Hmmmmm.... Well, I'm not sure how to do the solution you present in (1)... do I multiply the gl_TexCoord[0].xy by my coordinates to correct? And when I changed the sampler2D to sampler2DRect (and the textureSize2DRect, and the texture2DRect...), I then got a uniform reddish gray image in my viewer.
Thanks for your continued help, I feel I am quite close... Patrick On Aug 16, 2010, at 12:48 AM, Achim Breidenbach wrote: > Hi Patrick, > > I just improved the composition from Miroslaw in pretty much the same way as > your solution for the "gaussian" version of the filter looks like. Maybe you > can fiddle in there your code and get rid of all your questions ;-) > > 1) It is, because you don't respect the gl_TextureMatrix of the the src > texture. Textures can be flip, but the matrix always put them back correctly. > You have to use the gl_TexCoord[0].xy in the fragment shader to get correct > xy-coordinates, they are transformed in the Vertex Shader by the texture > matrix. > > 2) the "default" implementation of the GLSL shader puts in a "uniform > sampler2D texture;" which is misleading! This means, that the input for the > texture has to be a square. so QC is converting your input image to a square > texture and feeds this into the GLSL-shader (and manipulates the > texture-matrix that way, that the image-aspect ratio is still correct!). Your > code ready the native texture size with textureSize2D(src, 0) which is > 512x512 I guess in your case. Replace all "sample2D" with "sample2DRect" to > get your original texture in the correct size. > > 3) You have to use a "Render in Image"-Patch to render the GLSL-Shader into a > new texture to use it in following patches. > > Best, > > Achim > > <compound-gaussian 1.qtz> > > On 16.08.2010, at 09:27, Patrick Sheffield wrote: > >> Thank you, Miroslaw - that works, I'd never played with an OpenCL patch... >> >> Toward that end, I've been trying out some GLSL routines, but I have a few >> questions for anyone out there: >> >> <gaussian1.qtz> >> >> First, why does this composition flip the image? >> Why does it mess with the aspect ratio? >> And how would I feed the output of a GLSL patch to do further processing? >> >> I realize a Gaussian blur needn't be done in a GLSL patch - could be handled >> in a CI kernel, etc... but I have other GLSL routines I'd like to use. >> >> Thanks for any insight you might have, >> >> Patrick >> >> On Aug 15, 2010, at 5:31 AM, Miroslaw Rusin wrote: >> >>> thanks for the info. so it's something more like this then... >>> >>> <compound-3.qtz> >>> >>> >>> it's slow - O(x*y*r²), where: >>> x - image with >>> y - image height >>> r - radius >>> >>> can be O(x*y) with sum table >>> >>> M >>> >> >> _______________________________________________ >> Do not post admin requests to the list. They will be ignored. >> Quartzcomposer-dev mailing list ([email protected]) >> Help/Unsubscribe/Update your Subscription: >> http://lists.apple.com/mailman/options/quartzcomposer-dev/achim%40boinx.com >> >> This email sent to [email protected] >
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