Sprite2VdpCanvas.java

/*
  Sprite2VdpCanvas.java

  (c) 2011-2013 Edward Swartz

  All rights reserved. This program and the accompanying materials
  are made available under the terms of the Eclipse Public License v1.0
  which accompanies this distribution, and is available at
  http://www.eclipse.org/legal/epl-v10.html
 */
package v9t9.video;

import java.util.Arrays;

import v9t9.common.video.BaseVdpCanvas;
import v9t9.common.video.ISpriteVdpCanvas;

/**
 * This class is used for sprite 2 sprite drawing (since due to the
 * per-row early clock, a sprite would dirty so much, and vice versa
 * for underlying screen changes, we draw sprites separately then
 * blit then changes
 * @author ejs
 *
 */
public class Sprite2VdpCanvas extends BaseVdpCanvas implements ISpriteVdpCanvas {
	private final int UPDATEBLOCK_ROW_STRIDE = (256+64);
	private final byte[] bitmap = new byte[UPDATEBLOCK_ROW_STRIDE * 256];
	private final int UPDPTR(int y,int x) { return ((y)*UPDATEBLOCK_ROW_STRIDE)+(x)+32; }

    public Sprite2VdpCanvas() {
    	setSize(256, 212);
    	setClearColor(0);
    }

	public void doChangeSize() {
	}

	/* (non-Javadoc)
	 * @see v9t9.engine.video.ISprite2Canvas#getLineStride()
	 */
	@Override
	public int getLineStride() {
		return UPDATEBLOCK_ROW_STRIDE;
	}
	
	@Override
	public int getPixelStride() {
		return 1;
	}
	
	/* (non-Javadoc)
	 * @see v9t9.engine.video.ISprite2Canvas#drawEightSpritePixels(int, int, byte, byte, byte, boolean)
	 */
	@Override
	public void drawEightSpritePixels(int x, int y, byte mem, byte fg, byte bitmask, boolean isLogicalOr) {
		int offs = getBitmapOffset(x, y);
		if (isLogicalOr) {
			for (int i = 0; i < 8; i++) {
				if ((mem & 0x80) != 0) {
					bitmap[offs + i] |= fg;
				}
				mem <<= 1;
			}
		} else {
			for (int i = 0; i < 8; i++) {
				if ((mem & 0x80) != 0) {
					bitmap[offs + i] = fg;
				}
				mem <<= 1;
			}
		}
	}

	/* (non-Javadoc)
	 * @see v9t9.engine.video.ISprite2Canvas#drawEightMagnifiedSpritePixels(int, int, byte, byte, short, boolean)
	 */
	@Override
	public void drawEightMagnifiedSpritePixels(int x, int y, byte mem, byte fg, short bitmask, boolean isLogicalOr) {
		int offs = getBitmapOffset(x, y);
		for (int i = 0; i < 16; i += 2) {
			if ((mem & 0x80) != 0) {
				if (isLogicalOr) {
					bitmap[offs + i] |= fg;
					bitmap[offs + i + 1] |= fg;
				} else {
					bitmap[offs + i] = fg;
					bitmap[offs + i + 1] = fg;
				}
			}
			mem <<= 1;
		}
	}
	/* (non-Javadoc)
	 * @see v9t9.engine.video.ISprite2Canvas#drawEightDoubleMagnifiedSpritePixels(int, int, byte, byte, short, boolean)
	 */
	@Override
	public void drawEightDoubleMagnifiedSpritePixels(int x, int y, byte mem, byte fg, short bitmask, boolean isLogicalOr) {
		int offs = getBitmapOffset(x, y);
		for (int i = 0; i < 32; i += 4) {
			if ((mem & 0x80) != 0) {
				if (isLogicalOr) {
					bitmap[offs + i] |= fg;
					bitmap[offs + i + 1] |= fg;
					bitmap[offs + i + 2] |= fg;
					bitmap[offs + i + 3] |= fg;
				} else {
					bitmap[offs + i] = fg;
					bitmap[offs + i + 1] = fg;
					bitmap[offs + i + 2] = fg;
					bitmap[offs + i + 3] = fg;
				}
			}
			mem <<= 1;
		}
	}

	public void clear8x8Block(int offset) {
		for (int i = 0; i < 8; i++) {
			if (offset < bitmap.length)
				Arrays.fill(bitmap, offset, offset + 8, (byte) 0);
			offset += getLineStride();
		}
	}

	/* (non-Javadoc)
	 * @see v9t9.engine.video.ISprite2Canvas#getColorAtOffset(int)
	 */
	@Override
	public byte getColorAtOffset(int offset) {
		return bitmap[offset];
	}

	/* (non-Javadoc)
	 * @see v9t9.engine.video.ISprite2Canvas#getBitmapOffset(int, int)
	 */
	@Override
	public int getBitmapOffset(int x, int y) {
		return UPDPTR(y, x);
	}


}