Win,GDI,SWT: Fix pfd to caps conversion. Added thorough debug code.

Debug code added for use case: WinXP-32bit, GDI, SWT,
where WGL.wglGetCurrentDC() returns a non null value which is invalid.
Using the value (hdc) on eg GDI.GetObjectType(hdc) return 0 instead of
3 (OBJ_DC) and GDI.GetPixelFormat(hdc) returns 0 with last error 2000.

3 files changed, 30 insertions, 11 deletions

diff --git a/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsExternalWGLContext.java b/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsExternalWGLContext.java
index 569463db5..845460c58 100644
--- a/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsExternalWGLContext.java
+++ b/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsExternalWGLContext.java
@@ -70,21 +70,39 @@ public class WindowsExternalWGLContext extends WindowsWGLContext {
   }
 
   protected static WindowsExternalWGLContext create(GLDrawableFactory factory, GLProfile glp) {
-    long hdc = WGL.wglGetCurrentDC();
-    if (0==hdc) {
-      throw new GLException("Error: attempted to make an external GLDrawable without a drawable current, werr " + GDI.GetLastError());
+    /**
+     * Added thorough debug code, since we currently have problems with this code with use case:
+     *   - WinXP [32bit]
+     *   - GDI (Software GL)
+     *   - SWT
+     * However, it works on other combinations, eg Win7 [64bit], GDI, SWT, etc ..
+     */
+    if(DEBUG) {
+        System.err.println("WindowsExternalWGLContext 0: werr: " + GDI.GetLastError());
     }
+
     long ctx = WGL.wglGetCurrentContext();
-    if (ctx == 0) {
+    if (0 == ctx) {
       throw new GLException("Error: attempted to make an external GLContext without a context current, werr " + GDI.GetLastError());
     }
+
+    long hdc = WGL.wglGetCurrentDC();
+    if (0 == hdc) {
+      throw new GLException("Error: attempted to make an external GLDrawable without a drawable current, werr " + GDI.GetLastError());
+    }
+    int hdcType = GDI.GetObjectType(hdc);
+    if( GDI.OBJ_DC != hdcType ) {
+        // FIXME: Turns out in above use case (WinXP-32bit, GDI, SWT) the returned DC (not 0) is invalid!
+        throw new GLException("Error: current WGL DC ("+toHexString(hdc)+") is not a DC but: "+hdcType+", werr " + GDI.GetLastError());
+    }
+
     int pfdID = GDI.GetPixelFormat(hdc);
-    if (pfdID == 0) {
+    if (0 == pfdID) {
       throw new GLException("Error: attempted to make an external GLContext without a valid pixelformat, werr " + GDI.GetLastError());
     }
 
     AbstractGraphicsScreen aScreen = DefaultGraphicsScreen.createDefault(NativeWindowFactory.TYPE_WINDOWS);
-    WindowsWGLGraphicsConfiguration cfg = WindowsWGLGraphicsConfiguration.createFromCurrent(factory, hdc, pfdID, glp, aScreen, true, true);
+    WindowsWGLGraphicsConfiguration cfg = WindowsWGLGraphicsConfiguration.createFromCurrent(factory, hdc, pfdID, glp, aScreen, true);
     return new WindowsExternalWGLContext(new Drawable(factory, new ProxySurface(cfg, hdc)), ctx, cfg);
   }
 
diff --git a/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsExternalWGLDrawable.java b/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsExternalWGLDrawable.java
index 86cc705b5..742a42709 100644
--- a/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsExternalWGLDrawable.java
+++ b/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsExternalWGLDrawable.java
@@ -69,7 +69,7 @@ public class WindowsExternalWGLDrawable extends WindowsWGLDrawable {
     }
 
     AbstractGraphicsScreen aScreen = DefaultGraphicsScreen.createDefault(NativeWindowFactory.TYPE_WINDOWS);
-    WindowsWGLGraphicsConfiguration cfg = WindowsWGLGraphicsConfiguration.createFromCurrent(factory, hdc, pfdID, glp, aScreen, true, true);
+    WindowsWGLGraphicsConfiguration cfg = WindowsWGLGraphicsConfiguration.createFromCurrent(factory, hdc, pfdID, glp, aScreen, true);
     return new WindowsExternalWGLDrawable(factory, new ProxySurface(cfg, hdc));
   }
 
diff --git a/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsWGLGraphicsConfiguration.java b/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsWGLGraphicsConfiguration.java
index 82d170133..a80f68377 100644
--- a/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsWGLGraphicsConfiguration.java
+++ b/src/jogl/classes/jogamp/opengl/windows/wgl/WindowsWGLGraphicsConfiguration.java
@@ -83,7 +83,7 @@ public class WindowsWGLGraphicsConfiguration extends DefaultGraphicsConfiguratio
 
 
     static WindowsWGLGraphicsConfiguration createFromCurrent(GLDrawableFactory _factory, long hdc, int pfdID,
-                                                             GLProfile glp, AbstractGraphicsScreen screen, boolean onscreen, boolean usePBuffer)
+                                                             GLProfile glp, AbstractGraphicsScreen screen, boolean onscreen)
     {
         if(_factory==null) {
             throw new GLException("Null factory");
@@ -105,12 +105,13 @@ public class WindowsWGLGraphicsConfiguration extends DefaultGraphicsConfiguratio
         WGLGLCapabilities caps = null;
 
         if(hasARB) {
-            caps = wglARBPFID2GLCapabilities(sharedContext, hdc, pfdID, glp, onscreen, usePBuffer);
-        } else if(!usePBuffer) {
+            caps = wglARBPFID2GLCapabilities(sharedContext, hdc, pfdID, glp, onscreen, true /* pbuffer */);
+        } else {
             caps = PFD2GLCapabilities(glp, hdc, pfdID, onscreen);
         }
         if(null==caps) {
-            throw new GLException("Couldn't choose Capabilities by: HDC 0x"+Long.toHexString(hdc)+", pfdID "+pfdID+", hasARB "+hasARB);
+            throw new GLException("Couldn't choose Capabilities by: HDC 0x"+Long.toHexString(hdc)+
+                                  ", pfdID "+pfdID+", onscreen "+onscreen+", hasARB "+hasARB);
         }
 
         return new WindowsWGLGraphicsConfiguration(screen, caps, caps);