VS2012下基於Glut OpenGL繪製椎體示例程序：

這一節在OpneGL繪製椎體，並在單擊鼠標右鍵彈出的菜單裏面可以選擇打開或關閉：GL_DEPTH_TEST（深度測試）；GL_CULL_FACE（曲面是背面時是否顯示）功能；曲面是背面時是採用單色填充還是描邊。

顯示效果如下所示：

單擊鼠標右鍵彈出菜單效果如下所示：

源代碼：

// GlutConeDemo.cpp : 定義控制檯應用程序的入口點。
//
#include "stdafx.h"
#include <gl/glut.h>
#include <math.h>

//圓周率宏
#define GL_PI 3.1415f
//獲取屏幕的寬度
GLint SCREEN_WIDTH=0;
GLint SCREEN_HEIGHT=0;
//設置程序的窗口大小
GLint windowWidth=400;
GLint windowHeight=300;
//繞x軸旋轉角度
GLfloat xRotAngle=0.0f;
//繞y軸旋轉角度
GLfloat yRotAngle=0.0f;
//是否打開不顯示背面功能
GLint cullFace=0;
//是否打開深度測試功能
GLint depthTest=0;
//背面是採用線條描外框還是使用單色填充　
GLint outLine=0;
//菜單回調函數
void processMenu(int value){
	switch(value){
		case 1:
			depthTest=!depthTest;
			break;
		case 2:
			cullFace=!cullFace;
		case 3:
			outLine=!outLine;
			break;
			break;
		default:
			break;
	}
	//重新繪製
	glutPostRedisplay();
}


//顯示回調函數
void renderScreen(void){
    GLfloat x,y,z,angle;
	GLint i=0;
    //把整個窗口清理爲當前清理顏色：黑色,清理深度緩衝區
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    //將當前Matrix狀態入棧
    glPushMatrix();
    //座標系繞x軸旋轉xRotAngle
    glRotatef(xRotAngle,1.0f,0.0f,0.0f);
    //座標系繞y軸旋轉yRotAngle
    glRotatef(yRotAngle,0.0f,1.0f,0.0f);
	if(depthTest)
		glEnable(GL_DEPTH_TEST);//打開深度測試功能
	else
		glDisable(GL_DEPTH_TEST);//關閉深度測試功能
	if(cullFace)
		glEnable(GL_CULL_FACE);//打開不顯示背面功能
	else
		glDisable(GL_CULL_FACE);//關閉不顯示背面功能
	if(outLine)
		glPolygonMode(GL_BACK,GL_LINE);//多邊形背部使用線條描框
	else
		glPolygonMode(GL_BACK,GL_FILL);//多邊形背部使用單色填充
	//進行平滑處理　
	glEnable(GL_POINT_SMOOTH);
	glHint(GL_POINT_SMOOTH,GL_NICEST);
	glEnable(GL_LINE_SMOOTH);
	glHint(GL_LINE_SMOOTH,GL_NICEST);
	//使用白色繪製座標系
	glColor3f(1.0f,1.0f,1.0f);
	//繪製座標系
	glBegin(GL_LINES);
		glVertex3f(-80.0f,0.0f,0.0f);
		glVertex3f(80.0f,0.0f,0.0f);
		glVertex3f(0.0f,-80.0f,0.0f);
		glVertex3f(0.0f,80.0f,0.0f);
		glVertex3f(0.0f,0.0f,-80.0f);
		glVertex3f(0.0f,0.0f,80.0f);
	glEnd();

	glPushMatrix();
	glTranslatef(80.0f,0.0f,0.0f);
	glRotatef(90.0f,0.0f,1.0f,0.0f);
	glutWireCone(3,6,10,10);
	glPopMatrix();

	glPushMatrix();
	glTranslatef(0.0f,80.0f,0.0f);
	glRotatef(-90.0f,1.0f,0.0f,0.0f);
	glutWireCone(3,6,10,10);
	glPopMatrix();

	glPushMatrix();
	glTranslatef(0.0f,0.0f,80.0f);
	glRotatef(90.0f,0.0f,0.0f,1.0f);
	glutWireCone(3,6,10,10);
	glPopMatrix();


	glBegin(GL_TRIANGLE_FAN);
	glVertex3f(0.0f,0.0f,75.0f);
	for(angle=0.0f,i=0;i<=6;angle+=(GL_PI/3.0f),i++)
	{
		x=50*cos(angle);
		y=50*sin(angle);
		if(i%2==0)
			glColor3f(1.0f,0.0f,0.0f);
		else
			glColor3f(0.0f,1.0f,0.0f);
		glVertex3f(x,y,0.0f);
	}
	glEnd();
	

	glBegin(GL_TRIANGLE_FAN);
	glVertex3f(0.0f,0.0f,0.0f);
	for(angle=0.0f,i=0;i<=6;angle+=(GL_PI/3.0f),i++)
	{
		x=50*cos(angle);
		y=50*sin(angle);
		if(i%2==0)
			glColor3f(0.0f,1.0f,0.0f);
		else
			glColor3f(1.0f,0.0f,0.0f);
		glVertex3f(x,y,0.0f);
	}
	glEnd();

