xserver libX11 mesa git update 8 Jun 2011

2 files changed, 275 insertions, 238 deletions

diff --git a/mesalib/src/mesa/main/fbobject.c b/mesalib/src/mesa/main/fbobject.c
index d4400709a..2230b2623 100644
--- a/mesalib/src/mesa/main/fbobject.c
+++ b/mesalib/src/mesa/main/fbobject.c
@@ -2429,6 +2429,17 @@ _mesa_BlitFramebufferEXT(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
    if (mask & GL_COLOR_BUFFER_BIT) {
       colorReadRb = readFb->_ColorReadBuffer;
       colorDrawRb = drawFb->_ColorDrawBuffers[0];
+
+      /* From the EXT_framebuffer_object spec:
+       *
+       *     "If a buffer is specified in <mask> and does not exist in both
+       *     the read and draw framebuffers, the corresponding bit is silently
+       *     ignored."
+       */
+      if ((colorReadRb == NULL) || (colorDrawRb == NULL)) {
+	 colorReadRb = colorDrawRb = NULL;
+	 mask &= ~GL_COLOR_BUFFER_BIT;
+      }
    }
    else {
       colorReadRb = colorDrawRb = NULL;
@@ -2437,10 +2448,19 @@ _mesa_BlitFramebufferEXT(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
    if (mask & GL_STENCIL_BUFFER_BIT) {
       struct gl_renderbuffer *readRb = readFb->_StencilBuffer;
       struct gl_renderbuffer *drawRb = drawFb->_StencilBuffer;
-      if (!readRb ||
-          !drawRb ||
-          _mesa_get_format_bits(readRb->Format, GL_STENCIL_BITS) != 
-          _mesa_get_format_bits(drawRb->Format, GL_STENCIL_BITS)) {
+
+      /* From the EXT_framebuffer_object spec:
+       *
+       *     "If a buffer is specified in <mask> and does not exist in both
+       *     the read and draw framebuffers, the corresponding bit is silently
+       *     ignored."
+       */
+      if ((readRb == NULL) || (drawRb == NULL)) {
+	 readRb = drawRb = NULL;
+	 mask &= ~GL_STENCIL_BUFFER_BIT;
+      }
+      else if (_mesa_get_format_bits(readRb->Format, GL_STENCIL_BITS) !=
+	       _mesa_get_format_bits(drawRb->Format, GL_STENCIL_BITS)) {
          _mesa_error(ctx, GL_INVALID_OPERATION,
                      "glBlitFramebufferEXT(stencil buffer size mismatch)");
          return;
@@ -2450,10 +2470,19 @@ _mesa_BlitFramebufferEXT(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
    if (mask & GL_DEPTH_BUFFER_BIT) {
       struct gl_renderbuffer *readRb = readFb->_DepthBuffer;
       struct gl_renderbuffer *drawRb = drawFb->_DepthBuffer;
-      if (!readRb ||
-          !drawRb ||
-          _mesa_get_format_bits(readRb->Format, GL_DEPTH_BITS) != 
-          _mesa_get_format_bits(drawRb->Format, GL_DEPTH_BITS)) {
+
+      /* From the EXT_framebuffer_object spec:
+       *
+       *     "If a buffer is specified in <mask> and does not exist in both
+       *     the read and draw framebuffers, the corresponding bit is silently
+       *     ignored."
+       */
+      if ((readRb == NULL) || (drawRb == NULL)) {
+	 readRb = drawRb = NULL;
+	 mask &= ~GL_DEPTH_BUFFER_BIT;
+      }
+      else if (_mesa_get_format_bits(readRb->Format, GL_DEPTH_BITS) !=
+	       _mesa_get_format_bits(drawRb->Format, GL_DEPTH_BITS)) {
          _mesa_error(ctx, GL_INVALID_OPERATION,
                      "glBlitFramebufferEXT(depth buffer size mismatch)");
          return;
diff --git a/mesalib/src/mesa/swrast/s_clear.c b/mesalib/src/mesa/swrast/s_clear.c
index fac092f1e..9e9b53116 100644
--- a/mesalib/src/mesa/swrast/s_clear.c
+++ b/mesalib/src/mesa/swrast/s_clear.c
@@ -1,230 +1,238 @@
-/*

- * Mesa 3-D graphics library

- * Version:  7.1

- *

- * 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.

