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authorBrian Paul <brian.paul@tungstengraphics.com>2002-07-09 01:28:03 +0000
committerBrian Paul <brian.paul@tungstengraphics.com>2002-07-09 01:28:03 +0000
commit55c82c596e1c1e597da183942db002d3d0b8f29f (patch)
tree0c33faa25fb21454932852feedc0dbc748bf2b96 /docs
parent3b4fbbc129c711a5aec8d653d5c6eb2e195f947c (diff)
added Read/DrawBuffer porting info
Diffstat (limited to 'docs')
-rw-r--r--docs/RELNOTES-4.133
1 files changed, 31 insertions, 2 deletions
diff --git a/docs/RELNOTES-4.1 b/docs/RELNOTES-4.1
index 3a2178f4a47..ab95ea1950c 100644
--- a/docs/RELNOTES-4.1
+++ b/docs/RELNOTES-4.1
@@ -172,7 +172,7 @@ are some things to change:
<none> TEXTURE_RECT_BIT
These tokens are only used for the ctx->Texture.Unit[i].Enabled and
- ctx->Texture.Unit[i]._ReallyEnabled fields. Exactly 0 or 1 bit will
+ ctx->Texture.Unit[i]._ReallyEnabled fields. Exactly 0 or 1 bits will
be set in _ReallyEnabled at any time!
Q: "What's the purpose of Unit[i].Enabled vs Unit[i]._ReallyEnabled?"
@@ -202,5 +202,34 @@ are some things to change:
+3. Read/Draw Buffer changes
+
+ The business of setting the current read/draw buffers in Mesa 4.0.x
+ was complicated. It's much simpler now in Mesa 4.1.
+
+ Here are the changes:
+
+ - Rename ctx->Color.DrawDestMask to ctx->Color._DrawDestMask
+ - Rename ctx->Color.DriverDrawBuffer to ctx->Color._DriverDrawBuffer
+ - Rename ctx->Pixel.DriverReadBuffer to ctx->Pixel._DriverReadBuffer
+ - Removed ctx->Color.MultiDrawBuffer
+ - Removed ctx->Driver.SetDrawBuffer
+ - Added ctx->Driver.DrawBuffer and ctx->Driver.ReadBuffer. These functions
+ exactly correspond to glDrawBuffer and glReadBuffer calls.
+ Many drivers will set ctx->Driver.DrawBuffer = _swrast_DrawBuffer and
+ leave ctx->Draw.ReadBuffer NULL.
+ DRI drivers should implement their own function for ctx->Driver.DrawBuffer
+ and use it to set the current hardware drawing buffer. You'll probably
+ also want to check for GL_FRONT_AND_BACK mode and fall back to software.
+ Call _swrast_DrawBuffer() too, to update the swrast state.
+ - Removed swrast->Driver.SetReadBuffer
+ - Added swrast->Driver.SetBuffer. This function should be implemented by
+ _all_ device drivers. Mesa will call it to specify the buffer to use
+ for span reading AND writing and point/line/triangle rendering. There
+ should be no confusion between current read or draw buffer anymore.
+
+
+
+
----------------------------------------------------------------------
-$Id: RELNOTES-4.1,v 1.12 2002/06/30 15:49:03 brianp Exp $
+$Id: RELNOTES-4.1,v 1.13 2002/07/09 01:28:03 brianp Exp $