用OpenGL绘制图形

用OpenGL绘制图形

结果

clip_image002

代码
/*
* File: main.c
* Author: leo
*
* Drawing a simple 3D rectangle program with GLUT
* OpenGL ~~
*/
 
#include <stdio.h>
 
#include <stdlib.h>
 
#include <GL/gl.h>
 
#include <GL/glu.h>
 
#include <GL/glut.h>
 
//called to draw scene
 
void RenderScene(void)
 
{
 
//clear the window with current clearing color
 
glClear(GL_COLOR_BUFFER_BIT);
 
//set current drawing color to read
 
glColor3f(1.0f,0.0f,0.0f); //设置以后绘制操作所用的颜色
 
//draw a filled rectangle with current color
 
glRectf(100.f,150.0f,150.0f,100.0f); //绘制一个填充的矩形
 
//flush drawing commands
 
glFlush();
 
}
 
//set up the rendering state
 
void SetupRC(void)
 
{
 
glClearColor(0.0f,0.0f,1.0f,1.0f);
 
}
 
//called by GLUT library when the window has changed size
 
void ChangeSize(GLsizei w, GLsizei h)
 
{
 
//prevent a divide by zero
 
if(h == 0)
 
h = 1;
 
//set viewport to window dimensions
 
glViewport(0,0,w,h);
 
//reset coordinate system
 
glMatrixMode(GL_PROJECTION);
 
glLoadIdentity();//在每次进行任何矩阵处理之前都“复位”坐标系
 
//establish clipping volumn(left,right,bottom,top,near,far)
 
if(w <= h)
 
glOrtho(0.0f,250.0f,0.0f,250.0f*h/w,1.0,-1.0);
 
else
 
glOrtho(0.0f,250.0f*w/h,0.0f,250.0f,1.0,-1.0);
 
glMatrixMode(GL_MODELVIEW);
 
glLoadIdentity();
 
}
 
int main(int argc, char** argv) {
 
glutInit(&argc,argv);
 
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
 
glutCreateWindow("Plot Rect. using GLUT");
 
glutDisplayFunc(RenderScene);
 
glutReshapeFunc(ChangeSize);//窗口大小发生变化,就重新设置坐标系
 
SetupRC();
 
glutMainLoop();
 
return (EXIT_SUCCESS);
 
}
posted @ 2011-08-23 10:32  郭—大—侠  阅读(320)  评论(0编辑  收藏  举报