利用C语言编写能够画出任意圆算法程序(利用画点函数)_CMS教程

上次刚写过，在VC下运行的，

int

dx,dy,incrE,incrNE,d,x,y;

((point[1]x-point[0]x)==0){

//垂直的直线

x=point[0]x;

for(y=point[0]y;y<point[1]y;y++)

pDC->SetPixel(x,y,50);

}

else

if(abs((point[1]y-point[0]y)/(point[1]x-point[0]x))<=1){

//斜率

-1到

之间

dx=point[1]x-point[0]x;

dy=point[0]y-point[1]y;

d=dx-2dy;

incrE=-2dy;

incrNE=2(dx-dy);

x=point[0]x,y=point[0]y;

pDC->SetPixel(x,y,50);

if(point[0]y>point[1]y){

while(x<point[1]x)

{

if(d>=0){

d+=incrE;

x++;

}

else

{d+=incrNE;

x++;

y--;

}

pDC->SetPixel(x,y,50);

}

else

if(point[0]y<=point[1]y){

dy=point[1]y-point[0]y;

incrE=-2dy;

incrNE=2(dx-dy);

x=point[0]x,y=point[0]y;

pDC->SetPixel(x,y,50);

while(x<point[1]x)

{

if(d>=0){

d+=incrE;

x++;

}

else

{d+=incrNE;

x++;

y++;

}

pDC->SetPixel(x,y,50);

}

else

{

//斜率

<-1

和

>1的直线

if(point[1]x>=point[0]x){

dx=point[1]x-point[0]x;

dy=point[1]y-point[0]y;

d=2dx-dy;

incrE=2dx;

incrNE=2(dx-dy);

x=point[0]x,y=point[0]y;

pDC->SetPixel(x,y,50);

while(x<point[1]x)

{

if(d<0){

d+=incrE;

y++;

}

else

{d+=incrNE;

pDC->SetPixel(x,y,50);

x++;

y++;

}

pDC->SetPixel(x,y,50);

}

else

if((point[1]y-point[0]y)/(point[1]x-point[0]x)<-1){

dx=point[1]x-point[0]x;

dy=point[0]y-point[1]y;

d=2dx-dy;

incrE=2dx;

incrNE=2(dx-dy);

x=point[0]x,y=point[0]y;

pDC->SetPixel(x,y,50);

while(y<point[1]y)

{

if(d>0){

d+=incrE;

y++;

}

else

{d+=incrNE;

x--;

y++;

}

pDC->SetPixel(x,y,50);

}

import javaapplet;

import javaawt;

import javaawtevent;

import javautil;

import javaxswing;

import javaawtgeom;

import javaio;

class Point implements Serializable

{

int x,y;

Color col;

int tool;

int boarder;

Point(int x, int y, Color col, int tool, int boarder)

{

thisx = x;

thisy = y;

thiscol = col;

thistool = tool;

thisboarder = boarder;

}

class paintboard extends Frame implements ActionListener,MouseMotionListener,MouseListener,ItemListener

{

int x = -1, y = -1;

int con = 1;//画笔大小

int Econ = 5;//橡皮大小

int toolFlag = 0;//toolFlag:工具标记

//toolFlag工具对应表：

//（0--画笔）；（1--橡皮）；（2--清除）；

//（3--直线）；（4--圆）；（5--矩形）；

Color c = new Color(0,0,0); //画笔颜色

BasicStroke size = new BasicStroke(con,BasicStrokeCAP_BUTT,BasicStrokeJOIN_BEVEL);//画笔粗细

Point cutflag = new Point(-1, -1, c, 6, con);//截断标志

Vector paintInfo = null;//点信息向量组

int n = 1;

FileInputStream picIn = null;

FileOutputStream picOut = null;

ObjectInputStream VIn = null;

ObjectOutputStream VOut = null;

// 工具面板--画笔，直线，圆，矩形，多边形,橡皮，清除/

Panel toolPanel;

Button eraser, drLine,drCircle,drRect;

Button clear ,pen;

Choice ColChoice,SizeChoice,EraserChoice;

Button colchooser;

Label 颜色,大小B,大小E;

//保存功能

Button openPic,savePic;

FileDialog openPicture,savePicture;

paintboard(String s)

{

super(s);

addMouseMotionListener(this);

addMouseListener(this);

paintInfo = new Vector();

/各工具按钮及选择项/

//颜色选择

ColChoice = new Choice();

ColChoiceadd("black");

ColChoiceadd("red");

ColChoiceadd("blue");

ColChoiceadd("green");

ColChoiceaddItemListener(this);

//画笔大小选择

SizeChoice = new Choice();

SizeChoiceadd("1");

SizeChoiceadd("3");

