1、参考博客
https://blog.csdn.net/ZY_cat/article/details/78290047
注：参考博客内有原理介绍和算法的代码实现，但个人在运行时出现了bug，遂修改了代码。
2、代码实现

#include "pch.h"
#include <GL/glut.h>
#include<time.h>

#define left 1
#define right 2
#define bottom 4
#define top 8
#define number 5      //control the number of lines
class LineClass
{
public:
    GLfloat x1, y1, x2, y2;
    GLfloat x1_init, y1_init, x2_init, y2_init;
}lines[number];

/*the boundary of the rectangular area*/
GLfloat xleft = 30, xright = 70, ytop = 70, ybottom = 30;

/*to judge if the points of the line in the aimed area*/
GLint encode(GLfloat x, GLfloat y) {
    GLint code = 0;
    if (x < xleft)  code |= left;       //take or action
    if (x > xright)  code |= right;
    if (y > ytop) code |= top;
    if (y < ybottom)  code |= bottom;
    return code;
}

void pointChange() {
    /*temp location (x,y) and (x0,y0)*/
    GLfloat x, y, x0, y0;
    for (GLint i = 0; i < number; i++) {
        /*initial position of two terminal points*/
        /*to get different random number,or you can use random function to do this*/
        lines[i].x1 = 2 +i * 9;
        lines[i].x2 = 50+i * i * 3;
        lines[i].y1 = 100 - i * i * i ;
        lines[i].y2 = 19+i * i * 4;

        /*if k is 0 or 1 / k is 0*/
        if (lines[i].x1 == lines[i].x2)
            lines[i].x1++;
        if (lines[i].y1 == lines[i].y2)
            lines[i].y1++;

        lines[i].x1_init = lines[i].x1;
        lines[i].x2_init = lines[i].x2;
        lines[i].y1_init = lines[i].y1;
        lines[i].y2_init = lines[i].y2;

        /*the code of the two terminal points*/
        GLint code1, code2;
        code1 = encode(lines[i].x1, lines[i].y1);
        code2 = encode(lines[i].x2, lines[i].y2);
        /*temp code*/
        GLint code;
        /*gradient of line and its' value will not change*/

        /*if the line is not all in the area*/
        while (code1 != 0 || code2 != 0) {
            /*if the line is not in the area at all*/
            if (code1  & code2) {      //this part is that I changed
                lines[i].x1 = 0;
                lines[i].x2 = 0;
                lines[i].y1 = 0;
                lines[i].y2 = 0;
                break;
            }
            /*set code value of code1 and code 2 one by one*/
            if (code1 != 0) {
                code = code1;
            }
            else {
                code = code2;
            }
            y0 = lines[i].y1;
            x0 = lines[i].x1;
            /*to check if the line need to cut and cutting*/
            /*if the line is at left side of the rectangular area*/
            if (code & left) {
                x = xleft;
                /*using equation to caculate y*/
                y = y0 - (x0 - x) * (lines[i].y1 - lines[i].y2) / (lines[i].x1 - lines[i].x2);
            }
            /*checking right after updating data*/
            else if (code & right) {
                x = xright;
                y = y0 - (x0 - x) * (lines[i].y1 - lines[i].y2) / (lines[i].x1 - lines[i].x2);
            }
            /*checking top after updating data*/
            else if (code & bottom) {
                y = ybottom;
                x = x0 - (y0 - y) * (lines[i].x1 - lines[i].x2) / (lines[i].y1 - lines[i].y2);
            }
            /*checking top after updating data*/
            else if (code & top) {
                y = ytop;
                x = x0 - (y0 - y) * (lines[i].x1 - lines[i].x2) / (lines[i].y1 - lines[i].y2);
            }
            /*updating the data*/
            if (code == code1) {
                lines[i].x1 = x;
                lines[i].y1 = y;
                code1 = encode(lines[i].x1, lines[i].y1);
            }
            else {
                lines[i].x2 = x;
                lines[i].y2 = y;
                code2 = encode(lines[i].x2, lines[i].y2);
            }
        }
    }
}

/*initial the window*/
void init() {
    /*the color of window display is white*/
    glClearColor(1.0, 1.0, 1.0, 1.0);

    /*set the matrix projection matrix*/
    glMatrixMode(GL_PROJECTION);

    /*set relative cooedinate of the window*/
    gluOrtho2D(0.0, 100.0, 0.0, 100.0);

    pointChange();
}

void displayFcn() {
    /*draw a rectangular int the window*/
    /*clear the color of present frame*/
    glClear(GL_COLOR_BUFFER_BIT);
    /*set color of the boundary of rectangular to red*/
    glColor3f(1.0, 0.0, 0.0);
    /*set the bold of the boundary*/
    glPointSize(2);
    glBegin(GL_LINE_LOOP);
    glVertex2f(xleft, ybottom);
    glVertex2f(xright, ybottom);
    glVertex2f(xright, ytop);
    glVertex2f(xleft, ytop);
    glEnd();
    /*force execution of GL commands in finite time*/
    glFlush();

    for (GLint i = 0; i < number; i++) {
        /*draw original line*/
        glColor3f(1.0, 0.0, 0.0);
        glPointSize(2);
        glBegin(GL_LINES);
        glVertex2f(lines[i].x1_init, lines[i].y1_init);
        glVertex2f(lines[i].x2_init, lines[i].y2_init);
        glEnd();
        /*force execution of GL commands in finite time*/
        glFlush();

        /*draw the line after cutting*/
        glColor3f(0.0, 0.0, 0.0);
        glPointSize(2);
        glBegin(GL_LINES);
        glVertex2f(lines[i].x1, lines[i].y1);
        glVertex2f(lines[i].x2, lines[i].y2);
        glEnd();
        /*force execution of GL commands in finite time*/
        glFlush();
    }
}


int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
    glutInitWindowPosition(100, 100);
    glutInitWindowSize(400, 400);
    glutCreateWindow("Cohen-Sutherland");
    init();
    glutDisplayFunc(displayFcn);
    glutMainLoop();
    return 0;
}

3、实际效果

Cohen-Sutherland

4、注：此代码可能存在本人未发觉的bug，欢迎指正。