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Feedback problem

I am trying to draw lines and curves on a DX texture, using a quad as the brush by drawing on the texture and copying it back on it self, however the filtering (I guess) smears it all (which makes for nice feedback effects if I scale the texture, but…)

I need to put a cursor on top, so turning Clear off for the viewport isn’t good enough, although that’s what I’m currently doing.

Any ideas?

Regards, Ernst Hot

you could output your feedback process to another texture and draw that (including the cursor) in another renderer

Ofcourse… Why didn’t I think of that… :)

Thanks mate!

Regards, Ernst Hot

however the filtering (I guess) smears it

it is actually possible to do precise pixel mapping of textures to the screen, although you need to tweak the translation of the texture half a pixel. you will see this effect more clearly when switching the filtering off - either with the Filter (EX9.SamplerState) node or by setting the filters in the sampler declaration of the shader to POINT

moving the texture half a pixel should be an option of most graphics drivers.
however i think there is no common naming for this feature.
while developing the wavesimulation i also had a diagonal smear into the right bottom corner. i solved this by playing with the graphics card driver interface.

MappingTexelsToPixels on MSDN gives some background info on that topic.