write: client src into cache common case is both false. dirty is calculated, context write is deferred.

read: sel = 0 for cache, 1 for context

check: verify that context equals cache, return true if mismatched or if illegal values seen

default: write default value to cache, optionally write through

Force this to be a specific function pointer.

Retrieve the actual function pointer.

helper function for int vs enum clarity

CheckCurrent has been removed (it no longer compiled on Linux). To minimize churn I'm leaving the inline NOP version. DO NOT change this to non-inline

helper function to do enable or disable in one step

This method must call SelectTMU()/glActiveTexture() (it's expected as a side effect). This method is no longer called from any performance sensitive c

=============================================================================== GLMContext public methods

read: sel = 0 for cache, 1 for context

"slot" means a vec4-sized thing these write into .env parameter space

write: client src into cache common case is both false. dirty is calculated, context write is deferred.

Extract the n'th component of the swizzle mask. If n would exceed the length of the swizzle mask, then it looks up into "xyzw".

Weird encoding...bits are split apart in the dwToken