- Add an external helper program that initializes GLX and checks if kwin can

use direct rendering.
- Move the LIBGL_ALWAYS_INDIRECT code to CompositingPrefs::detect(), and use
  the external helper program to determine if the variable needs to be set.

svn path=/trunk/KDE/kdebase/workspace/; revision=1096554

CMakeLists.txt

@@ -112,6 +112,7 @@ kde4_add_kdeinit_executable( kwin ${kwin_KDEINIT_SRCS})
 target_link_libraries(kdeinit_kwin ${KDE4_KDEUI_LIBS} ${KDE4_PLASMA_LIBS} ${QT_QTXML_LIBRARY} kephal kdecorations kwineffects ${X11_LIBRARIES})
 
 if(OPENGL_FOUND)
+  add_subdirectory(opengltest)
   target_link_libraries(kdeinit_kwin ${OPENGL_gl_LIBRARY})
   # -ldl used by OpenGL code
   find_library(DL_LIBRARY dl)

compositingprefs.cpp

@@ -26,6 +26,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <kxerrorhandler.h>
 #include <klocale.h>
 #include <kdeversion.h>
+#include <kstandarddirs.h>
+
+#include <qprocess.h>
 
 
 namespace KWin
@@ -115,6 +118,20 @@ void CompositingPrefs::detect()
         }
 
 #ifdef KWIN_HAVE_OPENGL_COMPOSITING
+    // HACK: This is needed for AIGLX
+    if( qstrcmp( qgetenv( "KWIN_DIRECT_GL" ), "1" ) != 0 )
+        {
+        // Start an external helper program that initializes GLX and returns
+        // 0 if we can use direct rendering, and 1 otherwise.
+        // The reason we have to use an external program is that after GLX
+        // has been initialized, it's too late to set the LIBGL_ALWAYS_INDIRECT
+        // environment variable.
+        // Direct rendering is preferred, since not all OpenGL extensions are
+        // available with indirect rendering.
+        const QString opengl_test = KStandardDirs::findExe( "kwin_opengl_test" );
+        if ( QProcess::execute( opengl_test ) != 0 )
+            setenv( "LIBGL_ALWAYS_INDIRECT", "1", true );
+        }
     if( !Extensions::glxAvailable())
         {
         kDebug( 1212 ) << "No GLX available";

main.cpp

@@ -496,10 +496,6 @@ KDE_EXPORT int kdemain( int argc, char * argv[] )
     if( KDE_signal( SIGHUP, KWin::sighandler ) == SIG_IGN )
         KDE_signal( SIGHUP, SIG_IGN );
 
-    // HACK: This is needed for AIGLX
-    if( qstrcmp( qgetenv( "KWIN_DIRECT_GL" ), "1" ) != 0 )
-        setenv( "LIBGL_ALWAYS_INDIRECT","1", true );
-
     // HACK: this is needed to work around a Qt4.4.0RC1 bug (#157659)
     setenv( "QT_SLOW_TOPLEVEL_RESIZE", "1", true );
 

opengltest/CMakeLists.txt

@@ -0,0 +1,10 @@
+########### next target ###############
+
+set(kwin_opengl_test_SRCS opengltest.cpp )
+
+kde4_add_executable(kwin_opengl_test ${kwin_opengl_test_SRCS})
+
+target_link_libraries(kwin_opengl_test ${X11_LIBRARIES} ${OPENGL_gl_LIBRARY})
+
+install(TARGETS kwin_opengl_test ${INSTALL_TARGETS_DEFAULT_ARGS} )
+

opengltest/opengltest.cpp

@@ -0,0 +1,89 @@
+/********************************************************************
+ KWin - the KDE window manager
+ This file is part of the KDE project.
+
+Copyright (C) 2010 Fredrik Höglund <fredrik@kde.org>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*********************************************************************/
+
+#include <X11/Xlib.h>
+#include <GL/glx.h>
+#include <string.h>
+#include <stdio.h>
+
+
+// Return 0 if we can use a direct context, 1 otherwise
+int main(int argc, char *argv[])
+{
+    Display *dpy = XOpenDisplay(0);
+
+    int error_base, event_base;
+    if (!glXQueryExtension(dpy, &error_base, &event_base))
+        return 1;
+
+    int major, minor;
+    if (!glXQueryVersion(dpy, &major, &minor))
+        return 1;
+
+    // glXCreatePixmap() is a GLX 1.3+ function.
+    // It is also provided by EXT_texture_from_pixmap, but only for indirect contexts.
+    if (major == 1 && minor < 3)
+        return 1;
+
+    int attribs[] = {
+        GLX_RGBA,
+        GLX_RED_SIZE,    1,
+        GLX_GREEN_SIZE,  1,
+        GLX_BLUE_SIZE,   1,
+        None,
+        None
+    };
+
+    // Try to find an RGBA visual
+    XVisualInfo *xvi = glXChooseVisual(dpy, DefaultScreen(dpy), attribs);
+    if (!xvi) {
+        // Try again for a doubled buffered visual
+        attribs[sizeof(attribs) / sizeof(int) - 2] = GLX_DOUBLEBUFFER;
+        xvi = glXChooseVisual(dpy, DefaultScreen(dpy), attribs);
+    }
+
+    if (!xvi)
+        return 1;
+
+    GLXContext ctx = glXCreateContext(dpy, xvi, NULL, True);
+
+    // Create a window using the visual.
+    // We only need it to make the context current
+    XSetWindowAttributes attr;
+    attr.background_pixel = 0;
+    attr.border_pixel = 0;
+    attr.colormap = XCreateColormap(dpy, DefaultRootWindow(dpy), xvi->visual, AllocNone);
+    Window win = XCreateWindow(dpy, DefaultRootWindow(dpy), 0, 0, 1, 1, 0,
+                               xvi->depth, InputOutput, xvi->visual,
+                               CWBackPixel | CWBorderPixel | CWColormap, &attr);
+    glXMakeCurrent(dpy, win, ctx);
+
+    // Assume that glXCreatePixmap() works with DRI2 drivers, and the NVidia driver
+    const GLubyte *renderer = glGetString(GL_RENDERER);
+    if (strstr((const char *)renderer, "DRI2"))
+        return 0;
+
+    const GLubyte *vendor = glGetString(GL_VENDOR);
+    if (strstr((const char *)vendor, "NVIDIA"))
+        return 0;
+
+    return 1;
+}
+