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opengl绘制花环(点的个数可以手动输入) 源代码

花匠小妙招
2024-11-16 06:12

图片是程序对应的图片，多边形的点数可以输入的，合法输入：大于三的正整数，但是当点数大于45时，会出现缺口，不知道是什么原因，如果您知道是什么原因，请留言。本人感激不尽（予人玫瑰，手有余香）*/

#include <Windows.h>
#include<gl/glut.h>
#include <math.h>
#include <vector>
#include <iostream>

using namespace std;

const GLint screenWidth = 620;
const GLint screenHeight = 620;
const GLint xPosition = 100;
const GLint yPosition = 100;
const GLdouble PI = 3.1415926;

static GLint numPoint = 0;
static GLint size = 300;

struct GLPoint{
GLdouble x ,y;
};

//花环
/************************************************************************/
/* 三角形：180°，矩形：360°，五边形：540°，六边形：720°，七边形：900°
1*180， 2*180， 3*180 4*180， 5*180

（ n -2 ) * 180 n>2,n∈正整数

相邻两点分别与中心连线，夹角<AOB = 360 / numPoint;
三角形 180，四边形 90 ..... */
/************************************************************************/

void myDisplay(void);
void myInit(void);
void setWindow(GLdouble left, GLdouble right, GLdouble botton, GLdouble top);
void setViewport(GLint left, GLint right, GLint botton, GLint top);

int main(int argc, char ** argv){
   glutInit(&argc,argv);
   cout<<"多边形顶点数：";
   cin>>numPoint;
   glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
   glutInitWindowSize(screenWidth,screenHeight);
   glutInitWindowPosition(xPosition,yPosition);
   glutCreateWindow("Rosette");

   glutDisplayFunc(myDisplay);
   myInit();
   setWindow(-310,310,-310,310);
   setViewport(0.0,(GLdouble)screenWidth,0.0,(GLdouble)screenHeight);
   glutMainLoop();

return 0;
}

void setWindow(GLdouble left, GLdouble right, GLdouble botton, GLdouble top){
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   gluOrtho2D( left, right, botton, top);
}

void setViewport(GLint left, GLint right, GLint botton, GLint top){
glViewport(left,botton,right-left,top-botton);

}

void myDisplay(void){

      glClear(GL_COLOR_BUFFER_BIT);
   if (numPoint<3)
   {
       return;
   }
   vector<GLPoint> pt;
   //GLPoint topPoint = {0,300};
   cout<<"pt.size() = "<<pt.size()<<endl;
   GLdouble angle =(GLdouble) PI*(360 / numPoint)/180.0;
   for (int i = 0; i< numPoint; i++)
   {
       GLPoint *pp = new GLPoint();
       /*pp->x = (GLdouble)topPoint.x*sin(angle*i);
       pp->y = (GLdouble)topPoint.y*cos(angle*i);*/
       pp->x = (GLdouble)size*sin(angle*i) /* * A + C*/;
       pp->y = (GLdouble)size*cos(angle*i) /** B + D*/;
       cout<<"pt->x = "<<pp->x<<" pt->y = "<<pp->y<<endl;
       pt.push_back(*pp);
   }
   cout<<"pt.size() = "<<pt.size()<<endl;

   多边形
   //glBegin(GL_LINE_LOOP);
   //   for (int j = 0; j< numPoint; j++)
   //   {
   //       glVertex2d(pt[j].x,pt[j].y);
   //   }
   //glEnd();
   //连线
   glBegin(GL_LINES);
   for( int m = 0; m <numPoint; m++ ){
       for ( int n = m+1 ; n < numPoint; n++)
       {
           glVertex2d(pt[m].x,pt[m].y);
           glVertex2d(pt[n].x,pt[n].y);
       }
   }
   glEnd();
       glFlush();
}