JOGL (Windows):

    - WindowsWGLDrawableFactory is using [singleton] shared dummy resources for
        - Drawable and Context
      which are utilized in case they are needed ..
      They are removed at shutdown call

    - GLCapabilities
        - Set pbuffer as the HW capabilities show,
          hence onscreen && pbuffer is valid

        - DefaultGLCapabilitiesChooser: Respect PBuffer selection (fixed)
          Only skip a config, if request is !onscreen && pbuffer, but pbuffer n/a

Tests:
    - JUnit Passed (Windows32: Chromium - Except PBuffer (n/a)

8 files changed, 77 insertions, 84 deletions

diff --git a/src/jogl/classes/com/jogamp/opengl/impl/GLDrawableFactoryImpl.java b/src/jogl/classes/com/jogamp/opengl/impl/GLDrawableFactoryImpl.java
index 616640bad..0cc10b35e 100644
--- a/src/jogl/classes/com/jogamp/opengl/impl/GLDrawableFactoryImpl.java
+++ b/src/jogl/classes/com/jogamp/opengl/impl/GLDrawableFactoryImpl.java
@@ -79,9 +79,6 @@ public abstract class GLDrawableFactoryImpl extends GLDrawableFactory {
     GLCapabilities caps = (GLCapabilities) target.getGraphicsConfiguration().getNativeGraphicsConfiguration().getChosenCapabilities();
     GLDrawable result = null;
     if(caps.isOnscreen()) {
-        if(caps.isPBuffer()) {
-            throw new IllegalArgumentException("Onscreen target can't be PBuffer: "+caps);
-        }
         if(DEBUG) {
             System.out.println("GLDrawableFactoryImpl.createGLDrawable -> OnscreenDrawable: "+target);
         }
diff --git a/src/jogl/classes/com/jogamp/opengl/impl/egl/EGLGraphicsConfiguration.java b/src/jogl/classes/com/jogamp/opengl/impl/egl/EGLGraphicsConfiguration.java
index 2d5154442..176628633 100644
--- a/src/jogl/classes/com/jogamp/opengl/impl/egl/EGLGraphicsConfiguration.java
+++ b/src/jogl/classes/com/jogamp/opengl/impl/egl/EGLGraphicsConfiguration.java
@@ -179,11 +179,7 @@ public class EGLGraphicsConfiguration extends DefaultGraphicsConfiguration imple
             } */
         }
         if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_SURFACE_TYPE, val, 0)) {
-            if(EGLConfigDrawableTypeVerify(val[0], onscreen, usePBuffer)) {
-                caps.setDoubleBuffered(onscreen);
-                caps.setOnscreen(onscreen);
-                caps.setPBuffer(usePBuffer);
-            } else if(relaxed) {
+            if(EGLConfigDrawableTypeVerify(val[0], onscreen, usePBuffer) || relaxed) {
                 caps.setDoubleBuffered( 0 != (val[0] & EGL.EGL_WINDOW_BIT) );
                 caps.setOnscreen( 0 != (val[0] & EGL.EGL_WINDOW_BIT) );
                 caps.setPBuffer ( 0 != (val[0] & EGL.EGL_PBUFFER_BIT) );
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 cb3ee19e0..e3938f9fe 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
@@ -43,6 +43,7 @@ import com.jogamp.common.os.DynamicLookupHelper;
 import java.nio.*;
 import java.util.*;
 import javax.media.nativewindow.*;
+import javax.media.nativewindow.windows.*;
 import javax.media.opengl.*;
 import com.jogamp.opengl.impl.*;
 import com.jogamp.nativewindow.impl.NWReflection;
@@ -72,7 +73,45 @@ public class WindowsWGLDrawableFactory extends GLDrawableFactoryImpl implements
     loadOpenGL32Library();
   }
 
+  WindowsDummyWGLDrawable sharedDrawable=null;
+  WindowsWGLContext sharedContext=null;
+  boolean canCreateGLPbuffer = false;
+
+  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();
+        if (DEBUG) {
+          System.err.println("!!! SharedContext: "+sharedContext+", pbuffer supported "+canCreateGLPbuffer);
+        }
+        if(null==sharedContext) {
+            throw new GLException("Couldn't init shared resources");
+        }
+    }
+  }
+
+  public void shutdown() {
+     super.shutdown();
+     if (DEBUG) {
+          System.err.println("!!! Shutdown Shared:");
+          System.err.println("!!!          CTX     : "+sharedContext);
+          System.err.println("!!!          Drawable: "+sharedDrawable);
+          Exception e = new Exception("Debug");
+          e.printStackTrace();
+     }
+     if(null!=sharedContext) {
+        sharedContext.destroy(); // implies release, if current
+     }
+     if(null!=sharedDrawable) {
+        sharedDrawable.destroy();
+     }
+  }
+
   public GLDrawableImpl createOnscreenDrawable(NativeWindow target) {
+    validate();
     if (target == null) {
       throw new IllegalArgumentException("Null target");
     }
@@ -83,67 +122,33 @@ public class WindowsWGLDrawableFactory extends GLDrawableFactoryImpl implements
     return new WindowsOffscreenWGLDrawable(this, target);
   }
 
