The fbo spec states that this configuration results in an undefinied behaviour.
What i tried is to minimize memory usage for float textures where only one color channel is needed and a ping-pong algorithm is used.
In a fragment shader i read from channel green and write to channel red. In the next ping-pong pass i swap the source and target channels to read from channel red and write to channel green and so on.
In my head it would make sense but not in the context of opengl.
And because single channel textures are not color renderable, i tried it this way.
My card is an ATI Radeon 9600 Pro Mobile and the rendering results are really undefined
Is there an approach that would allow to ping pong between single channel float or even 16bit integer textures?
My next idea is using two 16 bit stencil textures, but i really dont know if it would work. And before i shoot in the dark i would like to know if there is a chance to hit something.