| #include<iostream>
#include<graphics.h> // 这样引用 EasyX 图形库
#include<conio.h>
#include<time.h>
#include<math.h>
#include<stdlib.h>
using namespace std;
//Bresenham画线
void Bresenham_line(int x0,int y0,int x1,int y1)
{
int x,y,dx,dy;
float k,e;
dx=x1-x0;
dy=y1-y0;
k=dy/dx;//这里是完成k值的初始化
e=-0.5;
x=x0;
y=y0;
//这里的i每次都是加一个格字，直到终点，y这是选择性的加一或者不加
for(int i=0;i<=dx;i++)
{
//画点的函数
putpixel(x,y,255);
x=x+1;
e=e+k;
if(e>=0)
{
y=y+1;
e=e-1;//如果e大于零了就要马上减一
}
}
} //中点画线
void MidpointLine(int x0,int y0,int x1,int y1)
{
int a,b,delta1,delta2,d,x,y;
a=y0-y1;
b=x1-x0;
d=2*a+b;
//这里的2是为了避免小数的计算
delta1=2*a;
delta2=2*(a+b);
x=x0;
y=y0;
putpixel(x,y,255);
while(x<x1){
if(d<0){//这样的话就会选取上面一个点
x++;y++;d+=delta2;
}else{//否者就选取下面的一个点
x++;d+=delta1;
}
putpixel(x,y,255);
}
} //中点画线 void MidpointLine2(int x1,int y1,int x2,int y2,COLORREF color) //中点画线法
{
int x = x1, y = y1; //初始化x,y
int a = y1 - y2, b = x2 - x1; //a,b分别为x和y的增量
//考虑四种情况，分别计算增量
int deltx = (b >= 0 ? 1 : (b = -b, -1));
int delty = (a <= 0 ? 1 : (a = -a, -1)); for(int i=0;i<=400;i++)
{putpixel(i, 200, color);putpixel(200, i, color);}
putpixel(x+200, y+200, color); int d, delt1, delt2;
if (-a <= b) // 斜率绝对值 <= 1
{
d = 2 * a + b;
delt1 = 2 * a;
delt2 = 2 * (a + b);
while(x != x2)
{
if (d < 0)
y += delty, d += delt2;
else
d += delt1;
x += deltx;
putpixel(x+200, y+200, color);
}
}
else // 斜率绝对值 > 1
{
d = 2 * b + a;
delt1 = 2 * b;
delt2 = 2 * (a + b);
while(y != y2)
{
if(d < 0)
d += delt1;
else
x += deltx, d += delt2;
y += delty;
putpixel(x+200, y+200, color);
}
}
} //中点画圆
void MidpointCircle(int x0,int y0,int r,int color) {
int x=0,y=r;
float d=5.0/4-r;
while(x<=y){
putpixel(x0+x,y0+y,color);
putpixel(x0+x,y0-y,color);
putpixel(x0-x,y0+y,color);
putpixel(x0-x,y0-y,color);
putpixel(x0+y,y0+x,color);
putpixel(x0+y,y0-x,color);
putpixel(x0-y,y0+x,color);
putpixel(x0-y,y0-x,color);
if(d<0)
d+=x*2.0+3;
else{
d+=2.0*(x-y)+5;y--;
}
x++;
}
} //Bresenhem画圆 void BresenhemCircle(int centerx, int centery, int radius, int color)
{
int x =0;
int y = radius;
int delta = 2*(1-radius);
int direction;
while (y >= 0) {
putpixel(centerx+x, centery+y, color);
putpixel(centerx-x, centery+y, color);
putpixel(centerx-x, centery-y, color);
putpixel(centerx+x, centery-y, color);
if (delta < 0) {
if ((2*(delta+y)-1) < 0) {
direction = 1;
}
else {
direction = 2;
}
}
else if(delta > 0) {
if ((2*(delta-x)-1) <= 0) {
direction = 2;
}
else {
direction = 3;
}
}
else {
direction=2;
}
switch(direction) {
case 1:
x++;
delta += (2*x+1);
break;
case 2:
x++;
y--;
delta += 2*(x-y+1);
break;
case 3:
y--;
delta += (-2*y+1);
break;
}
}
}
void main()
{
int x0,y0,x1,y1;
initgraph(640, 480);
Bresenham_line(10,10,56,56);
MidpointLine2(0,100,369,0,255);
MidpointCircle(100,100,50,255);
BresenhemCircle(100,100,100,255); getch(); // 按任意键继续
closegraph(); // 关闭图形界面
} 多的也不说了，源码直接可以使用，而且还是带有坐标轴的 
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