From 70fefbbbae3638ca0b96276035dba436a8f77b2d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Gr=C3=A4=C3=9Flin?= <ubuntu@martin-graesslin.com>
Date: Sun, 5 Dec 2010 11:55:19 +0100
Subject: [PATCH] Adding an initEGL method and check for required extension

---
 lib/kwinglutils.cpp  | 23 +++++++++++++++++++++--
 lib/kwinglutils.h    |  3 +++
 scene_opengl_egl.cpp |  9 +++++++++
 3 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/lib/kwinglutils.cpp b/lib/kwinglutils.cpp
index 8b1311b0b5..c02efa5229 100644
--- a/lib/kwinglutils.cpp
+++ b/lib/kwinglutils.cpp
@@ -48,9 +48,12 @@ namespace KWin
 static int glVersion;
 // GLX version, use MAKE_GL_VERSION() macro for comparing with a specific version
 static int glXVersion;
-// List of all supported GL and GLX extensions
+// 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
 static QStringList glExtensions;
 static QStringList glxExtensions;
+static QStringList eglExtension;
 
 int glTextureUnitsCount;
 
@@ -71,6 +74,17 @@ void initGLX()
 #endif
     }
 
+void initEGL()
+{
+#ifdef KWIN_HAVE_OPENGLES
+    EGLDisplay dpy = eglGetCurrentDisplay();
+    int major, minor;
+    eglInitialize(dpy, &major, &minor);
+    eglVersion = MAKE_GL_VERSION(major, minor, 0);
+    eglExtension = QString((const char*)eglQueryString(dpy, EGL_EXTENSIONS)).split(' ');
+#endif
+}
+
 void initGL()
     {
     // Get OpenGL version
@@ -104,9 +118,14 @@ 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);
+}
+
 bool hasGLExtension(const QString& extension)
     {
-    return glExtensions.contains(extension) || glxExtensions.contains(extension);
+    return glExtensions.contains(extension) || glxExtensions.contains(extension) || eglExtension.contains(extension);
     }
 
 static QString formatGLError( GLenum err )
diff --git a/lib/kwinglutils.h b/lib/kwinglutils.h
index a7b64bdd18..761a0cc5fb 100644
--- a/lib/kwinglutils.h
+++ b/lib/kwinglutils.h
@@ -58,6 +58,8 @@ void KWIN_EXPORT initGLX();
 //  well as checking for GL version and extensions
 //  Note that GL context has to be created by the time this function is called
 void KWIN_EXPORT initGL();
+// Initializes EGL function pointers
+void KWIN_EXPORT initEGL();
 
 
 // Number of supported texture units
@@ -66,6 +68,7 @@ extern KWIN_EXPORT int glTextureUnitsCount;
 
 bool KWIN_EXPORT hasGLVersion(int major, int minor, int release = 0);
 bool KWIN_EXPORT hasGLXVersion(int major, int minor, int release = 0);
+bool KWIN_EXPORT hasEGLVersion(int major, int minor, int release = 0);
 // use for both OpenGL and GLX extensions
 bool KWIN_EXPORT hasGLExtension(const QString& extension);
 
diff --git a/scene_opengl_egl.cpp b/scene_opengl_egl.cpp
index 5410cc7a5f..a3c26d18dd 100644
--- a/scene_opengl_egl.cpp
+++ b/scene_opengl_egl.cpp
@@ -38,7 +38,16 @@ SceneOpenGL::SceneOpenGL( Workspace* ws )
     if( !initRenderingContext() )
         return;
 
+    initEGL();
+    if (!hasGLExtension("EGL_KHR_image_pixmap")) {
+        kError(1212) << "Required extension EGL_KHR_image_pixmap not found, disabling compositing";
+        return;
+    }
     initGL();
+    if (!hasGLExtension("GL_OES_EGL_image")) {
+        kError(1212) << "Required extension GL_OES_EGL_image not found, disabling compositing";
+        return;
+    }
     debug = qstrcmp( qgetenv( "KWIN_GL_DEBUG" ), "1" ) == 0;
     if (!setupSceneShaders()) {
         kError( 1212 ) << "Shaders not valid, ES compositing not possible";