1-2.c

小试验

#include<graphics.h>/*加入c图形库*/
#include<math.h>/*数学库*/
#include<conio.h>/*键盘控制*/
void MidpointLine(int x0,int y0,int x1,int y1,int value)/*从坐标(x0,y0)到(x1,y1)画颜色为value的直线*/
{
int dy,dx,incrE,incrNE,d,x,y;
dy=y0-y1;
dx=x1-x0;
d=2*dy+dx;
incrE=2*dy;
incrNE=2*(dy+dx);
x=x0;
y=y0;
putpixel(x,y,value);/*画点函数*/
while(x<x1)
{
	if(d<0)
	{	
	x++;
	y++;
	d+=incrNE;
	}
	else
	{
	x++;
	d+=incrE;
	}
	if(getch()==17)exit();/*读入键盘按键*/
	putpixel(x,y,value);
}
}
void main()
{
int i,driver,mode;
driver=DETECT;/*初始化显示模式参数*/
initgraph(&driver,&mode,"..\\bgi");/*初始化显示为默认驱动的640*480、16色模式*/
printf("Press any key to continue except 'Ctrl+Q' to quit.\n");
MidpointLine(100,100,500,400,15);/*设置画线起始点*/
closegraph();/*关闭图形模式*/
}