JOGL GL4 preperation (cont):

    - Cont. on Context creation refactoring (bb028021be2714e66d9b1062298a3e308c649c56)
        - Added Windows/WGL implementation
        - Added efficienct sharedContext usage if ARB is available,
          ie no more temp context has to be created.

    - Added more GLProfile GL4* code ..

4 files changed, 251 insertions, 182 deletions

diff --git a/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLContext.java b/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLContext.java
index 7f9459a48..95706a7a1 100644
--- a/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLContext.java
+++ b/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLContext.java
@@ -122,48 +122,123 @@ public class WindowsWGLContext extends GLContextImpl {
 
   protected Map/*<String, String>*/ getExtensionNameMap() { return extensionNameMap; }
 
-    protected long createContextARBImpl(long share, boolean direct, int ctp, int major, int minor) {
-        return 0; // FIXME
+  protected long createContextARBImpl(long share, boolean direct, int ctp, int major, int minor) {
+    WindowsWGLDrawableFactory factory = (WindowsWGLDrawableFactory)drawable.getFactoryImpl();
+    WGLExt wglExt;
+    if(null==factory.getSharedContext()) {
+        wglExt = getWGLExt();
+    } else {
+        wglExt = factory.getSharedContext().getWGLExt();
+    }
+
+    boolean ctBwdCompat = 0 != ( CTX_PROFILE_COMPAT & ctp ) ;
+    boolean ctFwdCompat = 0 != ( CTX_OPTION_FORWARD & ctp ) ;
+    boolean ctDebug     = 0 != ( CTX_OPTION_DEBUG & ctp ) ;
+
+    long _context=0;
+
+    int attribs[] = {
+        /*  0 */ WGLExt.WGL_CONTEXT_MAJOR_VERSION_ARB, major,
+        /*  2 */ WGLExt.WGL_CONTEXT_MINOR_VERSION_ARB, minor,
+        /*  4 */ WGLExt.WGL_CONTEXT_LAYER_PLANE_ARB,   WGLExt.WGL_CONTEXT_LAYER_PLANE_ARB, // default
+        /*  6 */ WGLExt.WGL_CONTEXT_FLAGS_ARB,         0,
+        /*  8 */ 0,                                    0,
+        /* 10 */ 0
+    };
+
+    if ( major > 3 || major == 3 && minor >= 2  ) {
+        // FIXME: Verify with a None drawable binding (default framebuffer)
+        attribs[8+0]  = WGLExt.WGL_CONTEXT_PROFILE_MASK_ARB;
+        if( ctBwdCompat ) {
+            attribs[8+1]  = WGLExt.WGL_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB;
+        } else {
+            attribs[8+1]  = WGLExt.WGL_CONTEXT_CORE_PROFILE_BIT_ARB;
+        } 
+    } 
+
+    if ( major >= 3 ) {
+        if( !ctBwdCompat && ctFwdCompat ) {
+            attribs[6+1] |= WGLExt.WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
+        }
+        if( ctDebug) {
+            attribs[6+1] |= WGLExt.WGL_CONTEXT_DEBUG_BIT_ARB;
+        }
+    }
+
+    _context = wglExt.wglCreateContextAttribsARB(drawable.getNativeWindow().getSurfaceHandle(), share, attribs, 0); 
+    if(0==_context) {
+        if(DEBUG) {
+          System.err.println("WindowsWGLContext.createContextARB couldn't create "+getGLVersion(null, major, minor, ctp, "@creation"));
+        }
+    } else {
+        // In contrast to GLX no verification with a drawable binding, ie default framebuffer, is necessary,
+        // if no 3.2 is available creation fails already!
+        // Nevertheless .. we do it ..
+        if (!WGL.wglMakeCurrent(drawable.getNativeWindow().getSurfaceHandle(), _context)) {
+            if(DEBUG) {
+              System.err.println("WindowsWGLContext.createContextARB couldn't make current "+getGLVersion(null, major, minor, ctp, "@creation"));
+            }
+            WGL.wglMakeCurrent(0, 0);
+            WGL.wglDeleteContext(_context);
+            _context = 0;
+        }
     }
+    return _context;
+  }
 
