASK
+             || _mesa_bitcount(destMask[output]) > 1) {
+            _mesa_error(ctx, GL_INVALID_ENUM, "glDrawBuffersARB(buffer)");
+            return;
+         }         
+         destMask[output] &= supportedMask;
+         if (destMask[output] == 0) {
+            _mesa_error(ctx, GL_INVALID_OPERATION,
+                        "glDrawBuffersARB(unsupported buffer)");
+            return;
+         }
+         if (destMask[output] & usedBufferMask) {
+            /* can't specify a dest buffer more than once! */
+            _mesa_error(ctx, GL_INVALID_OPERATION,
+                        "glDrawBuffersARB(duplicated buffer)");
+            return;
+         }
+
+         /* update bitmask */
+         usedBufferMask |= destMask[output];
+      }
+   }
+
+   /* OK, if we get here, there were no errors so set the new state */
+   _mesa_drawbuffers(ctx, n, buffers, destMask);
+
+   /*
+    * Call device driver function.  Note that n can be equal to 0,
+    * in which case we don't want to reference buffers[0], which
+    * may not be valid.
+    */
+   if (ctx->Driver.DrawBuffers)
+      ctx->Driver.DrawBuffers(ctx, n, buffers);
+   else if (ctx->Driver.DrawBuffer)
+      ctx->Driver.DrawBuffer(ctx, n > 0 ? buffers[0] : GL_NONE);
+}
+
+/**
+ * Performs necessary state updates when _mesa_drawbuffers makes an
+ * actual change.
+ */
+static void
+updated_drawbuffers(struct gl_context *ctx)
+{
+   FLUSH_VERTICES(ctx, _NEW_BUFFERS);
+
+#if FEATURE_GL
+   if (ctx->API == API_OPENGL && !ctx->Extensions.ARB_ES2_compatibility) {
+      struct gl_framebuffer *fb = ctx->DrawBuffer;
+
+      /* Flag the FBO as requiring validation. */
+      if (fb->Name != 0) {
+	 fb->_Status = 0;
+      }
+   }
+#endif
+}
+
+/**
+ * Helper function to set the GL_DRAW_BUFFER state in the context and
+ * current FBO.  Called via glDrawBuffer(), glDrawBuffersARB()
+ *
+ * All error checking will have been done prior to calling this function
+ * so nothing should go wrong at this point.
+ *
+ * \param ctx  current context
+ * \param n    number of color outputs to set
+ * \param buffers  array[n] of colorbuffer names, like GL_LEFT.
+ * \param destMask  array[n] of BUFFER_BIT_* bitmasks which correspond to the
+ *                  colorbuffer names.  (i.e. GL_FRONT_AND_BACK =>
+ *                  BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT).
+ */
+void
+_mesa_drawbuffers(struct gl_context *ctx, GLuint n, const GLenum *buffers,
+                  const GLbitfield *destMask)
+{
+   struct gl_framebuffer *fb = ctx->DrawBuffer;
+   GLbitfield mask[MAX_DRAW_BUFFERS];
+
+   if (!destMask) {
+      /* compute destMask values now */
+      const GLbitfield supportedMask = supported_buffer_bitmask(ctx, fb);
+      GLuint output;
+      for (output = 0; output < n; output++) {
+         mask[output] = draw_buffer_enum_to_bitmask(buffers[output]);
+         ASSERT(mask[output] != BAD_MASK);
+         mask[output] &= supportedMask;
+      }
+      destMask = mask;
+   }
+
+   /*
+    * If n==1, destMask[0] may have up to four bits set.
+    * Otherwise, destMask[x] can only have one bit set.
