[Qt-interest] How can I get my job done with QGLWidget?

[John McClurkin]

fog public wrote:
> Hi all, I am a newbee in QT development, high performace real-time 
> graphic data rendering is what I want to archieved. I did try QGLWidget, 
> It's very easy to use, now I was woundering if I can use a off-screen 
> framebuffer object to get faster 2D graphic rendering speed, I try to 
> declare a QGLFrameBufferObject pointer member in my class 
> which inheritances from QGLWidget and initialized it in  constructor 
> just like
> QMyGLWidget::QMyGLWidget( QWidget *parent)
>   :QGLWidget( QGLFormat( QGL::SampleBuffers),parent)
> {
>      this->showFullScreen();
>      setAutoSwapBuffers(false);
>      setAutoFillbackground(false);
>      pFrameBuffer = NULL;
>      makeCurrent();
>      pFrameBuffer = new QGLFrameBufferObject(width(),height());
> ....
> }
> and rewrite the paintEvent(QPaintEvent *e) to get a shot.
> void QMyGLWidget::paintEvent(QPaintEvent *e)
> {
>     QPainter painter(pFrameBuffer);
>     //do some 2d painting
>    painter.end();
>    swapbuffers();
> }
> but I got nothing display on the screen, If I must call some functions 
> to force QGLWidget using framebuffer I declared,and swap it to 
> show??Please give me a advice thanks a lot
Does your system support OpenGL frame buffer objects?
You need to bind the texture in the frame buffer object to the 
QGLWidget. There are examples in examples/opengl/framebufferobject and 
examples/opengl/framebufferobject2