matheus leston

Is there anything like jit.scanwrap in GL? Being more specific, is there anyway to use jit.gl.pix in which the input dim size of the texture is different from the output?

Is there anything like jit.scanwrap in GL? Being more specific, is there anyway to use jit.gl.pix in which the input dim size of the texture

jit-scanwrap-in-gl

while it is possible to decouple input dims from output dims with jit.gl.pix (@adapt 0), the logic required for scanwrap functionality requires state to store current current input position and current output position, which is not possible in a single shader program. You could probably come up with something clever using multiple shader programs (i.e. cascading jit.gl.slab/pix objects), but I would have to think long about that.

ok I couldn't leave this alone. turns out it's pretty straight forward to get at least jit.scanwrap @mode 3 working in a jit.gl.pix. The jit.gl.pix dimension needs to be passed in as a parameter and synched with the dim attribute to get the scanwrap behavior.

Hey Rob, thank you very much! I'm glad that you didn't leave this alone.

It works great, and it does precisely what I needed to do, excellent! The only issue I'm getting is that there is a slight color discrepancy. Maybe I'm doing something quite stupid, but take a look at the example below, please. I thought it was an issue of using [sample] instead of [nearest] in your [jit.gl.pix] code, that that doesn't seem to be the issue. Any ideas?

 on the jit.gl.texture prior to sending to jit.gl.pix.

you simply need to set @filter none on the jit.gl.texture prior to sending to jit.gl.pix.

Perfect, thank you again, Rob. Sorry about that, I'm not that familiar with GL all that much. Could you explain the reasoning for that?

filter none disables interpolation when sampling. since the input texture needs to be upsampled to match the dims of the jit.gl.pix we want to make sure sampling interpolation is disabled in order to get our expected output colors (else we get a mix of colors as the upsample interpolates across texels). at least I think that's what's happening here.

filter none disables interpolation when sampling. since the input texture needs to be upsampled to match the dims of the jit.gl.pix we want to make sure sampling interpolation is disabled in order to get our expected output colors (else we get a mix of colors as the upsample interpolates across texels).  at least I think that's what's happening here.

Oh I see, it does make a lot of sense. Thank you for the explanation!