Remove duplicate representation of alpha values in image data from SVG

The image data generated for a rasterized SVG currently uses a 32 bit
data array and an alpha values array. The alpha values for every pixel
are stored in both the alpha values array as well as the alpha channel
of the 32 bit data array. This is a redundant representation not giving
any benefits but just leading to unnecessary memory consumption.

This change adapts the SVG rasterization to create image data with a 24
bit data array, such that the alpha values are only stored in the alpha
array.

Author: HeikoKlare

bundles/org.eclipse.swt.svg/src/org/eclipse/swt/svg/JSVGRasterizer.java

@@ -121,14 +121,14 @@ private ImageData convertToSWTImageData(BufferedImage rasterizedImage) {
 		int width = rasterizedImage.getWidth();
 		int height = rasterizedImage.getHeight();
 		int[] pixels = ((DataBufferInt) rasterizedImage.getRaster().getDataBuffer()).getData();
-		PaletteData paletteData = new PaletteData(0x00FF0000, 0x0000FF00, 0x000000FF);
-		ImageData imageData = new ImageData(width, height, 32, paletteData);
+		PaletteData paletteData = new PaletteData(0xFF0000, 0x00FF00, 0x0000FF);
+		ImageData imageData = new ImageData(width, height, 24, paletteData);
 		int index = 0;
 		for (int y = 0; y < imageData.height; y++) {
 			for (int x = 0; x < imageData.width; x++) {
 				int alpha = (pixels[index] >> 24) & 0xFF;
 				imageData.setAlpha(x, y, alpha);
-				imageData.setPixel(x, y, pixels[index++]);
+				imageData.setPixel(x, y, pixels[index++] & 0x00FFFFFF);
 			}
 		}
 		return imageData;