Bug 741 HiDPI: Add ScalableSurface interface to get/set pixelScale w/ full OSX impl.

Add ScalableSurface interface
  - To set pixelScale before and after realization
  - To get pixelScale

  - Implemented on:
    - NEWT Window
      - Generic impl. in WindowImpl
      - OSX WindowDriver impl.
        - Also propagetes pixelScale to parent JAWTWindow if offscreen (NewtCanvasAWT)
      - AWT WindowDriver impl.

    - JAWTWindow / OSXCalayer
      - AWT GLCanvas
      - AWT GLJPanel
      - NEWTCanvasAWT:
        - Propagates NEWT Window's pixelScale to underlying JAWTWindow

    - WrappedSurface for pixelScale propagation
      using offscreen drawables, i.e. GLJPanel

    - Generic helper in SurfaceScaleUtils (nativewindow package)

  - Fully implemented on OSX

  - Capable to switch pixelScale before realization,
    i.e. native-creation, as well as on-the-fly.

  - Impl. uses int[2] for pixelScale to support
    non-uniform scale.

Test cases:
  - com.jogamp.opengl.test.junit.jogl.demos.es2.newt.TestGearsES2NEWT
  - com.jogamp.opengl.test.junit.jogl.demos.es2.awt.TestGearsES2AWT
  - com.jogamp.opengl.test.junit.jogl.demos.es2.awt.TestGearsES2GLJPanelAWT
  - com.jogamp.opengl.test.junit.jogl.demos.es2.newt.TestGearsES2NewtCanvasAWT

  - Press 'x' to toggle HiDPI
  - Commandline '-pixelScale <value>'
  - Added basic auto unit test (setting pre-realization)

6 files changed, 418 insertions, 44 deletions

diff --git a/src/nativewindow/classes/com/jogamp/nativewindow/awt/JAWTWindow.java b/src/nativewindow/classes/com/jogamp/nativewindow/awt/JAWTWindow.java
index 690d77901..efe9409ac 100644
--- a/src/nativewindow/classes/com/jogamp/nativewindow/awt/JAWTWindow.java
+++ b/src/nativewindow/classes/com/jogamp/nativewindow/awt/JAWTWindow.java
@@ -61,6 +61,7 @@ import javax.media.nativewindow.NativeWindow;
 import javax.media.nativewindow.NativeWindowException;
 import javax.media.nativewindow.OffscreenLayerOption;
 import javax.media.nativewindow.OffscreenLayerSurface;
+import javax.media.nativewindow.ScalableSurface;
 import javax.media.nativewindow.SurfaceUpdatedListener;
 import javax.media.nativewindow.util.Insets;
 import javax.media.nativewindow.util.InsetsImmutable;
@@ -70,13 +71,14 @@ import javax.media.nativewindow.util.PointImmutable;
 import javax.media.nativewindow.util.Rectangle;
 import javax.media.nativewindow.util.RectangleImmutable;
 
+import jogamp.nativewindow.SurfaceScaleUtils;
 import jogamp.nativewindow.SurfaceUpdatedHelper;
 import jogamp.nativewindow.awt.AWTMisc;
 import jogamp.nativewindow.jawt.JAWT;
 import jogamp.nativewindow.jawt.JAWTUtil;
 import jogamp.nativewindow.jawt.JAWT_Rectangle;
 
-public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface, OffscreenLayerOption {
+public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface, OffscreenLayerOption, ScalableSurface {
   protected static final boolean DEBUG = JAWTUtil.DEBUG;
 
   // user properties
@@ -98,7 +100,10 @@ public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface,
   protected Rectangle bounds;
   protected Insets insets;
   private volatile long offscreenSurfaceLayer;
-  private volatile int pixelScale;
+
+  private volatile int[] hasPixelScale = new int[] { ScalableSurface.IDENTITY_PIXELSCALE, ScalableSurface.IDENTITY_PIXELSCALE };
+  protected final int[] reqPixelScale = new int[] { ScalableSurface.AUTOMAX_PIXELSCALE, ScalableSurface.AUTOMAX_PIXELSCALE };
+
   private long drawable_old;
 
