Properly handle disabled textures inside shaders (Regression in 2.1.2 - Handheld items not affected by light anymore)

[DarkShadow44]

Since the weird textures are fixed on handheld items, they are not affected by light anymore. Need to rework the lightmap, maybe remove it, to fix that issue properly.

[DarkShadow44]

Underlying problem with the "weird textures on blocks/entities" is that the code disables textures and then draws an overlay. However, the shaders are not affected by that disabled texture. My current workaround is to simply disable the shaders for that part, but that doesn't work properly either - see the missing light coloring. I need to disable the textures in the shaders as well, maybe look at how the shader mod does it...?

[DarkShadow44]

The ELN issue is probably similar, not 100% sure though.

[DarkShadow44]

Finally fixed in dev, the shaders now handle disabled textures properly.