GLCapabilities Native Aquisition: Set alpha bits at last - due to it's auto setting by setSampleBuffers(true) and setBackgroundOpaque(false)

This bug lead to X11 GLCapabilities rgba: 8/8/8/1 - which ofc is invalid. Sideeffect was a bad selected GLXFB configuration
and the GLContext couldn't be made current.

Patch sets alpha bits reflecting reality carefully after opaque/samples. Added API doc note.

7 files changed, 64 insertions, 52 deletions

diff --git a/src/jogl/classes/jogamp/opengl/GLGraphicsConfigurationUtil.java b/src/jogl/classes/jogamp/opengl/GLGraphicsConfigurationUtil.java
index 900d6a2a0..3f38f33bc 100644
--- a/src/jogl/classes/jogamp/opengl/GLGraphicsConfigurationUtil.java
+++ b/src/jogl/classes/jogamp/opengl/GLGraphicsConfigurationUtil.java
@@ -177,14 +177,16 @@ public class GLGraphicsConfigurationUtil {
         return capsRequested;
     }
 
+    /** Fix opaque setting while preserve alpha bits */
     public static GLCapabilitiesImmutable fixOpaqueGLCapabilities(GLCapabilitiesImmutable capsRequested, boolean isOpaque)
     {
         GLCapabilities caps2 = null;
         
         if( capsRequested.isBackgroundOpaque() != isOpaque) {
-            // fix caps ..
+            final int alphaBits = capsRequested.getAlphaBits();
             caps2 = (GLCapabilities) capsRequested.cloneMutable();
             caps2.setBackgroundOpaque(isOpaque);
+            caps2.setAlphaBits(alphaBits);
             return caps2;
         }
         return capsRequested;
diff --git a/src/jogl/classes/jogamp/opengl/egl/EGLGraphicsConfiguration.java b/src/jogl/classes/jogamp/opengl/egl/EGLGraphicsConfiguration.java
index 214b36493..73867fb40 100644
--- a/src/jogl/classes/jogamp/opengl/egl/EGLGraphicsConfiguration.java
+++ b/src/jogl/classes/jogamp/opengl/egl/EGLGraphicsConfiguration.java
@@ -209,24 +209,6 @@ public class EGLGraphicsConfiguration extends MutableGraphicsConfiguration imple
             return false;
         }        
                 
-        if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_RED_SIZE, val)) {
-            caps.setRedBits(val.get(0));
-        }
-        if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_GREEN_SIZE, val)) {
-            caps.setGreenBits(val.get(0));
-        }
-        if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_BLUE_SIZE, val)) {
-            caps.setBlueBits(val.get(0));
-        }
-        if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_ALPHA_SIZE, val)) {
-            caps.setAlphaBits(val.get(0));
-        }
-        if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_STENCIL_SIZE, val)) {
-            caps.setStencilBits(val.get(0));
-        }
-        if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_DEPTH_SIZE, val)) {
-            caps.setDepthBits(val.get(0));
-        }
         if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_SAMPLES, val)) {
             caps.setSampleBuffers(val.get(0)>0?true:false);
             caps.setNumSamples(val.get(0));
@@ -262,6 +244,25 @@ public class EGLGraphicsConfiguration extends MutableGraphicsConfiguration imple
                 caps.setTransparentAlphaValue(val.get(0)==EGL.EGL_DONT_CARE?-1:val.get(0));
             } */
         }
+        // ALPHA shall be set at last - due to it's auto setting by the above (!opaque / samples)
+        if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_RED_SIZE, val)) {
+            caps.setRedBits(val.get(0));
+        }
+        if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_GREEN_SIZE, val)) {
+            caps.setGreenBits(val.get(0));
+        }
+        if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_BLUE_SIZE, val)) {
+            caps.setBlueBits(val.get(0));
+        }
+        if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_ALPHA_SIZE, val)) {
+            caps.setAlphaBits(val.get(0));
+        }
+        if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_STENCIL_SIZE, val)) {
+            caps.setStencilBits(val.get(0));
+        }
+        if(EGL.eglGetConfigAttrib(display, config, EGL.EGL_DEPTH_SIZE, val)) {
+            caps.setDepthBits(val.get(0));
+        }
         return GLGraphicsConfigurationUtil.addGLCapabilitiesPermutations(capsBucket, caps, drawableTypeBits );
     }
 