   /**
@@ -122,7 +127,6 @@ public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface,
     invalidate();
     this.isApplet = false;
     this.offscreenSurfaceLayer = 0;
-    this.pixelScale = 1;
   }
   private static String id(Object obj) { return ( null!=obj ? toHexString(obj.hashCode()) : "nil" ); }
   private String jawtStr() { return "JAWTWindow["+id(JAWTWindow.this)+"]"; }
@@ -260,22 +264,37 @@ public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface,
     drawable_old = 0;
     bounds = new Rectangle();
     insets = new Insets();
-    pixelScale = 1;
+    hasPixelScale[0] = ScalableSurface.IDENTITY_PIXELSCALE;
+    hasPixelScale[1] = ScalableSurface.IDENTITY_PIXELSCALE;
   }
   protected abstract void invalidateNative();
 
   /**
+   * {@inheritDoc}
+   * <p>
+   * Per default impl. only works for not yet {@link #isRealized() realized} instances,
+   * current exception OSX.
+   * </p>
+   */
+  @Override
+  public void setSurfaceScale(final int[] pixelScale) {
+      SurfaceScaleUtils.validateReqPixelScale(reqPixelScale, pixelScale, DEBUG ? getClass().getSimpleName() : null);
+  }
+
+  @Override
+  public final int[] getSurfaceScale(final int[] result) {
+      // 0 != drawable -> locked at least once !
+      System.arraycopy(0 != drawable ? hasPixelScale : reqPixelScale, 0, result, 0, 2);
+      return result;
+  }
+
+  /**
    * Updates bounds and pixelScale
+   * @return true if bounds or pixelScale has changed, otherwise false
    */
   protected final boolean updateLockedData(JAWT_Rectangle jawtBounds) {
     final Rectangle jb = new Rectangle(jawtBounds.getX(), jawtBounds.getY(), jawtBounds.getWidth(), jawtBounds.getHeight());
-    final int newPixelScale;
-    {
-        final int s = JAWTUtil.getPixelScale(config.getAWTGraphicsConfiguration());
-        newPixelScale = 0 < s ? s : 1;
-    }
     final boolean changedBounds = !bounds.equals(jb);
-    final boolean changedPixelScale = newPixelScale != pixelScale;
 
     if( changedBounds ) {
         if( DEBUG ) {
@@ -288,20 +307,31 @@ public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface,
             insets.set(contInsets.left, contInsets.right, contInsets.top, contInsets.bottom);
         }
     }
-    if( changedPixelScale ) {
-        if( DEBUG ) {
-            System.err.println("JAWTWindow.updatePixelScale: "+pixelScale+" -> "+newPixelScale);
-        }
-        pixelScale = newPixelScale;
+
+    return updatePixelScale() || changedBounds;
+  }
+
+  /**
+   * Update pixelScale
+   * @return true if pixelScale has changed, otherwise false
+   */
+  protected final boolean updatePixelScale() {
+    final int[] pixelScaleInt;
+    {
+        final int ps = JAWTUtil.getPixelScale(config.getAWTGraphicsConfiguration());
+        pixelScaleInt = new int[] { ps, ps };
     }
-    return changedBounds || changedPixelScale;
+    return SurfaceScaleUtils.computePixelScale(hasPixelScale, hasPixelScale, reqPixelScale, pixelScaleInt, DEBUG ? getClass().getSimpleName() : null);
   }
 
   /** @return the JAWT_DrawingSurfaceInfo's (JAWT_Rectangle) bounds, updated with lock */
   public final RectangleImmutable getBounds() { return bounds; }
 
-  /** @return the safe pixelScale value, i.e. never negative or zero. Updated with lock. */
-  public final int getPixelScale() { return pixelScale; }
+  /** @return the safe pixelScale value for x-direction, i.e. never negative or zero. Updated with lock. */
+  protected final int getPixelScaleX() { return hasPixelScale[0]; }
+
+  /** @return the safe pixelScale value for y-direction, i.e. never negative or zero. Updated with lock. */
+  protected final int getPixelScaleY() { return hasPixelScale[1]; }
 