- */

-

-#include "main/glheader.h"

-#include "main/colormac.h"

-#include "main/condrender.h"

-#include "main/macros.h"

-#include "main/imports.h"

-#include "main/mtypes.h"

-

-#include "s_accum.h"

-#include "s_context.h"

-#include "s_depth.h"

-#include "s_masking.h"

-#include "s_stencil.h"

-

-

-/**

- * Clear the color buffer when glColorMask is in effect.

- */

-static void

-clear_rgba_buffer_with_masking(struct gl_context *ctx, struct gl_renderbuffer *rb,

-                               GLuint buf)

-{

-   const GLint x = ctx->DrawBuffer->_Xmin;

-   const GLint y = ctx->DrawBuffer->_Ymin;

-   const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;

-   const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;

-   SWspan span;

-   GLint i;

-

-   ASSERT(rb->PutRow);

-

-   /* Initialize color span with clear color */

-   /* XXX optimize for clearcolor == black/zero (bzero) */

-   INIT_SPAN(span, GL_BITMAP);

-   span.end = width;

-   span.arrayMask = SPAN_RGBA;

-   span.array->ChanType = rb->DataType;

-   if (span.array->ChanType == GL_UNSIGNED_BYTE) {

-      GLubyte clearColor[4];

-      UNCLAMPED_FLOAT_TO_UBYTE(clearColor[RCOMP], ctx->Color.ClearColor[0]);

-      UNCLAMPED_FLOAT_TO_UBYTE(clearColor[GCOMP], ctx->Color.ClearColor[1]);

-      UNCLAMPED_FLOAT_TO_UBYTE(clearColor[BCOMP], ctx->Color.ClearColor[2]);

-      UNCLAMPED_FLOAT_TO_UBYTE(clearColor[ACOMP], ctx->Color.ClearColor[3]);

-      for (i = 0; i < width; i++) {

-         COPY_4UBV(span.array->rgba[i], clearColor);

-      }

-   }

-   else if (span.array->ChanType == GL_UNSIGNED_SHORT) {

-      GLushort clearColor[4];

-      UNCLAMPED_FLOAT_TO_USHORT(clearColor[RCOMP], ctx->Color.ClearColor[0]);

-      UNCLAMPED_FLOAT_TO_USHORT(clearColor[GCOMP], ctx->Color.ClearColor[1]);

-      UNCLAMPED_FLOAT_TO_USHORT(clearColor[BCOMP], ctx->Color.ClearColor[2]);

-      UNCLAMPED_FLOAT_TO_USHORT(clearColor[ACOMP], ctx->Color.ClearColor[3]);

-      for (i = 0; i < width; i++) {

-         COPY_4V_CAST(span.array->rgba[i], clearColor, GLchan);

-      }

-   }

-   else {

-      ASSERT(span.array->ChanType == GL_FLOAT);

-      for (i = 0; i < width; i++) {

-         CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][0], ctx->Color.ClearColor[0]);

-         CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][1], ctx->Color.ClearColor[1]);

-         CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][2], ctx->Color.ClearColor[2]);

-         CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][3], ctx->Color.ClearColor[3]);

-      }

-   }

-

-   /* Note that masking will change the color values, but only the

-    * channels for which the write mask is GL_FALSE.  The channels

-    * which which are write-enabled won't get modified.

-    */

-   for (i = 0; i < height; i++) {

-      span.x = x;

-      span.y = y + i;

-      _swrast_mask_rgba_span(ctx, rb, &span, buf);

-      /* write masked row */

-      rb->PutRow(ctx, rb, width, x, y + i, span.array->rgba, NULL);

-   }

-}

-

-

-/**

- * Clear an rgba color buffer without channel masking.

- */

-static void

-clear_rgba_buffer(struct gl_context *ctx, struct gl_renderbuffer *rb, GLuint buf)

-{

-   const GLint x = ctx->DrawBuffer->_Xmin;

-   const GLint y = ctx->DrawBuffer->_Ymin;

-   const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;

-   const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;

-   GLubyte clear8[4];

-   GLushort clear16[4];

-   GLvoid *clearVal;

-   GLint i;

-

-   ASSERT(ctx->Color.ColorMask[buf][0] &&

-          ctx->Color.ColorMask[buf][1] &&

-          ctx->Color.ColorMask[buf][2] &&

-          ctx->Color.ColorMask[buf][3]);             

-

-   ASSERT(rb->PutMonoRow);

-

-   switch (rb->DataType) {

-      case GL_UNSIGNED_BYTE:

-         UNCLAMPED_FLOAT_TO_UBYTE(clear8[0], ctx->Color.ClearColor[0]);

