package j2dgame.gfx;

public class Screen {

	public static final int MAP_WIDTH = 64;
	public static final int MAP_WIDTH_MASK = MAP_WIDTH - 1;

	public int[] pixels;

	public int xOffset = 0;
	public int yOffset = 0;

	public int width;
	public int height;

	public SpriteSheet sheet;

	public Screen(int width, int height, SpriteSheet sheet) {
		this.width = width;
		this.height = height;
		this.sheet = sheet;

		pixels = new int[width * height];
	}

	public void render(int xPos, int yPos, int tile, int color) {
		xPos -= xOffset;
		yPos -= yOffset;

		int xTile = tile % 32;
		int yTile = tile / 32;
		int tileOffset = (xTile << 3) + (yTile << 3) * sheet.width;
		for (int y = 0; y < 8; y++) {
			if (y + yPos < 0 || y + yPos >= height)
				continue;
			int ySheet = y;
			for (int x = 0; x < 8; x++) {
				if (x + xPos < 0 || x + xPos >= width)
					continue;
				int xSheet = x;
				int col = (color >> (sheet.pixels[xSheet + ySheet * sheet.width
						+ tileOffset] * 8)) & 255;
				if (color < 255)
					pixels[(x + xPos) + (y + yPos) * width] = col;
			}
		}

	}
}