SizeChoiceadd("5");

SizeChoiceadd("7");

SizeChoiceadd("9");

SizeChoiceaddItemListener(this);

//橡皮大小选择

EraserChoice = new Choice();

EraserChoiceadd("5");

EraserChoiceadd("9");

EraserChoiceadd("13");

EraserChoiceadd("17");

EraserChoiceaddItemListener(this);

////////////////////////////////////////////////////

toolPanel = new Panel();

clear = new Button("清除");

eraser = new Button("橡皮");

pen = new Button("画笔");

drLine = new Button("画直线");

drCircle = new Button("画圆形");

drRect = new Button("画矩形");

openPic = new Button("打开图画");

savePic = new Button("保存图画");

colchooser = new Button("显示调色板");

//各组件事件监听

clearaddActionListener(this);

eraseraddActionListener(this);

penaddActionListener(this);

drLineaddActionListener(this);

drCircleaddActionListener(this);

drRectaddActionListener(this);

openPicaddActionListener(this);

savePicaddActionListener(this);

colchooseraddActionListener(this);

颜色 = new Label("画笔颜色",LabelCENTER);

大小B = new Label("画笔大小",LabelCENTER);

大小E = new Label("橡皮大小",LabelCENTER);

//面板添加组件

toolPaneladd(openPic);

toolPaneladd(savePic);

toolPaneladd(pen);

toolPaneladd(drLine);

toolPaneladd(drCircle);

toolPaneladd(drRect);

toolPaneladd(颜色); toolPaneladd(ColChoice);

toolPaneladd(大小B); toolPaneladd(SizeChoice);

toolPaneladd(colchooser);

toolPaneladd(eraser);

toolPaneladd(大小E); toolPaneladd(EraserChoice);

toolPaneladd(clear);

//工具面板到APPLET面板

add(toolPanel,BorderLayoutNORTH);

setBounds(60,60,900,600); setVisible(true);

validate();

//dialog for save and load

openPicture = new FileDialog(this,"打开图画",FileDialogLOAD);

openPicturesetVisible(false);

savePicture = new FileDialog(this,"保存图画",FileDialogSAVE);

savePicturesetVisible(false);

openPictureaddWindowListener(new WindowAdapter()

{

public void windowClosing(WindowEvent e)

{ openPicturesetVisible(false); }

});

savePictureaddWindowListener(new WindowAdapter()

{

public void windowClosing(WindowEvent e)

{ savePicturesetVisible(false); }

});

addWindowListener(new WindowAdapter()

{

public void windowClosing(WindowEvent e)

{ Systemexit(0);}

});

}

public void paint(Graphics g)

{

Graphics2D g2d = (Graphics2D)g;

Point p1,p2;

n = paintInfosize();

if(toolFlag==2)

gclearRect(0,0,getSize()width,getSize()height);//清除

for(int i=0; i<n ;i++){

p1 = (Point)paintInfoelementAt(i);

p2 = (Point)paintInfoelementAt(i+1);

size = new BasicStroke(p1boarder,BasicStrokeCAP_BUTT,BasicStrokeJOIN_BEVEL);

g2dsetColor(p1col);

g2dsetStroke(size);

if(p1tool==p2tool)

{

switch(p1tool)

{

case 0://画笔

Line2D line1 = new Line2DDouble(p1x, p1y, p2x, p2y);

g2ddraw(line1);

break;

case 1://橡皮

gclearRect(p1x, p1y, p1boarder, p1boarder);

break;

case 3://画直线

Line2D line2 = new Line2DDouble(p1x, p1y, p2x, p2y);

g2ddraw(line2);

break;

case 4://画圆

Ellipse2D ellipse = new Ellipse2DDouble(p1x, p1y, Mathabs(p2x-p1x) , Mathabs(p2y-p1y));

g2ddraw(ellipse);

break;

case 5://画矩形

Rectangle2D rect = new Rectangle2DDouble(p1x, p1y, Mathabs(p2x-p1x) , Mathabs(p2y-p1y));

g2ddraw(rect);

break;

case 6://截断，跳过

i=i+1;

break;

default :

}//end switch

}//end if

}//end for

}

public void itemStateChanged(ItemEvent e)

{

if(egetSource()==ColChoice)//预选颜色

{

String name = ColChoicegetSelectedItem();

if(name=="black")

{c = new Color(0,0,0); }

else if(name=="red")

{c = new Color(255,0,0);}

else if(name=="green")

{c = new Color(0,255,0);}

else if(name=="blue")

{c = new Color(0,0,255);}

}

else if(egetSource()==SizeChoice)//画笔大小

{

String selected = SizeChoicegetSelectedItem();

if(selected=="1")

{

con = 1;