   /**
    * Creates and initializes an appropriate OpenGL context. Should only be
    * called by {@link #makeCurrentImpl()}.
    */
   protected void create() {
-    GLCapabilities glCaps = drawable.getChosenGLCapabilities();
-    if(DEBUG) {
-          System.err.println("WindowsWGLContext.create got "+glCaps);
+    if(0!=context) {
+        throw new GLException("context is not null: "+context);
     }
+    WindowsWGLDrawableFactory factory = (WindowsWGLDrawableFactory)drawable.getFactoryImpl();
+    GLCapabilities glCaps = drawable.getChosenGLCapabilities();
 
     if (drawable.getNativeWindow().getSurfaceHandle() == 0) {
       throw new GLException("Internal error: attempted to create OpenGL context without an associated drawable");
     }
     // Windows can set up sharing of display lists after creation time
     WindowsWGLContext other = (WindowsWGLContext) GLContextShareSet.getShareContext(this);
-    long hglrc2 = 0;
+    long share = 0;
     if (other != null) {
-      hglrc2 = other.getHGLRC();
-      if (hglrc2 == 0) {
+      share = other.getHGLRC();
+      if (share == 0) {
         throw new GLException("GLContextShareSet returned an invalid OpenGL context");
       }
     }
 
-    // To use WGL_ARB_create_context, we have to make a temp context current,
-    // so we are able to use GetProcAddress
-    long temp_hglrc = WGL.wglCreateContext(drawable.getNativeWindow().getSurfaceHandle());
-    if (DEBUG) {
-      System.err.println(getThreadName() + ": !!! Created temp OpenGL context " + toHexString(temp_hglrc) + " for " + this + ", device context " + toHexString(drawable.getNativeWindow().getSurfaceHandle()) + ", not yet sharing");
+    int minor[] = new int[1];
+    int major[] = new int[1];
+    int ctp[] = new int[1];
+    boolean createContextARBTried = false;
+
+    // utilize the shared context's GLXExt in case it was using the ARB method and it already exists
+    if(null!=factory.getSharedContext() && factory.getSharedContext().isCreatedWithARBMethod()) {
+        if(DEBUG) {
+          System.err.println("WindowsWGLContext.createContext using shared Context: "+factory.getSharedContext());
+        }
+        hglrc = createContextARB(share, true, major, minor, ctp);
+        createContextARBTried = true;
     }
-    if (temp_hglrc == 0) {
-      throw new GLException("Unable to create temp OpenGL context for device context " + toHexString(drawable.getNativeWindow().getSurfaceHandle()));
-    } else {
+
+    long temp_hglrc = 0;
+    if(0==hglrc) {
+        // To use WGL_ARB_create_context, we have to make a temp context current,
+        // so we are able to use GetProcAddress
+        temp_hglrc = WGL.wglCreateContext(drawable.getNativeWindow().getSurfaceHandle());
+        if (temp_hglrc == 0) {
+          throw new GLException("Unable to create temp OpenGL context for device context " + toHexString(drawable.getNativeWindow().getSurfaceHandle()));
+        }
         if (!WGL.wglMakeCurrent(drawable.getNativeWindow().getSurfaceHandle(), temp_hglrc)) {
             throw new GLException("Error making temp context current: 0x" + Integer.toHexString(WGL.GetLastError()));
         }
         setGLFunctionAvailability(true, 0, 0, 0);
 
-        if( !isFunctionAvailable("wglCreateContextAttribsARB") ||
+        if( createContextARBTried ||
+            !isFunctionAvailable("wglCreateContextAttribsARB") ||
             !isExtensionAvailable("WGL_ARB_create_context") ) {
             if(glCaps.getGLProfile().isGL3()) {
               WGL.wglMakeCurrent(0, 0);
@@ -173,111 +248,51 @@ public class WindowsWGLContext extends GLContextImpl {
 
             // continue with temp context for GL < 3.0
             hglrc = temp_hglrc;
-            if(DEBUG) {
-              System.err.println("WindowsWGLContext.create done (old ctx < 3.0 - no WGL_ARB_create_context) 0x"+Long.toHexString(hglrc));
-            }
-        } else {
-            WGLExt wglExt = getWGLExt();
+            return;
+        } 
+        hglrc = createContextARB(share, true, major, minor, ctp);
+        createContextARBTried=true;
+    }
+    
+    if(0!=hglrc) {
+        share = 0; // mark as shared ..
 
