習(xí)題十四（第14章）

一、問答題

1．2個(gè)參數(shù)。

2．6個(gè)參數(shù)。

3．7個(gè)參數(shù)。

4．（1）創(chuàng)建AffineTransform對(duì)象，（2）進(jìn)行旋轉(zhuǎn)操作，（3）繪制旋轉(zhuǎn)的圖形。

二、編寫程序

1.??import java.awt.*;

import javax.swing.*;

class MyCanvas extends Canvas {

??static int pointX[]=new int[5],

???????pointY[]=new int[5];

???public void paint(Graphics g) {

??????g.translate(200,200) ; ???//進(jìn)行坐標(biāo)變換,將新的坐標(biāo)原點(diǎn)設(shè)置為(200,200)。

??????pointX[0]=0;

??????pointY[0]=-120;

??????double arcAngle=(72*Math.PI)/180;

??????for(int i=1;i<5;i++) {

?????????pointX[i]=(int)(pointX[i-1]*Math.cos(arcAngle)-pointY[i-1]*Math.sin(arcAngle));

?????????pointY[i]=(int)(pointY[i-1]*Math.cos(arcAngle)+pointX[i-1]*Math.sin(arcAngle));

??????}

??????g.setColor(Color.red);

??????int starX[]={pointX[0],pointX[2],pointX[4],pointX[1],pointX[3],pointX[0]};

??????int starY[]={pointY[0],pointY[2],pointY[4],pointY[1],pointY[3],pointY[0]};

??????g.drawPolygon(starX,starY,6);

???}

}

public class E {

???public static void main(String args[]) {

??????JFrame f=new JFrame();

??????f.setSize(500,450);

??????f.setVisible(true);

??????MyCanvas canvas=new MyCanvas();

??????f.add(canvas,"Center");

??????f.validate();

??????f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

??}

}

2.???import java.awt.*;

import javax.swing.*;

import java.awt.geom.*;

class MyCanvas extends Canvas {

???public void paint(Graphics g) {

?????g.setColor(Color.red) ;

??????Graphics2D g_2d=(Graphics2D)g;

??????QuadCurve2D quadCurve=

??????new ?QuadCurve2D.Double(2,10,51,90,100,10);

??????g_2d.draw(quadCurve);

??????quadCurve.setCurve(2,100,51,10,100,100);

??????g_2d.draw(quadCurve);

???}

}

public class E {

???public static void main(String args[]) {

??????JFrame f=new JFrame();

??????f.setSize(500,450);

??????f.setVisible(true);

??????MyCanvas canvas=new MyCanvas();

??????f.add(canvas,"Center");

??????f.validate();

??????f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

??}

}

3.???import java.awt.*;

import javax.swing.*;

import java.awt.geom.*;

class MyCanvas extends Canvas {

???public void paint(Graphics g) {

??????g.setColor(Color.red) ;

??????Graphics2D g_2d=(Graphics2D)g;

??????CubicCurve2D cubicCurve=

??????new CubicCurve2D.Double(0,70,70,140,140,0,210,70);

??????g_2d.draw(cubicCurve);

???}

}

public class E {

???public static void main(String args[]) {

??????JFrame f=new JFrame();

??????f.setSize(500,450);

??????f.setVisible(true);

??????MyCanvas canvas=new MyCanvas();

??????f.add(canvas,"Center");

??????f.validate();

??????f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

??}

}

4.???import java.awt.*;

import javax.swing.*;

import java.awt.geom.*;

class Flower extends Canvas

{ ?public void paint(Graphics g)

???{ ?Graphics2D ?g_2d=(Graphics2D)g;

??????//花葉兩邊的曲線: ?

??????QuadCurve2D

??????curve_1=new ?QuadCurve2D.Double(200,200,150,160,200,100);

??????CubicCurve2D curve_2=

??????new ?CubicCurve2D.Double(200,200,260,145,190,120,200,100);

??????//花葉中的紋線:

??????Line2D line=new Line2D.Double(200,200,200,110); ?

??????QuadCurve2D leaf_line1=

??????new ?QuadCurve2D.Double(200,180,195,175,190,170);

??????QuadCurve2D leaf_line2=

??????new ?QuadCurve2D.Double(200,180,210,175,220,170);

??????QuadCurve2D leaf_line3=

??????new ?QuadCurve2D.Double(200,160,195,155,190,150);

??????QuadCurve2D leaf_line4=

??????new ?QuadCurve2D.Double(200,160,214,155,220,150); ??

??????//利用旋轉(zhuǎn)來(lái)繪制花朵: ?

??????AffineTransform trans=new AffineTransform();

??????for(int i=0;i<6;i++)

??????{ ??trans.rotate(60*Math.PI/180,200,200);

??????????g_2d.setTransform(trans);

??????????GradientPaint gradient_1=

??????????new GradientPaint(200,200,Color.green,200,100,Color.yellow);

??????????g_2d.setPaint(gradient_1);

??????????g_2d.fill(curve_1);

??????????GradientPaint gradient_2=new

??????????GradientPaint(200,145,Color.green,260,145,Color.red,true);

??????????g_2d.setPaint(gradient_2);

??????????g_2d.fill(curve_2);

??????????Color c3=new Color(0,200,0); g_2d.setColor(c3);

??????????g_2d.draw(line);

??????????g_2d.draw(leaf_line1); g_2d.draw(leaf_line2); ?

??????????g_2d.draw(leaf_line3); g_2d.draw(leaf_line4);

??????}

??????//花瓣中間的花蕾曲線:

??????QuadCurve2D center_curve_1=

??????new QuadCurve2D.Double(200,200,190,185,200,180);

??????AffineTransform trans_1=new AffineTransform();

??????for(int i=0;i<12;i++)

??????{ ?trans_1.rotate(30*Math.PI/180,200,200);

?????????g_2d.setTransform(trans_1);

?????????GradientPaint gradient_3=

?????????new GradientPaint(200,200,Color.red,200,180,Color.yellow);

?????????g_2d.setPaint(gradient_3);

?????????g_2d.fill(center_curve_1);

??????}

???}

}

public class E {

???public static void main(String args[]) {

??????JFrame f=new JFrame();

??????f.setSize(500,450);

??????f.setVisible(true);

??????Flower canvas=new Flower();

??????f.add(canvas,"Center");

??????f.validate();

??????f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

??}

}

5．?import java.awt.*;

import javax.swing.*;

import java.awt.geom.*;

class Moon extends Canvas

{ ?public void paint(Graphics g)

???{ ?Graphics2D g_2d=(Graphics2D)g;

??????Ellipse2D ellipse1=

??????new Ellipse2D. Double (20,80,60,60),

??????ellipse2=

??????new Ellipse2D. Double (40,80,80,80);

??????g_2d.setColor(Color.white);

??????Area a1=new Area(ellipse1),

???????????a2=new Area(ellipse2);

??????a1.subtract(a2); ????????????//"差"

??????g_2d.fill(a1);

???}

}

public class E {

???public static void main(String args[]) {

??????JFrame f=new JFrame();

??????f.setSize(500,450);

??????f.setVisible(true);

??????Moon moon=new Moon();

??????moon.setBackground(Color.black);

??????f.add(moon,"Center");

??????f.validate();

??????f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

??}

}