Bug 1422: Emulate DPI Scaling on non-native DPI autoscale platforms (!MacOS)

Bug 1422 shows that it seems to be desired to emulate DPI scaling where
the native toolkit does not implmement the same.

On GTK, DPIUtil.mapDPIToZoom (int dpi) reads:
  double zoom = (double) dpi * 100 / 96;
  int roundedZoom = (int) Math.round (zoom);
  return roundedZoom;

While having dpi calculated as:

  dpi = 96 * GDK.gdk_monitor_get_scale_factor(monitor);

Well, this seems to exist to allow 96 dpi fixed layout to
'look' OK on high-dpi screens.
However, you get in trouble if you layout high-dpi aware,
i.e. using percentages etc.

There is one exception: If DPIUtil.useCairoAutoScale() is true, scalingFactor is 1f
and hence the scaling emulation dropped.

'DPIUtil.setUseCairoAutoScale((sx[0]*100) == scaleFactor || OS.isGNOME);'

6 files changed, 75 insertions, 13 deletions

diff --git a/src/nativewindow/classes/com/jogamp/nativewindow/swt/SWTAccessor.java b/src/nativewindow/classes/com/jogamp/nativewindow/swt/SWTAccessor.java
index b2428f7fa..0cf56c0c9 100644
--- a/src/nativewindow/classes/com/jogamp/nativewindow/swt/SWTAccessor.java
+++ b/src/nativewindow/classes/com/jogamp/nativewindow/swt/SWTAccessor.java
@@ -29,16 +29,19 @@ package com.jogamp.nativewindow.swt;
 
 import com.jogamp.common.os.Platform;
 
+import java.io.PrintStream;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
 
+import org.eclipse.swt.SWT;
 import org.eclipse.swt.graphics.GCData;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.internal.DPIUtil;
 import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Scrollable;
 
 import com.jogamp.nativewindow.AbstractGraphicsScreen;
@@ -288,11 +291,6 @@ public class SWTAccessor {
         OS_gdk_window_set_background_pattern = mb;
 
         isX11GTK = isX11 && null != OS_gtk_class;
-
-        if(DEBUG) {
-            System.err.println("SWTAccessor.<init>: isX11 "+isX11+", isX11GTK "+isX11GTK+" (GTK Version: "+OS_gtk_version+")");
-            System.err.println("SWTAccessor.<init>: isOSX "+isOSX+", isWindows "+isWindows);
-        }
     }
 
     private static Number getIntOrLong(final long arg) {
@@ -394,6 +392,46 @@ public class SWTAccessor {
     //
     // Common any toolkit
     //
+    public static void printInfo(final PrintStream out, final Display d) {
+        out.println("SWT: Platform: "+SWT.getPlatform()+", Version "+SWT.getVersion());
+        out.println("SWT: isX11 "+isX11+", isX11GTK "+isX11GTK+" (GTK Version: "+OS_gtk_version+")");
+        out.println("SWT: isOSX "+isOSX+", isWindows "+isWindows);
+        out.println("SWT: Display.DPI "+d.getDPI()+", DPIUtil: scalingFactor "+getScalingFactor()+", deviceZoom "+DPIUtil.getDeviceZoom()+
+                    ", useCairoAutoScale "+DPIUtil.useCairoAutoScale());
+    }
+
+    public static float getScalingFactor() {
+        final int deviceZoom = DPIUtil.getDeviceZoom();
+        if ( 100 == deviceZoom || DPIUtil.useCairoAutoScale() ) {
+            return 1f;
+        }
+        return deviceZoom/100f;
+    }
+    public static int autoScaleUp (final int v) {
+        final int deviceZoom = DPIUtil.getDeviceZoom();
+        if (100 == deviceZoom || DPIUtil.useCairoAutoScale()) {
+            return v;
+        }
+        final float scaleFactor = deviceZoom/100f;
+        return Math.round (v * scaleFactor);
+    }
+    public static com.jogamp.nativewindow.util.Point autoScaleUp (final com.jogamp.nativewindow.util.Point v) {
+        final int deviceZoom = DPIUtil.getDeviceZoom();
+        if (100 == deviceZoom || DPIUtil.useCairoAutoScale() || null == v) {
+            return v;
+        }
+        final float scaleFactor = deviceZoom/100f;
+        return v.set(Math.round(v.getX() * scaleFactor), Math.round(v.getY() * scaleFactor));
+    }
+    public static com.jogamp.nativewindow.util.Rectangle autoScaleUp (final com.jogamp.nativewindow.util.Rectangle v) {
+        final int deviceZoom = DPIUtil.getDeviceZoom();
+        if (100 == deviceZoom || DPIUtil.useCairoAutoScale() || null == v) {
+            return v;
+        }
+        final float scaleFactor = deviceZoom/100f;
+        return v.set(Math.round(v.getX() * scaleFactor), Math.round(v.getY() * scaleFactor),
+                     Math.round(v.getWidth() * scaleFactor), Math.round(v.getHeight() * scaleFactor));
+    }
 