   @Override
   public final InsetsImmutable getInsets() { return insets; }
@@ -625,12 +655,26 @@ public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface,
 
   @Override
   public final int getSurfaceWidth() {
-    return getWidth() * getPixelScale();
+    return getWidth() * getPixelScaleX();
   }
 
   @Override
   public final int getSurfaceHeight() {
-    return getHeight() * getPixelScale();
+    return getHeight() * getPixelScaleY();
+  }
+
+  @Override
+  public final int[] convertToWindowUnits(final int[] pixelUnitsAndResult) {
+      pixelUnitsAndResult[0] /= getPixelScaleX();
+      pixelUnitsAndResult[1] /= getPixelScaleY();
+      return pixelUnitsAndResult;
+  }
+
+  @Override
+  public final int[] convertToPixelUnits(final int[] windowUnitsAndResult) {
+      windowUnitsAndResult[0] *= getPixelScaleX();
+      windowUnitsAndResult[1] *= getPixelScaleY();
+      return windowUnitsAndResult;
   }
 
   @Override
@@ -651,22 +695,6 @@ public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface,
   }
 
   @Override
-  public final int[] convertToWindowUnits(final int[] pixelUnitsAndResult) {
-      final int scale = getPixelScale();
-      pixelUnitsAndResult[0] /= scale;
-      pixelUnitsAndResult[1] /= scale;
-      return pixelUnitsAndResult;
-  }
-
-  @Override
-  public final int[] convertToPixelUnits(final int[] windowUnitsAndResult) {
-      final int scale = getPixelScale();
-      windowUnitsAndResult[0] *= scale;
-      windowUnitsAndResult[1] *= scale;
-      return windowUnitsAndResult;
-  }
-
-  @Override
   public void destroy() {
     surfaceLock.lock();
     try {
@@ -810,7 +838,7 @@ public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface,
           append(", CA_LAYER: ").append(JAWTUtil.isJAWTUsingOffscreenLayer(jawt)).
           append(", isLayeredSurface ").append(isOffscreenLayerSurfaceEnabled()).
           append(", bounds ").append(bounds).append(", insets ").append(insets).
-          append(", pixelScale ").append(getPixelScale());
+          append(", pixelScale ").append(getPixelScaleX()).append("x").append(getPixelScaleY());
       } else {
           sb.append("JAWT n/a, bounds ").append(bounds).append(", insets ").append(insets);
       }
@@ -830,7 +858,7 @@ public abstract class JAWTWindow implements NativeWindow, OffscreenLayerSurface,
                 ", bounds "+bounds+", insets "+insets
                 );
     sb.append(", window ["+getX()+"/"+getY()+" "+getWidth()+"x"+getHeight()+
-             "], pixels[x"+getPixelScale()+" -> "+getSurfaceWidth()+"x"+getSurfaceHeight()+"]"+
+             "], pixels[s "+getPixelScaleX()+"x"+getPixelScaleY()+" -> "+getSurfaceWidth()+"x"+getSurfaceHeight()+"]"+
               ", visible "+component.isVisible());
     sb.append(", lockedExt "+isSurfaceLockedByOtherThread()+
               ",\n\tconfig "+config+
diff --git a/src/nativewindow/classes/javax/media/nativewindow/ScalableSurface.java b/src/nativewindow/classes/javax/media/nativewindow/ScalableSurface.java
new file mode 100644
index 000000000..024f22bc9
--- /dev/null
+++ b/src/nativewindow/classes/javax/media/nativewindow/ScalableSurface.java
@@ -0,0 +1,80 @@
+/**
+ * Copyright 2014 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ *
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
+
+package javax.media.nativewindow;
+
+/**
+ * Adding mutable surface pixel scale property to implementing class, usually to a {@link NativeSurface} implementation,
+ * see {@link #setSurfaceScale(int[])}.
+ */
+public interface ScalableSurface {
+  /** Setting surface-pixel-scale of {@value}, results in same pixel- and window-units. */
+  public static final int IDENTITY_PIXELSCALE = 1;
+  /** Setting surface-pixel-scale of {@value}, results in maximum platform dependent pixel-scale, i.e. pixel-units >> window-units where available. */
+  public static final int AUTOMAX_PIXELSCALE = 0;
+
+  /**
+   * Request a pixel scale in x- and y-direction for the associated {@link NativeSurface}.
+   * <p>
+   * Default pixel scale request for both directions is {@link #AUTOMAX_PIXELSCALE}.
+   * </p>
+   * <p>
+   * In case platform only supports uniform pixel scale, i.e. one scale for both directions,
+   * either {@link #AUTOMAX_PIXELSCALE} or the maximum requested pixel scale component is used.
+   * </p>
+   * <p>
+   * The <i>requested</i> pixel scale will be validated against platform limits before native scale-setup,
