tex3Dsize - returns the size of a given texture image for a given level of detail.
int3 tex3Dsize(sampler3D samp, int lod)
int3 tex3Dsize(isampler3D samp, int lod)
int3 tex3Dsize(usampler3D samp, int lod)
Sampler to be queried for size.
Level of detail to obtain size.
Given a sampler and a level of detail the size of the corresponding texture image is returned as
the result of the operation.
tex3Dsize is only supported in gp4 and newer profiles.