Fix SwtUtils conversion for no-alpha case.

Change-Id: I275b526670ca6e60cfc4f8749631dff2ef240b96

2 files changed, 103 insertions, 31 deletions

diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/SwtUtils.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/SwtUtils.java
index c2c46f1..88f91a0 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/SwtUtils.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/SwtUtils.java
@@ -31,13 +31,41 @@ import java.awt.image.Raster;
  * Various generic SWT utilities such as image conversion.
  */
 public class SwtUtils {
+
     private SwtUtils() {
     }
 
     /**
+     * Returns the {@link PaletteData} describing the ARGB ordering expected from
+     * integers representing pixels for AWT {@link BufferedImage}.
+     *
+     * @return A new {@link PaletteData} suitable for AWT images.
+     */
+    public static PaletteData getAwtPaletteData(int imageType) {
+        switch (imageType) {
+            case BufferedImage.TYPE_INT_RGB:
+            case BufferedImage.TYPE_INT_ARGB:
+            case BufferedImage.TYPE_INT_ARGB_PRE:
+                return new PaletteData(0x00FF0000, 0x0000FF00, 0x000000FF);
+
+            case BufferedImage.TYPE_3BYTE_BGR:
+            case BufferedImage.TYPE_4BYTE_ABGR:
+            case BufferedImage.TYPE_4BYTE_ABGR_PRE:
+                return new PaletteData(0x000000FF, 0x0000FF00, 0x00FF0000);
+
+            default:
+                throw new UnsupportedOperationException("RGB type not supported yet.");
+        }
+    }
+
+    /**
      * Converts an AWT {@link BufferedImage} into an equivalent SWT {@link Image}. Whether
      * the transparency data is transferred is optional, and this method can also apply an
      * alpha adjustment during the conversion.
+     * <p/>
+     * Implementation details: on Windows, the returned {@link Image} will have an ordering
+     * matching the Windows DIB (e.g. RGBA, not ARGB). Callers must make sure to use
+     * <code>Image.getImageData().paletteData</code> to get the right pixels out of the image.
      *
      * @param display The display where the SWT image will be shown
      * @param awtImage The AWT {@link BufferedImage}
@@ -55,8 +83,8 @@ public class SwtUtils {
         Raster raster = awtImage.getData(new java.awt.Rectangle(width, height));
         int[] imageDataBuffer = ((DataBufferInt) raster.getDataBuffer()).getData();
 
-        ImageData imageData = new ImageData(width, height, 32, new PaletteData(0x00FF0000,
-                0x0000FF00, 0x000000FF));
+        ImageData imageData =
+            new ImageData(width, height, 32, getAwtPaletteData(awtImage.getType()));
 
         imageData.setPixels(0, 0, imageDataBuffer.length, imageDataBuffer, 0);
 
@@ -83,8 +111,7 @@ public class SwtUtils {
             imageData.alpha = globalAlpha;
         }
 
-        Image image = new Image(display, imageData);
-        return image;
+        return new Image(display, imageData);
     }
 
     /**
@@ -96,14 +123,41 @@ public class SwtUtils {
      * @return an AWT image representing the source SWT image
      */
     public static BufferedImage convertToAwt(Image swtImage) {
-        ImageData data = swtImage.getImageData();
-        BufferedImage awtImage = new BufferedImage(data.width, data.height, BufferedImage.TYPE_INT_ARGB);
-        PaletteData palette = data.palette;
-        if (palette.isDirect) {
-            for (int y = 0; y < data.height; y++) {
-                for (int x = 0; x < data.width; x++) {
-                  int pixel = data.getPixel(x, y);
-                  awtImage.setRGB(x, y, 0xFF000000 | pixel);
+        ImageData swtData = swtImage.getImageData();
+        BufferedImage awtImage =
+            new BufferedImage(swtData.width, swtData.height, BufferedImage.TYPE_INT_ARGB);
+        PaletteData swtPalette = swtData.palette;
+        if (swtPalette.isDirect) {
+            PaletteData awtPalette = getAwtPaletteData(awtImage.getType());
+
+            if (swtPalette.equals(awtPalette)) {
+                // No color conversion needed.
+                for (int y = 0; y < swtData.height; y++) {
+                    for (int x = 0; x < swtData.width; x++) {
+                      int pixel = swtData.getPixel(x, y);
+                      awtImage.setRGB(x, y, 0xFF000000 | pixel);
+                    }
+                }
+            } else {
+                // We need to remap the colors
+                int sr = -awtPalette.redShift   + swtPalette.redShift;
+                int sg = -awtPalette.greenShift + swtPalette.greenShift;
+                int sb = -awtPalette.blueShift  + swtPalette.blueShift;
+
+                for (int y = 0; y < swtData.height; y++) {
+                    for (int x = 0; x < swtData.width; x++) {
+                      int pixel = swtData.getPixel(x, y);
+
+                      int r = pixel & swtPalette.redMask;
+                      int g = pixel & swtPalette.greenMask;
+                      int b = pixel & swtPalette.blueMask;
+                      r = (sr < 0) ? r >>> -sr : r << sr;
+                      g = (sg < 0) ? g >>> -sg : g << sg;
+                      b = (sb < 0) ? b >>> -sb : b << sb;
+
+                      pixel = 0xFF000000 | r | g | b;
+                      awtImage.setRGB(x, y, pixel);
+                    }
                 }
             }
         } else {
diff --git a/eclipse/plugins/com.android.ide.eclipse.tests/unittests/com/android/ide/eclipse/adt/internal/editors/layout/gle2/SwtUtilsTest.java b/eclipse/plugins/com.android.ide.eclipse.tests/unittests/com/android/ide/eclipse/adt/internal/editors/layout/gle2/SwtUtilsTest.java
index c575f46..8b11887 100644
--- a/eclipse/plugins/com.android.ide.eclipse.tests/unittests/com/android/ide/eclipse/adt/internal/editors/layout/gle2/SwtUtilsTest.java
+++ b/eclipse/plugins/com.android.ide.eclipse.tests/unittests/com/android/ide/eclipse/adt/internal/editors/layout/gle2/SwtUtilsTest.java
@@ -20,6 +20,8 @@ import com.android.ide.common.api.Rect;
 