     /**
      * Returns the unscaled {@link Scrollable#getClientArea()} in pixels.
diff --git a/src/newt/classes/com/jogamp/newt/swt/NewtCanvasSWT.java b/src/newt/classes/com/jogamp/newt/swt/NewtCanvasSWT.java
index 2930a4fd3..2615ebbb5 100644
--- a/src/newt/classes/com/jogamp/newt/swt/NewtCanvasSWT.java
+++ b/src/newt/classes/com/jogamp/newt/swt/NewtCanvasSWT.java
@@ -176,6 +176,29 @@ public class NewtCanvasSWT extends Canvas implements NativeWindowHolder, WindowC
         addListener (SWT.FocusOut, swtListener);
     }
 
+    /**
+     * Set's the NEWT {@link Window}'s size using {@link Window#setSize(int, int)}.
+     * <p>
+     * For all non-native DPI autoscale platforms, it utilizes {@link SWTAccessor#autoScaleUp(Point)}
+     * by multiplying the given {@link Rectangle} size to emulate DPI scaling, see Bug 1422.
+     * </p>
+     * <p>
+     * Currently native DPI autoscale platforms are
+     * <ul>
+     *  <li>{@link SWTAccessor#isOSX}</li>
+     * </ul>
+     * hence the emulated DPI scaling is enabled for all other platforms.
+     * </p>
+     * @param r containing desired size
+     */
+    private final void setNewtChildSize(final Rectangle r) {
+        if( !SWTAccessor.isOSX ) {
+            final Point p = SWTAccessor.autoScaleUp(new Point(r.width, r.height));
+            newtChild.setSize(p.getX(), p.getY());
+        } else {
+            newtChild.setSize(r.width, r.height);
+        }
+    }
     private final Listener swtListener = new Listener () {
         @Override
         public void handleEvent (final Event event) {
@@ -187,7 +210,7 @@ public class NewtCanvasSWT extends Canvas implements NativeWindowHolder, WindowC
                 }
                 if( validateNative() && newtChildReady ) {
                     if( postSetSize ) {
-                        newtChild.setSize(clientAreaWindow.width, clientAreaWindow.height);
+                        setNewtChildSize(clientAreaWindow);
                         postSetSize = false;
                     }
                     if( postSetPos ) {
@@ -357,7 +380,7 @@ public class NewtCanvasSWT extends Canvas implements NativeWindowHolder, WindowC
         }
         if( sizeChanged ) {
             if( newtChildReady ) {
-                newtChild.setSize(nClientAreaWindow.width, nClientAreaWindow.height);
+                setNewtChildSize(nClientAreaWindow);
                 newtChild.setSurfaceScale(pixelScale);
             } else {
                 postSetSize = true;
@@ -529,7 +552,7 @@ public class NewtCanvasSWT extends Canvas implements NativeWindowHolder, WindowC
                 newtDisplay.setEDTUtil( edtUtil );
             }
 
-            newtChild.setSize(clientAreaWindow.width, clientAreaWindow.height);
+            setNewtChildSize(clientAreaWindow);
             newtChild.reparentWindow(nativeWindow, -1, -1, Window.REPARENT_HINT_BECOMES_VISIBLE);
             newtChild.setPosition(clientAreaWindow.x, clientAreaWindow.y);
             newtChild.setVisible(true);
diff --git a/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestGLCanvasSWTNewtCanvasSWTPosInTabs.java b/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestGLCanvasSWTNewtCanvasSWTPosInTabs.java
index a5bafd15d..86e0f9d9b 100644
--- a/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestGLCanvasSWTNewtCanvasSWTPosInTabs.java
+++ b/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestGLCanvasSWTNewtCanvasSWTPosInTabs.java
@@ -184,6 +184,7 @@ public class TestGLCanvasSWTNewtCanvasSWTPosInTabs extends UITestCase {
     {

         display = new Display();