	
    //恢復壓入棧的Matrix
    glPopMatrix();
    //交換兩個緩衝區的指針
    glutSwapBuffers();
}
//設置Redering State 
void setupRederingState(void){
    //設置清理顏色爲黑色
    glClearColor(0.0f,0.0,0.0,1.0f);
    //設置繪畫顏色爲綠色
    glColor3f(0.0f,1.0f,0.0f);
	//改變正反面
	//glFrontFace(GL_CW);
	//單色填充模式
	glShadeModel(GL_FLAT);
}
//窗口大小變化回調函數
void changSize(GLint w,GLint h){
    //橫寬比率
    GLfloat ratio;
    //設置座標系爲x(-100.0f,100.0f)、y(-100.0f,100.0f)、z(-100.0f,100.0f)
    GLfloat coordinatesize=100.0f;
    //窗口寬高爲零直接返回
    if((w==0)||(h==0))
        return;
    //設置視口和窗口大小一致
    glViewport(0,0,w,h);
    //對投影矩陣應用隨後的矩陣操作
    glMatrixMode(GL_PROJECTION);
    //重置當前指定的矩陣爲單位矩陣　
    glLoadIdentity();
    ratio=(GLfloat)w/(GLfloat)h;
    //正交投影
    if(w<h)
        glOrtho(-coordinatesize,coordinatesize,-coordinatesize/ratio,coordinatesize/ratio,-coordinatesize,coordinatesize);
    else
        glOrtho(-coordinatesize*ratio,coordinatesize*ratio,-coordinatesize,coordinatesize,-coordinatesize,coordinatesize);
    //對模型視圖矩陣堆棧應用隨後的矩陣操作
    glMatrixMode(GL_MODELVIEW);
    //重置當前指定的矩陣爲單位矩陣　
    glLoadIdentity();
}

//按鍵輸入處理回調函數
void specialKey(int key,int x,int y){

    if(key==GLUT_KEY_UP){
        xRotAngle-=5.0f;
    }
    else if(key==GLUT_KEY_DOWN){
        xRotAngle+=5.0f;
    }
    else if(key==GLUT_KEY_LEFT){
        yRotAngle-=5.0f;
    }
    else if(key==GLUT_KEY_RIGHT){
        yRotAngle+=5.0f;
    }
    //重新繪製
    glutPostRedisplay();
}

int main(int argc, char* argv[])
{
    //初始化glut 
    glutInit(&argc,argv);
    //使用雙緩衝區模式
    glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGBA|GLUT_DEPTH);
    //獲取系統的寬像素
    SCREEN_WIDTH=glutGet(GLUT_SCREEN_WIDTH);
    //獲取系統的高像素
    SCREEN_HEIGHT=glutGet(GLUT_SCREEN_HEIGHT);
	//創建窗口，窗口名字爲OpenGL BackAndFront Demo
    glutCreateWindow("OpenGL Cone Demo");
	//菜單回調函數
	glutCreateMenu(processMenu);
	//添加菜單
	glutAddMenuEntry("Toggle depth test",1);
	glutAddMenuEntry("Toggle cull face",2);
	glutAddMenuEntry("Toggle back outline",3);
	//將菜單榜定到鼠標右鍵上
	glutAttachMenu(GLUT_RIGHT_BUTTON);
    //設置窗口大小
    glutReshapeWindow(windowWidth,windowHeight);
    //窗口居中顯示
    glutPositionWindow((SCREEN_WIDTH-windowWidth)/2,(SCREEN_HEIGHT-windowHeight)/2);
    //窗口大小變化時的處理函數
    glutReshapeFunc(changSize);
    //設置顯示回調函數 
    glutDisplayFunc(renderScreen);
    //設置按鍵輸入處理回調函數
    glutSpecialFunc(specialKey);
    //設置全局渲染參數
    setupRederingState();
    glutMainLoop();
    return 0;
}