*GLContext: resetStates(); getPlatformExtensionsString(); GLX/WGL NV_swap_group support; setSwapInterval();

resetStates()
  - fixes a bug where X11GLXContext impl. resetState() !!
  - marked all with @Override tag
  - ensured super.resetStates() is called at end (oops)

getPlatformExtensionsStringImpl()*
  - fixes a bug where X11GLXContext overrides GLContext cached GLX extension string query
  - marked 'final' in GLContext to avoid bugs
  - using abstract 'getPlatformExtensionsStringImpl()' called by ExtensionAvailabilityCache

Add premiliry GLX/WGL NV_swap_group support
  - thought it might be a solution to sync swap of 2 windows
  - none of my drivers/platforms support it, event though extension is avail on Linux

Promote setSwapInterval() (1 up)
 - bumped above API up to public GLContext
 - those extension should not spam the GL interfaces .. hmm

10 files changed, 326 insertions, 91 deletions

diff --git a/src/jogl/classes/javax/media/opengl/GLContext.java b/src/jogl/classes/javax/media/opengl/GLContext.java
index 0727dad1b..47a453484 100644
--- a/src/jogl/classes/javax/media/opengl/GLContext.java
+++ b/src/jogl/classes/javax/media/opengl/GLContext.java
@@ -549,6 +549,48 @@ public abstract class GLContext {
       return isGL2ES2() ;
   }
 
+  public final void setSwapInterval(int interval) {
+    if (!isCurrent()) {
+        throw new GLException("This context is not current. Current context: "+getCurrent()+", this context "+this);
+    }
+    setSwapIntervalImpl(interval);
+  }
+  protected void setSwapIntervalImpl(int interval) { /** nop per default .. **/  }
+  protected int currentSwapInterval = -1; // default: not set yet ..
+  public int getSwapInterval() {
+    return currentSwapInterval;
+  }
+  
+  public final boolean queryMaxSwapGroups(int[] maxGroups, int maxGroups_offset,
+                                          int[] maxBarriers, int maxBarriers_offset) {
+      
+    if (!isCurrent()) {
+        throw new GLException("This context is not current. Current context: "+getCurrent()+", this context "+this);
+    }
+    return queryMaxSwapGroupsImpl(maxGroups, maxGroups_offset, maxBarriers, maxBarriers_offset);
+  }
+  protected boolean queryMaxSwapGroupsImpl(int[] maxGroups, int maxGroups_offset,
+                                          int[] maxBarriers, int maxBarriers_offset) { return false; }
+  public final boolean joinSwapGroup(int group) {
+    if (!isCurrent()) {
+        throw new GLException("This context is not current. Current context: "+getCurrent()+", this context "+this);
+    }
+    return joinSwapGroupImpl(group);
+  }
+  protected boolean joinSwapGroupImpl(int group) { /** nop per default .. **/  return false; }
+  protected int currentSwapGroup = -1; // default: not set yet ..  
+  public int getSwapGroup() {
+      return currentSwapGroup;
+  }
+  public final boolean bindSwapBarrier(int group, int barrier) {
+    if (!isCurrent()) {
+        throw new GLException("This context is not current. Current context: "+getCurrent()+", this context "+this);
+    }
+    return bindSwapBarrierImpl(group, barrier);    
+  }
+  protected boolean bindSwapBarrierImpl(int group, int barrier) { /** nop per default .. **/  return false; }
+
+  
   /**
    * @return The extension implementing the GLDebugOutput feature, 
    *         either <i>GL_ARB_debug_output</i> or <i>GL_AMD_debug_output</i>. 
diff --git a/src/jogl/classes/jogamp/opengl/ExtensionAvailabilityCache.java b/src/jogl/classes/jogamp/opengl/ExtensionAvailabilityCache.java
index 971b32d47..a35137f15 100644
--- a/src/jogl/classes/jogamp/opengl/ExtensionAvailabilityCache.java
+++ b/src/jogl/classes/jogamp/opengl/ExtensionAvailabilityCache.java
@@ -41,6 +41,7 @@
 package jogamp.opengl;
 
 import javax.media.opengl.*;
+
 import java.util.*;
 
