Re: [Opensg-users] OpenSG 2: ShadowStage with PassiveBackround

[Gerrit V. <vo...@vo...>]

Hi,

On Fri, 2012-12-07 at 10:32 +0100, Johannes wrote:
> Hello Gerrit,
> 
> On 26.11.2012 03:15, Gerrit Voß wrote:
> >
>>
> >
> >> Has anyone a idea with respect to the clearing operation?
> >
> > The problem is the PassiveBackground, which acutally does not clear
> > anything, it relies on the application having cleared the (window)
> > buffers. As the shadow stage render everything in it's own FBO but
> > reuses the outside background is misses this clear. It is a general
> > problem for stages and passive backgrounds. I'll see if I can find a
> > solution where the stages blit the framebuffer contents into their
> > FBO's.
> >
> Did you have time to think about this one? As I'm relying on the 
> PassiveBackground it is very important for me.

I extended the PassiveBackground so that it can do something if used
within an FBO. This has to be enabled setting 

PassiveBackground clearFrameBufferObject 

to true. Than there are two options, either the application sets a 
callback which gets called if PassiveBackground::clear is called with
a FBO active. If the callback is not set the PassiveBackground will
blit the window contents (color + stencil + depth) to the active FBO.
Currently it assumes that the active FBO size does not exceed the 
window size (right now it's the first version). 

I also added an example (Examples/CSM/Shadow/SimplePassive). For me
it works, could you check and see if it works for your setup.

kind regards
  gerrit