From 47fa65c34a52271811da54e29c7ddbbdbc5da452 Mon Sep 17 00:00:00 2001
From: David Rose <david@ddrose.com>
Date: Tue, 7 Aug 2007 03:30:40 +0000
Subject: [PATCH] mesa buffers are single-buffered, and don't you forget it
 again

---
 panda/src/mesadisplay/osMesaGraphicsBuffer.cxx |  2 +-
 panda/src/mesadisplay/osMesaGraphicsPipe.cxx   | 10 +++++++---
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/panda/src/mesadisplay/osMesaGraphicsBuffer.cxx b/panda/src/mesadisplay/osMesaGraphicsBuffer.cxx
index 10bb33c48c..b2bf23320a 100644
--- a/panda/src/mesadisplay/osMesaGraphicsBuffer.cxx
+++ b/panda/src/mesadisplay/osMesaGraphicsBuffer.cxx
@@ -39,7 +39,7 @@ OsMesaGraphicsBuffer(GraphicsPipe *pipe,
   GraphicsBuffer(pipe, name, fb_prop, win_prop, flags, gsg, host)
 {
   _type = GL_UNSIGNED_BYTE;
-  _draw_buffer_type = RenderBuffer::T_front;
+  _screenshot_buffer_type = _draw_buffer_type;
 }
 
 ////////////////////////////////////////////////////////////////////
diff --git a/panda/src/mesadisplay/osMesaGraphicsPipe.cxx b/panda/src/mesadisplay/osMesaGraphicsPipe.cxx
index 01d5cc3ac4..105e3b4c2b 100644
--- a/panda/src/mesadisplay/osMesaGraphicsPipe.cxx
+++ b/panda/src/mesadisplay/osMesaGraphicsPipe.cxx
@@ -90,8 +90,6 @@ make_output(const string &name,
   if (!_is_valid) {
     return NULL;
   }
-  
-  // First thing to try: an OsMesaGraphicsBuffer
 
   if (retry == 0) {
     if ((!support_render_texture)||
@@ -102,7 +100,13 @@ make_output(const string &name,
         ((flags&BF_rtt_cumulative)!=0)) {
       return NULL;
     }
-    return new OsMesaGraphicsBuffer(this, name, fb_prop, win_prop,
+
+    // We know that OsMesa windows only support single buffering.  So
+    // don't bother asking for more than that.
+    FrameBufferProperties fb_prop2 = fb_prop;
+    fb_prop2.set_back_buffers(0);
+
+    return new OsMesaGraphicsBuffer(this, name, fb_prop2, win_prop,
                                     flags, gsg, host);
   }