xserver and mesa git update 28-12-2010

1 files changed, 525 insertions, 525 deletions

diff --git a/mesalib/src/mesa/main/buffers.c b/mesalib/src/mesa/main/buffers.c
index fb30b5996..cdc174454 100644
--- a/mesalib/src/mesa/main/buffers.c
+++ b/mesalib/src/mesa/main/buffers.c
@@ -1,525 +1,525 @@
-/*
- * 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"
-
-
-#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 GLcontext *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(GLcontext *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;
-            }
-            fb->ColorDrawBuffer[buf] = buffers[buf];
-            count = buf + 1;
-         }
-         else {
-            if (fb->_ColorDrawBufferIndexes[buf] != -1) {
-               fb->_ColorDrawBufferIndexes[buf] = -1;
-               newState = GL_TRUE;
-            }
-         }
-      }
-      /* 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(GLcontext *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"

+

+

+#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;

+            }

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

+            count = buf + 1;

+         }

+         else {

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

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

+               newState = GL_TRUE;

+            }

+         }

+      }

+      /* 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);

+}