Am Dienstag 25 Juli 2006 11:54 schrieb H. Verbeet:
On 25/07/06, Stefan Dösinger stefandoesinger@gmx.at wrote:
Can we flip around the y axis in the shader?
Well, that is essentially what Jason's hack does :-)
Or can we flip around the texture coords when drawing from the offscreen texture? If I understand it correctly this only affects offscreen rendering.
I was hoping you would know :-) We would have to do some fixups when locking the surface as well, but I don't think that should be a problem.
Well, I'm not the shader expert in here, but if the y flip only affects offscreen render targets and we can find out in which conditions it needs flipping then we can just create a SFLAG_INVY surface flag(there are quite a lot of them already :-| ). The tricky part is to actually flip it around when drawing because we have to modify the vertices. This could be a case for drawStridedSlow or VBO vertex fixups. Or do the texture matrices help here? (/me reads up the red book)
Surface locking is the least problem, just check the flag and order reversed coordinates from opengl or flip the lines in software.