c++实现cohen-sutherland裁剪算法

Cohen-Sutherland裁剪算法是一种较为简单的线段裁剪算法，常用于计算机图形学中的线段裁剪。它的主要思想是通过一个矩形窗口对线段进行裁剪，将其裁剪成可见部分和不可见部分。

步骤如下：

1.对线段的端点进行编码。

2.对线段被矩形所包含或者相交的情况进行判断。

3.将可见部分进行输出。

4.如有必要，对不可见部分进行递归判断。

具体实现可以使用二进制码来表示区域，比如左边界为0001，右边界为0010，下边界为0100，上边界为1000，所以一个点在矩形左下的区域是0001 | 0100 = 0101。通过这种方式，可以快速判断线段是否在矩形范围内，从而进行裁剪。

相关问题

请给出c++实现cohen-sutherland裁剪算法的具体代码

以下是一个简单的C语言实现cohen-sutherland裁剪算法的代码：

#include<stdio.h>

int INSIDE = 0;
int LEFT = 1;
int RIGHT = 2;
int BOTTOM = 4;
int TOP = 8;
double x_max, y_max, x_min, y_min;

int getCode(double x, double y) {
    int code = INSIDE;
    if(x < x_min)
        code |= LEFT;
    else if(x > x_max)
        code |= RIGHT;
    if(y < y_min)
        code |= BOTTOM;
    else if(y > y_max)
        code |= TOP;

    return code;
}

void cohenSutherlandClip(double x1, double y1, double x2, double y2) {
    int code1 = getCode(x1, y1);
    int code2 = getCode(x2, y2);

    int accept = 0;

    while(1) {
        if((code1 == 0) && (code2 == 0)) { //Both points inside
            accept = 1;
            break;
        } else if (code1 & code2) { //Both points outside, and in same region
            break;
        } else {
            int code_out;
            double x, y;

            if(code1 != 0) {
                code_out = code1;
            } else {
                code_out = code2;
            }

            if (code_out & TOP) {           
                x = x1 + (x2 - x1) * (y_max - y1) / (y2 - y1);
                y = y_max;
            } else if(code_out & BOTTOM) {         
                x = x1 + (x2 - x1) * (y_min - y1) / (y2 - y1);
                y = y_min;
            } else if(code_out & RIGHT) {          
                y = y1 + (y2 - y1) * (x_max - x1) / (x2 - x1);
                x = x_max;
            } else if(code_out & LEFT) {           
                y = y1 + (y2 - y1) * (x_min - x1) / (x2 - x1);
                x = x_min;
            }

            if(code_out == code1) {
                x1 = x; y1 = y;
                code1 = getCode(x1, y1);
            } else {
                x2 = x; y2 = y;
                code2 = getCode(x2, y2);
            }
        }
    }

    if(accept) {
        printf("Line accepted from (%lf,%lf) to (%lf,%lf)\n", x1, y1, x2, y2);
    } else {
        printf("Line rejected\n");
    }
}

int main() {
    printf("Enter x_min: ");
    scanf("%lf", &x_min);
    printf("Enter y_min: ");
    scanf("%lf", &y_min);
    printf("Enter x_max: ");
    scanf("%lf", &x_max);
    printf("Enter y_max: ");
    scanf("%lf", &y_max);

    double x1, y1, x2, y2;
    printf("Enter x1: ");
    scanf("%lf", &x1);
    printf("Enter y1: ");
    scanf("%lf", &y1);
    printf("Enter x2: ");
    scanf("%lf", &x2);
    printf("Enter y2: ");
    scanf("%lf", &y2);

    cohenSutherlandClip(x1, y1, x2, y2);

    return 0;
}

这是一个控制台程序，在运行时会提示用户输入裁剪区域的坐标和待裁剪的线段的坐标，然后输出裁剪后的结果或拒绝裁剪的信息。

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。