OpenGL鼠標點擊事件

#include <windows.h>    // Windows的頭文件

#include <gl\gl.h>        // OpenGL32庫的頭文件
#include <gl\glu.h>        // GLu32庫的頭文件
#include <gl\glaux.h>    // GLaux庫的頭文件
#include <gl\glut.h>    // Glut庫頭文件

#pragma comment( lib, "opengl32.lib")    // OpenGL32連接庫
#pragma comment( lib, "glu32.lib")        // GLu32連接庫
#pragma comment( lib, "glaux.lib")        // GLaux連接庫
#pragma comment( lib, "glut.lib")        // Glut鏈接庫

int screenWidth=640;
int screenHeight=480;

void myInit()
{
    glClearColor(1.0,1.0,1.0,0.0);            //設置背景顏色為亮白
    glColor3f(0.0f,0.0f,0.0f);                //設置繪圖顏色為黑色
    glPointSize(4.0);                        //設置點的大小為4*4像素
    glMatrixMode(GL_PROJECTION);            //設置合適的矩陣
    glLoadIdentity();                        
    gluOrtho2D(0.0,screenWidth,0.0,screenHeight);

}

void drawDot(int x,int y)
{
     glBegin(GL_POINTS);
        glVertex2i(x,y);                    //畫一些點
    glEnd();

}

void myMouse(int button,int state,int x,int y)
{
    if(state==GLUT_DOWN)
    {
        if(button==GLUT_LEFT_BUTTON)
        {
            drawDot(x,screenHeight-y);
            glFlush();
        }
        else if(button==GLUT_RIGHT_BUTTON)
        {
            glClearColor(1.0f,0.0f,0.0f,0.0f);
            glClear(GL_COLOR_BUFFER_BIT);
            glFlush();
        
        }    
    
    }
    return;
}


void myDisplay()
{
    glClear(GL_COLOR_BUFFER_BIT);            //清屏
    glBegin(GL_POINTS);
        glVertex2i(100,50);                    //畫一些點
        glVertex2i(100,130);
        glVertex2i(150,130);
        glVertex2i(320,240);
    glEnd();
    glFlush();                                //送所有輸出到顯示設備
}

void main(int argc, char **argv)
{
    glutInit(&argc,argv);                        //初始化工具包    
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);//設置顯示模式
    glutInitWindowSize(640,480);                //設置窗口大小
    glutInitWindowPosition(100,150);            //設置窗口在屏幕上的位置
    glutCreateWindow("my first attempt");        //打開屏幕窗口

    //注冊回調函數
    glutDisplayFunc(myDisplay);
    glutMouseFunc(myMouse);

    myInit();
    glutMainLoop();                                //進入循環
}