标签：while init poi sam 交换 算法 graph 交换值 pixel
#include<stdio.h>
#include<stdlib.h>
#include"graphics.h"
//函数声明
void MidBrehansem(int x0, int y0, int x1, int y1); //中点MidBrehansem算法
void swap(int &x, int &y); //利用引用传递交换值
int main()
{
int gdriver = DETECT, gmode;
int x0, y0, x1, y1;
printf("Please input start point：\n");
scanf("%d%d", &x0, &y0);
printf("Please input end point：\n");
scanf("%d%d", &x1, &y1);
initgraph(&gdriver, &gmode, "");
MidBrehansem(x0, y0, x1, y1);
system("pause");
closegraph();
return 0;
}
//中点MidBrehansem算法
void MidBrehansem(int x0, int y0, int x1, int y1)
{
int dx, dy,i,di;
double k;
if (x0 > x1)
{
swap(x0, x1);
swap(y0, y1);
}
int x = x0, y = y0; //定义到前面会从x1，y1开始画线
dx = x1 - x0;
dy = y1 - y0;
k = 1.0*dy / dx;
i = (abs(dy)>abs(dx)) ? abs(dy): abs(dx);
if (k > 1)
{
di = 2 * dx + dy;
while (i--)
{
putpixel(x, y, RED);
if (di >= 0)
{
di += 2 * (dx - dy);
x++;
}
else
di += 2 * dx;
y++;
}
}
else if (k >= 0 && k < 1)
{
di = dx - 2 * dy;
while (i--)
{
putpixel(x, y, YELLOW);
if (di < 0)
{
di += 2 * (dx - dy);
y++;
}
else
di += (-2)*dy;
x++;
}
}
else if (k >= -1 && k < 0)
{
di = -dx - 2 * dy;
while (i--)
{
putpixel(x, y, YELLOW);
if (di >= 0)
{
di += (-2)*(dx + dy);
y--;
}
else
di += (-2)*dy;
x++;
}
}
else
{
di = -2 * (dx + dy);
while (i--)
{
putpixel(x, y, WHITE);
if (di < 0)
{
di += (-2)*(dx + dy);
x++;
}
else
di += (-2)*dx;
y--;
}
}
}
//利用引用传递交换值
void swap(int &x, int &y)
{
int t;
t = x;
x = y;
y = t;
}
标签：while init poi sam 交换 算法 graph 交换值 pixel
原文地址：http://www.cnblogs.com/cdp1591652208/p/6823058.html