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.ImageData;
+import org.eclipse.swt.graphics.PaletteData;
+import org.eclipse.swt.graphics.RGB;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Shell;
@@ -33,36 +35,52 @@ import junit.framework.TestCase;
 public class SwtUtilsTest extends TestCase {
 
     public void testImageConvertNoAlpha() throws Exception {
-        BufferedImage image = new BufferedImage(100, 100, BufferedImage.TYPE_INT_ARGB_PRE);
-        Graphics g = image.getGraphics();
-        g.setColor(new Color(0xFF00FF00, true));
-        g.fillRect(0, 0, image.getWidth(), image.getHeight());
+        BufferedImage inImage = new BufferedImage(100, 100, BufferedImage.TYPE_INT_ARGB_PRE);
+        Graphics g = inImage.getGraphics();
+        g.setColor(new Color(0xFF00FF00, true));  // green
+        g.fillRect(0, 0, inImage.getWidth(), inImage.getHeight());
         g.dispose();
 
         Shell shell = new Shell();
         Display display = shell.getDisplay();
-        Image swtImage = SwtUtils.convertToSwt(display, image, false, -1);
-        assertNotNull(swtImage);
-        ImageData data = swtImage.getImageData();
-        assertEquals(image.getWidth(), data.width);
-        assertEquals(image.getHeight(), data.height);
-        assertNull(data.alphaData);
-        for (int y = 0; y < data.height; y++) {
-            for (int x = 0; x < data.width; x++) {
-                assertEquals(image.getRGB(x, y) & 0xFFFFFF, data.getPixel(x, y));
+
+        Image outImage = SwtUtils.convertToSwt(display, inImage, false, -1);
+        assertNotNull(outImage);
+
+        ImageData outData = outImage.getImageData();
+        assertEquals(inImage.getWidth(), outData.width);
+        assertEquals(inImage.getHeight(), outData.height);
+        assertNull(outData.alphaData);
+
+        PaletteData inPalette  = SwtUtils.getAwtPaletteData(inImage.getType());
+        PaletteData outPalette = outData.palette;
+
+        for (int y = 0; y < outData.height; y++) {
+            for (int x = 0; x < outData.width; x++) {
+                // Note: we can't compare pixel directly as integers since convertToSwt() might
+                // have changed the RGBA ordering depending on the platform (e.g. it will on
+                // Windows.)
+                RGB expected = outPalette.getRGB(outData.getPixel(x, y));
+                RGB actual   = inPalette.getRGB( inImage.getRGB(  x, y));
+                assertEquals(expected, actual);
             }
         }
 
         // Convert back to AWT and compare with original AWT image
-        BufferedImage awtImage = SwtUtils.convertToAwt(swtImage);
+        BufferedImage awtImage = SwtUtils.convertToAwt(outImage);
         assertNotNull(awtImage);
-        for (int y = 0; y < data.height; y++) {
-            for (int x = 0; x < data.width; x++) {
-                assertEquals(image.getRGB(x, y), awtImage.getRGB(x, y));
-            }
-        }
 
+        // Both image have compatible RGB orderings
+        assertEquals(BufferedImage.TYPE_INT_ARGB_PRE, inImage.getType());
+        assertEquals(BufferedImage.TYPE_INT_ARGB,     awtImage.getType());
 
+        for (int y = 0; y < outData.height; y++) {
+            for (int x = 0; x < outData.width; x++) {
+                // Note: we can compare pixels as integers since we just
+                // asserted both images have the same color image type.
+                assertEquals(inImage.getRGB(x, y), awtImage.getRGB(x, y));
+            }
+        }
     }
 
     public void testImageConvertGlobalAlpha() throws Exception {