opengl 学习第一日

#include "stdafx.h"
#include <windows.h>
#include <GL/glu.h>
#include <GL/gl.h>
#include <GL/glut.h>
#include <GL/glaux.h> 
#include <gl\glut.h>
#include <string> 
using namespace std;
//http://space.itpub.net/17267437/viewspace-545635
//http://www.cnblogs.com/CodeBlove/articles/1669945.html

/////////////////////////////////////init

float x1 = 100;
float y1 = 150;
int size = 50;

float setp = 1; 
float ww,wh;

void SetupRC()
{
    glClearColor(0.0f,0.0f,1.0f,1.0f);
}

void RenderSence()
{
    glClear(GL_COLOR_BUFFER_BIT);
        glColor3f(1.5,0.5,0.5);
        glRectf(x1,y1,x1+size,y1+size);
    glutSwapBuffers();
    //glFlush();
}
/*
修剪视图两个重要方法
glViewport
glOrtho
*/
void ChangeSize(int w , GLsizei h)
{
    if(h==0)
    {
        h=1;
    }
    glViewport(0,0,w,h);        //窗口可视范围...
    glMatrixMode(GL_PROJECTION); //投射模式
    glLoadIdentity();            //观察。。。

    //char to int
    char t[20];
    itoa(w,t,10);
    //MessageBox(NULL,t,NULL,NULL);

    itoa(h,t,10);
    //MessageBox(NULL,t,NULL,NULL);

    /*
     下面这句很重要     //剪载视图
    */
    if(w<=h)    
        glOrtho(0,250,0,250,1,-1);
    else
        glOrtho(0,250,0,250,1,-1);
    // left,right,buttom,top,near,far
    /*
     left,right x 轴最少最大值
     然后到，y,z
    */
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
}



void eventKeys(unsigned char key,int x,int y)
{

    switch(key)
    {
        case 'a':
            MessageBox(NULL,"a",NULL,NULL);
            break;
        case 'b':
                MessageBox(NULL,"b",NULL,NULL);
            break;
        default:
            //char to string 
            string s=""; 
            s.insert(0,key);
            MessageBox(NULL,s.c_str(),NULL,NULL);
            break;
    }
}
void eventMouses(int e , int type,int x, inty)
{

switch (e)
{
case GLUT_LEFT_BUTTON:
if(type==GLUT_DOWN)
{
　　MessageBox(NULL,"MOUSE DOWN",NULL,NULL);
}
　　break;
}

}
void MyTimer(int v)
{
    x1+=setp;
    y1+=setp;
    glutPostRedisplay(); //刷新 glutDisplayFunc
    glutTimerFunc(33,MyTimer,1);
}
int main(int argc, char* argv[])
{
    //GLUT_SINGLE
    //GLUT_DOUBLE 双缓冲技术
    glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);
    
    glutCreateWindow("Simple");        //窗口名为

    glutDisplayFunc(RenderSence);    //绘制场景
    glutReshapeFunc(ChangeSize);    //监听窗口更改 size 事件
    glutTimerFunc(33,MyTimer,1);    //监听计时器

    glutKeyboardFunc(eventKeys);    //监听 keyboard 事件
    glutMouseFunc(eventMouses);        //监听 mouse 事件
    //glutWireCube(50);                //画一个 cube
     
    SetupRC();
    glutMainLoop();
    return 0;
}