[PD] GEM: multitexturing in GEM

[Kyle Klipowicz]

This thread is getting nice and infotacious.

~Kyle

On 7/1/07, vade <doktorp at mac.com> wrote:
>  now my secret identity is known. my vigilante days are numbered!
>
> :)
>
> Here is a sample fragment shader that implements one of the blend modes
> (overlay) for A/B mixing. If you can show me how to get this working in a
> patch that has two texture inputs for one rect object at the end of a
> gemhead render chain, that would really  be awesome, and I could wrap it
> easily in an abstraction.
>
> Thanks for taking the time to look at it. Yeah, I know, weird Jitter
> texcoord template, deal with it :)
>
> ---- fragment shader
> uniform vec4 amount;
>
> // define our rectangular texture samplers
> uniform sampler2DRect tex0;
> uniform sampler2DRect tex1;
>
> // define our varying texture coordinates
> varying vec2 texcoord0;
> varying vec2 texcoord1;
>
> vec4 one = vec4(1.0);
> vec4 two = vec4(2.0);
> vec4 lumcoeff = vec4(0.2125,0.7154,0.0721,0.0);
>
>
> vec4 overlay(vec4 myInput, vec4 previousmix, vec4 amount)
> {
>  float luminance = dot(previousmix,lumcoeff);
>  float mixamount = clamp((luminance - 0.45) * 10., 0., 1.);
>
>  vec4 branch1 = two * previousmix * myInput;
>  vec4 branch2 = one - (two * (one - previousmix) * (one - myInput));
>
>  vec4 result = mix(branch1, branch2, vec4(mixamount) );
>  vec4 mixresult = mix(previousmix, result, amount);
>
>  return mixresult;
> }
>
> void main(void)
> {
>  vec4 input0 = texture2DRect(tex0, texcoord0);
>  vec4 input1 = texture2DRect(tex1, texcoord1);
>
>  vec4 mix1 = overlay(input1, input0, amount* two );
>  vec4 mix2 = overlay(input0, input1, (1.0 - amount) * two );
>
>  vec4 result = mix(vec4(mix1.rgb,1.),vec4(mix2.rgb,1), amount);
>
>  gl_FragColor = result;
> }
> ---- vert shader
>
> varying vec2 texcoord0;
> varying vec2 texcoord1;
>
>
> void main()
> {
>     // perform standard transform on vertex
>     gl_Position = ftransform();
>
>     // transform texcoords
>     texcoord0 = vec2(gl_TextureMatrix[0] * gl_MultiTexCoord0);
>     texcoord1 = vec2(gl_TextureMatrix[1] * gl_MultiTexCoord1);
> }
>
>
>
>
> On Jul 1, 2007, at 11:47 AM, chris clepper wrote:
>
> Anton
>
> You want to set the texture unit that pix_texture uses correct?  pix_texture
> should take a 'texunit $1' (or texUnit) message to do this.  Multitexturing
> was one of Jamie's projects which remains unfinished...
>
> Send me a shader to work with if you can't get it working.
>
>
> On 6/29/07, vade <doktorp at mac.com> wrote:
> >
> > Hello
> >
> >
> > i am looking for an example patch, or how to for multitexturing. Im trying
> to port some GLSL shaders that implement mixers over to GEM. How do I
> get gl_TextureMatrix[0] and [1], etc so to speak onto a rect?
> >
> >
> > thanks, forgive me if this is obvious, but I looked around and did not see
> any example code.
> >
> >
> >
> > v a d e //
> >
> >
> > www.vade.info
> > abstrakt.vade.info
> >
> >
> >
> >
> > _______________________________________________
> > PD-list at iem.at mailing list
> > UNSUBSCRIBE and account-management ->
> http://lists.puredata.info/listinfo/pd-list
> >
> >
>
>
>
> v a d e //
>
> www.vade.info
> abstrakt.vade.info
>
>
>
>
> _______________________________________________
> PD-list at iem.at mailing list
> UNSUBSCRIBE and account-management ->
> http://lists.puredata.info/listinfo/pd-list
>
>


-- 
-----
------------
    ----     -----
---- -------- - ------
http://perhapsidid.wordpress.com