+   * i.e. clipped to {@link #IDENTITY_PIXELSCALE} if not supported or the platform maximum.
+   * </p>
+   * <p>
+   * The actual <i>realized</i> pixel scale values of the {@link NativeSurface}
+   * can be queried via {@link #getSurfaceScale(int[])} or
+   * computed via <code>surface.{@link NativeSurface#convertToPixelUnits(int[]) convertToPixelUnits}(new int[] { 1, 1 })</code>
+   * </p>
+   *
+   * @param pixelScale <i>requested</i> surface pixel scale int[2] values for x- and y-direction.
+   */
+  public void setSurfaceScale(final int[] pixelScale);
+
+  /**
+   * Returns the pixel scale of the associated {@link NativeSurface}.
+   * <p>
+   * In case the {@link NativeSurface} is not yet realized, method returns the
+   * requested pixel scale as validated via {@link #setSurfaceScale(int[])}
+   * if called earlier or the implementation default, usually {@link #AUTOMAX_PIXELSCALE}.
+   * </p>
+   * <p>
+   * In case the {@link NativeSurface} is already realized, method returns the
+   * actual used pixel scale.
+   * </p>
+   * @param result int[2] storage for the result
+   * @return the passed storage for chaining
+   */
+  public int[] getSurfaceScale(final int[] result);
+}
+
diff --git a/src/nativewindow/classes/jogamp/nativewindow/SurfaceScaleUtils.java b/src/nativewindow/classes/jogamp/nativewindow/SurfaceScaleUtils.java
new file mode 100644
index 000000000..22e67ecff
--- /dev/null
+++ b/src/nativewindow/classes/jogamp/nativewindow/SurfaceScaleUtils.java
@@ -0,0 +1,175 @@
+/**
+ * Copyright 2014 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ *
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
+package jogamp.nativewindow;
+
+import javax.media.nativewindow.NativeWindowFactory;
+import javax.media.nativewindow.ScalableSurface;
+
+/**
+ * Basic {@link ScalableSurface} utility to validate and compute pixel-scale values.
+ */
+public class SurfaceScaleUtils {
+
+    private static final int[] PlatformMaxPixelScale;
+    private static final boolean PlatformUniformPixelScale;
+    private static final boolean PlatformPixelScaleSupported;
+
+    static {
+      if( NativeWindowFactory.TYPE_MACOSX == NativeWindowFactory.getNativeWindowType(true) ) {
+          PlatformMaxPixelScale = new int[] { jogamp.nativewindow.macosx.OSXUtil.MAX_PIXELSCALE, jogamp.nativewindow.macosx.OSXUtil.MAX_PIXELSCALE };
+          PlatformUniformPixelScale = true;
+          PlatformPixelScaleSupported = true;
+      } else {
+          PlatformMaxPixelScale = new int[] { ScalableSurface.IDENTITY_PIXELSCALE, ScalableSurface.IDENTITY_PIXELSCALE };
+          PlatformUniformPixelScale = false;
+          PlatformPixelScaleSupported = false;
+      }
+    }
+
+    /**
+     * Compute a new valid pixelScale to be used by {@link NativeSurface} implementations,
+     * based on the given request and surface's pixelScale
+     *
+     * @param result int[2] storage for result, maybe same as <code>prePixelScale</code> for in-place
+     * @param prePixelScale previous pixelScale
+     * @param reqPixelScale requested pixelScale, validated via {@link #validateReqPixelScale(int[], int, String)}.
+     * @param surfPixelScaleRaw raw surface pixelScale
+     * @param DEBUG_PREFIX if set, dumps debug info on stderr using this prefix
+     * @return true if pixelScale has changed, otherwise false
+     */
+    public static boolean computePixelScale(int[] result, final int[] prePixelScale, final int[] reqPixelScale, final int[] surfPixelScaleRaw, final String DEBUG_PREFIX) {
+        final int surfPixelScaleSafeX = 0 < surfPixelScaleRaw[0] ? surfPixelScaleRaw[0] : ScalableSurface.IDENTITY_PIXELSCALE;
+        final int surfPixelScaleSafeY = 0 < surfPixelScaleRaw[1] ? surfPixelScaleRaw[1] : ScalableSurface.IDENTITY_PIXELSCALE;
+        final boolean useHiDPI = ScalableSurface.IDENTITY_PIXELSCALE != reqPixelScale[0] || ScalableSurface.IDENTITY_PIXELSCALE != reqPixelScale[1];
+        final int prePixelScaleX = prePixelScale[0];
+        final int prePixelScaleY = prePixelScale[1];
+
+        if( useHiDPI ) {
+            result[0] = surfPixelScaleSafeX;
+            result[1] = surfPixelScaleSafeY;
+        } else {
+            result[0] = ScalableSurface.IDENTITY_PIXELSCALE;
+            result[1] = ScalableSurface.IDENTITY_PIXELSCALE;
+        }
+
+        if( result[0] != prePixelScaleX || result[1] != prePixelScaleY ) {
+            if( null != DEBUG_PREFIX ) {
