[PAID BOUNTY] - Implementation of OpenGL ES3 and/or Difference Blend Mode

Hi there,

I am developing an app that requires the “Difference” blend mode:

abs(a-b)

Within the iOS implementation of openframeworks the current build afaik only support OpenGL ES2 which doesn’t support Difference Mode. A solve that uses a shader will be too intensive and overkill (I suspect). So I think (with my limited knowledge) that implementing OpenGL ES3 or just adding Difference Mode to OpenGL ES2 would be the best way to go, very open to suggestions here though!

I don’t have a specific budget for this, and also want to make sure that obviously if this is a development that can benefit core OF, that it is set up to do so, saying that there is £50 around for if it is simple enough to achieve, otherwise let me know and I might be able to pull down some actual budget

Did you try something like this?

Not sure if this works, but maybe just add:
#include <GLES3/gl3.h>
in ofConstants.h for IOS (I tried that for Emscripten…)?

I haven’t. I’m worried about using shaders, as I have had shaders highly impact the performance of the app. This might be solely down to me being inexperienced with shaders.

Unfortunately not, worth a punt though!