#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(){    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);    GLboolean bEdgeflag;    glBegin(GL_TRIANGLES);        glEdgeFlag(bEdgeflag);        glVertex2f(-20.0f,0.0f);        glEdgeFlag(true);        glVertex2f(20.0f,0.0f);        glVertex2f(0.0f,40.0f);        glVertex2f(-20.0f,0.0f);        glVertex2f(-60.0f,-20.0f);        glEdgeFlag(bEdgeflag);        glVertex2f(-20.0f,-40.0f);        glEdgeFlag(true);        glVertex2f(-20.0f,-40.0f);        glVertex2f(0.0f,-80.0f);        glEdgeFlag(bEdgeflag);        glVertex2f(20.0f,-40.0f);        glEdgeFlag(true);        glVertex2f(20.0f,-40.0f);        glVertex2f(60.0f,-20.0f);        glEdgeFlag(bEdgeflag);        glVertex2f(20.0f,0.0f);        glEdgeFlag(true);        glEdgeFlag(bEdgeflag);        glVertex2f(-20.0f,0.0f);        glVertex2f(-20.0f,-40.0f);        glVertex2f(20.0f,0.0f);        glVertex2f(-20.0f,-40.0f);        glVertex2f(20.0f,-40.0f);        glVertex2f(20.0f,0.0f);        glEdgeFlag(true);    glEnd();    glutSwapBuffers();}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,100.0,-100.0);    else        glOrtho(-100*aspectRatio,100*aspectRatio,-100,100,100.0,-100.0);    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_DOUBLE|GLUT_RGB|GLUT_DEPTH);   glutInitWindowSize(800,600);   glutCreateWindow("Simple");   glutDisplayFunc(RenderScene);   glutReshapeFunc(ChangeSize);   SetupRC();   glutMainLoop();   return 0;}