用c++编程实现二维cohen-sutherland裁剪算法

二维Cohen-Sutherland裁剪算法的C语言代码如下：

#include<stdio.h>
#include<graphics.h>

#define LEFT 1
#define RIGHT 2
#define BOTTOM 4
#define TOP 8
#define INSIDE 0
#define ROUND(a) ((int)(a + 0.5))

int xmin, ymin, xmax, ymax;

int computeCode(double x, double y)
{
    int code = INSIDE;
    if (x < xmin)
        code |= LEFT;
    else if (x > xmax)
        code |= RIGHT;
    if (y < ymin)
        code |= BOTTOM;
    else if (y > ymax)
        code |= TOP;
    return code;
}

void cohenSutherland(double x1, double y1, double x2, double y2)
{
    int outcode1 = computeCode(x1, y1);
    int outcode2 = computeCode(x2, y2);
    int accept = 0;
    while (1)
    {
        if (!(outcode1 | outcode2))
        {
            accept = 1;
            break;
        }
        else if (outcode1 & outcode2)
            break;
        else
        {
            double x, y;
            int outcode = outcode1 ? outcode1 : outcode2;
            if (outcode & TOP)    
            {
                x = x1 + (x2 - x1) * (ymax - y1) / (y2 - y1);
                y = ymax;
            }
            else if (outcode & BOTTOM)
            {
                x = x1 + (x2 - x1) * (ymin - y1) / (y2 - y1);
                y = ymin;
            }
            else if (outcode & RIGHT)
            {
                y = y1 + (y2 - y1) * (xmax - x1) / (x2 - x1);
                x = xmax;
            }
            else
            {
                y = y1 + (y2 - y1) * (xmin - x1) / (x2 - x1);
                x = xmin;
            }
            if (outcode == outcode1)
            {
                x1 = x;
                y1 = y;
                outcode1 = computeCode(x1, y1);
            }
            else
            {
                x2 = x;
                y2 = y;
                outcode2 = computeCode(x2, y2);
            }
        }
    }
    if (accept)
        line(ROUND(x1), ROUND(y1), ROUND(x2), ROUND(y2));
}

int main()
{
    int gd = DETECT, gm;
    initgraph(&gd, &gm, "");
    printf("Enter window coordinates (xmin ymin xmax ymax): ");
    scanf("%d%d%d%d", &xmin, &ymin, &xmax, &ymax);
    rectangle(xmin, ymin, xmax, ymax);
    int n;
    printf("Enter the number of lines: ");
    scanf("%d", &n);
    printf("Enter line coordinates (x1 y1 x2 y2):\n");
    for (int i = 0; i < n; i++)
    {
        double x1, y1, x2, y2;
        scanf("%lf%lf%lf%lf", &x1, &y1, &x2, &y2);
        cohenSutherland(x1, y1, x2, y2);
    }
    getch();
    closegraph();
    return 0;
}

该代码实现的是以交互的方式输入最大可视区域大小和线段数量，并可以通过键盘按下任意键退出程序。