-         UNCLAMPED_FLOAT_TO_UBYTE(clear8[1], ctx->Color.ClearColor[1]);

-         UNCLAMPED_FLOAT_TO_UBYTE(clear8[2], ctx->Color.ClearColor[2]);

-         UNCLAMPED_FLOAT_TO_UBYTE(clear8[3], ctx->Color.ClearColor[3]);

-         clearVal = clear8;

-         break;

-      case GL_UNSIGNED_SHORT:

-         UNCLAMPED_FLOAT_TO_USHORT(clear16[0], ctx->Color.ClearColor[0]);

-         UNCLAMPED_FLOAT_TO_USHORT(clear16[1], ctx->Color.ClearColor[1]);

-         UNCLAMPED_FLOAT_TO_USHORT(clear16[2], ctx->Color.ClearColor[2]);

-         UNCLAMPED_FLOAT_TO_USHORT(clear16[3], ctx->Color.ClearColor[3]);

-         clearVal = clear16;

-         break;

-      case GL_FLOAT:

-         clearVal = ctx->Color.ClearColor;

-         break;

-      default:

-         _mesa_problem(ctx, "Bad rb DataType in clear_color_buffer");

-         return;

-   }

-

-   for (i = 0; i < height; i++) {

-      rb->PutMonoRow(ctx, rb, width, x, y + i, clearVal, NULL);

-   }

-}

-

-

-/**

- * Clear the front/back/left/right/aux color buffers.

- * This function is usually only called if the device driver can't

- * clear its own color buffers for some reason (such as with masking).

- */

-static void

-clear_color_buffers(struct gl_context *ctx)

-{

-   GLuint buf;

-

-   for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {

-      struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[buf];

-      if (ctx->Color.ColorMask[buf][0] == 0 ||

-          ctx->Color.ColorMask[buf][1] == 0 ||

-          ctx->Color.ColorMask[buf][2] == 0 ||

-          ctx->Color.ColorMask[buf][3] == 0) {

-         clear_rgba_buffer_with_masking(ctx, rb, buf);

-      }

-      else {

-         clear_rgba_buffer(ctx, rb, buf);

-      }

-   }

-}

-

-

-/**

- * Called via the device driver's ctx->Driver.Clear() function if the

- * device driver can't clear one or more of the buffers itself.

- * \param buffers  bitfield of BUFFER_BIT_* values indicating which

- *                 renderbuffers are to be cleared.

- * \param all  if GL_TRUE, clear whole buffer, else clear specified region.

- */

-void

-_swrast_Clear(struct gl_context *ctx, GLbitfield buffers)

-{

-#ifdef DEBUG_FOO

-   {

-      const GLbitfield legalBits =

-         BUFFER_BIT_FRONT_LEFT |

-	 BUFFER_BIT_FRONT_RIGHT |

-	 BUFFER_BIT_BACK_LEFT |

-	 BUFFER_BIT_BACK_RIGHT |

-	 BUFFER_BIT_DEPTH |

-	 BUFFER_BIT_STENCIL |

-	 BUFFER_BIT_ACCUM |

-         BUFFER_BIT_AUX0;

-      assert((buffers & (~legalBits)) == 0);

-   }

-#endif

-

-   if (!_mesa_check_conditional_render(ctx))

-      return; /* don't clear */

-

-   swrast_render_start(ctx);

-

-   /* do software clearing here */

-   if (buffers) {

-      if ((buffers & BUFFER_BITS_COLOR)

-          && (ctx->DrawBuffer->_NumColorDrawBuffers > 0)) {

-         clear_color_buffers(ctx);

-      }

-      if (buffers & BUFFER_BIT_DEPTH) {

-         _swrast_clear_depth_buffer(ctx, ctx->DrawBuffer->_DepthBuffer);

-      }

-      if (buffers & BUFFER_BIT_ACCUM) {

-         _swrast_clear_accum_buffer(ctx,

-                       ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer);

-      }

-      if (buffers & BUFFER_BIT_STENCIL) {

-         _swrast_clear_stencil_buffer(ctx, ctx->DrawBuffer->_StencilBuffer);

-      }

-   }

-

-   swrast_render_finish(ctx);

