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java實現笛卡兒公式

//program: 笛卡爾數學公式
//files: Heart.java

import java.applet.*;
import java.awt.*;

public class Heart extends Applet
{
    int AppletWidth,AppletHeight;
    Image OffScreen;
    Graphics drawOffScreen;
   
    public void init()
    {
        setBackground(Color.black);
       
        //取得顯示區域
        AppletWidth = getSize().width;
        AppletHeight = getSize().height;
       
        //建立次畫面
        OffScreen = createImage(AppletWidth,AppletHeight);
        drawOffScreen = OffScreen.getGraphics();
    }
   
    public void paint(Graphics g)
    {
        drawOffScreen.clearRect(0,0,AppletWidth,AppletHeight);
        drawOffScreen.setColor(Color.white);
       
        int i,j;
        double x,y,r;
       
        for(i = 0;i <= 90;i++)
            for(j = 0;j <= 90;j++)
            {
                //轉換為直角坐標
                r = Math.PI/45*i*(1-Math.sin(Math.PI/45*j))*18;
                x = r*Math.cos(Math.PI/45*j)*Math.sin(Math.PI/45*i)+AppletWidth/2;
                y = -r*Math.sin(Math.PI/45*j)+AppletHeight/4;
               
                //投影到xz平面
                drawOffScreen.fillOval((int)x,(int)y,2,2);
             }
         g.drawImage(OffScreen,0,0,this);
     }
}

posted on 2005-08-01 17:09 蘑菇 閱讀(375) 評論(0)  編輯  收藏 所屬分類: JAVA