+                System.err.println(DEBUG_PREFIX+".computePixelScale: useHiDPI "+useHiDPI+", ["+prePixelScaleX+"x"+prePixelScaleY+" (pre), "+
+                        reqPixelScale[0]+"x"+reqPixelScale[1]+" (req)] -> "+
+                        surfPixelScaleRaw[0]+"x"+surfPixelScaleRaw[1]+" (raw) -> "+
+                        surfPixelScaleSafeX+"x"+surfPixelScaleSafeY+" (safe) -> "+
+                        result[0]+"x"+result[1]+" (use)");
+            }
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    /**
+     * Validate the given requested pixelScale value pair, i.e. clip it to the
+     * limits of {@link ScalableSurface#AUTOMAX_PIXELSCALE} and {@link #getPlatformMaxPixelScale(int[])}
+     * <p>
+     * To be used by {@link ScalableSurface#setSurfaceScale(int[])} implementations.
+     * </p>
+     *
+     * @param result int[2] storage for result
+     * @param reqPixelScale requested pixelScale
+     * @param DEBUG_PREFIX if set, dumps debug info on stderr using this prefix
+     */
+    public static void validateReqPixelScale(final int[] result, final int[] reqPixelScale, final String DEBUG_PREFIX) {
+        final int minPS = Math.min(reqPixelScale[0], reqPixelScale[1]);
+        if( ScalableSurface.AUTOMAX_PIXELSCALE >= minPS ) {
+            result[0] = ScalableSurface.AUTOMAX_PIXELSCALE;
+            result[1] = ScalableSurface.AUTOMAX_PIXELSCALE;
+        } else if( PlatformUniformPixelScale ) {
+            final int maxPS = Math.max(reqPixelScale[0], reqPixelScale[1]);
+            if( maxPS >= PlatformMaxPixelScale[0] ) {
+                result[0] = PlatformMaxPixelScale[0];
+                result[1] = PlatformMaxPixelScale[1];
+            } else {
+                result[0] = maxPS;
+                result[1] = maxPS;
+            }
+        } else {
+            if( reqPixelScale[0] >= PlatformMaxPixelScale[0] ) {
+                result[0] = PlatformMaxPixelScale[0];
+            } else {
+                result[0] = reqPixelScale[0];
+            }
+            if( reqPixelScale[1] >= PlatformMaxPixelScale[1] ) {
+                result[1] = PlatformMaxPixelScale[1];
+            } else {
+                result[1] = reqPixelScale[1];
+            }
+        }
+        if( null != DEBUG_PREFIX ) {
+            System.err.println(DEBUG_PREFIX+".validateReqPixelScale: ["+reqPixelScale[0]+"x"+reqPixelScale[1]+" (req), "+
+                    PlatformMaxPixelScale[0]+"x"+PlatformMaxPixelScale[1]+" (max)] -> "+
+                    result[0]+"x"+result[1]+" (valid)");
+        }
+    }
+
+    /**
+     * Replaces {@link ScalableSurface#AUTOMAX_PIXELSCALE} with {@link #getPlatformMaxPixelScale(int[])},
+     * for each component.
+     *
+     * @param pixelScale int[2] value array to be tested and replaced
+     */
+    public static void replaceAutoMaxWithPlatformMax(final int[] pixelScale) {
+        if( ScalableSurface.AUTOMAX_PIXELSCALE == pixelScale[0] ) {
+            pixelScale[0] = PlatformMaxPixelScale[0];
+        }
+        if( ScalableSurface.AUTOMAX_PIXELSCALE == pixelScale[1] ) {
+            pixelScale[1] = PlatformMaxPixelScale[1];
+        }
+    }
+
+    /**
+     * Returns the maximum platform pixelScale
+     */
+    public static int[] getPlatformMaxPixelScale(final int[] result) {
+        System.arraycopy(PlatformMaxPixelScale, 0, result, 0, 2);
+        return result;
+    }
+
+    /**
+     * Returns true if platform pixelScale is uniform, i.e. same scale factor for x- and y-direction, otherwise false.
+     */
+    public static boolean isPlatformPixelScaleUniform() {
+        return PlatformUniformPixelScale;
+    }
+
+    /**
+     * Returns whether the platform supports pixelScale
+     */
+    public static boolean isPlatformPixelScaleSupported() {
+        return PlatformPixelScaleSupported;
+    }
+
+}
diff --git a/src/nativewindow/classes/jogamp/nativewindow/WrappedSurface.java b/src/nativewindow/classes/jogamp/nativewindow/WrappedSurface.java
index 902223c80..1a8772988 100644
--- a/src/nativewindow/classes/jogamp/nativewindow/WrappedSurface.java
+++ b/src/nativewindow/classes/jogamp/nativewindow/WrappedSurface.java
@@ -31,6 +31,7 @@ package jogamp.nativewindow;
 import javax.media.nativewindow.AbstractGraphicsConfiguration;
 import javax.media.nativewindow.AbstractGraphicsDevice;
 import javax.media.nativewindow.ProxySurface;
+import javax.media.nativewindow.ScalableSurface;
 import javax.media.nativewindow.UpstreamSurfaceHook;
 