-}

+/*
+ * Mesa 3-D graphics library
+ * Version:  7.1
+ *
+ * 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.
+ */
+
+#include "main/glheader.h"
+#include "main/colormac.h"
+#include "main/condrender.h"
+#include "main/macros.h"
+#include "main/imports.h"
+#include "main/mtypes.h"
+
+#include "s_accum.h"
+#include "s_context.h"
+#include "s_depth.h"
+#include "s_masking.h"
+#include "s_stencil.h"
+
+
+/**
+ * Clear the color buffer when glColorMask is in effect.
+ */
+static void
+clear_rgba_buffer_with_masking(struct gl_context *ctx, struct gl_renderbuffer *rb,
+                               GLuint buf)
+{
+   const GLint x = ctx->DrawBuffer->_Xmin;
+   const GLint y = ctx->DrawBuffer->_Ymin;
+   const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
+   const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
+   SWspan span;
+   GLint i;
+
+   ASSERT(rb->PutRow);
+
+   /* Initialize color span with clear color */
+   /* XXX optimize for clearcolor == black/zero (bzero) */
+   INIT_SPAN(span, GL_BITMAP);
+   span.end = width;
+   span.arrayMask = SPAN_RGBA;
+   span.array->ChanType = rb->DataType;
+   if (span.array->ChanType == GL_UNSIGNED_BYTE) {
+      GLubyte clearColor[4];
+      UNCLAMPED_FLOAT_TO_UBYTE(clearColor[RCOMP], ctx->Color.ClearColor[0]);
+      UNCLAMPED_FLOAT_TO_UBYTE(clearColor[GCOMP], ctx->Color.ClearColor[1]);
+      UNCLAMPED_FLOAT_TO_UBYTE(clearColor[BCOMP], ctx->Color.ClearColor[2]);
+      UNCLAMPED_FLOAT_TO_UBYTE(clearColor[ACOMP], ctx->Color.ClearColor[3]);
+      for (i = 0; i < width; i++) {
+         COPY_4UBV(span.array->rgba[i], clearColor);
+      }
+   }
+   else if (span.array->ChanType == GL_UNSIGNED_SHORT) {
+      GLushort clearColor[4];
+      UNCLAMPED_FLOAT_TO_USHORT(clearColor[RCOMP], ctx->Color.ClearColor[0]);
+      UNCLAMPED_FLOAT_TO_USHORT(clearColor[GCOMP], ctx->Color.ClearColor[1]);
+      UNCLAMPED_FLOAT_TO_USHORT(clearColor[BCOMP], ctx->Color.ClearColor[2]);
+      UNCLAMPED_FLOAT_TO_USHORT(clearColor[ACOMP], ctx->Color.ClearColor[3]);
+      for (i = 0; i < width; i++) {
+         COPY_4V_CAST(span.array->rgba[i], clearColor, GLchan);
+      }
+   }
+   else {
+      ASSERT(span.array->ChanType == GL_FLOAT);
+      for (i = 0; i < width; i++) {
+         CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][0], ctx->Color.ClearColor[0]);
+         CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][1], ctx->Color.ClearColor[1]);
+         CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][2], ctx->Color.ClearColor[2]);
+         CLAMPED_FLOAT_TO_CHAN(span.array->rgba[i][3], ctx->Color.ClearColor[3]);
+      }
+   }
+
+   /* Note that masking will change the color values, but only the
+    * channels for which the write mask is GL_FALSE.  The channels
+    * which which are write-enabled won't get modified.
+    */
+   for (i = 0; i < height; i++) {
+      span.x = x;
+      span.y = y + i;
+      _swrast_mask_rgba_span(ctx, rb, &span, buf);
+      /* write masked row */
+      rb->PutRow(ctx, rb, width, x, y + i, span.array->rgba, NULL);
+   }
+}
+
+
+/**
+ * Clear an rgba color buffer without channel masking.
+ */
+static void
+clear_rgba_buffer(struct gl_context *ctx, struct gl_renderbuffer *rb, GLuint buf)
+{
+   const GLint x = ctx->DrawBuffer->_Xmin;
+   const GLint y = ctx->DrawBuffer->_Ymin;
+   const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
+   const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
+   GLubyte clear8[4];
+   GLushort clear16[4];
+   GLvoid *clearVal;
+   GLint i;
+
+   ASSERT(ctx->Color.ColorMask[buf][0] &&
+          ctx->Color.ColorMask[buf][1] &&
+          ctx->Color.ColorMask[buf][2] &&
