PlatformGraphics: More enhancements to drawing routines.

flushGraphics wasn't accessing indices correctly in cases where
the image to be rendered didn't cover the whole canvas (games that
do partial screen repaints tend to use this a lot), and
draw/getPixels didn't have very robust validation steps.

Probably fixes all the remaining Karma Studios games. See #50.

src/org/recompile/mobile/PlatformGraphics.java

@@ -232,8 +232,7 @@ 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();
+			final int[] pixels = ((DataBufferInt) image.platformImage.getCanvas().getRaster().getDataBuffer()).getData();
 			int[] overlayData = null;
 
 			// This one is rather costly, as it has to draw overlays on the corners of the screen with gaussian filtering applied.
@@ -244,16 +243,16 @@ public void flushGraphics(Image image, int x, int y, int width, int height)
 			}
 
 			// Render the resulting image
-			for (int j = 0; j < height; j++) 
+			for (int j = y; j < height+y; j++) 
 			{
-				for (int i = 0; i < width; i++) 
+				for (int i = x; i < width+x; i++) 
 				{
 					int destIndex = j * canvas.getWidth() + i;
-					int srcIndex = j * width + i;
+					int srcIndex = j * image.getWidth() + i;
 
 					// The image data CAN go out of the destination bounds, we just can't draw it whenever it does.
-					if (x + i < 0 || x + i >= canvas.getWidth()) { continue; }
-					if (y + j < 0 || y + j >= canvas.getHeight()) { continue; }
+					if (i < 0 || i >= canvas.getWidth()) { continue; }
+					if (j < 0 || j >= canvas.getHeight()) { continue; }
 					if (destIndex < 0 || destIndex >= canvasData.length) { continue; }
 					if (srcIndex < 0 || srcIndex >= pixels.length) { continue; }
 
@@ -698,20 +697,29 @@ public void drawPixels(short[] pixels, boolean transparency, int offset, int sca
 		if (pixels == null) { throw new NullPointerException("drawPixels(short) received a null pixel array"); }
 		if (offset < 0 || offset >= pixels.length) { throw new ArrayIndexOutOfBoundsException("drawPixels(short) index out of bounds:" + width + " * " + height + "| len:" + pixels.length); }
 
+		if (scanlength > 0) 
+		{
+			if (offset + scanlength * (height - 1) + width > pixels.length) { throw new ArrayIndexOutOfBoundsException(); }
+		} 
+		else 
+		{
+			if (offset + width > pixels.length || offset + scanlength * (height - 1) < 0) { throw new ArrayIndexOutOfBoundsException(); }
+		}
+
 		BufferedImage temp = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
     	int[] data = ((DataBufferInt) temp.getRaster().getDataBuffer()).getData();
-
+		
 		// Prepare the pixel data
 		for (int row = 0; row < height; row++) 
 		{
+			int srcIndex = offset + row * scanlength;
 			for (int col = 0; col < width; col++) 
 			{
-				int index = offset + (col) + (row * scanlength);
-				data[row * width + col] = pixelToColor(pixels[index], format);
+				data[row * width + col] = pixelToColor(pixels[srcIndex + col], format);
 				if (!transparency) { data[row * width + col] = (data[row * width + col] & 0x00FFFFFF) | 0xFF000000; } // Set alpha to 255
 			}
 		}
-	
+
 		gc.drawImage(manipulateImage(temp, manipulation), x, y, null);
 	}
 
@@ -824,17 +832,31 @@ public void getPixels(byte[] pixels, byte[] transparencyMask, int offset, int sc
 
 	public void getPixels(int[] pixels, int offset, int scanlength, int x, int y, int width, int height, int format)
 	{
+		if (width <= 0 || height <= 0) { return; } // We have no pixels to copy
+		if (pixels == null) { throw new NullPointerException("int array cannot be null"); }
+		if (x < 0 || y < 0 || x + width > canvas.getWidth() || y + height > canvas.getHeight()) 
+		{
+			throw new IllegalArgumentException("Requested copy area exceeds bounds of the image");
+		}
+
 		canvas.getRGB(x, y, width, height, pixels, offset, scanlength);
 	}
 
 	public void getPixels(short[] pixels, int offset, int scanlength, int x, int y, int width, int height, int format)
 	{
+		if (width <= 0 || height <= 0) { return; } // We have no pixels to copy
+		if (pixels == null) { throw new NullPointerException("short array cannot be null"); }
+		if (x < 0 || y < 0 || x + width > canvas.getWidth() || y + height > canvas.getHeight()) 
+		{
+			throw new IllegalArgumentException("Requested copy area exceeds bounds of the image");
+		}
+
 		for(int row=0; row<height; row++)
 		{
 			for (int col=0; col<width; col++)
 			{
-				int pixelIndex = offset + (col) + (row * scanlength);
-				pixels[pixelIndex] = colorToShortPixel(canvas.getRGB(col+x, row+y), format);
+				int pixelIndex = offset + col + (row * scanlength);
+				pixels[pixelIndex] = colorToShortPixel(canvasData[col+x + (row+y)*canvas.getWidth()], format);
 			}
 		}
 	}