screen.java~58~

j2me源代码

package pinball;

import javax.microedition.lcdui.*;

public class Screen extends Canvas {
    private Font font;        //字体
    public static int width;  //宽度
    public static int height; //高度
    private static final int TL_ANCHOR = Graphics.TOP | Graphics.LEFT;
    private static final int TH_ANCHOR = Graphics.TOP | Graphics.HCENTER;
    private Image img;
    public static Graphics GRAPHICS;
    public static int VDIVIDER;
    public static final int BACKGROUND = ThreeDColor.gray.getRGB();
    private int nLastState;  //状态
    private int nLastScore;  //得分
    private int nLastLives;  //剩余生命数
    private Engine engine;   //游戏引擎
    private EngineState state;  //游戏引擎状态
    private int nFontVoff;

    public Screen() {
        width = getWidth();   //屏幕宽度
        height = getHeight(); //屏幕高度

        font = height < 150 ? Font.getFont(Font.FACE_SYSTEM, Font.STYLE_PLAIN,
                                  Font.SIZE_SMALL)
                            : Font.getFont(Font.FACE_SYSTEM, Font.STYLE_PLAIN,
                                   Font.SIZE_MEDIUM);  //选用字体
        nFontVoff = font.getHeight();
        img = Image.createImage(width, height - (nFontVoff + 5));
        VDIVIDER = img.getHeight();
        GRAPHICS = img.getGraphics();
        state = new EngineState();
        nLastState = -1;
        nLastScore = -1;
        nLastLives = -1;
    }

    public void setEngine(Engine engine) {
        this.engine = engine;
    }

    public void keyPressed(int keycode) {
        engine.keyPressed(keycode, getGameAction(keycode));
    }

    public void keyReleased(int keycode) {
        engine.keyReleased(keycode, getGameAction(keycode));
    }

    /**
     * 绘制背景
     */
    private void paintBackground(Graphics g) {
        g.setColor(BACKGROUND);
        g.fillRect(0, 0, width, height);
    }

    /**
     * 绘制标题
     */
    private void paintTitle(Graphics g) {
        engine.getState(state);

        if (nLastState != Engine.TITLE) {
            paintBackground(GRAPHICS);
            state.bricks.paintShadow(GRAPHICS);
            state.bricks.paint(GRAPHICS);

            g.setFont(Font.getFont(Font.FACE_SYSTEM, Font.STYLE_PLAIN,
                                  Font.SIZE_SMALL));
            g.setColor(ThreeDColor.red.getRGB());
            g.drawString("按任意键开始游戏", width/2, 2 * height /3 + 20, TH_ANCHOR);
        }

        g.drawImage(img, 0, 0, TL_ANCHOR);
        g.setColor(BACKGROUND);
        g.fillRect(0, height - (nFontVoff + 5), width, nFontVoff + 5);
        g.setFont(Font.getFont(Font.FACE_PROPORTIONAL, Font.STYLE_BOLD,
                                  Font.SIZE_LARGE));
        g.setColor(ThreeDColor.black.getRGB());
        g.drawString("PinBall", width / 2 + 1, height / 2 + 20, TH_ANCHOR);
        g.setColor(ThreeDColor.red.getRGB());
        g.drawString("PinBall", width / 2, height / 2 + 19, TH_ANCHOR);
    }

    /**
     * 绘制游戏结束信息
     */
    private void paintOver(Graphics g) {
        paintBackground(g);
        g.setFont(Font.getFont(Font.FACE_PROPORTIONAL, Font.STYLE_BOLD,
                                  Font.SIZE_LARGE));
        g.setColor(ThreeDColor.black.getRGB());
        g.drawString("Game Over", width / 2 + 1, height / 3 - 10 + 1, TH_ANCHOR);
        g.setColor(ThreeDColor.red.getRGB());
        g.drawString("Game Over", width / 2, height / 3 - 10, TH_ANCHOR);
    }

    public void paint(Graphics g) {
        boolean bFullRepaint = engine.levelStarted();

        engine.getState(state);
        g.setFont(font);

        if (state.state == Engine.TITLE) {   //处于标题状态
            paintTitle(g);
        } else if (state.state == Engine.OVER) {  //游戏结束
            paintOver(g);
        } else {   //游戏正在运行
            if (bFullRepaint) {
                paintBackground(GRAPHICS);   //绘制背景
                state.bricks.paintShadow(GRAPHICS);  //绘制砖块
                state.bricks.paint(GRAPHICS);
            }

            g.drawImage(img, 0, 0, TL_ANCHOR);

            if (state.state == Engine.PLAY) {  //PLAY状态
                if (state.score != nLastScore || bFullRepaint) {
                    g.setColor(BACKGROUND);
                    g.fillRect(width / 3, height - (nFontVoff + 5),
                               width * 2 / 3, nFontVoff + 5);
                    g.setColor(ThreeDColor.black.getRGB());
                    g.drawString("分数: " + state.score, width * 1 / 3 + 1,
                                height - (nFontVoff + 3), TL_ANCHOR);
                    g.drawString("最高分: " + state.highscore, width * 2 / 3 + 1,
                                 height - (nFontVoff + 3), TL_ANCHOR);
                    g.setColor(ThreeDColor.orange.getRGB());
                    g.drawString("分数: " + state.score, width * 1 / 3,
                                 height - (nFontVoff + 5), TL_ANCHOR);
                    g.drawString("最高分: " + state.highscore, width * 2 / 3,
                                 height - (nFontVoff + 5), TL_ANCHOR);
                }

                if (state.lives != nLastLives || bFullRepaint) {
                    g.setColor(BACKGROUND);
                    g.fillRect(0, height - (nFontVoff + 5), width / 3,
                               nFontVoff + 5);

                    for (int i = 0; i < state.lives; i++) {
                        g.setColor(ThreeDColor.black.getRGB());
                        g.fillArc(BrickList.XOFFSET + 1
                                  + 3 * Ball.RADIUS * i,
                                   height - (nFontVoff - 1),
                                   Math.max(4, height / 50),
                                   Math.max(4, height / 50),
                                   0, 360);
                        g.setColor(ThreeDColor.red.getRGB());
                        g.fillArc(BrickList.XOFFSET + 3 * Ball.RADIUS * i,
                                  height - nFontVoff,
                                  Math.max(4, height / 50),
                                  Math.max(4, height / 50), 0, 360);
                    }
                }
            }

            state.ball.paintShadow(g);
            state.board.paintShadow(g);
            state.ball.paint(g);
            state.board.paint(g);
        }

        nLastState = state.state;
        nLastScore = state.score;
        nLastLives = state.lives;
    }
}