bitarray.java

手机上一个坦克游戏

package demo;

/*
 * Created on 2004-1-14
 *
 */

/**
 * @author Dabao
 */
public class BitArray {
    private int _width, _height;
    private byte[] content = null;
    public int m_nX = 0, m_nY = 0;


    /**
     * 设置数组的宽度和高度
     * @param width
     * @param height
     */
    public BitArray(int w, int h, int cx, int cy) {
        this._width = w;
        this._height = h;
        this.m_nX = cx;
        this.m_nY = cy;
        if (w > 0 && h > 0) {
            int temp = w * h;
            if (temp % 7 != 0) {
                temp = temp / 7 + 1;
            }
            else {
                temp = temp / 7;
            }
            content = new byte[temp];
            for (int i = 0; i < content.length; i++) {
                content[i] = 0;
            }
        }
    }

    /**
     * 参数是按照数组的坐标来计算的，都是从0 到width-1
     * 从0 到height -1
     * @param col
     * @param row
     * @return
     */
    public byte get(int x, int y) {
        int tranlatedX = x - m_nX;
        int tranlatedY = y - m_nY;
        if ( (tranlatedX * tranlatedY) >= (_width * _height)) {
            System.out.println(tranlatedX);
            System.out.println(tranlatedY);
            return -1;
        }

        if (tranlatedX >= 0
            && tranlatedX < _width
            && tranlatedY >= 0
            && tranlatedY < _height) {
            byte temp = content[getCursor(tranlatedX, tranlatedY)];
            return (byte)
                ( (temp >> getOffset(tranlatedX, tranlatedY)) & 1);
        }
        return 0;
    }

    public void set(int x, int y) {
        int tranlatedX = x - m_nX;
        int tranlatedY = y - m_nY;

        if (tranlatedX >= 0
            && tranlatedX < _width
            && tranlatedY >= 0
            && tranlatedY < _height) {
            //int temp = (tranlatedX * _height + tranlatedY + 1) / 7;
            int temp = getCursor(tranlatedX, tranlatedY);
            try {
                content[temp] =
                    (byte) (content[temp]
                            | (1 << getOffset(tranlatedX, tranlatedY)));
            }
            catch (Exception ex) {
                ex.printStackTrace();
            }

        }

    }

    public void reSet(int x, int y) {
        int tranlatedX = x - m_nX;
        int tranlatedY = y - m_nY;
        if (tranlatedX >= 0
            && tranlatedX < _width
            && tranlatedY >= 0
            && tranlatedY < _height) {
            int temp = getCursor(tranlatedX, tranlatedY);

            byte max = Byte.MAX_VALUE;
            max =
                (byte) (max
                        ^ (1 << getOffset(tranlatedX, tranlatedY)));
            content[temp] = (byte) (content[temp] & max);
        }
    }

    public int getWidth() {
        return _width + m_nX;
    }

    public int getHeight() {
        return _height + m_nY;
    }

    private int getCursor(int tx, int ty) {
        if (tx < 0 || ty < 0 || tx >= _width || ty >= _height) {
            return -1;
        }
        int cur = tx * _height + ty + 1;
        if (cur % 7 == 0) {
            return cur / 7 - 1;
        }
        else {
            return cur / 7;
        }
    }

    private int getOffset(int tx, int ty) {
        if (tx < 0 || ty < 0 || tx >= _width || ty >= _height) {
            return -1;
        }
        int cur = tx * _height + ty + 1;
        if (cur % 7 == 0) {
            return 6;
        }
        else {
            return cur % 7 - 1;
        }

    }
}