-  private boolean pbufferSupportInitialized = false;
-  private boolean canCreateGLPbuffer = false;
   public boolean canCreateGLPbuffer(AbstractGraphicsDevice device) {
-    if (!pbufferSupportInitialized) {
-      final GLDrawableFactory factory = this;
-      Runnable r = new Runnable() {
-          public void run() {
-            WindowsDummyWGLDrawable dummyDrawable = new WindowsDummyWGLDrawable(factory, null);
-            GLContext dummyContext  = dummyDrawable.createContext(null);
-            if (dummyContext != null) {
-              GLContext lastContext = GLContext.getCurrent();
-              if (lastContext != null) {
-                lastContext.release();
-              }
-              dummyContext.makeCurrent();
-              GL dummyGL = dummyContext.getGL();
-              canCreateGLPbuffer = dummyGL.isExtensionAvailable("GL_ARB_pbuffer");
-              pbufferSupportInitialized = true;
-              dummyContext.release();
-              dummyContext.destroy();
-              dummyDrawable.destroy();
-              if (lastContext != null) {
-                lastContext.makeCurrent();
-              }
-            }
-          }
-        };
-      maybeDoSingleThreadedWorkaround(r);
-    }
-    if (DEBUG) {
-      System.err.println("WindowsWGLDrawableFactory.canCreateGLPbuffer() = " + canCreateGLPbuffer);
-    }
+    validate();
+    initShared();
     return canCreateGLPbuffer;
   }
 
   protected GLDrawableImpl createGLPbufferDrawableImpl(final NativeWindow target) {
+    initShared();
     final List returnList = new ArrayList();
     final GLDrawableFactory factory = this;
+    final WindowsWGLContext _sharedContext = sharedContext;
+    final WindowsDummyWGLDrawable _sharedDrawable = sharedDrawable;
     Runnable r = new Runnable() {
         public void run() {
-          WindowsDummyWGLDrawable dummyDrawable = new WindowsDummyWGLDrawable(factory, null);
-          WindowsWGLContext       dummyContext  = (WindowsWGLContext) dummyDrawable.createContext(null);
           GLContext lastContext = GLContext.getCurrent();
           if (lastContext != null) {
             lastContext.release();
           }
-          dummyContext.makeCurrent();
-          WGLExt dummyWGLExt = dummyContext.getWGLExt();
+          _sharedContext.makeCurrent();
+          WGLExt wglExt = _sharedContext.getWGLExt();
           try {
             GLDrawableImpl pbufferDrawable = new WindowsPbufferWGLDrawable(factory, target,
-                                                                           dummyDrawable,
-                                                                           dummyWGLExt);
+                                                                           _sharedDrawable,
+                                                                           wglExt);
             returnList.add(pbufferDrawable);
           } finally {
-            if(null!=dummyContext) {
-                dummyContext.release();
-                dummyContext.destroy();
-            }
-            if(null!=dummyDrawable) {
-                dummyDrawable.destroy();
-            }
+            _sharedContext.release();
             if (lastContext != null) {
               lastContext.makeCurrent();
             }
@@ -163,18 +168,22 @@ public class WindowsWGLDrawableFactory extends GLDrawableFactoryImpl implements
   }
  
   public GLContext createExternalGLContext() {
+    validate();
     return WindowsExternalWGLContext.create(this, null);
   }
 
   public boolean canCreateExternalGLDrawable(AbstractGraphicsDevice device) {
+    validate();
     return true;
   }
 
   public GLDrawable createExternalGLDrawable() {
+    validate();
     return WindowsExternalWGLDrawable.create(this, null);
   }
 
   public void loadOpenGL32Library() {
+    validate();
     if (hopengl32 == 0) {
       hopengl32 = WGL.LoadLibraryA("OpenGL32");
       if (DEBUG) {
@@ -186,6 +195,7 @@ public class WindowsWGLDrawableFactory extends GLDrawableFactoryImpl implements
   }
 
   public void loadGLULibrary() {
+    validate();
     if (hglu32 == 0) {
       hglu32 = WGL.LoadLibraryA("GLU32");
       if (hglu32 == 0) {
@@ -195,6 +205,7 @@ public class WindowsWGLDrawableFactory extends GLDrawableFactoryImpl implements
   }
 