 /**
@@ -132,9 +133,9 @@ final class ExtensionAvailabilityCache {
       if(useGetStringi) {
         GL2GL3 gl2gl3 = gl.getGL2GL3();
         int[] numExtensions = { 0 } ;
-        gl2gl3.glGetIntegerv(gl2gl3.GL_NUM_EXTENSIONS, numExtensions, 0);
+        gl2gl3.glGetIntegerv(GL2GL3.GL_NUM_EXTENSIONS, numExtensions, 0);
         for (int i = 0; i < numExtensions[0]; i++) {
-            sb.append(gl2gl3.glGetStringi(gl2gl3.GL_EXTENSIONS, i));
+            sb.append(gl2gl3.glGetStringi(GL.GL_EXTENSIONS, i));
             if(i < numExtensions[0]) {
                 sb.append(" ");
             }
@@ -151,8 +152,21 @@ final class ExtensionAvailabilityCache {
         sb.append(gl.glGetString(GL.GL_EXTENSIONS));
       }
       glExtensions = sb.toString();
-      glXExtensions = context.getPlatformExtensionsString();
-
+      
+      // Platform Extensions
+      {         
+          // unify platform extension .. might have duplicates
+          HashSet<String> platformSet = new HashSet<String>(50);
+          StringTokenizer tok = new StringTokenizer(context.getPlatformExtensionsStringImpl().toString());
+          while (tok.hasMoreTokens()) {
+              platformSet.add(tok.nextToken().trim());              
+          }
+          final StringBuffer sb2 = new StringBuffer();
+          for(Iterator<String> iter = platformSet.iterator(); iter.hasNext(); ) {
+              sb2.append(iter.next()).append(" ");
+          }
+          glXExtensions = sb2.toString();
+      }
       sb.append(" ");
       sb.append(glXExtensions);
 
@@ -210,7 +224,7 @@ final class ExtensionAvailabilityCache {
   private boolean initialized = false;
   private String glExtensions = null;
   private String glXExtensions = null;
-  private HashSet availableExtensionCache = new HashSet(50);
+  private HashSet<String> availableExtensionCache = new HashSet<String>(50);
   private GLContextImpl context;
 
   static String getThreadName() {
diff --git a/src/jogl/classes/jogamp/opengl/GLContextImpl.java b/src/jogl/classes/jogamp/opengl/GLContextImpl.java
index cf4a71a8a..c3fcc5057 100644
--- a/src/jogl/classes/jogamp/opengl/GLContextImpl.java
+++ b/src/jogl/classes/jogamp/opengl/GLContextImpl.java
@@ -126,6 +126,7 @@ public abstract class GLContextImpl extends GLContext {
     this.glDebugHandler = new GLDebugMessageHandler(this);
   }
 
+  @Override
   protected void resetStates() {
       // Because we don't know how many other contexts we might be
       // sharing with (and it seems too complicated to implement the
@@ -800,24 +801,10 @@ public abstract class GLContextImpl extends GLContext {
 
   public abstract ByteBuffer glAllocateMemoryNV(int arg0, float arg1, float arg2, float arg3);
 
-  public final void setSwapInterval(final int interval) {
-    GLContext current = getCurrent();
-    if (current != this) {
-        throw new GLException("This context is not current. Current context: "+current+
-                              ", this context "+this);
-    }
-    setSwapIntervalImpl(interval);
-  }
-  protected void setSwapIntervalImpl(final int interval) { /** nop per default .. **/  }
-  protected int currentSwapInterval = -1; // default: not set yet ..
-  public int getSwapInterval() {
-    return currentSwapInterval;
-  }
-
   /** Maps the given "platform-independent" function name to a real function
       name. Currently this is only used to map "glAllocateMemoryNV" and
       associated routines to wglAllocateMemoryNV / glXAllocateMemoryNV. */
-  protected String mapToRealGLFunctionName(String glFunctionName) {
+  protected final String mapToRealGLFunctionName(String glFunctionName) {
     Map<String, String> map = getFunctionNameMap();
     String lookup = ( null != map ) ? map.get(glFunctionName) : null;
     if (lookup != null) {
@@ -832,7 +819,7 @@ public abstract class GLContextImpl extends GLContext {
       "GL_ARB_pbuffer"      to  "WGL_ARB_pbuffer/GLX_SGIX_pbuffer" and 
       "GL_ARB_pixel_format" to  "WGL_ARB_pixel_format/n.a." 
    */
-  protected String mapToRealGLExtensionName(String glExtensionName) {
+  protected final String mapToRealGLExtensionName(String glExtensionName) {
     Map<String, String> map = getExtensionNameMap();
     String lookup = ( null != map ) ? map.get(glExtensionName) : null;
     if (lookup != null) {
@@ -844,7 +831,7 @@ public abstract class GLContextImpl extends GLContext {
 
   /** Helper routine which resets a ProcAddressTable generated by the
       GLEmitter by looking up anew all of its function pointers. */
-  protected void resetProcAddressTable(ProcAddressTable table) {
+  protected final void resetProcAddressTable(ProcAddressTable table) {
     table.reset(getDrawableImpl().getGLDynamicLookupHelper() );
   }
 