-            // preset with default values
-            int attribs[] = {
-                /*  0 */ WGLExt.WGL_CONTEXT_MAJOR_VERSION_ARB, 3,
-                /*  2 */ WGLExt.WGL_CONTEXT_MINOR_VERSION_ARB, 0,
-                /*  4 */ WGLExt.WGL_CONTEXT_FLAGS_ARB,         0 /* WGLExt.WGL_CONTEXT_DEBUG_BIT_ARB */,
-                /*  6 */ 0,                                    0,
-                /*  8 */ 0
-            };
+        // need to update the GL func table ..
+        setGLFunctionAvailability(true, major[0], minor[0], ctp[0]);
 
-            if(glCaps.getGLProfile().isGL3()) {
-                // Try >= 3.2 core first !
-                // In contrast to GLX no verify with a None drawable binding (default framebuffer) is necessary,
-                // if no 3.2 is available creation fails already!
-                attribs[0+1]  = 3;
-                attribs[2+1]  = 2;
-                if(glCaps.getGLProfile().isGL3bc()) {
-                    attribs[6+0]  = WGLExt.WGL_CONTEXT_PROFILE_MASK_ARB;
-                    attribs[6+1]  = WGLExt.WGL_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB;
-                }
-                /**
-                 * don't stricten requirements any further, even compatible would be fine
-                 *
-                 } else {
-                    attribs[6+0]  = WGLExt.WGL_CONTEXT_PROFILE_MASK_ARB;
-                    attribs[6+1]  = WGLExt.WGL_CONTEXT_CORE_PROFILE_BIT_ARB;
-                 } 
-                 */
-                hglrc = wglExt.wglCreateContextAttribsARB(drawable.getNativeWindow().getSurfaceHandle(), hglrc2, attribs, 0); 
-                if(0==hglrc) {
-                    if(DEBUG) {
-                        System.err.println("WindowsWGLContext.createContext couldn't create >= 3.2 core context - fallback");
-                    }
-                    // Try >= 3.1 forward compatible - last resort for GL3 !
-                    attribs[0+1]  = 3;
-                    attribs[2+1]  = 1;
-                    if(!glCaps.getGLProfile().isGL3bc()) {
-                        attribs[4+1] |= WGLExt.WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
-                    }
-                    attribs[6+0]  = 0;
-                    attribs[6+1]  = 0;
-                } else if(DEBUG) {
-                  System.err.println("WindowsWGLContext.createContext >= 3.2 available 0x"+Long.toHexString(hglrc));
-                }
-            }
-            if(0==hglrc) {
-                // 3.1 or 3.0 ..
-                hglrc = wglExt.wglCreateContextAttribsARB(drawable.getNativeWindow().getSurfaceHandle(), hglrc2, attribs, 0); 
-                if(DEBUG) {
-                  if(0==hglrc) {
-                      System.err.println("WindowsWGLContext.createContext couldn't create >= 3.0 context - fallback");
-                  } else {
-                      System.err.println("WindowsWGLContext.createContext >= 3.0 available 0x"+Long.toHexString(hglrc));
-                  }
-                }
-            }
+        WGL.wglMakeCurrent(0, 0);
+        WGL.wglDeleteContext(temp_hglrc);
 
