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authorBrian Paul <brian.paul@tungstengraphics.com>2003-04-29 13:16:37 +0000
committerBrian Paul <brian.paul@tungstengraphics.com>2003-04-29 13:16:37 +0000
commitf34de59b3eb631f98db907aea04b055c87f77900 (patch)
treed19fae54cad7f245239f59852836a7be004cea24 /src/mesa/main/buffers.c
parent370d7ad007fc9a083c958fe12c1fa834aefb3c61 (diff)
don't try to clear non-existant buffers
Diffstat (limited to 'src/mesa/main/buffers.c')
-rw-r--r--src/mesa/main/buffers.c20
1 files changed, 12 insertions, 8 deletions
diff --git a/src/mesa/main/buffers.c b/src/mesa/main/buffers.c
index ab579b3d33..f7e922e2a2 100644
--- a/src/mesa/main/buffers.c
+++ b/src/mesa/main/buffers.c
@@ -1,5 +1,3 @@
-/* $Id: buffers.c,v 1.43 2003/03/01 01:50:20 brianp Exp $ */
-
/*
* Mesa 3-D graphics library
* Version: 5.1
@@ -118,13 +116,19 @@ _mesa_Clear( GLbitfield mask )
if (!ctx->Depth.Mask)
mask &= ~GL_DEPTH_BUFFER_BIT;
- /* Build bitmask to send to driver Clear function */
- ddMask = mask & (GL_DEPTH_BUFFER_BIT |
- GL_STENCIL_BUFFER_BIT |
- GL_ACCUM_BUFFER_BIT);
- if (mask & GL_COLOR_BUFFER_BIT) {
+ /* Build the bitmask to send to device driver's Clear function.
+ * Note that the GL_COLOR_BUFFER_BIT flag will expand to 0, 1, 2 or 4
+ * of the FRONT/BACK_LEFT/RIGHT_BIT flags.
+ */
+ ddMask = 0;
+ if (mask & GL_COLOR_BUFFER_BIT)
ddMask |= ctx->Color._DrawDestMask;
- }
+ if ((mask & GL_DEPTH_BUFFER_BIT) && ctx->Visual.depthBits > 0)
+ ddMask |= GL_DEPTH_BUFFER_BIT;
+ if ((mask & GL_STENCIL_BUFFER_BIT) && ctx->Visual.stencilBits > 0)
+ ddMask |= GL_STENCIL_BUFFER_BIT;
+ if ((mask & GL_ACCUM_BUFFER_BIT) && ctx->Visual.accumRedBits > 0)
+ ddMask |= GL_ACCUM_BUFFER_BIT;
ASSERT(ctx->Driver.Clear);
ctx->Driver.Clear( ctx, ddMask, (GLboolean) !ctx->Scissor.Enabled,