#include<stdio.h>
#include<graphics.h>
#include<math.h>
#include<conio.h>
void DDA(float x1, float y1, float x2, float y2)
//x1,y1起始点，x2,y2终止点
{int i, steps;int x0 = 400, y0 = 300;              //坐标轴原点float x, y, delta_x, delta_y, dx, dy;dx = x2 - x1;dy = y2 - y1;if (fabs(dx) >= fabs(dy))			//令跨度大的轴步数变化为1steps = fabs(dx);				elsesteps = fabs(dy);delta_x = float(1.0*dx / steps);         //让结果为浮点数delta_y = float(1.0*dy / steps);x = x1;y = y1;putpixel((x + x0), (y0 - y), RED);        //画第一个点for (i = 1; i <= steps; i++) {x = x + delta_x;y = y + delta_y;putpixel((x + x0), (y0 - int(y + 0.5)), RED);        //y+0.5四舍五入运算Sleep(50);                                          //两个点间隔50毫秒}
}
void main() 
{float x1, x2, y1, y2;int x0 = 400, y0 = 300;			printf("请输入两点的坐标:\n");scanf("%f %f %f %f",&x1,&y1,&x2,&y2);initgraph(800, 600);		     //初始化图形窗口大小setbkcolor(WHITE);               //设置背景色为白色cleardevice();setcolor(BLACK);                //设置坐标颜色为黑色line(0, y0, x0 * 2, y0);			//坐标轴Xline(x0, 0, x0, y0 * 2);			//坐标轴YDDA(x1, y1, x2, y2);                //DDA画线算法_getch();                           //等待一个任意输入结束closegraph();                       //关闭图形窗口