@@ -957,6 +944,8 @@ public abstract class GLContextImpl extends GLContext {
    */
   protected abstract void updateGLXProcAddressTable();
 
+  protected abstract StringBuffer getPlatformExtensionsStringImpl();
+  
   /**
    * Returns true if the specified OpenGL core- or extension-function can be
    * successfully called using this GL context given the current host (OpenGL
@@ -968,7 +957,7 @@ public abstract class GLContextImpl extends GLContext {
    * "glPolygonOffsetEXT" or "glPolygonOffset" to check if the {@link
    * javax.media.opengl.GL#glPolygonOffset(float,float)} is available).
    */
-  public boolean isFunctionAvailable(String glFunctionName) {
+  public final boolean isFunctionAvailable(String glFunctionName) {
     // Check GL 1st (cached)
     ProcAddressTable pTable = getGLProcAddressTable(); // null if ctx not created once
     if(null!=pTable) {
@@ -1023,14 +1012,14 @@ public abstract class GLContextImpl extends GLContext {
       return false;
   }
 
-  public String getPlatformExtensionsString() {
+  public final String getPlatformExtensionsString() {
       if(null!=extensionAvailability) {
         return extensionAvailability.getPlatformExtensionsString();
       }
       return null;
   }
 
-  public String getGLExtensionsString() {
+  public final String getGLExtensionsString() {
       if(null!=extensionAvailability) {
         return extensionAvailability.getGLExtensionsString();
       }
diff --git a/src/jogl/classes/jogamp/opengl/GLDrawableFactoryImpl.java b/src/jogl/classes/jogamp/opengl/GLDrawableFactoryImpl.java
index e04ced6fa..704f71457 100644
--- a/src/jogl/classes/jogamp/opengl/GLDrawableFactoryImpl.java
+++ b/src/jogl/classes/jogamp/opengl/GLDrawableFactoryImpl.java
@@ -44,6 +44,8 @@ import java.nio.*;
 import javax.media.nativewindow.*;
 import javax.media.opengl.*;
 
+import com.jogamp.common.util.VersionNumber;
+
 /** Extends GLDrawableFactory with a few methods for handling
     typically software-accelerated offscreen rendering (Device
     Independent Bitmaps on Windows, pixmaps on X11). Direct access to
@@ -51,6 +53,11 @@ import javax.media.opengl.*;
     they may be instantiated by the GLJPanel implementation. */
 public abstract class GLDrawableFactoryImpl extends GLDrawableFactory {
   protected static final boolean DEBUG = GLDrawableImpl.DEBUG;
+  public static final VersionNumber versionOneZero = new VersionNumber(1, 0, 0);
+  public static final VersionNumber versionOneOne = new VersionNumber(1, 1, 0);
+  public static final VersionNumber versionOneTwo = new VersionNumber(1, 2, 0);
+  public static final VersionNumber versionOneThree = new VersionNumber(1, 3, 0);
+  public static final VersionNumber versionOneFour = new VersionNumber(1, 4, 0);
 
   protected GLDrawableFactoryImpl() {
     super();
diff --git a/src/jogl/classes/jogamp/opengl/egl/EGLContext.java b/src/jogl/classes/jogamp/opengl/egl/EGLContext.java
index 4d39472a4..2deae65fb 100644
--- a/src/jogl/classes/jogamp/opengl/egl/EGLContext.java
+++ b/src/jogl/classes/jogamp/opengl/egl/EGLContext.java
@@ -42,13 +42,14 @@ import com.jogamp.gluegen.runtime.ProcAddressTable;
 import com.jogamp.gluegen.runtime.opengl.GLProcAddressResolver;
 import java.nio.*;
 import java.util.*;
+
 import javax.media.nativewindow.AbstractGraphicsConfiguration;
 import javax.media.nativewindow.AbstractGraphicsDevice;
 
 public abstract class EGLContext extends GLContextImpl {
     private boolean eglQueryStringInitialized;
     private boolean eglQueryStringAvailable;
-    private EGLExt eglExt;
+    private EGLExt _eglExt;
     // Table that holds the addresses of the native C-language entry points for
     // EGL extension functions.
     private EGLExtProcAddressTable eglExtProcAddressTable;
@@ -58,15 +59,23 @@ public abstract class EGLContext extends GLContextImpl {
         super(drawable, shareWith);
     }
 
+    @Override
+    protected void resetStates() {
+        eglQueryStringInitialized = false;
+        eglQueryStringAvailable = false;
+        // no inner state _eglExt = null;
+        super.resetStates();
+    }
+    
     public Object getPlatformGLExtensions() {
       return getEGLExt();
     }
 
     public EGLExt getEGLExt() {
-      if (eglExt == null) {
-        eglExt = new EGLExtImpl(this);
+      if (_eglExt == null) {
+        _eglExt = new EGLExtImpl(this);
       }
-      return eglExt;
+      return _eglExt;
     }
 
     public final ProcAddressTable getPlatformExtProcAddressTable() {
@@ -237,22 +246,22 @@ public abstract class EGLContext extends GLContextImpl {
         }
     }
   
