tex2Dsize - returns the size of a given texture image for a given level of detail.
int3 tex2Dsize(sampler2D samp, int lod)
int3 tex2Dsize(isampler2D samp, int lod)
int3 tex2Dsize(usampler2D 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.
tex2Dsize is only supported in gp4 and newer profiles.