diff --git a/src/jogl/classes/jogamp/opengl/egl/EGLGraphicsConfigurationFactory.java b/src/jogl/classes/jogamp/opengl/egl/EGLGraphicsConfigurationFactory.java
index 6be9cb547..d79c351a0 100644
--- a/src/jogl/classes/jogamp/opengl/egl/EGLGraphicsConfigurationFactory.java
+++ b/src/jogl/classes/jogamp/opengl/egl/EGLGraphicsConfigurationFactory.java
@@ -253,12 +253,12 @@ public class EGLGraphicsConfigurationFactory extends GLGraphicsConfigurationFact
             //
             // rgb888 - d16, s4
             final GLCapabilities fixedCaps = new GLCapabilities(glp);
+            fixedCaps.setSampleBuffers(true);
+            fixedCaps.setNumSamples(4);
             fixedCaps.setRedBits(8);
             fixedCaps.setGreenBits(8);
             fixedCaps.setBlueBits(8);
             fixedCaps.setDepthBits(16);
-            fixedCaps.setSampleBuffers(true);
-            fixedCaps.setNumSamples(4);
             if( !capsChosen.isOnscreen() ) {
                 fixedCaps.setOnscreen(false);
                 fixedCaps.setPBuffer(capsChosen.isPBuffer());
@@ -291,12 +291,12 @@ public class EGLGraphicsConfigurationFactory extends GLGraphicsConfigurationFact
             //
             // rgb565 - d16, s4
             final GLCapabilities fixedCaps = new GLCapabilities(glp);
+            fixedCaps.setSampleBuffers(true);
+            fixedCaps.setNumSamples(4);
             fixedCaps.setRedBits(5);
             fixedCaps.setGreenBits(6);
             fixedCaps.setBlueBits(5);
             fixedCaps.setDepthBits(16);
-            fixedCaps.setSampleBuffers(true);
-            fixedCaps.setNumSamples(4);
             if( !capsChosen.isOnscreen() ) {
                 fixedCaps.setOnscreen(false);
                 fixedCaps.setPBuffer(capsChosen.isPBuffer());
diff --git a/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXCGLGraphicsConfiguration.java b/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXCGLGraphicsConfiguration.java
index 421e1ef96..202644bb3 100644
--- a/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXCGLGraphicsConfiguration.java
+++ b/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXCGLGraphicsConfiguration.java
@@ -281,6 +281,7 @@ public class MacOSXCGLGraphicsConfiguration extends MutableGraphicsConfiguration
             glp = GLProfile.get(GLProfile.GL2);
         }
         GLCapabilities caps = new GLCapabilities(glp);
+        int alphaBits = 0;
         for (int i = 0; i < len; i++) {
           int attr = cglInternalAttributeToken[i+off];
           switch (attr) {
@@ -317,7 +318,8 @@ public class MacOSXCGLGraphicsConfiguration extends MutableGraphicsConfiguration
                 break;
 
               case CGL.NSOpenGLPFAAlphaSize:
-                caps.setAlphaBits(ivalues[i]);
+                // ALPHA shall be set at last - due to it's auto setting by !opaque / samples
+                alphaBits = ivalues[i];
                 break;
 
               case CGL.NSOpenGLPFADepthSize:
@@ -350,6 +352,7 @@ public class MacOSXCGLGraphicsConfiguration extends MutableGraphicsConfiguration
                 break;
           }
         }
+        caps.setAlphaBits(alphaBits);
 
         return caps;
       }
diff --git a/src/jogl/classes/jogamp/opengl/windows/wgl/WGLGLCapabilities.java b/src/jogl/classes/jogamp/opengl/windows/wgl/WGLGLCapabilities.java
index e255a0672..6a4ce5a4e 100644
--- a/src/jogl/classes/jogamp/opengl/windows/wgl/WGLGLCapabilities.java
+++ b/src/jogl/classes/jogamp/opengl/windows/wgl/WGLGLCapabilities.java
@@ -52,10 +52,11 @@ public class WGLGLCapabilities extends GLCapabilities {
   public boolean setValuesByGDI() {
       arb_pixelformat = -1;
 
