mipmapping about hydra HOT 2 OPEN

Right now it is using linear filtering, but it shouldn't be hard to expose the texture filtering options.

I am hoping to implement blur and other convolution filters using multi-pass rendering.
The idea is that some functions, instead of all becoming part of the same shader, would become a separate render pass. I need to revisit it, but somehow I wasn't getting the expected results.

I started to work on it here:
https://github.com/ojack/hydra-synth/blob/master/src/renderpass-functions.js

and here: https://github.com/ojack/hydra-synth/blob/cdbb882a3c9cecac5cf8d3024c8a64f3b71d7e61/src/GeneratorFactory.js#L234

from hydra.

ok, looking at the code again its pretty messy because I was trying things out! Will clean it up and post updates here.

from hydra.