ReadPixels implementation in Jitter?

Jul 22, 2007 at 12:01pm

ReadPixels implementation in Jitter?

So I’ve given up plans of sussing the most predominant colours in a stream of texture, due to lack of overhead here. In an attempt to keep my patch as light on cpu as possible I was wondering if we can do “ReadPixels(100, 100, sizei 1, sizei 1″… etc etc. – basically what I am looking to do is to sample colours from the framebuffer.

Alternatively: What is the cheapest way of sampling colours from a texture?

I have very little experience in doing direct GL calls, and I’d really appreciate any pointers you may have.

Andreas

#32988
Jul 22, 2007 at 3:36pm

Maybe jit.gl.sketch’s:

glreadpixels

On Jul 22, 2007, at 2:01 PM, Andreas Wetterberg wrote:

> looking to do is to sample colours from the framebuffer.

#109309
Jul 22, 2007 at 5:19pm

doh!

thanks, nesa. I’ve always found jit.gl.sketch’s possibilities a bit confusing, since the manual is one big blur of “Please see the Red Book”, and so on.

Have you used “glreadpixels”?

Cheers,
A.

#109310
Jul 28, 2007 at 10:54am

yes, very long time ago(in jitter time scale) it was the only (sane)
way to get gpu gl rendering back to jit.matrix.

I was using it with just the matrix name: glreadpixel readbackmatrix,
where readbackmatrix was the 4 char matrix with the same size as
render context.

On Jul 22, 2007, at 7:19 PM, Andreas Wetterberg wrote:

>
> doh!
>
> thanks, nesa. I’ve always found jit.gl.sketch’s possibilities a
> bit confusing, since the manual is one big blur of “Please see the
> Red Book”, and so on.
>
> Have you used “glreadpixels”?
>
> Cheers,
> A.

#109311

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