C++ (Cpp) Matrix::makeFrustum示例

void ScreenBase::computeDefaultViewProj(osg::Vec3d eyePos, osg::Matrix & view,
        osg::Matrix & proj)
{
    //translate screen to origin
    osg::Matrix screenTrans;
    screenTrans.makeTranslate(-_myInfo->xyz);

    //rotate screen to xz
    osg::Matrix screenRot;
    screenRot.makeRotate(-_myInfo->h * M_PI / 180.0,osg::Vec3(0,0,1),
            -_myInfo->p * M_PI / 180.0,osg::Vec3(1,0,0),
            -_myInfo->r * M_PI / 180.0,osg::Vec3(0,1,0));

    eyePos = eyePos * screenTrans * screenRot;

    //make frustum
    float top, bottom, left, right;
    float screenDist = -eyePos.y();

    top = _near * (_myInfo->height / 2.0 - eyePos.z()) / screenDist;
    bottom = _near * (-_myInfo->height / 2.0 - eyePos.z()) / screenDist;
    right = _near * (_myInfo->width / 2.0 - eyePos.x()) / screenDist;
    left = _near * (-_myInfo->width / 2.0 - eyePos.x()) / screenDist;

    proj.makeFrustum(left,right,bottom,top,_near,_far);

    // move camera to origin
    osg::Matrix cameraTrans;
    cameraTrans.makeTranslate(-eyePos);

    //make view
    view = screenTrans * screenRot * cameraTrans
            * osg::Matrix::lookAt(osg::Vec3(0,0,0),osg::Vec3(0,1,0),
                    osg::Vec3(0,0,1));
}