Allow for transparent pixels to work

[Justanidiotonline]

Basically, my skin has transparent pixels, they work with every other shader i have tried except this one, they just show up as hard white without the opacity. I'd like to see that added, because i feel like its missing.

Honestly just make this work with transparent pixels and you're golden

[rre36]

The player model is only rendered as a solid object, thus any kind of translucency is incompatible with a deferred shading pipeline like i use. This is more of an optifine/vanilla issue since the rendering order is what makes it impossible to handle a case like this correctly.