#include<math.h>
#include<GL/glut.h>
#include<stdio.h>
GLsizei winWidth=500;
GLsizei winHeight=500;
void Initial(void)
{
glClearColor(1.0f,1.0f,1.0f,1.0f);
glMatrixMode(GL_PROJECTION);
gluOrtho2D(0.0,200.0,0.0,150.0);
}
void DDALine(int x0,int y0,int x1,int y1)
{
glColor3f(1.0,0.0,0.0);
int dx,dy,epsl,k;
float x,y,xIncre,yIncre;
dx=x1-x0; dy=y1-y0;
x=x0; y=y0;
if(abs(dx)>abs(dy)) epsl=abs(dx);
else epsl=abs(dy);
xIncre=(float)dx/(float)epsl;
yIncre=(float)dy/(float)epsl;
for(k=0;k<=epsl;k++)
{
glPointSize(3);
glBegin(GL_POINTS);
glVertex2i(int(x+0.5),(int)(y+0.5));
glEnd();
x+=xIncre;
y+=yIncre;
}
}
void Display(void)
{
glClear(GL_COLOR_BUFFER_BIT);
DDALine(100,100,200,180);
glFlush();
}