-            if(0==hglrc) {
-                if(glCaps.getGLProfile().isGL3()) {
-                  WGL.wglMakeCurrent(0, 0);
-                  WGL.wglDeleteContext(temp_hglrc);
-                  throw new GLException("Unable to create OpenGL >= 3.1 context (have WGL_ARB_create_context)");
-                }
-
-                // continue with temp context for GL < 3.0
-                hglrc = temp_hglrc;
-                if (!WGL.wglMakeCurrent(drawable.getNativeWindow().getSurfaceHandle(), hglrc)) {
-                    throw new GLException("Error making old context current: 0x" + Integer.toHexString(WGL.GetLastError()));
-                }
-                updateGLProcAddressTable(0, 0, 0);
-                if(DEBUG) {
-                  System.err.println("WindowsWGLContext.create done (old ctx < 3.0 - no 3.0) 0x"+Long.toHexString(hglrc));
-                }
-            } else {
-                hglrc2 = 0; // mark as shared ..
-                WGL.wglMakeCurrent(0, 0);
-                WGL.wglDeleteContext(temp_hglrc);
-
-                if (!WGL.wglMakeCurrent(drawable.getNativeWindow().getSurfaceHandle(), hglrc)) {
-                    throw new GLException("Error making new context current: 0x" + Integer.toHexString(WGL.GetLastError()));
-                }
-                updateGLProcAddressTable(0, 0, 0);
-                if(DEBUG) {
-                  System.err.println("WindowsWGLContext.create done (new ctx >= 3.0) 0x"+Long.toHexString(hglrc));
-                }
-            }
+        if (!wglMakeContextCurrent(drawable.getNativeWindow().getSurfaceHandle(), drawableRead.getNativeWindow().getSurfaceHandle(), hglrc)) {
+            throw new GLException("Cannot make previous verified context current: 0x" + Integer.toHexString(WGL.GetLastError()));
+        }
+    } else {
+        if(glCaps.getGLProfile().isGL3()) {
+          WGL.wglMakeCurrent(0, 0);
+          WGL.wglDeleteContext(temp_hglrc);
+          throw new GLException("WindowsWGLContext.createContext failed, but context > GL2 requested "+getGLVersion(null, major[0], minor[0], ctp[0], "@creation")+", ");
+        }
+        if(DEBUG) {
+          System.err.println("WindowsWGLContext.createContext failed, fall back to !ARB context "+getGLVersion(null, major[0], minor[0], ctp[0], "@creation"));
+        }
+
+        // continue with temp context for GL < 3.0
+        hglrc = temp_hglrc;
+        if (!wglMakeContextCurrent(drawable.getNativeWindow().getSurfaceHandle(), drawableRead.getNativeWindow().getSurfaceHandle(), hglrc)) {
+            WGL.wglMakeCurrent(0, 0);
+            WGL.wglDeleteContext(hglrc);
+            throw new GLException("Error making old context current: 0x" + Integer.toHexString(WGL.GetLastError()));
         }
     }
-    if(0!=hglrc2) {
-        if (!WGL.wglShareLists(hglrc2, hglrc)) {
-            throw new GLException("wglShareLists(" + toHexString(hglrc2) +
+
+    if(0!=share) {
+        if (!WGL.wglShareLists(share, hglrc)) {
+            throw new GLException("wglShareLists(" + toHexString(share) +
                                   ", " + toHexString(hglrc) + ") failed: error code 0x" +
                                   Integer.toHexString(WGL.GetLastError()));
         }
     }
     GLContextShareSet.contextCreated(this);
-    WGL.wglMakeCurrent(0, 0); // release immediatly to gain from ARB/EXT wglMakeContextCurrent(draw, read, ctx)!
-    if (DEBUG) {
-      System.err.println(getThreadName() + ": !!! Created OpenGL context " + toHexString(hglrc) + " for " + this + ", device context " + toHexString(drawable.getNativeWindow().getSurfaceHandle()) + ", sharing with " + toHexString(hglrc2));
-    }
   }
   
   protected int makeCurrentImpl() throws GLException {
diff --git a/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLDrawableFactory.java b/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLDrawableFactory.java
index e3938f9fe..bc99338ab 100644
--- a/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLDrawableFactory.java
+++ b/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLDrawableFactory.java
@@ -77,13 +77,22 @@ public class WindowsWGLDrawableFactory extends GLDrawableFactoryImpl implements
   WindowsWGLContext sharedContext=null;
   boolean canCreateGLPbuffer = false;
 
+  // package private ..
+  final WindowsWGLContext getSharedContext() {
+    validate();
+    return sharedContext; 
+  }
+
   void initShared() {
     if(null==sharedDrawable) {
         sharedDrawable = new WindowsDummyWGLDrawable(this, null);
-        sharedContext  = (WindowsWGLContext) sharedDrawable.createContext(null);
-        sharedContext.makeCurrent();
-        canCreateGLPbuffer = sharedContext.getGL().isExtensionAvailable("GL_ARB_pbuffer");
-        sharedContext.release();
+        WindowsWGLContext _sharedContext  = (WindowsWGLContext) sharedDrawable.createContext(null);
+        {
+            _sharedContext.makeCurrent();
+            canCreateGLPbuffer = _sharedContext.getGL().isExtensionAvailable("GL_ARB_pbuffer");
+            _sharedContext.release();
+        }
+        _sharedContext = _sharedContext;
         if (DEBUG) {
           System.err.println("!!! SharedContext: "+sharedContext+", pbuffer supported "+canCreateGLPbuffer);
         }
@@ -115,20 +124,30 @@ public class WindowsWGLDrawableFactory extends GLDrawableFactoryImpl implements
     if (target == null) {
       throw new IllegalArgumentException("Null target");
     }
+    initShared();
     return new WindowsOnscreenWGLDrawable(this, target);
   }
 
   protected GLDrawableImpl createOffscreenDrawable(NativeWindow target) {
+    validate();
+    if (target == null) {
+      throw new IllegalArgumentException("Null target");
+    }
+    initShared();
     return new WindowsOffscreenWGLDrawable(this, target);
   }
 
   public boolean canCreateGLPbuffer(AbstractGraphicsDevice device) {
     validate();
-    initShared();
+    initShared(); // setup canCreateGLPBuffer
     return canCreateGLPbuffer;
   }
 
