[EXPERIMENTAL] PlatformGraphics: Faster copyArea and flushGraphics

Those are now using direct dataBuffer manipulation to write to
the screen, skipping overheads from temporary images and drawImage
calls where applicable. This also simplifies DirectGraphics'
getPixels(byte) operation by not needing to create an int array
with the canvas pixel data anymore.

src/org/recompile/mobile/PlatformGraphics.java

@@ -34,6 +34,7 @@ public class PlatformGraphics extends javax.microedition.lcdui.Graphics implemen
 {
 	protected BufferedImage canvas;
 	protected Graphics2D gc;
+	protected int[] canvasData;
 
 	protected Color awtColor;
 
@@ -72,6 +73,9 @@ public PlatformGraphics(PlatformImage image)
 		canvas = image.getCanvas();
 		gc = canvas.createGraphics();
 
+		canvasData = ((DataBufferInt) canvas.getRaster().getDataBuffer()).getData();
+
+
 		platformGraphics = this;
 
 		clipX = 0;
@@ -110,18 +114,31 @@ public void copyArea(int subx, int suby, int subw, int subh, int x, int y, int a
 		x = AnchorX(x, subw, anchor);
 		y = AnchorY(y, subh, anchor);
 
-		BufferedImage sub = new BufferedImage(subw, subh, BufferedImage.TYPE_INT_ARGB);
-
-		// Copy the pixels from the source area to the new image. getSubImage() makes both images contain the same data reference
-		for (int i = 0; i < subw; i++) 
+		/* 
+		 * A neat trick here is that we don't need to check for types, as the copied
+		 * subregion will always have the same data type as the original canvas it
+		 * was copied from, be it INT_RGB, INT_ARGB, etc.
+		 */
+		// Create a data buffer to hold the copied pixel area
+		final int[] subPixels = new int[subw * subh];
+
+		// Copy pixels from the canvas subRegion to the subPixel array
+		for (int j = 0; j < subh; j++) {
+			for (int i = 0; i < subw; i++) {
+				subPixels[j * subw + i] = canvasData[(suby + j) * canvas.getWidth() + (subx + i)];
+			}
+		}
+
+		// Draw the copied pixels to the graphics context
+		int canvasWidth = canvas.getWidth();
+		for (int j = 0; j < subh; j++) 
 		{
-			for (int j = 0; j < subh; j++) 
+			for (int i = 0; i < subw; i++) 
 			{
-				sub.setRGB(i, j, canvas.getRGB(subx + i, suby + j));
+				// Directly set pixels in the canvasData at the new position
+				canvasData[(y + j) * canvasWidth + (x + i)] = subPixels[j * subw + i];
 			}
 		}
-
-		gc.drawImage(sub, x, y, null);
 	}
 
 	public void drawArc(int x, int y, int width, int height, int startAngle, int arcAngle)
@@ -193,11 +210,11 @@ public void flushGraphics(Image image, int x, int y, int width, int height)
 		try
 		{
 			BufferedImage sub = image.platformImage.getCanvas().getSubimage(x, y, width, height);
+			final int[] pixels = ((DataBufferInt) sub.getRaster().getDataBuffer()).getData();
 
 			// Apply the backlight mask if Display, nokia's DeviceControl, or others request it for backlight effects.
 			if(Mobile.renderLCDMask)
 			{
-				final int[] pixels = ((DataBufferInt) sub.getRaster().getDataBuffer()).getData();
 				for(int i = 0; i < pixels.length; i++) { pixels[i] = pixels[i] & Mobile.lcdMaskColors[Mobile.maskIndex]; }
 			}
 
@@ -206,13 +223,13 @@ public void flushGraphics(Image image, int x, int y, int width, int height)
 			{
 				// Create an overlay image for the fun lights
 				BufferedImage overlayImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
+				int[] overlayData = ((DataBufferInt)overlayImage.getRaster().getDataBuffer()).getData();
+				drawFunLights(overlayData, width, height);
 
-				drawFunLights(overlayImage, width, height);
-
-				gc.drawImage(sub, x, y, null);
+				System.arraycopy(pixels, 0, canvasData, y * canvas.getWidth() + x, pixels.length);
 				gc.drawImage(overlayImage, x, y, null);
-			} 
-			else { gc.drawImage(sub, x, y, null); }
+			}
+			else { System.arraycopy(pixels, 0, canvasData, y * canvas.getWidth() + x, pixels.length); }
 		}
 		catch (Exception e)
 		{
@@ -679,8 +696,6 @@ public void getPixels(byte[] pixels, byte[] transparencyMask, int offset, int sc
 		}
 		if (Math.abs(scanlength) < width) { throw new IllegalArgumentException("scanlength must be >= width");}
 
-		// Temporary canvas data array to read raw pixel data from.
-		int[] canvasData = ((DataBufferInt) canvas.getRaster().getDataBuffer()).getData();
 		// Just like DrawPixels(byte), we only handle BYTE_1_GRAY_VERTICAL and BYTE_1_GRAY yet
 		switch (format) 
 		{
@@ -885,10 +900,8 @@ private static final BufferedImage manipulateImage(final BufferedImage image, fi
 			Motorola FunLights
 		****************************
 	*/
-	public void drawFunLights(BufferedImage overlayImage, int width, int height) 
-	{
-		int[] pixelData = ((DataBufferInt)overlayImage.getRaster().getDataBuffer()).getData();
-
+	public void drawFunLights(int[] pixelData, int width, int height) 
+	{		
 		// Set pixels for the fun lights directly
 		for (int y = 0; y < height; y++) 
 		{
@@ -914,12 +927,11 @@ else if (x >= width - Mobile.funLightRegionSize / 2) // Right Sideband Region
 		}
 
 		// Now apply a Gaussian blur using direct pixel manipulation
-		applyGaussianBlur(overlayImage, width, height);
+		applyGaussianBlur(pixelData, width, height);
 	}
 
-	private void applyGaussianBlur(BufferedImage image, int width, int height) 
+	private void applyGaussianBlur(int[] pixels, int width, int height) 
 	{
-		final int[] pixels = ((DataBufferInt) image.getRaster().getDataBuffer()).getData();
 		final int[] result = new int[pixels.length];
 
 		int kernelSize = 7;