Move GLX detection from kwinglobals to CompositingPrefs

Removes the Extension::glxAvailable() from kwinglobals and
implements the functionality in CompositingPrefs, where it
is only needed. There used to be one additional check in
scene_opengl_glx.cpp which is moved into composite.cpp
before the OpenGL Scene is created.

REVIEW: 102002

composite.cpp

@@ -122,6 +122,14 @@ void Workspace::setupCompositing()
         else {
             unsafeConfig.writeEntry("OpenGLIsUnsafe", true);
             unsafeConfig.sync();
+#ifndef KWIN_HAVE_OPENGLES
+            if (!CompositingPrefs::hasGlx()) {
+                unsafeConfig.writeEntry("OpenGLIsUnsafe", false);
+                unsafeConfig.sync();
+                kDebug(1212) << "No glx extensions available";
+                break;
+            }
+#endif
 
             scene = new SceneOpenGL(this);
 

compositingprefs.cpp

@@ -80,7 +80,7 @@ bool CompositingPrefs::compositingPossible()
         return false;
     }
 #ifdef KWIN_HAVE_OPENGL_COMPOSITING
-    if (Extensions::glxAvailable())
+    if (hasGlx())
         return true;
 #endif
 #ifdef KWIN_HAVE_XRENDER_COMPOSITING
@@ -116,14 +116,14 @@ QString CompositingPrefs::compositingNotPossibleReason()
         return i18n("Required X extensions (XComposite and XDamage) are not available.");
     }
 #if defined( KWIN_HAVE_OPENGL_COMPOSITING ) && !defined( KWIN_HAVE_XRENDER_COMPOSITING )
-    if (!Extensions::glxAvailable())
+    if (!hasGlx())
         return i18n("GLX/OpenGL are not available and only OpenGL support is compiled.");
 #elif !defined( KWIN_HAVE_OPENGL_COMPOSITING ) && defined( KWIN_HAVE_XRENDER_COMPOSITING )
     if (!(Extensions::renderAvailable() && Extensions::fixesAvailable()))
         return i18n("XRender/XFixes extensions are not available and only XRender support"
                     " is compiled.");
 #else
-    if (!(Extensions::glxAvailable()
+    if (!(hasGlx()
             || (Extensions::renderAvailable() && Extensions::fixesAvailable()))) {
         return i18n("GLX/OpenGL and XRender/XFixes are not available.");
     }
@@ -135,6 +135,24 @@ QString CompositingPrefs::compositingNotPossibleReason()
 #endif
 }
 
+static bool s_glxDetected = false;
+static bool s_hasGlx = false;
+
+bool CompositingPrefs::hasGlx()
+{
+    if (s_glxDetected) {
+        return s_hasGlx;
+    }
+#ifdef KWIN_HAVE_OPENGL_COMPOSITING
+#ifndef KWIN_HAVE_OPENGLES
+    int event_base, error_base;
+    s_hasGlx = glXQueryExtension(display(), &event_base, &error_base);
+#endif
+#endif
+    s_glxDetected = true;
+    return s_hasGlx;
+}
+
 void CompositingPrefs::detect()
 {
     if (!compositingPossible() || openGlIsBroken()) {
@@ -186,7 +204,7 @@ void CompositingPrefs::detect()
         if (QProcess::execute(opengl_test) != 0)
             setenv("LIBGL_ALWAYS_INDIRECT", "1", true);
     }
-    if (!Extensions::glxAvailable()) {
+    if (!hasGlx()) {
         kDebug(1212) << "No GLX available";
         gl_workaround_config.writeEntry("OpenGLIsUnsafe", false);
         gl_workaround_config.sync();

compositingprefs.h

@@ -40,6 +40,16 @@ public:
     static bool compositingPossible();
     static QString compositingNotPossibleReason();
     static bool openGlIsBroken();
+    /**
+     * Tests whether GLX is supported and returns @c true
+     * in case KWin is compiled with OpenGL support and GLX
+     * is available.
+     *
+     * If KWin is compiled with OpenGL ES or without OpenGL at
+     * all, @c false is returned.
+     * @returns @c true if GLX is available, @c false otherwise and if not build with OpenGL support.
+     **/
+    static bool hasGlx();
     bool recommendCompositing() const;
     bool enableVSync() const  {
         return mEnableVSync;

libkwineffects/kwinglobals.cpp

@@ -49,9 +49,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifdef HAVE_XCOMPOSITE
 #include <X11/extensions/Xcomposite.h>
 #endif
-#ifdef HAVE_OPENGL
-#include <GL/glx.h>
-#endif
 #ifdef HAVE_XSYNC
 #include <X11/extensions/sync.h>
 #endif
@@ -68,7 +65,6 @@ int Extensions::damage_event_base = 0;
 int Extensions::composite_version = 0;
 int Extensions::fixes_version = 0;
 int Extensions::render_version = 0;
-bool Extensions::has_glx = false;
 bool Extensions::has_sync = false;
 int Extensions::sync_event_base = 0;
 bool Extensions::non_native_pixmaps = false;
@@ -145,14 +141,6 @@ void Extensions::init()
         render_version = major * 0x10 + minor;
         addData("RENDER");
     }
-#endif
-    has_glx = false;
-#ifdef HAVE_OPENGL
-#ifndef KWIN_HAVE_OPENGLES
-    has_glx = glXQueryExtension(display(), &event_base, &error_base);
-    if (has_glx)
-        addData("GLX");
-#endif
 #endif
 #ifdef HAVE_XSYNC
     if (XSyncQueryExtension(display(), &sync_event_base, &error_base)) {

libkwineffects/kwinglobals.h

@@ -165,9 +165,6 @@ public:
         return fixes_version > 0;
     }
     static bool fixesRegionAvailable();
-    static bool glxAvailable() {
-        return has_glx;
-    }
     static bool syncAvailable() {
         return has_sync;
     }
@@ -187,7 +184,6 @@ private:
     static int composite_version;
     static int render_version;
     static int fixes_version;
-    static bool has_glx;
     static bool has_sync;
     static int sync_event_base;
     static const char* data_extensions[ 32 ];

scene_opengl_glx.cpp

@@ -39,10 +39,6 @@ SceneOpenGL::SceneOpenGL(Workspace* ws)
     : Scene(ws)
     , init_ok(false)
 {
-    if (!Extensions::glxAvailable()) {
-        kDebug(1212) << "No glx extensions available";
-        return; // error
-    }
     initGLX();
     // check for FBConfig support
     if (!hasGLExtension("GLX_SGIX_fbconfig") || !glXGetFBConfigAttrib || !glXGetFBConfigs ||