屏幕坐标系 到世界坐标系

转自nehe的教程:Using gluUnProject http://nehe.gamedev.net/article/using_gluunproject/16013/

CVector3 GetOGLPos(int x, int y)
{
    GLint viewport[4];
    GLdouble modelview[16];
    GLdouble projection[16];
    GLfloat winX, winY, winZ;
    GLdouble posX, posY, posZ;
 
    glGetDoublev( GL_MODELVIEW_MATRIX, modelview );  
    glGetDoublev( GL_PROJECTION_MATRIX, projection );
    glGetIntegerv( GL_VIEWPORT, viewport );
 
    winX = (float)x;
    winY = (float)viewport[3] - (float)y;
    glReadPixels( x, int(winY), 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &winZ ); //获取深度值
 
    gluUnProject( winX, winY, winZ, modelview, projection, viewport, &posX, &posY, &posZ); //使用glu，如果高版本的opengl,3D数学库中通常包含此函数，
 
    return CVector3(posX, posY, posZ);
}

来源：CSDN

作者：漂_泊

链接：https://blog.csdn.net/iMatt/article/details/103829532