   protected GLDrawableImpl createGLPbufferDrawableImpl(final NativeWindow target) {
+    validate();
+    if (target == null) {
+      throw new IllegalArgumentException("Null target");
+    }
     initShared();
     final List returnList = new ArrayList();
     final GLDrawableFactory factory = this;
@@ -160,6 +179,8 @@ public class WindowsWGLDrawableFactory extends GLDrawableFactoryImpl implements
   }
 
   protected NativeWindow createOffscreenWindow(GLCapabilities capabilities, GLCapabilitiesChooser chooser, int width, int height) {
+    validate();
+    initShared();
     AbstractGraphicsScreen screen = DefaultGraphicsScreen.createDefault();
     NullWindow nw = new NullWindow(WindowsWGLGraphicsConfigurationFactory.chooseGraphicsConfigurationStatic(
                                    capabilities, chooser, screen) );
@@ -169,6 +190,7 @@ public class WindowsWGLDrawableFactory extends GLDrawableFactoryImpl implements
  
   public GLContext createExternalGLContext() {
     validate();
+    initShared();
     return WindowsExternalWGLContext.create(this, null);
   }
 
@@ -179,6 +201,7 @@ public class WindowsWGLDrawableFactory extends GLDrawableFactoryImpl implements
 
   public GLDrawable createExternalGLDrawable() {
     validate();
+    initShared();
     return WindowsExternalWGLDrawable.create(this, null);
   }
 
diff --git a/src/jogl/classes/com/jogamp/opengl/impl/x11/glx/X11GLXContext.java b/src/jogl/classes/com/jogamp/opengl/impl/x11/glx/X11GLXContext.java
index ad4cb2da5..f5e291c5f 100644
--- a/src/jogl/classes/com/jogamp/opengl/impl/x11/glx/X11GLXContext.java
+++ b/src/jogl/classes/com/jogamp/opengl/impl/x11/glx/X11GLXContext.java
@@ -111,9 +111,16 @@ public abstract class X11GLXContext extends GLContextImpl {
   protected abstract void create();
 
   protected long createContextARBImpl(long share, boolean direct, int ctp, int major, int minor) {
+    X11GLXDrawableFactory factory = (X11GLXDrawableFactory)drawable.getFactoryImpl();
     X11GLXGraphicsConfiguration config = (X11GLXGraphicsConfiguration)drawable.getNativeWindow().getGraphicsConfiguration().getNativeGraphicsConfiguration();
     long display = config.getScreen().getDevice().getHandle();
-    GLXExt glXExt = getGLXExt();
+
+    GLXExt glXExt;
+    if(null==factory.getSharedContext()) {
+        glXExt = getGLXExt();
+    } else {
+        glXExt = factory.getSharedContext().getGLXExt();
+    }
 
     boolean ctBwdCompat = 0 != ( CTX_PROFILE_COMPAT & ctp ) ;
     boolean ctFwdCompat = 0 != ( CTX_OPTION_FORWARD & ctp ) ;
@@ -121,12 +128,10 @@ public abstract class X11GLXContext extends GLContextImpl {
 
     long _context=0;
 
-    String verstr = getGLVersion(null, major, minor, ctp, "@creation");
-
     int attribs[] = {
         /*  0 */ GLX.GLX_CONTEXT_MAJOR_VERSION_ARB, major,
         /*  2 */ GLX.GLX_CONTEXT_MINOR_VERSION_ARB, minor,
-        /*  4 */ GLX.GLX_RENDER_TYPE,               GLX.GLX_RGBA_TYPE,
+        /*  4 */ GLX.GLX_RENDER_TYPE,               GLX.GLX_RGBA_TYPE, // default
         /*  6 */ GLX.GLX_CONTEXT_FLAGS_ARB,         0,
         /*  8 */ 0,                                 0,
         /* 10 */ 0
@@ -154,7 +159,7 @@ public abstract class X11GLXContext extends GLContextImpl {
     _context = glXExt.glXCreateContextAttribsARB(display, config.getFBConfig(), share, direct, attribs, 0);
     if(0==_context) {
         if(DEBUG) {
-          System.err.println("X11GLXContext.createContextARB couldn't create "+verstr+" _context");
+          System.err.println("X11GLXContext.createContextARB couldn't create "+getGLVersion(null, major, minor, ctp, "@creation"));
         }
     } else {
         if (!GLX.glXMakeContextCurrent(display,
@@ -162,13 +167,11 @@ public abstract class X11GLXContext extends GLContextImpl {
                                        drawableRead.getNativeWindow().getSurfaceHandle(), 
                                        _context)) {
             if(DEBUG) {
-              System.err.println("X11GLXContext.createContextARB couldn't make "+verstr+" context current");
+              System.err.println("X11GLXContext.createContextARB couldn't make current "+getGLVersion(null, major, minor, ctp, "@creation"));
             }
             GLX.glXMakeContextCurrent(display, 0, 0, 0);
             GLX.glXDestroyContext(display, _context);
             _context = 0;
-        } else if(DEBUG) {
-          System.err.println("X11GLXContext.createContextARB "+verstr+" available "+toHexString(_context));
         }
     }
     return _context;
@@ -180,10 +183,11 @@ public abstract class X11GLXContext extends GLContextImpl {
    * Note: The direct parameter may be overwritten by the direct state of a shared context.
    */
   protected void createContext(boolean direct) {
-    X11GLXGraphicsConfiguration config = (X11GLXGraphicsConfiguration)drawable.getNativeWindow().getGraphicsConfiguration().getNativeGraphicsConfiguration();
-    if(DEBUG) {
-          System.err.println("X11GLXContext.createContext got "+config);
+    if(0!=context) {
+        throw new GLException("context is not null: "+context);
     }
+    X11GLXDrawableFactory factory = (X11GLXDrawableFactory)drawable.getFactoryImpl();
+    X11GLXGraphicsConfiguration config = (X11GLXGraphicsConfiguration)drawable.getNativeWindow().getGraphicsConfiguration().getNativeGraphicsConfiguration();
     long display = config.getScreen().getDevice().getHandle();
 