 import com.jogamp.nativewindow.UpstreamSurfaceHookMutableSize;
@@ -40,8 +41,9 @@ import com.jogamp.nativewindow.UpstreamSurfaceHookMutableSize;
  *
  * @see ProxySurface
  */
-public class WrappedSurface extends ProxySurfaceImpl {
-  protected long surfaceHandle;
+public class WrappedSurface extends ProxySurfaceImpl implements ScalableSurface {
+  private final int[] hasPixelScale = new int[] { ScalableSurface.IDENTITY_PIXELSCALE, ScalableSurface.IDENTITY_PIXELSCALE };
+  private long surfaceHandle;
 
   /**
    * Utilizes a {@link UpstreamSurfaceHook.MutableSize} to hold the size information,
@@ -76,6 +78,8 @@ public class WrappedSurface extends ProxySurfaceImpl {
   @Override
   protected void invalidateImpl() {
     surfaceHandle = 0;
+    hasPixelScale[0] = ScalableSurface.IDENTITY_PIXELSCALE;
+    hasPixelScale[1] = ScalableSurface.IDENTITY_PIXELSCALE;
   }
 
   @Override
@@ -97,14 +101,61 @@ public class WrappedSurface extends ProxySurfaceImpl {
   protected final void unlockSurfaceImpl() {
   }
 
