Matrix-style reordering still applies to the indices, except limited
to up to 2 Dimensions (X,Y). Ordering is therefore limited to (X,Y) or
(Y,X). Only one dimension may optionally be skipped. Inversion of either
-X or Y or both is possible. Pseudocode for Indexed Mode (without elwidth
+X or Y or both is possible. Pseudocode for Indexed Mode (including elwidth
overrides) may be written in terms of Matrix Mode, specifically
purposed to ensure that the 3rd dimension (Z) has no effect:
MSHAPE.invxyz = 0b0 || ISHAPE.invxy
MSHAPE.xdimsz = ISHAPE.xdimsz
MSHAPE.ydimsz = ISHAPE.ydimsz
- MSHAPE.zdimsz = MAXVL-1
+ MSHAPE.zdimsz = MAXVL-1 # dimensions are inclusive
if ISHAPE.permute = 0b110 # 0,1
MSHAPE.permute = 0b000 # 0,1,2
if ISHAPE.permute = 0b111 # 1,0