+      // ALPHA shall be set at last - due to it's auto setting by !opaque / samples
       setRedBits(pfd.getCRedBits());
       setGreenBits(pfd.getCGreenBits());
       setBlueBits(pfd.getCBlueBits());
-      setAlphaBits(pfd.getCAlphaBits());
+      setAlphaBits(pfd.getCAlphaBits()); 
       setAccumRedBits(pfd.getCAccumRedBits());
       setAccumGreenBits(pfd.getCAccumGreenBits());
       setAccumBlueBits(pfd.getCAccumBlueBits());
@@ -77,6 +78,7 @@ public class WGLGLCapabilities extends GLCapabilities {
   public boolean setValuesByARB(final int[] iattribs, final int niattribs, final int[] iresults) {
       arb_pixelformat = 1;
 
+      int alphaBits = 0;
       for (int i = 0; i < niattribs; i++) {
           int attr = iattribs[i];
           switch (attr) {
@@ -143,7 +145,8 @@ public class WGLGLCapabilities extends GLCapabilities {
                   break;
 
               case WGLExt.WGL_ALPHA_BITS_ARB:
-                  setAlphaBits(iresults[i]);
+                  // ALPHA shall be set at last - due to it's auto setting by !opaque / samples
+                  alphaBits = iresults[i];
                   break;
 
               case WGLExt.WGL_ACCUM_RED_BITS_ARB:
@@ -174,6 +177,7 @@ public class WGLGLCapabilities extends GLCapabilities {
                   throw new GLException("Unknown pixel format attribute " + iattribs[i]);
           }
       }
+      setAlphaBits(alphaBits);
       return true;
   }
 
diff --git a/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXContext.java b/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXContext.java
index e6b74a769..e1e25be67 100644
--- a/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXContext.java
+++ b/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXContext.java
@@ -152,7 +152,7 @@ public abstract class X11GLXContext extends GLContextImpl {
             throw new InternalError("Given readDrawable but no driver support");
         }
     } catch (RuntimeException re) {
-        if(TRACE_SWITCH) {
+        if(DEBUG || TRACE_SWITCH) {
           System.err.println(getThreadName()+": Warning: X11GLXContext.glXMakeContextCurrent failed: "+re+", with "+
             "dpy "+toHexString(dpy)+
             ", write "+toHexString(writeDrawable)+
diff --git a/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXGraphicsConfiguration.java b/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXGraphicsConfiguration.java
index b5b80e0b3..95b1cc457 100644
--- a/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXGraphicsConfiguration.java
+++ b/src/jogl/classes/jogamp/opengl/x11/glx/X11GLXGraphicsConfiguration.java
@@ -308,19 +308,6 @@ public class X11GLXGraphicsConfiguration extends X11GraphicsConfiguration implem
     }
 