-    public synchronized String getPlatformExtensionsString() {
+    protected final StringBuffer getPlatformExtensionsStringImpl() {
+        StringBuffer sb = new StringBuffer();        
         if (!eglQueryStringInitialized) {
           eglQueryStringAvailable =
             getDrawableImpl().getGLDynamicLookupHelper().dynamicLookupFunction("eglQueryString") != 0;
           eglQueryStringInitialized = true;
         }
         if (eglQueryStringAvailable) {
-            String ret = EGL.eglQueryString(((EGLDrawable)drawable).getDisplay(), 
-                                            EGL.EGL_EXTENSIONS);
+            final String ret = EGL.eglQueryString(((EGLDrawable)drawable).getDisplay(), 
+                                                  EGL.EGL_EXTENSIONS);
             if (DEBUG) {
               System.err.println("!!! EGL extensions: " + ret);
             }
-            return ret;
-        } else {
-          return "";
+            sb.append(ret);
         }
+        return sb;
     }
 
     protected void setSwapIntervalImpl(int interval) {
diff --git a/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXCGLContext.java b/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXCGLContext.java
index f6fe16eae..150a5e105 100644
--- a/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXCGLContext.java
+++ b/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXCGLContext.java
@@ -51,7 +51,7 @@ import com.jogamp.gluegen.runtime.opengl.GLProcAddressResolver;
 public abstract class MacOSXCGLContext extends GLContextImpl
 {    
   protected boolean isNSContext;
-  private CGLExt cglExt;
+  private CGLExt _cglExt;
   // Table that holds the addresses of the native C-language entry points for
   // CGL extension functions.
   private CGLExtProcAddressTable cglExtProcAddressTable;
@@ -61,6 +61,13 @@ public abstract class MacOSXCGLContext extends GLContextImpl
     super(drawable, shareWith);
   }
   
+  @Override
+  protected void resetStates() {
+    isNSContext = false;
+    // no inner state _cglExt = null;
+    super.resetStates();
+  }
+
   public Object getPlatformGLExtensions() {
     return getCGLExt();
   }
@@ -68,10 +75,10 @@ public abstract class MacOSXCGLContext extends GLContextImpl
   protected boolean isNSContext() { return isNSContext; }
 
   public CGLExt getCGLExt() {
-    if (cglExt == null) {
-      cglExt = new CGLExtImpl(this);
+    if (_cglExt == null) {
+      _cglExt = new CGLExtImpl(this);
     }
-    return cglExt;
+    return _cglExt;
   }
 
   public final ProcAddressTable getPlatformExtProcAddressTable() {
@@ -255,9 +262,8 @@ public abstract class MacOSXCGLContext extends GLContextImpl
     }
   }
     
-  public String getPlatformExtensionsString()
-  {
-    return "";
+  protected final StringBuffer getPlatformExtensionsStringImpl() {
+    return new StringBuffer();
   }
     
   protected void swapBuffers() {
diff --git a/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsWGLContext.java b/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsWGLContext.java
index d48f76c13..b95b7edbf 100644
--- a/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsWGLContext.java
+++ b/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsWGLContext.java
@@ -46,6 +46,7 @@ import java.util.Map;
 
 import javax.media.nativewindow.AbstractGraphicsConfiguration;
 import javax.media.nativewindow.AbstractGraphicsDevice;
+import javax.media.nativewindow.NativeSurface;
 import javax.media.opengl.GLContext;
 import javax.media.opengl.GLException;
 import javax.media.opengl.GLCapabilitiesImmutable;
@@ -64,10 +65,12 @@ public class WindowsWGLContext extends GLContextImpl {
   private boolean wglGetExtensionsStringEXTAvailable;
   private boolean wglGLReadDrawableAvailableSet;
   private boolean wglGLReadDrawableAvailable;
-  private WGLExt wglExt;
+  private WGLExt _wglExt;
   // Table that holds the addresses of the native C-language entry points for
   // WGL extension functions.
   private WGLExtProcAddressTable wglExtProcAddressTable;
+  private int hasSwapIntervalSGI = 0;
+  private int hasSwapGroupNV = 0;
 
   static {
     functionNameMap = new HashMap<String, String>();
@@ -85,13 +88,17 @@ public class WindowsWGLContext extends GLContextImpl {
     super(drawable, shareWith);
   }
 