+  /**
+   * {@inheritDoc}
+   * <p>
+   * {@link WrappedSurface}'s implementation uses the {@link #setSurfaceScale(int[]) given pixelScale} directly.
+   * </p>
+   */
   @Override
   public final int[] convertToWindowUnits(final int[] pixelUnitsAndResult) {
-      return pixelUnitsAndResult; // FIXME HiDPI: use 'pixelScale'
+      pixelUnitsAndResult[0] /= hasPixelScale[0];
+      pixelUnitsAndResult[1] /= hasPixelScale[1];
+      return pixelUnitsAndResult;
   }
 
+  /**
+   * {@inheritDoc}
+   * <p>
+   * {@link WrappedSurface}'s implementation uses the {@link #setSurfaceScale(int[]) given pixelScale} directly.
+   * </p>
+   */
   @Override
   public final int[] convertToPixelUnits(final int[] windowUnitsAndResult) {
-      return windowUnitsAndResult; // FIXME HiDPI: use 'pixelScale'
+      windowUnitsAndResult[0] *= hasPixelScale[0];
+      windowUnitsAndResult[1] *= hasPixelScale[1];
+      return windowUnitsAndResult;
+  }
+
+  /**
+   * {@inheritDoc}
+   * <p>
+   * {@link WrappedSurface}'s implementation is to simply pass the given pixelScale
+   * from the caller <i>down</i> to this instance without validation to be applied in the {@link #convertToPixelUnits(int[]) conversion} {@link #convertToWindowUnits(int[]) methods} <b>only</b>.<br/>
+   * This allows the caller to pass down knowledge about window- and pixel-unit conversion and utilize mentioned conversion methods.
+   * </p>
+   * <p>
+   * The given pixelScale will not impact the actual {@link #getSurfaceWidth()} and {@link #getSurfaceHeight()},
+   * which is determinated by this instances {@link #getUpstreamSurface() upstream surface}.
+   * </p>
+   * <p>
+   * Implementation uses the default pixelScale {@link ScalableSurface#IDENTITY_PIXELSCALE}
+   * and resets to default values on {@link #invalidateImpl()}, i.e. {@link #destroyNotify()}.
+   * </p>
+   * <p>
+   * Implementation returns the given pixelScale array.
+   * </p>
+   */
+  @Override
+  public final void setSurfaceScale(final int[] pixelScale) {
+      hasPixelScale[0] = pixelScale[0];
+      hasPixelScale[1] = pixelScale[1];
+  }
+
+  @Override
+  public final int[] getSurfaceScale(final int[] result) {
+      System.arraycopy(hasPixelScale, 0, result, 0, 2);
+      return result;
   }
 
 }
\ No newline at end of file
diff --git a/src/nativewindow/classes/jogamp/nativewindow/jawt/macosx/MacOSXJAWTWindow.java b/src/nativewindow/classes/jogamp/nativewindow/jawt/macosx/MacOSXJAWTWindow.java
index 3b91fc8ab..3d88049b2 100644
--- a/src/nativewindow/classes/jogamp/nativewindow/jawt/macosx/MacOSXJAWTWindow.java
+++ b/src/nativewindow/classes/jogamp/nativewindow/jawt/macosx/MacOSXJAWTWindow.java
@@ -114,6 +114,27 @@ public class MacOSXJAWTWindow extends JAWTWindow implements MutableSurface {
   }
 
   @Override
+  public void setSurfaceScale(final int[] pixelScale) {
+      super.setSurfaceScale(pixelScale);
+      if( 0 != drawable ) { // locked at least once !
+          final int hadPixelScaleX = getPixelScaleX();
+          updatePixelScale();
+
+          if( hadPixelScaleX != getPixelScaleX() && 0 != getAttachedSurfaceLayer() ) {
+              OSXUtil.RunOnMainThread(false, new Runnable() {
+                  @Override
+                  public void run() {
+                      final long osl = getAttachedSurfaceLayer();
+                      if( 0 != osl ) {
+                          OSXUtil.SetCALayerPixelScale(rootSurfaceLayer, osl, getPixelScaleX());
+                      }
+                  }
+              });
+          }
+      }
+  }
+
+  @Override
   protected void attachSurfaceLayerImpl(final long layerHandle) {
       OSXUtil.RunOnMainThread(false, new Runnable() {
           @Override
@@ -143,7 +164,8 @@ public class MacOSXJAWTWindow extends JAWTWindow implements MutableSurface {
               } else if( DEBUG ) {
                   System.err.println("JAWTWindow.attachSurfaceLayerImpl: "+toHexString(layerHandle) + ", [ins "+outterInsets+"], p0 "+p0+" -> "+p1+", bounds "+bounds);
               }
-              OSXUtil.AddCASublayer(rootSurfaceLayer, layerHandle, p1.getX(), p1.getY(), getWidth(), getHeight(), getPixelScale(), JAWTUtil.getOSXCALayerQuirks());
+              // HiDPI: uniform pixel scale
+              OSXUtil.AddCASublayer(rootSurfaceLayer, layerHandle, p1.getX(), p1.getY(), getWidth(), getHeight(), getPixelScaleX(), JAWTUtil.getOSXCALayerQuirks());
           } } );
   }
 