+    */
+   if (n == 1) {
+      GLuint count = 0, destMask0 = destMask[0];
+      while (destMask0) {
+         GLint bufIndex = _mesa_ffs(destMask0) - 1;
+         if (fb->_ColorDrawBufferIndexes[count] != bufIndex) {
+            updated_drawbuffers(ctx);
+            fb->_ColorDrawBufferIndexes[count] = bufIndex;
+         }
+         count++;
+         destMask0 &= ~(1 << bufIndex);
+      }
+      fb->ColorDrawBuffer[0] = buffers[0];
+      if (fb->_NumColorDrawBuffers != count) {
+	 updated_drawbuffers(ctx);
+         fb->_NumColorDrawBuffers = count;
+      }
+   }
+   else {
+      GLuint buf, count = 0;
+      for (buf = 0; buf < n; buf++ ) {
+         if (destMask[buf]) {
+            GLint bufIndex = _mesa_ffs(destMask[buf]) - 1;
+            /* only one bit should be set in the destMask[buf] field */
+            ASSERT(_mesa_bitcount(destMask[buf]) == 1);
+            if (fb->_ColorDrawBufferIndexes[buf] != bufIndex) {
+	       updated_drawbuffers(ctx);
+               fb->_ColorDrawBufferIndexes[buf] = bufIndex;
+            }
+            count = buf + 1;
+         }
+         else {
+            if (fb->_ColorDrawBufferIndexes[buf] != -1) {
+	       updated_drawbuffers(ctx);
+               fb->_ColorDrawBufferIndexes[buf] = -1;
+            }
+         }
+         fb->ColorDrawBuffer[buf] = buffers[buf];
+      }
+      /* set remaining outputs to -1 (GL_NONE) */
+      while (buf < ctx->Const.MaxDrawBuffers) {
+         if (fb->_ColorDrawBufferIndexes[buf] != -1) {
+	    updated_drawbuffers(ctx);
+            fb->_ColorDrawBufferIndexes[buf] = -1;
+         }
+         fb->ColorDrawBuffer[buf] = GL_NONE;
+         buf++;
+      }
+      fb->_NumColorDrawBuffers = count;
+   }
+
+   if (fb->Name == 0) {
+      /* also set context drawbuffer state */
+      GLuint buf;
+      for (buf = 0; buf < ctx->Const.MaxDrawBuffers; buf++) {
+         if (ctx->Color.DrawBuffer[buf] != fb->ColorDrawBuffer[buf]) {
+	    updated_drawbuffers(ctx);
+            ctx->Color.DrawBuffer[buf] = fb->ColorDrawBuffer[buf];
+         }
+      }
+   }
+}
+
+
+/**
+ * Like \sa _mesa_drawbuffers(), this is a helper function for setting
+ * GL_READ_BUFFER state in the context and current FBO.
+ * \param ctx  the rendering context
+ * \param buffer  GL_FRONT, GL_BACK, GL_COLOR_ATTACHMENT0, etc.
+ * \param bufferIndex  the numerical index corresponding to 'buffer'
+ */
+void
+_mesa_readbuffer(struct gl_context *ctx, GLenum buffer, GLint bufferIndex)
+{
+   struct gl_framebuffer *fb = ctx->ReadBuffer;
+
+   if (fb->Name == 0) {
+      /* Only update the per-context READ_BUFFER state if we're bound to
+       * a window-system framebuffer.
+       */
+      ctx->Pixel.ReadBuffer = buffer;
+   }
+
+   fb->ColorReadBuffer = buffer;
+   fb->_ColorReadBufferIndex = bufferIndex;
+
+   ctx->NewState |= _NEW_BUFFERS;
+}
+
+
+
+/**
+ * Called by glReadBuffer to set the source renderbuffer for reading pixels.
+ * \param mode color buffer such as GL_FRONT, GL_BACK, etc.
+ */
+void GLAPIENTRY
+_mesa_ReadBuffer(GLenum buffer)
+{
+   struct gl_framebuffer *fb;
+   GLbitfield supportedMask;
+   GLint srcBuffer;
+   GET_CURRENT_CONTEXT(ctx);
+   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
+
+   if (MESA_VERBOSE & VERBOSE_API)
+      _mesa_debug(ctx, "glReadBuffer %s\n", _mesa_lookup_enum_by_nr(buffer));
+
+   fb = ctx->ReadBuffer;
+
+   if (MESA_VERBOSE & VERBOSE_API)
+      _mesa_debug(ctx, "glReadBuffer %s\n", _mesa_lookup_enum_by_nr(buffer));
+
+   if (fb->Name > 0 && buffer == GL_NONE) {
+      /* This is legal for user-created framebuffer objects */
+      srcBuffer = -1;
+   }
+   else {
+      /* general case / window-system framebuffer */
+      srcBuffer = read_buffer_enum_to_index(buffer);
+      if (srcBuffer == -1) {
+         _mesa_error(ctx, GL_INVALID_ENUM,
+                     "glReadBuffer(buffer=0x%x)", buffer);
+         return;
+      }
+      supportedMask = supported_buffer_bitmask(ctx, fb);
+      if (((1 << srcBuffer) & supportedMask) == 0) {
+         _mesa_error(ctx, GL_INVALID_OPERATION,
+                     "glReadBuffer(buffer=0x%x)", buffer);
+         return;
+      }
+   }
+
+   /* OK, all error checking has been completed now */
+
+   _mesa_readbuffer(ctx, buffer, srcBuffer);
+   ctx->NewState |= _NEW_BUFFERS;
+
+   /*
+    * Call device driver function.
+    */
+   if (ctx->Driver.ReadBuffer)
+      (*ctx->Driver.ReadBuffer)(ctx, buffer);
+}