-  protected void resetState() {
+  @Override
+  protected void resetStates() {
     wglGetExtensionsStringEXTInitialized=false;
     wglGetExtensionsStringEXTAvailable=false;
     wglGLReadDrawableAvailableSet=false;
     wglGLReadDrawableAvailable=false;
     // no inner state _wglExt=null;
     wglExtProcAddressTable=null;
+    hasSwapIntervalSGI = 0;
+    hasSwapGroupNV = 0;    
+    super.resetStates();    
   }
   
   public Object getPlatformGLExtensions() {
@@ -102,10 +109,10 @@ public class WindowsWGLContext extends GLContextImpl {
     if( null == getWGLExtProcAddressTable()) {
         throw new InternalError("Null WGLExtProcAddressTable");
     }
-    if (wglExt == null) {
-      wglExt = new WGLExtImpl(this);
+    if (_wglExt == null) {
+      _wglExt = new WGLExtImpl(this);
     }
-    return wglExt;
+    return _wglExt;
   }
 
   public final boolean isGLReadDrawableAvailable() {
@@ -141,8 +148,8 @@ public class WindowsWGLContext extends GLContextImpl {
     int werr = ( !ok ) ? GDI.GetLastError() : GDI.ERROR_SUCCESS;
     if(DEBUG && !ok) {
         Throwable t = new Throwable ("Info: wglMakeContextCurrent draw "+
-                this.toHexString(hDrawDC) + ", read " + this.toHexString(hReadDC) +
-                ", ctx " + this.toHexString(ctx) + ", werr " + werr);
+                GLContext.toHexString(hDrawDC) + ", read " + GLContext.toHexString(hReadDC) +
+                ", ctx " + GLContext.toHexString(ctx) + ", werr " + werr);
         t.printStackTrace();
     }
     if(!ok && 0==hDrawDC && 0==hReadDC) {
@@ -427,27 +434,95 @@ public class WindowsWGLContext extends GLContextImpl {
     }
   }
   
-  public String getPlatformExtensionsString() {
+  protected final StringBuffer getPlatformExtensionsStringImpl() {
+    StringBuffer sb = new StringBuffer();
+    
     if (!wglGetExtensionsStringEXTInitialized) {
       wglGetExtensionsStringEXTAvailable = (WGL.wglGetProcAddress("wglGetExtensionsStringEXT") != 0);
       wglGetExtensionsStringEXTInitialized = true;
     }
     if (wglGetExtensionsStringEXTAvailable) {
-      return getWGLExt().wglGetExtensionsStringEXT();
-    } else {
-      return "";
+      sb.append(getWGLExt().wglGetExtensionsStringEXT());
     }
+    return sb;
   }
-
+  
+  @Override
   protected void setSwapIntervalImpl(int interval) {
     WGLExt wglExt = getWGLExt();
-    if (wglExt.isExtensionAvailable("WGL_EXT_swap_control")) {
-      if ( wglExt.wglSwapIntervalEXT(interval) ) {
-        currentSwapInterval = interval ;
-      }
+    if(0==hasSwapIntervalSGI) {
+        try {
+            hasSwapIntervalSGI = wglExt.isExtensionAvailable("WGL_EXT_swap_control")?1:-1;
+        } catch (Throwable t) { hasSwapIntervalSGI=1; }
+    }
+    if (hasSwapIntervalSGI>0) {
+        try {
+            if ( wglExt.wglSwapIntervalEXT(interval) ) {
+                currentSwapInterval = interval ;
+            }
+        } catch (Throwable t) { hasSwapIntervalSGI=-1; }
     }
   }
-
+  
+  private final int initSwapGroupImpl(WGLExt wglExt) {
+      if(0==hasSwapGroupNV) {
+        try {
+            hasSwapGroupNV = wglExt.isExtensionAvailable("WGL_NV_swap_group")?1:-1;
+        } catch (Throwable t) { hasSwapGroupNV=1; }
+        if(DEBUG) {
+            System.err.println("initSwapGroupImpl: hasSwapGroupNV: "+hasSwapGroupNV);
+        }
+      }
+      return hasSwapGroupNV;
+  }
+  
+  @Override
+  protected final boolean queryMaxSwapGroupsImpl(int[] maxGroups, int maxGroups_offset,
+                                                 int[] maxBarriers, int maxBarriers_offset) {
+      boolean res = false;
+      WGLExt wglExt = getWGLExt();
+      if (initSwapGroupImpl(wglExt)>0) {
+        final NativeSurface ns = drawable.getNativeSurface();
+        try {
+            if( wglExt.wglQueryMaxSwapGroupsNV(ns.getDisplayHandle(), 
+                                               maxGroups, maxGroups_offset,
+                                               maxBarriers, maxBarriers_offset) ) {
+                res = true;
+            }
+        } catch (Throwable t) { hasSwapGroupNV=-1; }
+      }
+      return res;
+  }
+  
+  @Override
+  protected final boolean joinSwapGroupImpl(int group) {
+      boolean res = false;
+      WGLExt wglExt = getWGLExt();
+      if (initSwapGroupImpl(wglExt)>0) {
+        try {
+            if( wglExt.wglJoinSwapGroupNV(drawable.getHandle(), group) ) {
+                currentSwapGroup = group;
+                res = true;
+            }
+        } catch (Throwable t) { hasSwapGroupNV=-1; }
+      }
+      return res;
+  }
+  
+  @Override
+  protected final boolean bindSwapBarrierImpl(int group, int barrier) {
+      boolean res = false;
+      WGLExt wglExt = getWGLExt();
+      if (initSwapGroupImpl(wglExt)>0) {
+        try {
+            if( wglExt.wglBindSwapBarrierNV(group, barrier) ) {
+                res = true;
+            }
+        } catch (Throwable t) { hasSwapGroupNV=-1; }
+      }
+      return res;  
+  }
+  
   public ByteBuffer glAllocateMemoryNV(int arg0, float arg1, float arg2, float arg3) {
     return getWGLExt().wglAllocateMemoryNV(arg0, arg1, arg2, arg3);
   }
diff --git a/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXContext.java b/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXContext.java
index 104fc031e..26ad41fc7 100644
--- a/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXContext.java
+++ b/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXContext.java
@@ -60,14 +60,14 @@ public abstract class X11GLXContext extends GLContextImpl {
   private static final Map<String, String> functionNameMap;
   private static final Map<String, String> extensionNameMap;
   private VersionNumber glXVersion;
+  private boolean glXVersionOneOneCapable;
   private boolean glXVersionOneThreeCapable;
-  private boolean glXQueryExtensionsStringInitialized;
-  private boolean glXQueryExtensionsStringAvailable;
-  private GLXExt glXExt;
+  private GLXExt _glXExt;
   // Table that holds the addresses of the native C-language entry points for
   // GLX extension functions.
   private GLXExtProcAddressTable glXExtProcAddressTable;
   private int hasSwapIntervalSGI = 0;
+  private int hasSwapGroupNV = 0;
 
