* Fix issue 506

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@9616 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/lwjgl/com/jme3/system/lwjgl/LwjglCanvas.java

@@ -84,8 +84,9 @@ public class LwjglCanvas extends LwjglAbstractDisplay implements JmeCanvasContex
         public void addNotify(){
             super.addNotify();
 
-            if (renderThread != null && renderThread.getState() == Thread.State.TERMINATED)
+            if (renderThread != null && renderThread.getState() == Thread.State.TERMINATED) {
                 return; // already destroyed.
+            }
 
             if (renderThread == null){
                 logger.log(Level.INFO, "EDT: Creating OGL thread.");
@@ -166,8 +167,9 @@ public class LwjglCanvas extends LwjglAbstractDisplay implements JmeCanvasContex
         }
         // do not do anything.
         // superclass's create() will be called at initInThread()
-        if (waitFor)
+        if (waitFor) {
             waitFor(true);
+        }
     }
 
     @Override
@@ -307,10 +309,7 @@ public class LwjglCanvas extends LwjglAbstractDisplay implements JmeCanvasContex
             return pbufferFormat;
         }else{
             if (canvasFormat == null){
-			int samples = 0;
-		      if (settings.getSamples() > 1){
-                    samples = settings.getSamples();
-                }
+                int samples = getNumSamplesToUse();
                 canvasFormat = new PixelFormat(settings.getBitsPerPixel(),
                                                0,
                                                settings.getDepthBits(),

engine/src/lwjgl/com/jme3/system/lwjgl/LwjglContext.java

@@ -35,6 +35,7 @@ package com.jme3.system.lwjgl;
 import com.jme3.input.lwjgl.JInputJoyInput;
 import com.jme3.input.lwjgl.LwjglKeyInput;
 import com.jme3.input.lwjgl.LwjglMouseInput;
+import com.jme3.math.FastMath;
 import com.jme3.renderer.Renderer;
 import com.jme3.renderer.lwjgl.LwjglGL1Renderer;
 import com.jme3.renderer.lwjgl.LwjglRenderer;
@@ -45,6 +46,7 @@ import com.jme3.system.Timer;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import org.lwjgl.LWJGLException;
 import org.lwjgl.opengl.*;
 
 /**
@@ -108,6 +110,73 @@ public abstract class LwjglContext implements JmeContext {
             return null;
         }
     }
+    
+    protected int determineMaxSamples(int requestedSamples) {
+        if ((Pbuffer.getCapabilities() & Pbuffer.PBUFFER_SUPPORTED) == 0) {
+            // No pbuffer, assume everything is supported.
+            return Integer.MAX_VALUE;
+        } else {
+            Pbuffer pb = null;
+            
+            // OpenGL2 method: Create pbuffer and query samples
+            // from GL_ARB_framebuffer_object or GL_EXT_framebuffer_multisample.
+            try {
+                pb = new Pbuffer(1, 1, new PixelFormat(0, 0, 0), null);
+                pb.makeCurrent();
+                
+                if (GLContext.getCapabilities().GL_ARB_framebuffer_object) {
+                    return GL11.glGetInteger(ARBFramebufferObject.GL_MAX_SAMPLES);
+                } else if (GLContext.getCapabilities().GL_EXT_framebuffer_multisample) {
+                    return GL11.glGetInteger(EXTFramebufferMultisample.GL_MAX_SAMPLES_EXT);
+                }
+                
+                // OpenGL2 method failed.
+            } catch (LWJGLException ex) {
+                // Something else failed.
+                return Integer.MAX_VALUE;
+            } finally { 
+                if (pb != null) {
+                    pb.destroy();
+                    pb = null;
+                }
+            }
+            
+            // OpenGL1 method
+            requestedSamples = FastMath.nearestPowerOfTwo(requestedSamples);
+            while (requestedSamples > 1) {
+                try {
+                    pb = new Pbuffer(1, 1, new PixelFormat(0, 0, 0, requestedSamples), null);
+                } catch (LWJGLException ex) {
+                    if (ex.getMessage().startsWith("Failed to find ARB pixel format")) {
+                        // Unsupported format, so continue.
+                        requestedSamples /= 2;
+                    } else {
+                        // Something else went wrong ..
+                        return Integer.MAX_VALUE;
+                    }
+                } finally {
+                    if (pb != null){
+                        pb.destroy();
+                        pb = null;
+                    }
+                }
+            }
+            
+            return requestedSamples;
+        }
+    }
+    
+    protected int getNumSamplesToUse() {
+        int samples = 0;
+        if (settings.getSamples() > 1){
+            samples = settings.getSamples();
+            int supportedSamples = determineMaxSamples(samples);
+            if (supportedSamples < samples) {
+                samples = supportedSamples;
+            }
+        }
+        return samples;
+    }
 
     protected void initContextFirstTime(){
         if (settings.getRenderer().equals(AppSettings.LWJGL_OPENGL2)
@@ -136,14 +205,17 @@ public abstract class LwjglContext implements JmeContext {
         }
 
         // Init input
-        if (keyInput != null)
+        if (keyInput != null) {
             keyInput.initialize();
+        }
 
-        if (mouseInput != null)
+        if (mouseInput != null) {
             mouseInput.initialize();
+        }
 
-        if (joyInput != null)
+        if (joyInput != null) {
             joyInput.initialize();
+        }
     }
 
     public void internalDestroy(){

engine/src/lwjgl/com/jme3/system/lwjgl/LwjglDisplay.java

@@ -82,10 +82,7 @@ public class LwjglDisplay extends LwjglAbstractDisplay {
             displayMode = new DisplayMode(settings.getWidth(), settings.getHeight());
         }
 
-        int samples = 0;
-        if (settings.getSamples() > 1){
-            samples = settings.getSamples();
-        }
+        int samples = getNumSamplesToUse();
         PixelFormat pf = new PixelFormat(settings.getBitsPerPixel(),
                                          0,
                                          settings.getDepthBits(),
@@ -133,9 +130,9 @@ public class LwjglDisplay extends LwjglAbstractDisplay {
 
         if (!created.get() || pixelFormatChanged){
             ContextAttribs attr = createContextAttribs();
-            if (attr != null){
+            if (attr != null) {
                 Display.create(pixelFormat, attr);
-            }else{
+            } else {
                 Display.create(pixelFormat);
             }
             renderable.set(true);

engine/src/lwjgl/com/jme3/system/lwjgl/LwjglOffscreenBuffer.java

@@ -61,15 +61,12 @@ public class LwjglOffscreenBuffer extends LwjglContext implements Runnable {
             return;
         }
 
-        int samples = 0;
-        if (settings.getSamples() > 1) {
-            samples = settings.getSamples();
-        }
+        int samples = getNumSamplesToUse();
         pixelFormat = new PixelFormat(settings.getBitsPerPixel(),
                                       0,
                                       settings.getDepthBits(),
                                       settings.getStencilBits(),
-                                      settings.getSamples());
+                                      samples);
 
         width = settings.getWidth();
         height = settings.getHeight();