Mesa (master): gallium: Explain what happens if buffer_flush_mapped_range isn't called.

[Jose Fonseca]

Module: Mesa
Branch: master
Commit: 48f6e754898879898165dca013157dffe2babb12
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=48f6e754898879898165dca013157dffe2babb12

Author: José Fonseca <jfonseca at vmware.com>
Date:   Wed Mar 18 16:54:25 2009 +0000

gallium: Explain what happens if buffer_flush_mapped_range isn't called.

---

 src/gallium/include/pipe/p_screen.h |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/src/gallium/include/pipe/p_screen.h b/src/gallium/include/pipe/p_screen.h
index ed3a026..ceac755 100644
--- a/src/gallium/include/pipe/p_screen.h
+++ b/src/gallium/include/pipe/p_screen.h
@@ -223,6 +223,13 @@ struct pipe_screen {
     * specified to buffer_map_range. This is different from the 
     * ARB_map_buffer_range semantics because we don't forbid multiple mappings 
     * of the same buffer (yet).
+    * 
+    * If the buffer was mapped for writing and no buffer_flush_mapped_range 
+    * call was done until the buffer_unmap is called then the pipe driver will
+    * assumed that the whole buffer was written. This is for backward 
+    * compatibility purposes and may affect performance -- the state tracker 
+    * should always specify exactly what got written while the buffer was 
+    * mapped.  
     */
    void (*buffer_flush_mapped_range)( struct pipe_screen *screen,
                                       struct pipe_buffer *buf,