   public long dynamicLookupFunction(String glFuncName) {
+    validate();
     long res = WGL.wglGetProcAddress(glFuncName);
     if (res == 0) {
       // It may happen that a driver doesn't return the OpenGL32 core function pointer
@@ -227,11 +238,13 @@ public class WindowsWGLDrawableFactory extends GLDrawableFactoryImpl implements
   }
 
   public boolean canCreateContextOnJava2DSurface(AbstractGraphicsDevice device) {
+    validate();
     return false;
   }
 
   public GLContext createContextOnJava2DSurface(Object graphics, GLContext shareWith)
     throws GLException {
+    validate();
     throw new GLException("Unimplemented on this platform");
   }
 
diff --git a/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLGraphicsConfiguration.java b/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLGraphicsConfiguration.java
index aed4012a4..15823b6dc 100644
--- a/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLGraphicsConfiguration.java
+++ b/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLGraphicsConfiguration.java
@@ -428,10 +428,7 @@ public class WindowsWGLGraphicsConfiguration extends DefaultGraphicsConfiguratio
                                                          boolean relaxed, boolean onscreen, boolean usePBuffer) {
         GLCapabilities res = new GLCapabilities(glp);
         int drawableTypeBits = WGLConfig2DrawableTypeBits(iattribs, niattribs, iresults);
-        if(WGLConfigDrawableTypeVerify(drawableTypeBits, onscreen, usePBuffer)) {
-            res.setOnscreen(onscreen);
-            res.setPBuffer(usePBuffer);
-        } else if(relaxed) {
+        if(WGLConfigDrawableTypeVerify(drawableTypeBits, onscreen, usePBuffer) || relaxed) {
             res.setOnscreen( 0 != (drawableTypeBits & WINDOW_BIT) );
             res.setPBuffer ( 0 != (drawableTypeBits & PBUFFER_BIT) );
         } else {
diff --git a/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLGraphicsConfigurationFactory.java b/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLGraphicsConfigurationFactory.java
index 1a375699c..c9805fef1 100644
--- a/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLGraphicsConfigurationFactory.java
+++ b/src/jogl/classes/com/jogamp/opengl/impl/windows/wgl/WindowsWGLGraphicsConfigurationFactory.java
@@ -87,7 +87,8 @@ public class WindowsWGLGraphicsConfigurationFactory extends GraphicsConfiguratio
     }
 
     protected static void updateGraphicsConfiguration(CapabilitiesChooser chooser,
-                                                      GLDrawableFactory factory, NativeWindow nativeWindow) {
+                                                      GLDrawableFactory _factory, NativeWindow nativeWindow) {
+        WindowsWGLDrawableFactory factory = (WindowsWGLDrawableFactory) _factory;
         if (nativeWindow == null) {
             throw new IllegalArgumentException("NativeWindow is null");
         }
@@ -134,25 +135,16 @@ public class WindowsWGLGraphicsConfigurationFactory extends GraphicsConfiguratio
           pfd = WindowsWGLGraphicsConfiguration.createPixelFormatDescriptor();
           // Produce a recommended pixel format selection for the GLCapabilitiesChooser.
           // Use wglChoosePixelFormatARB if user requested multisampling and if we have it available
-          WindowsWGLDrawable dummyDrawable = null;
-          GLContextImpl     dummyContext  = null;
-          WGLExt            dummyWGLExt   = null;
-          if (capabilities.getSampleBuffers()) {
-              dummyDrawable = new WindowsDummyWGLDrawable(factory, glProfile);
-              dummyContext  = (GLContextImpl) dummyDrawable.createContext(null);
-              if (dummyContext != null) {
-                dummyContext.makeCurrent();
-                dummyWGLExt = (WGLExt) dummyContext.getPlatformGLExtensions();
-              }
-          } else if (DEBUG) {
-              System.err.println(getThreadName() + ": Not using WGL_ARB_pixel_format, because multisampling not requested");
-          }
+          factory.initShared();
+          factory.sharedContext.makeCurrent();
+          WGLExt wglExt = factory.sharedContext.getWGLExt();
+
           int recommendedPixelFormat = pixelFormat; // 1-based pixel format
           boolean haveWGLChoosePixelFormatARB = false;
           boolean gotAvailableCaps = false;
-          if (dummyWGLExt != null) {
+          if (wglExt != null) {
             try {
-              haveWGLChoosePixelFormatARB = dummyWGLExt.isExtensionAvailable("WGL_ARB_pixel_format");
+              haveWGLChoosePixelFormatARB = wglExt.isExtensionAvailable("WGL_ARB_pixel_format");
               if (haveWGLChoosePixelFormatARB) {
                 if(pixelFormat<=0) {
                   int[]   iattributes = new int  [2*WindowsWGLGraphicsConfiguration.MAX_ATTRIBS];
@@ -160,12 +152,12 @@ public class WindowsWGLGraphicsConfigurationFactory extends GraphicsConfiguratio
 
