In the cases where we support the binding layout keyword, use it for more than binding UBO location.
This changes it so it is supported for samplers as well.
Instances when this is enabled is if a device supports GL_ARB_shading_language_420pack, or if it supports GLES 3.10.
- remove unused variables
- reduce the scope where it makes sense
- correct limits (did you know that strcat()'s last parameter does not
include the \0 that is always added?)
- set some free()'d pointers to NULL
This one was introduced to reduce the glBindTexture and glActiveTexture calls. But it was quite a bit of logic and only an improvment on uploading/creating a texture, which is done rarely.
Shawn Hoffman