A port of glsl-blend to Hydra.
This extension adds most of the blending modes that you see on raster image software to Hydra. You should use them with the following syntax: tex.blendModeName(tex2, opacity), where tex and tex2 are any two Hydra textures and opacity is a number (or array or function as in regular Hydra).
Please read the disclaimer about alpha here below
- darken
- multiply
- colorBurn
- linearBurn
- lighten
- screen
- colorDodge
- linearDodge
- overlay
- softLight
- hardLight
- vividLight
- linearLight
- pinLight
- hardMix
- difference
- exclusion
- subtract
- divide
- negation / negate
- add2 (i didn't want to replace the regular Hydra
add) - glow
- reflect
- phoenix
glsl-blend doesn't have any functions that work with RGBA, all function work with opaque textures of RGB. After lots of playing around with Photopea I realized that what most raster image softwares do is apply the blending over premultiplied sources and then, wherever the base texture is transparent, layer over the texture to be blended, and that's how I implemented it
This extension overwrites Hydra's layer, luma and mask in order for them to stricly use premultiplied alpha. This means that if something doesn't look as expected, it's probably because the textures you're using aren't premultiplied and in a range from 0.0 to 1.0. noise will surely give you problems as it ranges from -1 to 1.
I could've handled this inside the blending modes but I didn't want to taker over your ability to purposefully glitch stuff. If something doesn't look as you expect it to look you can try to premultiply it by doing tex.premultiply() alias tex.pm(). It's a function I've added that will take care of any overloaded or mismatched values.
If you're interested in alpha compositing inside Hydra, please join the discussion here