Jsmooth patch : improve icon scaling

git-svn-id: http://svn.code.sf.net/p/davmail/code/trunk@137 3d1905a2-6b24-0410-a738-b14d5a86fcbd

jsmooth-0.9.9-7-patch/src/net/charabia/jsmoothgen/application/ExeCompiler.java

@@ -430,7 +430,7 @@ public class ExeCompiler
 
 	if (biggest != null)
 	    {
-		Image result = biggest.getScaledInstance(32, 32, Image.SCALE_AREA_AVERAGING);
+		BufferedImage result = getScaledInstance((BufferedImage)biggest, 32, 32, RenderingHints.VALUE_INTERPOLATION_BILINEAR, true);
 		checkImageLoaded(result);
 		return getQuantizedImage(result);
 	    }
@@ -439,6 +439,79 @@ public class ExeCompiler
 	//
 	return null;
     }
+    
+    /**
+     * Convenience method that returns a scaled instance of the
+     * provided {@code BufferedImage}.
+     *
+     * @param img the original image to be scaled
+     * @param targetWidth the desired width of the scaled instance,
+     *    in pixels
+     * @param targetHeight the desired height of the scaled instance,
+     *    in pixels
+     * @param hint one of the rendering hints that corresponds to
+     *    {@code RenderingHints.KEY_INTERPOLATION} (e.g.
+     *    {@code RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR},
+     *    {@code RenderingHints.VALUE_INTERPOLATION_BILINEAR},
+     *    {@code RenderingHints.VALUE_INTERPOLATION_BICUBIC})
+     * @param higherQuality if true, this method will use a multi-step
+     *    scaling technique that provides higher quality than the usual
+     *    one-step technique (only useful in downscaling cases, where
+     *    {@code targetWidth} or {@code targetHeight} is
+     *    smaller than the original dimensions, and generally only when
+     *    the {@code BILINEAR} hint is specified)
+     * @return a scaled version of the original {@code BufferedImage}
+     */
+    public BufferedImage getScaledInstance(BufferedImage img,
+                                           int targetWidth,
+                                           int targetHeight,
+                                           Object hint,
+                                           boolean higherQuality)
+    {
+        int type = (img.getTransparency() == Transparency.OPAQUE) ?
+            BufferedImage.TYPE_INT_RGB : BufferedImage.TYPE_INT_ARGB;
+        BufferedImage ret = (BufferedImage)img;
+        int w, h;
+        if (higherQuality) {
+            // Use multi-step technique: start with original size, then
+            // scale down in multiple passes with drawImage()
+            // until the target size is reached
+            w = img.getWidth();
+            h = img.getHeight();
+        } else {
+            // Use one-step technique: scale directly from original
+            // size to target size with a single drawImage() call
+            w = targetWidth;
+            h = targetHeight;
+        }
+        
+        do {
+            if (higherQuality && w > targetWidth) {
+                w /= 2;
+                if (w < targetWidth) {
+                    w = targetWidth;
+                }
+            }
+
+            if (higherQuality && h > targetHeight) {
+                h /= 2;
+                if (h < targetHeight) {
+                    h = targetHeight;
+                }
+            }
+
+            BufferedImage tmp = new BufferedImage(w, h, type);
+            Graphics2D g2 = tmp.createGraphics();
+            g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, hint);
+            g2.drawImage(ret, 0, 0, w, h, null);
+            g2.dispose();
+
+            ret = tmp;
+        } while (w != targetWidth || h != targetHeight);
+
+        return ret;
+    }
+
 
 
     private ByteBuffer load(File in) throws Exception