[PD] using the same shader in multiple places

Matteo Sisti Sette matteosistisette at gmail.com
Thu Dec 31 16:59:28 CET 2009


Is it legal to load the same shader (i.e. the same .vert and .frag 
files) multiple times? I.e. have an abstraction with a [glsl_vertex], a 
[glsl_fragment] and a [glsl_program], and multiple instances of this 

I ask this because I did this and pd crashes as soon as I open the 
gemwin. I had some trivial errors in the shader files before, and I got 
the compiler error messages without crashes, but then I corrected the 
error and now it crashes.
Obviously there may be a lot of other reasons for the crash but I have 
to guess.

Is there another way to use the same shader in multiple places? For 
example, I see [glsl_program] outputs an id in its right outlet: can I 
perhaps use that ID to use that shader elsewhere? If so, how? In this 
case, would each "instance" of the shader have its own value of 
"uniform" parameters?

By the way, I should probably ask a more basic question: is it legal to 
have more than one [glsl_program]s (meaning a [glsl_vertex] a 
[glsl_fragment] and a [glsl_program]), no matter whether with the same 
or different shader programs, "under" the same [gemhead], provided that 
they are in different "subchains" with [separator]s?


Matteo Sisti Sette
matteosistisette at gmail.com

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