Roderick Colenbrander : winex11.drv: pbuffer detection.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: c026faaeed9035aff21b31ee167e3a8f3018d88d
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=c026faaeed9035aff21b31ee167e3a8f3018d88d

Author: Roderick Colenbrander <thunderbird2k at gmx.net>
Date:   Tue Dec 19 20:24:25 2006 +0100

winex11.drv: pbuffer detection.

---

 dlls/winex11.drv/opengl.c |   13 ++++++++++++-
 1 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/dlls/winex11.drv/opengl.c b/dlls/winex11.drv/opengl.c
index 418067a..cb7366a 100644
--- a/dlls/winex11.drv/opengl.c
+++ b/dlls/winex11.drv/opengl.c
@@ -2947,7 +2947,18 @@ static void X11DRV_WineGL_LoadExtensions
     if (glxRequireExtension("GLX_ARB_multisample"))
         register_extension(&WGL_ARB_multisample);
 
-    if (glxRequireVersion(3) && glxRequireExtension("GLX_SGIX_pbuffer"))
+    /* In general pbuffer functionality requires support in the X-server. The functionality is
+     * available either when the GLX_SGIX_pbuffer is present or when the GLX server version is 1.3.
+     * All display drivers except for Nvidia's use the GLX module from Xfree86/Xorg which only
+     * supports GLX 1.2. The endresult is that only Nvidia's drivers support pbuffers.
+     *
+     * The only other drive which has pbuffer support is Ati's FGLRX driver. They provide clientside GLX 1.3 support
+     * without support in the X-server (which other Mesa based drivers require).
+     *
+     * Support pbuffers when the GLX version is 1.3 and GLX_SGIX_pbuffer is available. Further pbuffers can
+     * also be supported when GLX_ATI_render_texture is available. This extension depends on pbuffers, so when it
+     * is available pbuffers must be available too. */
+    if ( (glxRequireVersion(3) && glxRequireExtension("GLX_SGIX_pbuffer")) || glxRequireExtension("GLX_ATI_render_texture"))
         register_extension(&WGL_ARB_pbuffer);
 
     register_extension(&WGL_ARB_pixel_format);