     X11GLXContext other = (X11GLXContext) GLContextShareSet.getShareContext(this);
@@ -198,7 +202,7 @@ public abstract class X11GLXContext extends GLContextImpl {
 
     GLCapabilities glCaps = (GLCapabilities) config.getChosenCapabilities();
     GLProfile glp = glCaps.getGLProfile();
-    isVendorATI = ((X11GLXDrawableFactory)(drawable.getFactoryImpl())).isVendorATI();
+    isVendorATI = factory.isVendorATI();
 
     if(config.getFBConfigID()<0) {
         // not able to use FBConfig
@@ -216,70 +220,78 @@ public abstract class X11GLXContext extends GLContextImpl {
           throw new GLException("Error making temp context(0) current: display "+toHexString(display)+", context "+toHexString(context)+", drawable "+drawable);
         }
         setGLFunctionAvailability(true, 0, 0, 0); // use GL_VERSION
-        if(DEBUG) {
-              System.err.println("X11GLXContext.createContext(0) done "+toHexString(context));
-        }
         return;
     }
 
-    // To use GLX_ARB_create_context, we have to make a temp context current,
-    // so we are able to use GetProcAddress
-    long temp_context = GLX.glXCreateNewContext(display, config.getFBConfig(), GLX.GLX_RGBA_TYPE, share, direct);
-    if (temp_context == 0) {
-        throw new GLException("Unable to create temp OpenGL context(1)");
-    }
-    if (!GLX.glXMakeContextCurrent(display,
-                                   drawable.getNativeWindow().getSurfaceHandle(), 
-                                   drawableRead.getNativeWindow().getSurfaceHandle(), 
-                                   temp_context)) {
-      throw new GLException("Error making temp context(1) current: display "+toHexString(display)+", context "+toHexString(context)+", drawable "+drawable);
+    int minor[] = new int[1];
+    int major[] = new int[1];
+    int ctp[] = new int[1];
+    boolean createContextARBTried = false;
+
+    // utilize the shared context's GLXExt in case it was using the ARB method and it already exists
+    if(null!=factory.getSharedContext() && factory.getSharedContext().isCreatedWithARBMethod()) {
+        if(DEBUG) {
+          System.err.println("X11GLXContext.createContext using shared Context: "+factory.getSharedContext());
+        }
+        context = createContextARB(share, direct, major, minor, ctp);
+        createContextARBTried = true;
     }
-    setGLFunctionAvailability(true, 0, 0, 0); // use GL_VERSION
 
