多边形的Sutherland-Hodgman裁减算法用c++和opengl实现代码
时间: 2024-06-09 08:08:11 浏览: 20
以下是一个简单的用C++和OpenGL实现Sutherland-Hodgman裁剪算法的代码示例:
```c++
#include <iostream>
#include <vector>
#include <GL/glut.h>
using namespace std;
struct Point {
float x, y;
Point(float x = 0, float y = 0) : x(x), y(y) {}
};
vector<Point> clipPolygon(vector<Point> polygon, Point p1, Point p2) {
vector<Point> outputList;
for (int i = 0; i < polygon.size(); i++) {
Point P = polygon[i];
Point Q = polygon[(i+1)%polygon.size()];
float t1 = (p1.x - P.x) * (p2.y - P.y) - (p1.y - P.y) * (p2.x - P.x);
float t2 = (p1.x - Q.x) * (p2.y - Q.y) - (p1.y - Q.y) * (p2.x - Q.x);
if (t1 >= 0)
outputList.push_back(P);
if (t1 * t2 < 0) {
Point intersect;
intersect.x = (Q.x - P.x) * t1 / (t1 - t2) + P.x;
intersect.y = (Q.y - P.y) * t1 / (t1 - t2) + P.y;
outputList.push_back(intersect);
}
}
return outputList;
}
void display() {
glClearColor(1, 1, 1, 1);
glClear(GL_COLOR_BUFFER_BIT);
glColor3f(0, 0, 0);
glLineWidth(2);
// 原多边形
vector<Point> polygon;
polygon.push_back(Point(0.2, 0.2));
polygon.push_back(Point(0.5, 0.6));
polygon.push_back(Point(0.8, 0.2));
polygon.push_back(Point(0.6, 0.1));
polygon.push_back(Point(0.4, 0.1));
glBegin(GL_LINE_LOOP);
for (int i = 0; i < polygon.size(); i++)
glVertex2f(polygon[i].x, polygon[i].y);
glEnd();
// 裁剪线段
Point p1(0.3, 0.1);
Point p2(0.7, 0.7);
glBegin(GL_LINES);
glVertex2f(p1.x, p1.y);
glVertex2f(p2.x, p2.y);
glEnd();
// 裁剪后的多边形
vector<Point> clippedPolygon = polygon;
for (int i = 0; i < clippedPolygon.size(); i++)
clippedPolygon = clipPolygon(clippedPolygon, p1, p2);
glBegin(GL_LINE_LOOP);
for (int i = 0; i < clippedPolygon.size(); i++)
glVertex2f(clippedPolygon[i].x, clippedPolygon[i].y);
glEnd();
glFlush();
}
int main(int argc, char *argv[]) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(400, 400);
glutCreateWindow("Sutherland-Hodgman Clipping");
glutDisplayFunc(display);
glutMainLoop();
return 0;
}
```
该示例使用OpenGL绘制多边形和线段,并使用Sutherland-Hodgman裁剪算法将多边形剪切为指定的线段。该算法的实现是通过迭代每个边缘并计算与剪切线段的交点来完成的。计算交点后,将其添加到输出列表中以生成剪切后的多边形。
相关推荐
![application/x-zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![cpp](https://img-home.csdnimg.cn/images/20210720083646.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)