     GLCapabilities res = new X11GLCapabilities(visualInfo, fbcfg, fbcfgid, glp);
-    res.setDoubleBuffered(glXGetFBConfig(display, fbcfg, GLX.GLX_DOUBLEBUFFER,     tmp, 0) != 0);
-    res.setStereo        (glXGetFBConfig(display, fbcfg, GLX.GLX_STEREO,           tmp, 0) != 0);
-    res.setHardwareAccelerated(glXGetFBConfig(display, fbcfg, GLX.GLX_CONFIG_CAVEAT, tmp, 0) != GLX.GLX_SLOW_CONFIG);
-    res.setDepthBits     (glXGetFBConfig(display, fbcfg, GLX.GLX_DEPTH_SIZE,       tmp, 0));
-    res.setStencilBits   (glXGetFBConfig(display, fbcfg, GLX.GLX_STENCIL_SIZE,     tmp, 0));
-    res.setRedBits       (glXGetFBConfig(display, fbcfg, GLX.GLX_RED_SIZE,         tmp, 0));
-    res.setGreenBits     (glXGetFBConfig(display, fbcfg, GLX.GLX_GREEN_SIZE,       tmp, 0));
-    res.setBlueBits      (glXGetFBConfig(display, fbcfg, GLX.GLX_BLUE_SIZE,        tmp, 0));
-    res.setAlphaBits     (glXGetFBConfig(display, fbcfg, GLX.GLX_ALPHA_SIZE,       tmp, 0));
-    res.setAccumRedBits  (glXGetFBConfig(display, fbcfg, GLX.GLX_ACCUM_RED_SIZE,   tmp, 0));
-    res.setAccumGreenBits(glXGetFBConfig(display, fbcfg, GLX.GLX_ACCUM_GREEN_SIZE, tmp, 0));
-    res.setAccumBlueBits (glXGetFBConfig(display, fbcfg, GLX.GLX_ACCUM_BLUE_SIZE,  tmp, 0));
-    res.setAccumAlphaBits(glXGetFBConfig(display, fbcfg, GLX.GLX_ACCUM_ALPHA_SIZE, tmp, 0));
     if (isMultisampleAvailable) {
       res.setSampleBuffers(glXGetFBConfig(display, fbcfg, GLX.GLX_SAMPLE_BUFFERS, tmp, 0) != 0);
       res.setNumSamples   (glXGetFBConfig(display, fbcfg, GLX.GLX_SAMPLES,        tmp, 0));
@@ -336,6 +323,20 @@ public class X11GLXGraphicsConfiguration extends X11GraphicsConfiguration implem
         res.setTransparentBlueValue(xrmask.getBlueMask());
         res.setTransparentAlphaValue(alphaMask);
     }
+    // ALPHA shall be set at last - due to it's auto setting by the above (!opaque / samples)    
+    res.setDoubleBuffered(glXGetFBConfig(display, fbcfg, GLX.GLX_DOUBLEBUFFER,     tmp, 0) != 0);
+    res.setStereo        (glXGetFBConfig(display, fbcfg, GLX.GLX_STEREO,           tmp, 0) != 0);
+    res.setHardwareAccelerated(glXGetFBConfig(display, fbcfg, GLX.GLX_CONFIG_CAVEAT, tmp, 0) != GLX.GLX_SLOW_CONFIG);
+    res.setRedBits       (glXGetFBConfig(display, fbcfg, GLX.GLX_RED_SIZE,         tmp, 0));
+    res.setGreenBits     (glXGetFBConfig(display, fbcfg, GLX.GLX_GREEN_SIZE,       tmp, 0));
+    res.setBlueBits      (glXGetFBConfig(display, fbcfg, GLX.GLX_BLUE_SIZE,        tmp, 0));
+    res.setAlphaBits     (glXGetFBConfig(display, fbcfg, GLX.GLX_ALPHA_SIZE,       tmp, 0));
+    res.setAccumRedBits  (glXGetFBConfig(display, fbcfg, GLX.GLX_ACCUM_RED_SIZE,   tmp, 0));
+    res.setAccumGreenBits(glXGetFBConfig(display, fbcfg, GLX.GLX_ACCUM_GREEN_SIZE, tmp, 0));
+    res.setAccumBlueBits (glXGetFBConfig(display, fbcfg, GLX.GLX_ACCUM_BLUE_SIZE,  tmp, 0));
+    res.setAccumAlphaBits(glXGetFBConfig(display, fbcfg, GLX.GLX_ACCUM_ALPHA_SIZE, tmp, 0));
+    res.setDepthBits     (glXGetFBConfig(display, fbcfg, GLX.GLX_DEPTH_SIZE,       tmp, 0));
+    res.setStencilBits   (glXGetFBConfig(display, fbcfg, GLX.GLX_STENCIL_SIZE,     tmp, 0));
     
