#include <windows.h>//#include <GLUT/glut.h>#include <GL/glut.h>#include <math.h>#include <iostream>using namespace std;#define GL_PI 3.1415fvoid RenderScene(){    GLfloat sizes[2];    GLfloat step;    GLfloat curSize;    glClear(GL_COLOR_BUFFER_BIT);    glGetFloatv(GL_POINT_SIZE_RANGE,sizes);    glGetFloatv(GL_POINT_SIZE_GRANULARITY,&step);    curSize = sizes[0];    GLfloat x,y,angle;    glBegin(GL_LINES);    for(angle = 0.0f;angle <= GL_PI;angle += 0.1f)    {        x = 50.0f*sin(angle);        y = 50.0f*cos(angle);        glVertex2f(x,y);        x = 50.0f*sin(angle+GL_PI);        y = 50.0f*cos(angle+GL_PI);        glVertex2f(x,y);    }    glEnd();    glFlush();}void ChangeSize(GLsizei w,GLsizei h){    if(h==0)        h = 1;    GLfloat aspectRatio = (GLfloat)w/(GLfloat)h;    glViewport(0,0,w,h);    glMatrixMode(GL_PROJECTION);    glLoadIdentity();    if(w<=h)        glOrtho(-100,100,-100/aspectRatio,100/aspectRatio,1.0,-1.0);    else        glOrtho(-100*aspectRatio,100*aspectRatio,-100,100,1.0,-1.0);    glMatrixMode(GL_MODELVIEW);    glLoadIdentity();}void SetupRC(){    glClearColor(0.0f,0.0f,0.0f,1.0f);    glColor3f(1.0f,0.0f,0.0f);}int main(int argc, char *argv[]){   glutInit(&argc,argv);   glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);   glutInitWindowSize(800,600);   glutCreateWindow("Simple");   glutDisplayFunc(RenderScene);   glutReshapeFunc(ChangeSize);   SetupRC();   glutMainLoop();   return 0;}