Move glx version check functionality to platform plugin

Summary:
Glx version is only required once in the standalone x11 platform. No
need to have that in the shared kwinglutils library.

Removes one xlib usage from shared kwin.

Reviewers: #kwin, #plasma_on_wayland

Subscribers: plasma-devel, kwin

Tags: #plasma_on_wayland, #kwin

Differential Revision: https://phabricator.kde.org/D3329

libkwineffects/kwinglutils.cpp

@@ -64,8 +64,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 namespace KWin
 {
 // Variables
-// GLX version, use MAKE_GL_VERSION() macro for comparing with a specific version
-static int glXVersion;
 // EGL version, use MAKE_GL_VERSION() macro for comparing with a specific version
 static int eglVersion;
 // List of all supported GL, EGL and GLX extensions
@@ -80,10 +78,6 @@ int glTextureUnitsCount;
 void initGLX()
 {
 #if HAVE_EPOXY_GLX
-    // Get GLX version
-    int major, minor;
-    glXQueryVersion(display(), &major, &minor);
-    glXVersion = MAKE_GL_VERSION(major, minor, 0);
     // Get list of supported GLX extensions
     const QByteArray string = (const char *) glXQueryExtensionsString(display(), QX11Info::appScreen());
     s_glxExtensions = string.split(' ');
@@ -138,7 +132,6 @@ void cleanupGL()
     s_glxExtensions.clear();
     s_eglExtensions.clear();
 
-    glXVersion = 0;
     eglVersion = 0;
     glTextureUnitsCount = 0;
 }
@@ -148,11 +141,6 @@ bool hasGLVersion(int major, int minor, int release)
     return GLPlatform::instance()->glVersion() >= kVersionNumber(major, minor, release);
 }
 
-bool hasGLXVersion(int major, int minor, int release)
-{
-    return glXVersion >= MAKE_GL_VERSION(major, minor, release);
-}
-
 bool hasEGLVersion(int major, int minor, int release)
 {
     return eglVersion >= MAKE_GL_VERSION(major, minor, release);

libkwineffects/kwinglutils.h

@@ -65,7 +65,6 @@ extern KWINGLUTILS_EXPORT int glTextureUnitsCount;
 
 
 bool KWINGLUTILS_EXPORT hasGLVersion(int major, int minor, int release = 0);
-bool KWINGLUTILS_EXPORT hasGLXVersion(int major, int minor, int release = 0);
 bool KWINGLUTILS_EXPORT hasEGLVersion(int major, int minor, int release = 0);
 // use for both OpenGL and GLX extensions
 bool KWINGLUTILS_EXPORT hasGLExtension(const QByteArray &extension);

plugins/platforms/x11/standalone/glxbackend.cpp

@@ -153,7 +153,7 @@ void GlxBackend::init()
     initGLX();
 
     // Require at least GLX 1.3
-    if (!hasGLXVersion(1, 3)) {
+    if (!checkVersion()) {
         setFailed(QStringLiteral("Requires at least GLX 1.3"));
         return;
     }
@@ -246,6 +246,13 @@ void GlxBackend::init()
     qCDebug(KWIN_X11STANDALONE) << "Direct rendering:" << isDirectRendering();
 }
 
+bool GlxBackend::checkVersion()
+{
+    int major, minor;
+    glXQueryVersion(display(), &major, &minor);
+    return kVersionNumber(major, minor) >= kVersionNumber(1, 3);
+}
+
 bool GlxBackend::initRenderingContext()
 {
     const bool direct = true;

plugins/platforms/x11/standalone/glxbackend.h

@@ -78,6 +78,7 @@ protected:
 
 private:
     bool initBuffer();
+    bool checkVersion();
     void waitSync();
     bool initRenderingContext();
     bool initFbConfig();