+          ctx->Color.ColorMask[buf][3]);             
+
+   ASSERT(rb->PutMonoRow);
+
+   switch (rb->DataType) {
+      case GL_UNSIGNED_BYTE:
+         UNCLAMPED_FLOAT_TO_UBYTE(clear8[0], ctx->Color.ClearColor[0]);
+         UNCLAMPED_FLOAT_TO_UBYTE(clear8[1], ctx->Color.ClearColor[1]);
+         UNCLAMPED_FLOAT_TO_UBYTE(clear8[2], ctx->Color.ClearColor[2]);
+         UNCLAMPED_FLOAT_TO_UBYTE(clear8[3], ctx->Color.ClearColor[3]);
+         clearVal = clear8;
+         break;
+      case GL_UNSIGNED_SHORT:
+         UNCLAMPED_FLOAT_TO_USHORT(clear16[0], ctx->Color.ClearColor[0]);
+         UNCLAMPED_FLOAT_TO_USHORT(clear16[1], ctx->Color.ClearColor[1]);
+         UNCLAMPED_FLOAT_TO_USHORT(clear16[2], ctx->Color.ClearColor[2]);
+         UNCLAMPED_FLOAT_TO_USHORT(clear16[3], ctx->Color.ClearColor[3]);
+         clearVal = clear16;
+         break;
+      case GL_FLOAT:
+         clearVal = ctx->Color.ClearColor;
+         break;
+      default:
+         _mesa_problem(ctx, "Bad rb DataType in clear_color_buffer");
+         return;
+   }
+
+   for (i = 0; i < height; i++) {
+      rb->PutMonoRow(ctx, rb, width, x, y + i, clearVal, NULL);
+   }
+}
+
+
+/**
+ * Clear the front/back/left/right/aux color buffers.
+ * This function is usually only called if the device driver can't
+ * clear its own color buffers for some reason (such as with masking).
+ */
+static void
+clear_color_buffers(struct gl_context *ctx)
+{
+   GLuint buf;
+
+   for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {
+      struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[buf];
+
+      /* If this is an ES2 context or GL_ARB_ES2_compatibility is supported,
+       * the framebuffer can be complete with some attachments be missing.  In
+       * this case the _ColorDrawBuffers pointer will be NULL.
+       */
+      if (rb == NULL)
+	 continue;
+
+      if (ctx->Color.ColorMask[buf][0] == 0 ||
+          ctx->Color.ColorMask[buf][1] == 0 ||
+          ctx->Color.ColorMask[buf][2] == 0 ||
+          ctx->Color.ColorMask[buf][3] == 0) {
+         clear_rgba_buffer_with_masking(ctx, rb, buf);
+      }
+      else {
+         clear_rgba_buffer(ctx, rb, buf);
+      }
+   }
+}
+
+
+/**
+ * Called via the device driver's ctx->Driver.Clear() function if the
+ * device driver can't clear one or more of the buffers itself.
+ * \param buffers  bitfield of BUFFER_BIT_* values indicating which
+ *                 renderbuffers are to be cleared.
+ * \param all  if GL_TRUE, clear whole buffer, else clear specified region.
+ */
+void
+_swrast_Clear(struct gl_context *ctx, GLbitfield buffers)
+{
+#ifdef DEBUG_FOO
+   {
+      const GLbitfield legalBits =
+         BUFFER_BIT_FRONT_LEFT |
+	 BUFFER_BIT_FRONT_RIGHT |
+	 BUFFER_BIT_BACK_LEFT |
+	 BUFFER_BIT_BACK_RIGHT |
+	 BUFFER_BIT_DEPTH |
+	 BUFFER_BIT_STENCIL |
+	 BUFFER_BIT_ACCUM |
+         BUFFER_BIT_AUX0;
+      assert((buffers & (~legalBits)) == 0);
+   }
+#endif
+
+   if (!_mesa_check_conditional_render(ctx))
+      return; /* don't clear */
+
+   swrast_render_start(ctx);
+
+   /* do software clearing here */
+   if (buffers) {
+      if ((buffers & BUFFER_BITS_COLOR)
+          && (ctx->DrawBuffer->_NumColorDrawBuffers > 0)) {
+         clear_color_buffers(ctx);
+      }
+      if (buffers & BUFFER_BIT_DEPTH) {
+         _swrast_clear_depth_buffer(ctx, ctx->DrawBuffer->_DepthBuffer);
+      }
+      if (buffers & BUFFER_BIT_ACCUM) {
+         _swrast_clear_accum_buffer(ctx,
+                       ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer);
+      }
+      if (buffers & BUFFER_BIT_STENCIL) {
+         _swrast_clear_stencil_buffer(ctx, ctx->DrawBuffer->_StencilBuffer);
+      }
+   }
+
+   swrast_render_finish(ctx);
+}