-    if( !isFunctionAvailable("glXCreateContextAttribsARB") ||
-        !isExtensionAvailable("GLX_ARB_create_context") )  {
-        if(glp.isGL3()) {
-          GLX.glXMakeContextCurrent(display, 0, 0, 0);
-          GLX.glXDestroyContext(display, temp_context);
-          throw new GLException("Unable to create OpenGL >= 3.1 context (no GLX_ARB_create_context)");
+    long temp_context = 0;
+    if(0==context) {
+        // To use GLX_ARB_create_context, we have to make a temp context current,
+        // so we are able to use GetProcAddress
+        temp_context = GLX.glXCreateNewContext(display, config.getFBConfig(), GLX.GLX_RGBA_TYPE, share, direct);
+        if (temp_context == 0) {
+            throw new GLException("Unable to create temp OpenGL context(1)");
         }
+        if (!GLX.glXMakeContextCurrent(display,
+                                       drawable.getNativeWindow().getSurfaceHandle(), 
+                                       drawableRead.getNativeWindow().getSurfaceHandle(), 
+                                       temp_context)) {
+          throw new GLException("Error making temp context(1) current: display "+toHexString(display)+", context "+toHexString(context)+", drawable "+drawable);
+        }
+        setGLFunctionAvailability(true, 0, 0, 0); // use GL_VERSION
 
-        // continue with temp context for GL < 3.0
-        context = temp_context;
-        if(DEBUG) {
-          System.err.println("X11GLXContext.createContext(1) done (!GLX_ARB_create_context) "+toHexString(context));
+        if( createContextARBTried ||
+            !isFunctionAvailable("glXCreateContextAttribsARB") ||
+            !isExtensionAvailable("GLX_ARB_create_context") )  {
+            if(glp.isGL3()) {
+              GLX.glXMakeContextCurrent(display, 0, 0, 0);
+              GLX.glXDestroyContext(display, temp_context);
+              throw new GLException("Unable to create OpenGL >= 3.1 context (no GLX_ARB_create_context)");
+            }
+
+            // continue with temp context for GL < 3.0
+            context = temp_context;
+            return;
         }
-        return;
+        context = createContextARB(share, direct, major, minor, ctp);
+        createContextARBTried=true;
     }
 
-    int minor[] = new int[1];
-    int major[] = new int[1];
-    int ctp[] = new int[1];
-    context = createContextARB(share, direct, major, minor, ctp);
-
     if(0!=context) {
         // need to update the GL func table ..
         setGLFunctionAvailability(true, major[0], minor[0], ctp[0]);
 
-        GLX.glXMakeContextCurrent(display, 0, 0, 0);
-        GLX.glXDestroyContext(display, temp_context);
-        if (!GLX.glXMakeContextCurrent(display,
-                                       drawable.getNativeWindow().getSurfaceHandle(), 
-                                       drawableRead.getNativeWindow().getSurfaceHandle(), 
-                                       context)) {
-            throw new GLException("Cannot make previous verified context current");
-        }
-        if(DEBUG) {
-          System.err.println("X11GLXContext.createContext(2) done "+getGLVersion(null, major[0], minor[0], ctp[0], "@creation")+", "+toHexString(context));
+        if(0!=temp_context) {
+            GLX.glXMakeContextCurrent(display, 0, 0, 0);
+            GLX.glXDestroyContext(display, temp_context);
+            if (!GLX.glXMakeContextCurrent(display,
+                                           drawable.getNativeWindow().getSurfaceHandle(), 
+                                           drawableRead.getNativeWindow().getSurfaceHandle(), 
+                                           context)) {
+                throw new GLException("Cannot make previous verified context current");
+            }
         }
     } else {
-        if(DEBUG) {
-          System.err.println("X11GLXContext.createContext(2) failed "+getGLVersion(null, major[0], minor[0], ctp[0], "@creation"));
-        }
         if(!glp.isGL2()) {
           GLX.glXMakeContextCurrent(display, 0, 0, 0);
           GLX.glXDestroyContext(display, temp_context);
-          throw new GLException("Unable to create context(2) (have GLX_ARB_create_context)");
+          throw new GLException("X11GLXContext.createContext failed, but context > GL2 requested "+getGLVersion(null, major[0], minor[0], ctp[0], "@creation")+", ");
+        }
+        if(DEBUG) {
+          System.err.println("X11GLXContext.createContext failed, fall back to !ARB context "+getGLVersion(null, major[0], minor[0], ctp[0], "@creation"));
         }
 