   // This indicates whether the context we have created is indirect
   // and therefore requires the toolkit to be locked around all GL
@@ -89,15 +89,17 @@ public abstract class X11GLXContext extends GLContextImpl {
     super(drawable, shareWith);
   }
   
-  protected void resetState() {
+  @Override
+  protected void resetStates() {
     glXVersion = null;
+    glXVersionOneOneCapable = false;
     glXVersionOneThreeCapable = false;
-    glXQueryExtensionsStringInitialized=false;
-    glXQueryExtensionsStringAvailable=false;
-    // no inner state glXExt=null;
+    // no inner state _glXExt=null;
     glXExtProcAddressTable = null;
     hasSwapIntervalSGI = 0;
+    hasSwapGroupNV = 0;
     isDirect = false;
+    super.resetStates();
   }
 
   public final ProcAddressTable getPlatformExtProcAddressTable() {
@@ -113,24 +115,32 @@ public abstract class X11GLXContext extends GLContextImpl {
   }
 
   public GLXExt getGLXExt() {
-    if (glXExt == null) {
-      glXExt = new GLXExtImpl(this);
+    if (_glXExt == null) {
+      _glXExt = new GLXExtImpl(this);
     }
-    return glXExt;
+    return _glXExt;
   }
 
   protected Map<String, String> getFunctionNameMap() { return functionNameMap; }
 
   protected Map<String, String> getExtensionNameMap() { return extensionNameMap; }
 
-  public final boolean isGLXVersionGreaterEqualOneThree() {
+  private final void initGLXVersion() {
     if(null == glXVersion) {
         X11GLXGraphicsConfiguration config = (X11GLXGraphicsConfiguration)drawable.getNativeSurface().getGraphicsConfiguration().getNativeGraphicsConfiguration();
         X11GraphicsDevice device = (X11GraphicsDevice) config.getScreen().getDevice();
 
         glXVersion = X11GLXDrawableFactory.getGLXVersion(device);
-        glXVersionOneThreeCapable = ( null != glXVersion ) ? glXVersion.compareTo(X11GLXDrawableFactory.versionOneThree) >= 0 : false ;
-    }
+        glXVersionOneOneCapable   = ( null != glXVersion ) ? glXVersion.compareTo(GLDrawableFactoryImpl.versionOneOne) >= 0 : false ;
+        glXVersionOneThreeCapable = ( null != glXVersion ) ? glXVersion.compareTo(GLDrawableFactoryImpl.versionOneThree) >= 0 : false ;
+    }      
+  }
+  public final boolean isGLXVersionGreaterEqualOneOne() {
+    initGLXVersion();
+    return glXVersionOneOneCapable;
+  }
+  public final boolean isGLXVersionGreaterEqualOneThree() {
+    initGLXVersion();
     return glXVersionOneThreeCapable;
   }
 
