Merge lp:~3v1n0/compiz/msaa-configs-ignore-0.9.9 into lp:compiz/0.9.9

[Marco Trevisan (Treviño)]

OpenGL Screen: Ignore the MSAA configs during initialization

This fixes a crash with new MESA drivers and high monitor resolutions
caused by the fact that we're accidentally using some MSAA configs with
some drivers in Mesa 9.0.
Taking in account the values of GLX_SAMPLES and GLX_SAMPLE_BUFFERS
fixes the issue.

See mesa bug https://bugs.freedesktop.org/show_bug.cgi?id=61182

Backport of lp:~3v1n0/compiz/msaa-configs-ignore/+merge/163550 to 0.9.9 branch.

[Sam Spilsbury (smspillaz)]

review: Approve

[lp:~3v1n0/compiz/msaa-configs-ignore-0.9.9]

3655. By Marco Trevisan (Treviño) on 2013-05-13

GLScreen: use compiz name conventions

[PS Jenkins bot (ps-jenkins)]

review: Approve (continuous-integration)

=== modified file 'plugins/opengl/src/screen.cpp'
--- plugins/opengl/src/screen.cpp	2013-01-09 10:57:03 +0000
+++ plugins/opengl/src/screen.cpp	2013-05-13 15:57:27 +0000
@@ -1058,7 +1058,7 @@
 
     for (i = 0; i <= MAX_DEPTH; i++)
     {
-	int j, db, stencil, depth, alpha, mipmap, rgba;
+	int j, db, stencil, depth, alpha, mipmap, msaaBuffers, msaaSamples, rgba;
 
 	priv->glxPixmapFBConfigs[i].fbConfig       = NULL;
 	priv->glxPixmapFBConfigs[i].mipmap         = 0;
@@ -1066,11 +1066,13 @@
 	priv->glxPixmapFBConfigs[i].textureFormat  = 0;
 	priv->glxPixmapFBConfigs[i].textureTargets = 0;
 
-	db      = MAXSHORT;
-	stencil = MAXSHORT;
-	depth   = MAXSHORT;
-	mipmap  = 0;
-	rgba    = 0;
+	db          = MAXSHORT;
+	stencil     = MAXSHORT;
+	depth       = MAXSHORT;
+	msaaBuffers = MAXSHORT;
+	msaaSamples = MAXSHORT;
+	mipmap      = 0;
+	rgba        = 0;
 
 	for (j = 0; j < nElements; j++)
 	{
@@ -1146,7 +1148,21 @@
 	    depth = value;
 
 	    (*GL::getFBConfigAttrib) (dpy, fbConfigs[j],
-	                              GLX_BIND_TO_MIPMAP_TEXTURE_EXT, &value);
+				      GLX_SAMPLE_BUFFERS, &value);
+	    if (value > msaaBuffers)
+	        continue;
+
+	    msaaBuffers = value;
+
+	    (*GL::getFBConfigAttrib) (dpy, fbConfigs[j],
+				      GLX_SAMPLES, &value);
+	    if (value > msaaSamples)
+	        continue;
+
+	    msaaSamples = value;
+
+	    (*GL::getFBConfigAttrib) (dpy, fbConfigs[j],
+				      GLX_BIND_TO_MIPMAP_TEXTURE_EXT, &value);
 	    if (value < mipmap)
 		continue;