         // continue with temp context for GL <= 3.0
@@ -292,9 +304,6 @@ public abstract class X11GLXContext extends GLContextImpl {
           GLX.glXDestroyContext(display, temp_context);
           throw new GLException("Error making context(1) current: display "+toHexString(display)+", context "+toHexString(context)+", drawable "+drawable);
         }
-        if(DEBUG) {
-          System.err.println("X11GLXContext.createContext(1) done "+toHexString(context));
-        }
     }
   }
 
diff --git a/src/jogl/classes/com/jogamp/opengl/impl/x11/glx/X11GLXDrawableFactory.java b/src/jogl/classes/com/jogamp/opengl/impl/x11/glx/X11GLXDrawableFactory.java
index cfcd5cbe3..0d74bb791 100644
--- a/src/jogl/classes/com/jogamp/opengl/impl/x11/glx/X11GLXDrawableFactory.java
+++ b/src/jogl/classes/com/jogamp/opengl/impl/x11/glx/X11GLXDrawableFactory.java
@@ -86,15 +86,24 @@ public class X11GLXDrawableFactory extends GLDrawableFactoryImpl implements Dyna
   public boolean isVendorNVIDIA() { return isVendorNVIDIA; }
 
   private X11DummyGLXDrawable sharedDrawable=null;
-  private GLContext sharedContext=null;
+  private X11GLXContext sharedContext=null;
+
+  // package private ..
+  final X11GLXContext getSharedContext() {
+    validate();
+    return sharedContext; 
+  }
 
   private void initShared() {
     if(null==sharedDrawable) {
         X11Lib.XLockDisplay(sharedScreen.getDevice().getHandle());
         sharedDrawable = new X11DummyGLXDrawable(sharedScreen, this, null);
-        sharedContext  = sharedDrawable.createContext(null);
-        sharedContext.makeCurrent();
-        sharedContext.release();
+        X11GLXContext _sharedContext  = (X11GLXContext) sharedDrawable.createContext(null);
+        {
+            _sharedContext.makeCurrent();
+            _sharedContext.release();
+        }
+        sharedContext = _sharedContext;
         X11Lib.XUnlockDisplay(sharedScreen.getDevice().getHandle());
         if (DEBUG) {
           System.err.println("!!! SharedContext: "+sharedContext);
@@ -136,6 +145,7 @@ public class X11GLXDrawableFactory extends GLDrawableFactoryImpl implements Dyna
     if (target == null) {
       throw new IllegalArgumentException("Null target");
     }
+    initShared();
     if( isVendorATI() ) {
         X11Util.markGlobalDisplayUndeletable(target.getDisplayHandle()); // ATI hack ..
     }
@@ -143,9 +153,11 @@ public class X11GLXDrawableFactory extends GLDrawableFactoryImpl implements Dyna
   }
 
   protected GLDrawableImpl createOffscreenDrawable(NativeWindow target) {
+    validate();
     if (target == null) {
       throw new IllegalArgumentException("Null target");
     }
+    initShared();
     if( isVendorATI() ) {
         X11Util.markGlobalDisplayUndeletable(target.getDisplayHandle()); // ATI hack ..
     }
@@ -187,6 +199,12 @@ public class X11GLXDrawableFactory extends GLDrawableFactoryImpl implements Dyna
   }
 
   protected GLDrawableImpl createGLPbufferDrawableImpl(final NativeWindow target) {
+    validate();
+    if (target == null) {
+      throw new IllegalArgumentException("Null target");
+    }
+    initShared();
+
     GLDrawableImpl pbufferDrawable;
 
     /** 
@@ -197,7 +215,6 @@ public class X11GLXDrawableFactory extends GLDrawableFactoryImpl implements Dyna
      */
     boolean usedSharedContext=false;
     if( isVendorATI() && null == GLContext.getCurrent() ) {
-        initShared();
         sharedContext.makeCurrent();
         usedSharedContext=true;
     }
@@ -216,6 +233,8 @@ public class X11GLXDrawableFactory extends GLDrawableFactoryImpl implements Dyna
 
 
   protected NativeWindow createOffscreenWindow(GLCapabilities capabilities, GLCapabilitiesChooser chooser, int width, int height) {
+    validate();
+    initShared();
     X11Lib.XLockDisplay(sharedScreen.getDevice().getHandle());
     NullWindow nw = new NullWindow(X11GLXGraphicsConfigurationFactory.chooseGraphicsConfigurationStatic(capabilities, chooser, sharedScreen));
     X11Lib.XUnlockDisplay(sharedScreen.getDevice().getHandle());
@@ -225,16 +244,19 @@ public class X11GLXDrawableFactory extends GLDrawableFactoryImpl implements Dyna
 
   public GLContext createExternalGLContext() {
     validate();
+    initShared();
     return X11ExternalGLXContext.create(this, null);
   }
 
   public boolean canCreateExternalGLDrawable(AbstractGraphicsDevice device) {
     validate();
+    initShared();
     return canCreateGLPbuffer(device);
   }
 
   public GLDrawable createExternalGLDrawable() {
     validate();
+    initShared();
     return X11ExternalGLXDrawable.create(this, null);
   }