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)

1 files changed, 7 insertions, 3 deletions

diff --git a/src/newt/native/NewtMacWindow.m b/src/newt/native/NewtMacWindow.m
index c4800bd26..fe761833d 100644
--- a/src/newt/native/NewtMacWindow.m
+++ b/src/newt/native/NewtMacWindow.m
@@ -778,8 +778,12 @@ static jmethodID windowRepaintID = NULL;
 {
     [super viewDidChangeBackingProperties];
 
-    CGFloat pixelScale = [[self window] backingScaleFactor];
-    [[self layer] setContentsScale: pixelScale];
+    // HiDPI scaling
+    BOOL useHiDPI = [self wantsBestResolutionOpenGLSurface];
+    CGFloat pixelScaleRaw = [[self window] backingScaleFactor];
+    CGFloat pixelScaleUse = useHiDPI ? pixelScaleRaw : 1.0;
+    DBG_PRINT("viewDidChangeBackingProperties: PixelScale: HiDPI %d, raw %f -> use %f\n", useHiDPI, (float)pixelScaleRaw, (float)pixelScaleUse);
+    [[self layer] setContentsScale: pixelScaleUse];
 
     if (javaWindowObject == NULL) {
         DBG_PRINT("viewDidChangeBackingProperties: null javaWindowObject\n");
@@ -792,7 +796,7 @@ static jmethodID windowRepaintID = NULL;
         return;
     }
 
-    (*env)->CallVoidMethod(env, javaWindowObject, updatePixelScaleID, JNI_TRUE, (jfloat)pixelScale); // defer 
+    (*env)->CallVoidMethod(env, javaWindowObject, updatePixelScaleID, JNI_TRUE, (jfloat)pixelScaleUse); // defer 
 
     // detaching thread not required - daemon
     // NewtCommon_ReleaseJNIEnv(shallBeDetached);