VS2012下基於Glut OpenGL繪製點示例程序：

在VS2012下使用glut繪製一些列點的示例程序，繪製的是四個螺紋，效果如下圖所示，按PC的UP,DOWN,LEFT,RIGHT按鍵可以從不同的角度查看螺紋。繪製點的規則如下圖所示：

源代碼如下所示：

#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;
//顯示回調函數
void renderScreen(void){
	GLfloat x,y,z,angle;
	//把整個窗口清理爲當前清理顏色：黑色
	glClear(GL_COLOR_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);
	//開始繪點
	glBegin(GL_POINTS);
	z=-50.0f;
	//繪製四個螺紋
	for(angle=0.0f;angle<=((2.0f*GL_PI)*4.0f);angle+=0.05f){
		x=50.0f*sin(angle);
		y=50.0f*cos(angle);
		glVertex3f(x,y,z);
		z+=0.2f;
	}
	//結束繪點
	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);
}
//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();
}

void sPecialkeyFuc(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);
	glutCreateWindow("PointsDemo");
	//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(sPecialkeyFuc);
	//設置全局渲染參數
	setupRederingState();
	glutMainLoop();
	return 0;
}