                   if(WindowsWGLGraphicsConfiguration.GLCapabilities2AttribList(capabilities,
                                                                                iattributes,
-                                                                               dummyWGLExt,
+                                                                               wglExt,
                                                                                false,
                                                                                null)) {
                     int[] pformats = new int[WindowsWGLGraphicsConfiguration.MAX_PFORMATS];
                     int[] numFormatsTmp = new int[1];
-                    if (dummyWGLExt.wglChoosePixelFormatARB(hdc,
+                    if (wglExt.wglChoosePixelFormatARB(hdc,
                                                          iattributes, 0,
                                                          fattributes, 0,
                                                          WindowsWGLGraphicsConfiguration.MAX_PFORMATS,
@@ -196,16 +188,14 @@ public class WindowsWGLGraphicsConfigurationFactory extends GraphicsConfiguratio
                   }
                 }
 
-                availableCaps = WindowsWGLGraphicsConfiguration.HDC2GLCapabilities(dummyWGLExt, hdc, -1, glProfile, pixelFormatSet, onscreen, usePBuffer);
+                availableCaps = WindowsWGLGraphicsConfiguration.HDC2GLCapabilities(wglExt, hdc, -1, glProfile, pixelFormatSet, onscreen, usePBuffer);
                 gotAvailableCaps = null!=availableCaps ;
                 choosenBywGLPixelFormat = gotAvailableCaps ;
               } else if (DEBUG) {
                 System.err.println(getThreadName() + ": wglChoosePixelFormatARB not available");
               }
             } finally {
-              dummyContext.release();
-              dummyContext.destroy();
-              dummyDrawable.destroy();
+              factory.sharedContext.release();
             }
           }
 
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 eda480d5f..cfcd5cbe3 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
@@ -99,6 +99,9 @@ public class X11GLXDrawableFactory extends GLDrawableFactoryImpl implements Dyna
         if (DEBUG) {
           System.err.println("!!! SharedContext: "+sharedContext);
         }
+        if(null==sharedContext) {
+            throw new GLException("Couldn't init shared resources");
+        }
     }
   }
 
diff --git a/src/jogl/classes/com/jogamp/opengl/impl/x11/glx/X11GLXGraphicsConfiguration.java b/src/jogl/classes/com/jogamp/opengl/impl/x11/glx/X11GLXGraphicsConfiguration.java
index 35daf0ae0..393891bab 100644
--- a/src/jogl/classes/com/jogamp/opengl/impl/x11/glx/X11GLXGraphicsConfiguration.java
+++ b/src/jogl/classes/com/jogamp/opengl/impl/x11/glx/X11GLXGraphicsConfiguration.java
@@ -250,10 +250,7 @@ public class X11GLXGraphicsConfiguration extends X11GraphicsConfiguration implem
     GLCapabilities res = new GLCapabilities(glp);
 
     val = glXGetFBConfig(display, fbcfg, GLX.GLX_DRAWABLE_TYPE, tmp, 0);
-    if(GLXFBConfigDrawableTypeVerify(val, onscreen, usePBuffer)) {
-        res.setOnscreen(onscreen);
-        res.setPBuffer(usePBuffer);
-    } else if(relaxed) {
+    if(GLXFBConfigDrawableTypeVerify(val, onscreen, usePBuffer) || relaxed) {
         res.setOnscreen( 0 != (val & GLX.GLX_WINDOW_BIT) );
         res.setPBuffer ( 0 != (val & GLX.GLX_PBUFFER_BIT) );
     } else {
diff --git a/src/jogl/classes/javax/media/opengl/DefaultGLCapabilitiesChooser.java b/src/jogl/classes/javax/media/opengl/DefaultGLCapabilitiesChooser.java
index c5ded88f6..ee41c9161 100644
--- a/src/jogl/classes/javax/media/opengl/DefaultGLCapabilitiesChooser.java
+++ b/src/jogl/classes/javax/media/opengl/DefaultGLCapabilitiesChooser.java
@@ -138,8 +138,8 @@ public class DefaultGLCapabilitiesChooser implements GLCapabilitiesChooser {
       if (_desired.isOnscreen() != cur.isOnscreen()) {
         continue;
       }
-      if (_desired.isPBuffer() != cur.isPBuffer()) {
-        continue;
+      if (!_desired.isOnscreen() && _desired.isPBuffer() && !cur.isPBuffer()) {
+        continue; // only skip if requested Offscreen && PBuffer, but no PBuffer available
       }
       if (_desired.getStereo() != cur.getStereo()) {
         continue;