Cohen-Sutherland 剪裁算法源程序

#include<windows.h>
#include <gl\glu.h>
#include <gl\glut.h>
#include<iostream.h>
#include <gl\glaux.h>
///////////////////////////定义剪裁窗口
#define xmin -100
#define xmax 100
#define ymin -100
#define ymax 100
////////////////////////////


//////////////////////////定义全局变量
int flag;
double a1,a2,a3,a4 ; 
/////////////////////////


typedef unsigned int outcode;
enum{TOP=1,BOTTOM=2,RIGHT=4,LEFT=8};




/////////////////////////初始化
void init (void)
{
    glClearColor (1.0, 1.0, 1.0, 0.0);  // Set display-window color to white.

    glMatrixMode (GL_PROJECTION);       // Set projection parameters.
gluOrtho2D (-200, 200.0, -200, 200.0);

}
////////////////////////



/////////////////////////初始状态的图形
void Resetcondition(void)
{
glColor3f (0.0, 0.0, 1.0); 
glBegin(GL_LINES);
glVertex2d(120,140);
glVertex2d(120,70);
glVertex2d(75,130);
glVertex2d(75,65);
glVertex2d(-30,180);
glVertex2d(-90,50);
glVertex2d(-45,-30);
glVertex2d(58,10);
glVertex2d(150,-120);
glVertex2d(-120,42);
glEnd();

glColor3f (1.0, 0.0, 0.0); 
glBegin(GL_LINES);///////////画剪裁窗口
glVertex2d(xmin,ymin);
glVertex2d(xmax,ymin);
glVertex2d(xmax,ymin);