@@ -470,9 +480,6 @@ public abstract class X11GLXContext extends GLContextImpl {
     if (DEBUG) {
       System.err.println(getThreadName() + ": !!! Initializing GLX extension address table: "+key);
     }
-    glXQueryExtensionsStringInitialized = false;
-    glXQueryExtensionsStringAvailable = false;
-
     ProcAddressTable table = null;
     synchronized(mappedContextTypeObjectLock) {
         table = mappedGLXProcAddress.get( key );
@@ -497,22 +504,36 @@ public abstract class X11GLXContext extends GLContextImpl {
     }
   }
 
-  public synchronized String getPlatformExtensionsString() {
-    if (!glXQueryExtensionsStringInitialized) {
-      glXQueryExtensionsStringAvailable =
-        getDrawableImpl().getGLDynamicLookupHelper().dynamicLookupFunction("glXQueryExtensionsString") != 0;
-      glXQueryExtensionsStringInitialized = true;
+  protected final StringBuffer getPlatformExtensionsStringImpl() {
+    StringBuffer sb = new StringBuffer();
+    if (DEBUG) {
+      System.err.println("!!! GLX Version "+glXVersion);
     }
-    if (glXQueryExtensionsStringAvailable) {
-        NativeSurface ns = drawable.getNativeSurface();
-        String ret = GLX.glXQueryExtensionsString(ns.getDisplayHandle(), ns.getScreenIndex());
-        if (DEBUG) {
-          System.err.println("!!! GLX extensions: " + ret);
+    if(isGLXVersionGreaterEqualOneOne()) {
+        final NativeSurface ns = drawable.getNativeSurface();
+        {
+            final String ret = GLX.glXGetClientString(ns.getDisplayHandle(), GLX.GLX_EXTENSIONS);
+            if (DEBUG) {
+              System.err.println("!!! GLX extensions (glXGetClientString): " + ret);
+            }
+            sb.append(ret).append(" ");
+        }
+        {
+            final String ret = GLX.glXQueryExtensionsString(ns.getDisplayHandle(), ns.getScreenIndex());
+            if (DEBUG) {
+              System.err.println("!!! GLX extensions (glXQueryExtensionsString): " + ret);
+            }
+            sb.append(ret).append(" ");
+        }
+        {
+            final String ret = GLX.glXQueryServerString(ns.getDisplayHandle(), ns.getScreenIndex(), GLX.GLX_EXTENSIONS);
+            if (DEBUG) {
+              System.err.println("!!! GLX extensions (glXQueryServerString): " + ret);
+            }
+            sb.append(ret).append(" ");
         }
-        return ret;
-    } else {
-      return "";
     }
+    return sb;
   }
 
   public boolean isExtensionAvailable(String glExtensionName) {
@@ -524,6 +545,7 @@ public abstract class X11GLXContext extends GLContextImpl {
     return super.isExtensionAvailable(glExtensionName);
   }
 
+  @Override
   protected void setSwapIntervalImpl(int interval) {
     X11GLXGraphicsConfiguration config = (X11GLXGraphicsConfiguration)drawable.getNativeSurface().getGraphicsConfiguration().getNativeGraphicsConfiguration();
     GLCapabilitiesImmutable glCaps = (GLCapabilitiesImmutable) config.getChosenCapabilities();
@@ -544,6 +566,66 @@ public abstract class X11GLXContext extends GLContextImpl {
     }
   }
 