@@ -309,7 +331,7 @@ public class MacOSXJAWTWindow extends JAWTWindow implements MutableSurface {
                 public void run() {
                     String errMsg = null;
                     if(0 == rootSurfaceLayer && 0 != jawtSurfaceLayersHandle) {
-                        rootSurfaceLayer = OSXUtil.CreateCALayer(bounds.getWidth(), bounds.getHeight(), getPixelScale());
+                        rootSurfaceLayer = OSXUtil.CreateCALayer(bounds.getWidth(), bounds.getHeight(), getPixelScaleX()); // HiDPI: uniform pixel scale
                         if(0 == rootSurfaceLayer) {
                           errMsg = "Could not create root CALayer";
                         } else {
diff --git a/src/nativewindow/classes/jogamp/nativewindow/macosx/OSXUtil.java b/src/nativewindow/classes/jogamp/nativewindow/macosx/OSXUtil.java
index 12e574ced..a91698f62 100644
--- a/src/nativewindow/classes/jogamp/nativewindow/macosx/OSXUtil.java
+++ b/src/nativewindow/classes/jogamp/nativewindow/macosx/OSXUtil.java
@@ -44,6 +44,9 @@ public class OSXUtil implements ToolkitProperties {
     private static boolean isInit = false;
     private static final boolean DEBUG = Debug.debug("OSXUtil");
 
+    /** FIXME HiDPI: OSX unique and maximum value {@value} */
+    public static final int MAX_PIXELSCALE = 2;
+
     /**
      * Called by {@link NativeWindowFactory#initSingleton()}
      * @see ToolkitProperties
@@ -201,6 +204,20 @@ public class OSXUtil implements ToolkitProperties {
     }
 
     /**
+     * Set root and sub CALayer pixelScale / contentScale for HiDPI
+     *
+     * @param rootCALayer the root surface layer, maybe null.
+     * @param subCALayer the client surface layer, maybe null.
+     * @param contentsScale scale for HiDPI support: pixel-dim = window-dim x scale
+     */
+    public static void SetCALayerPixelScale(final long rootCALayer, final long subCALayer, final float contentsScale) {
+        if( 0==rootCALayer && 0==subCALayer ) {
+            return;
+        }
+        SetCALayerPixelScale0(rootCALayer, subCALayer, contentsScale);
+    }
+
+    /**
      * Detach a sub CALayer from the root CALayer.
      */
     public static void RemoveCASublayer(final long rootCALayer, final long subCALayer) {
@@ -364,6 +381,7 @@ public class OSXUtil implements ToolkitProperties {
     private static native long CreateCALayer0(int width, int height, float contentsScale);
     private static native void AddCASublayer0(long rootCALayer, long subCALayer, int x, int y, int width, int height, float contentsScale, int caLayerQuirks);
     private static native void FixCALayerLayout0(long rootCALayer, long subCALayer, boolean visible, int x, int y, int width, int height, int caLayerQuirks);
+    private static native void SetCALayerPixelScale0(long rootCALayer, long subCALayer, float contentsScale);
     private static native void RemoveCASublayer0(long rootCALayer, long subCALayer);
     private static native void DestroyCALayer0(long caLayer);
     private static native void RunOnMainThread0(Runnable runnable);