     try { 
         res.setPbufferFloatingPointBuffers(glXGetFBConfig(display, fbcfg, GLXExt.GLX_FLOAT_COMPONENTS_NV, tmp, 0) != GL.GL_FALSE);
@@ -429,18 +430,7 @@ public class X11GLXGraphicsConfiguration extends X11GraphicsConfiguration implem
     // Note: use of hardware acceleration is determined by
     // glXCreateContext, not by the XVisualInfo. Optimistically claim
     // that all GLCapabilities have the capability to be hardware
-    // accelerated.
-    res.setHardwareAccelerated(true);
-    res.setDepthBits     (glXGetConfig(display, info, GLX.GLX_DEPTH_SIZE,       tmp, 0));
-    res.setStencilBits   (glXGetConfig(display, info, GLX.GLX_STENCIL_SIZE,     tmp, 0));
-    res.setRedBits       (glXGetConfig(display, info, GLX.GLX_RED_SIZE,         tmp, 0));
-    res.setGreenBits     (glXGetConfig(display, info, GLX.GLX_GREEN_SIZE,       tmp, 0));
-    res.setBlueBits      (glXGetConfig(display, info, GLX.GLX_BLUE_SIZE,        tmp, 0));
-    res.setAlphaBits     (glXGetConfig(display, info, GLX.GLX_ALPHA_SIZE,       tmp, 0));
-    res.setAccumRedBits  (glXGetConfig(display, info, GLX.GLX_ACCUM_RED_SIZE,   tmp, 0));
-    res.setAccumGreenBits(glXGetConfig(display, info, GLX.GLX_ACCUM_GREEN_SIZE, tmp, 0));
-    res.setAccumBlueBits (glXGetConfig(display, info, GLX.GLX_ACCUM_BLUE_SIZE,  tmp, 0));
-    res.setAccumAlphaBits(glXGetConfig(display, info, GLX.GLX_ACCUM_ALPHA_SIZE, tmp, 0));
+    // accelerated.    
     if (isMultisampleEnabled) {
       res.setSampleBuffers(glXGetConfig(display, info, GLX.GLX_SAMPLE_BUFFERS, tmp, 0) != 0);
       res.setNumSamples   (glXGetConfig(display, info, GLX.GLX_SAMPLES,        tmp, 0));
@@ -456,6 +446,18 @@ public class X11GLXGraphicsConfiguration extends X11GraphicsConfiguration implem
         res.setTransparentBlueValue(xrmask.getBlueMask());
         res.setTransparentAlphaValue(alphaMask);
     }
+    // ALPHA shall be set at last - due to it's auto setting by the above (!opaque / samples)
+    res.setHardwareAccelerated(true);
+    res.setDepthBits     (glXGetConfig(display, info, GLX.GLX_DEPTH_SIZE,       tmp, 0));
+    res.setStencilBits   (glXGetConfig(display, info, GLX.GLX_STENCIL_SIZE,     tmp, 0));
+    res.setRedBits       (glXGetConfig(display, info, GLX.GLX_RED_SIZE,         tmp, 0));
+    res.setGreenBits     (glXGetConfig(display, info, GLX.GLX_GREEN_SIZE,       tmp, 0));
+    res.setBlueBits      (glXGetConfig(display, info, GLX.GLX_BLUE_SIZE,        tmp, 0));
+    res.setAlphaBits     (glXGetConfig(display, info, GLX.GLX_ALPHA_SIZE,       tmp, 0));
+    res.setAccumRedBits  (glXGetConfig(display, info, GLX.GLX_ACCUM_RED_SIZE,   tmp, 0));
+    res.setAccumGreenBits(glXGetConfig(display, info, GLX.GLX_ACCUM_GREEN_SIZE, tmp, 0));
+    res.setAccumBlueBits (glXGetConfig(display, info, GLX.GLX_ACCUM_BLUE_SIZE,  tmp, 0));
+    res.setAccumAlphaBits(glXGetConfig(display, info, GLX.GLX_ACCUM_ALPHA_SIZE, tmp, 0));
 
     return GLGraphicsConfigurationUtil.addGLCapabilitiesPermutations(capsBucket, res, drawableTypeBits);
   }