+  private final int initSwapGroupImpl(GLXExt glXExt) {
+      if(0==hasSwapGroupNV) {
+        try {
+            hasSwapGroupNV = glXExt.isExtensionAvailable("GLX_NV_swap_group")?1:-1;
+        } catch (Throwable t) { hasSwapGroupNV=1; }
+        if(DEBUG) {
+            System.err.println("initSwapGroupImpl: hasSwapGroupNV: "+hasSwapGroupNV);
+        }
+      }
+      return hasSwapGroupNV;
+  }
+  
+  @Override
+  protected final boolean queryMaxSwapGroupsImpl(int[] maxGroups, int maxGroups_offset,
+                                                 int[] maxBarriers, int maxBarriers_offset) {
+      boolean res = false;
+      GLXExt glXExt = getGLXExt();
+      if (initSwapGroupImpl(glXExt)>0) {
+        final NativeSurface ns = drawable.getNativeSurface();
+        try {
+            if( glXExt.glXQueryMaxSwapGroupsNV(ns.getDisplayHandle(), ns.getScreenIndex(), 
+                                               maxGroups, maxGroups_offset,
+                                               maxBarriers, maxBarriers_offset) ) {
+                res = true;
+            }
+        } catch (Throwable t) { hasSwapGroupNV=-1; }
+      }
+      return res;
+  }
+  
+  @Override
+  protected final boolean joinSwapGroupImpl(int group) {
+      boolean res = false;
+      GLXExt glXExt = getGLXExt();
+      if (initSwapGroupImpl(glXExt)>0) {
+        try {
+            if( glXExt.glXJoinSwapGroupNV(drawable.getNativeSurface().getDisplayHandle(), drawable.getHandle(), group) ) {
+                currentSwapGroup = group;
+                res = true;
+            }
+        } catch (Throwable t) { hasSwapGroupNV=-1; }
+      }
+      return res;
+  }
+  
+  @Override
+  protected final boolean bindSwapBarrierImpl(int group, int barrier) {
+      boolean res = false;
+      GLXExt glXExt = getGLXExt();
+      if (initSwapGroupImpl(glXExt)>0) {
+        try {
+            if( glXExt.glXBindSwapBarrierNV(drawable.getNativeSurface().getDisplayHandle(), group, barrier) ) {
+                res = true;
+            }
+        } catch (Throwable t) { hasSwapGroupNV=-1; }
+      }
+      return res;  
+  }
+
+  @Override
   public ByteBuffer glAllocateMemoryNV(int arg0, float arg1, float arg2, float arg3) {
     return getGLXExt().glXAllocateMemoryNV(arg0, arg1, arg2, arg3);
   }
diff --git a/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXDrawableFactory.java b/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXDrawableFactory.java
index d37d6c53a..51316dc77 100644
--- a/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXDrawableFactory.java
+++ b/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXDrawableFactory.java
@@ -56,7 +56,6 @@ import jogamp.nativewindow.x11.*;
 public class X11GLXDrawableFactory extends GLDrawableFactoryImpl {
   
   private static final DesktopGLDynamicLookupHelper x11GLXDynamicLookupHelper;
-  static final VersionNumber versionOneThree = new VersionNumber(1, 3, 0);
 
   static {
     DesktopGLDynamicLookupHelper tmp = null;
diff --git a/src/test/com/jogamp/opengl/test/junit/jogl/demos/es2/GearsES2.java b/src/test/com/jogamp/opengl/test/junit/jogl/demos/es2/GearsES2.java
index 7567679d4..296a3604a 100644
--- a/src/test/com/jogamp/opengl/test/junit/jogl/demos/es2/GearsES2.java
+++ b/src/test/com/jogamp/opengl/test/junit/jogl/demos/es2/GearsES2.java
@@ -37,6 +37,7 @@ import java.nio.FloatBuffer;
 import javax.media.opengl.GL;
 import javax.media.opengl.GL2ES2;
 import javax.media.opengl.GLAutoDrawable;
+import javax.media.opengl.GLContext;
 import javax.media.opengl.GLEventListener;
 import javax.media.opengl.GLProfile;
 import javax.media.opengl.GLUniformData;
@@ -173,6 +174,19 @@ public class GearsES2 implements GLEventListener {
             new com.jogamp.newt.event.awt.AWTKeyAdapter(gearsKeys).addTo(comp);
         }
         st.useProgram(gl, false);
+        
+        int[] maxVals = new int[] { -1, -1 } ;
+        GLContext glc = drawable.getContext();
+        boolean r = glc.queryMaxSwapGroups(maxVals, 0, maxVals, 1);
+        System.err.println("swap group max groups "+maxVals[0]+", barriers "+maxVals[0]+", "+r);
+        if(maxVals[0]>0) {
+            System.err.println("swap group joing 1: "+glc.joinSwapGroup(1));
+            if(maxVals[1]>0) {
+                System.err.println("swap group bind 1-1: "+glc.bindSwapBarrier(1, 1));
+            }
+        }
+        glc.setSwapInterval(swapInterval);
+        
         System.err.println(Thread.currentThread()+" GearsES2.init FIN");
     }
 
@@ -181,8 +195,6 @@ public class GearsES2 implements GLEventListener {
         Assert.assertEquals("not init or already disposed", true, initialized);
         GL2ES2 gl = drawable.getGL().getGL2ES2();
 
-        gl.setSwapInterval(swapInterval);
-
         float h = (float)height / (float)width;
 
         st.useProgram(gl, true);