same texture for read and render?

Quote:

Original post by DuckMaestro i am wondering if it is possible (in dx9 and ps13+) to use a renderable texture as a source texture as well as the render target at the same time during the execution of a single pixel shader?

Although D3D will not flag this as an error (the Debug Runtime will generate a warning, however), on most hardware, this produces "unexpected results". Depending on the hardware, driver, position of the moon, alignment of the planets, and whether or not you've made your daily sacrifice to the programming gods, this may or may not work. Both ATI and NVIDIA technical relations representatives have advised against attempting to do this in discussions in the DirectXDev mailing list because the results are not guaranteed to be consistant. If you talk to driver people about doing this, they will cringe and curse your name. :)

There is usually a way to achieve the same result by rendering to texture first and then performing another pass. The blending modes in D3D are pretty flexible. If you're using pixel shaders, then blending is even simpler. What is it you're trying to do? Perhaps people on the board could suggest alternative approaches.

neneboricua