给出一个OpenGL扩展应用的实例

// opngl_kuozhan.cpp : Defines the entry point for the console application.
//其中，画红线的部分是要注意的。

#include "stdafx.h"
#include <iostream>

#include <windows.h>

#include <GL/glew.h>//顺序要正确。

#include <GL/glut.h>

using namespace std ;

void init(void)

{

glClearColor(1.0, 1.0, 0.0, 0.0) ;

glBlendFunc(GL_ONE, GL_ONE) ;

glEnable(GL_BLEND) ;

}

void display(void)

{

glClear(GL_COLOR_BUFFER_BIT) ;

glColor3f(0.0, 0.0, 1.0) ;

glRectf(-0.5, -0.5, 0.5, 0.5) ;

glFlush() ;

}

void reshape(int w, int h)

{

glViewport(0, 0, (GLsizei)w, (GLsizei)h) ;

glMatrixMode(GL_PROJECTION) ;

glLoadIdentity() ;

if(w<=h)

glOrtho(-1.5, 1.5, -1.5*(GLfloat)h/(GLfloat)w,

1.5*(GLfloat)h/(GLfloat)w, -10.0, 10.0) ;

else

glOrtho(-1.5*(GLfloat)w/(GLfloat)h,

1.5*(GLfloat)w/(GLfloat)h, -1.5, 1.5, -10.0, 10.0) ;

glMatrixMode(GL_MODELVIEW) ;

glLoadIdentity() ;

}

void keyboard(unsigned char key, int x, int y)

{

switch(key)

{

case 'a':

case 'A':

//Note: glBlendEquation is a subset of GL_ARB_imaging, please call glGetString

//first to confirm whether your video card support this extension.

glBlendEquation(GL_FUNC_ADD) ;

break ;

case 's':

case 'S':

glBlendEquation(GL_FUNC_SUBTRACT) ;

break ;

case 'r':

case 'R':

glBlendEquation(GL_FUNC_REVERSE_SUBTRACT) ;

case 'm':

case 'M':

glBlendEquation(GL_MIN) ;

break ;

case 'x':

case 'X':

glBlendEquation(GL_MAX) ;

break ;

case 27:

exit(0) ;

break ;

}

glutPostRedisplay() ;

}

int main(int argc, char* argv[])
{
glutInit(&argc, argv) ;

glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB) ;

glutInitWindowSize(200, 200) ;

glutCreateWindow("Blend") ;

GLenum err = glewInit();//初始化glew库

if (GLEW_OK != err)

{

MessageBoxA(NULL, "error", "My Window", 1) ;

}

//if the return value contains "GL_ARB_imaging " then you can use glBlendEquation

const GLubyte *str = glGetString(GL_EXTENSIONS) ;

cout << str << endl ;//输出硬件所支持的所有扩展本例中主要是"GL_ARB_imaging "

init() ;

glutReshapeFunc(reshape) ;

glutKeyboardFunc(keyboard) ;

glutDisplayFunc(display) ;

glutMainLoop() ;

return 0 ;

}
实例图片在博客相册部分