         Assert.assertNotNull( display );

+        SWTAccessor.printInfo(System.err, display);

 

         shell = new Shell( display );

         shell.setText( getSimpleTestName(".") );

diff --git a/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestSWTAccessor01.java b/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestSWTAccessor01.java
index bf98a8e95..79dc71406 100644
--- a/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestSWTAccessor01.java
+++ b/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestSWTAccessor01.java
@@ -83,12 +83,11 @@ public class TestSWTAccessor01 extends UITestCase {
     }
 
     protected void init() throws InterruptedException, InvocationTargetException {
-        System.err.println("SWT Platform: "+SWT.getPlatform()+", Version "+SWT.getVersion());
-        System.err.println("GTK_VERSION: "+SWTAccessor.GTK_VERSION());
         SWTAccessor.invoke(true, new Runnable() {
             public void run() {
                 display = new Display();
                 Assert.assertNotNull( display );
+                SWTAccessor.printInfo(System.err, display);
                 shell = new Shell( display );
                 Assert.assertNotNull( shell );
                 shell.setLayout( new GridLayout(3, false) );
diff --git a/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestSWTAccessor02NewtGLWindow.java b/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestSWTAccessor02NewtGLWindow.java
index 787858175..b40eb3203 100644
--- a/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestSWTAccessor02NewtGLWindow.java
+++ b/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestSWTAccessor02NewtGLWindow.java
@@ -92,12 +92,11 @@ public class TestSWTAccessor02NewtGLWindow extends UITestCase {
     Composite composite = null;
 
     protected void init() throws InterruptedException, InvocationTargetException {
-        System.err.println("SWT Platform: "+SWT.getPlatform()+", Version "+SWT.getVersion());
-        System.err.println("GTK_VERSION: "+SWTAccessor.GTK_VERSION());
         SWTAccessor.invoke(true, new Runnable() {
             public void run() {
                 display = new Display();
                 Assert.assertNotNull( display );
+                SWTAccessor.printInfo(System.err, display);
                 shell = new Shell( display );
                 Assert.assertNotNull( shell );
                 shell.setLayout( new GridLayout(3, false) );
diff --git a/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestSWTAccessor03AWTGLn.java b/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestSWTAccessor03AWTGLn.java
index d3c4de885..732db5c51 100644
--- a/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestSWTAccessor03AWTGLn.java
+++ b/src/test/com/jogamp/opengl/test/junit/jogl/swt/TestSWTAccessor03AWTGLn.java
@@ -55,6 +55,7 @@ import org.junit.FixMethodOrder;
 import org.junit.runners.MethodSorters;
 
 import com.jogamp.common.os.Platform;
+import com.jogamp.junit.util.JunitTracer;
 import com.jogamp.nativewindow.swt.SWTAccessor;
 import com.jogamp.opengl.test.junit.jogl.demos.es1.OneTriangle;
 import com.jogamp.opengl.test.junit.util.MiscUtils;
@@ -82,7 +83,7 @@ public class TestSWTAccessor03AWTGLn extends UITestCase {
             // NSLocking issues on OSX and AWT, able to freeze whole test suite!
             // Since this test is merely a technical nature to validate the accessor w/ SWT
             // we can drop it w/o bothering.
-            UITestCase.setTestSupported(false);
+            JunitTracer.setTestSupported(false);
             return;
         }
         System.out.println( "GLProfile " + GLProfile.glAvailabilityToString() );
@@ -107,6 +108,7 @@ public class TestSWTAccessor03AWTGLn extends UITestCase {
             public void run() {
                 display = new Display();
                 Assert.assertNotNull( display );
+                SWTAccessor.printInfo(System.err, display);
                 shell = new Shell( display );
                 Assert.assertNotNull( shell );
                 shell.setLayout( new FillLayout() );