Iterating over it returns each side number in turn. This allows
converting many loops of the form:
```
for (int i = 0; i < MAX_SIDES_PER_SEGMENT; ++i)
```
to the compact form:
```
for (const auto i : MAX_SIDES_PER_SEGMENT)
```
The compact form brings the usual benefit of range-based for: delegating
iteration to the compiler prevents the loop body from skipping a step,
and makes clear in the code that this is the case.
Define separate enum values for rotation data in both the high bits,
where it is usually kept, and the low bits, where it is sometimes used
for math or comparisons.
Define an enum value to represent the composite of the index and the
rotation, since the composite is not suitable for use as an array
subscript. Add helper functions to extract the component pieces.
Various functions need to access both `shared_segment` and
`unique_segment` data. Using `segment &` for this blocks eliminating
the `segment` type. Add `susegment` and type aliases to it.
`susegment` records a reference to a `shared_segment` and a
`unique_segment` together, so that users cannot accidentally mismatch
`shared_segment` #1 with `unique_segment` #2 when passing references
down to a function which needs both `shared_segment` and
`unique_segment`.
d2x::segment has all members of d1x::segment, as well as two new members
exclusive to d2x::segment. Structure layout is such that d1x::segment
requires the same size allocation, and places anonymous pad members in
the locations that become named members in d2x::segment. Thus, reusing
d2x::segment for d1x::segment does not change the size of the structure
nor the offsets of any members used. This reuse may enable some
functions to be better shared by the dsx project.
Early unification efforts missed this one because it was in gamemine.c
for Descent 1, but segment.c for Descent 2. Move it to gamemine.cpp for
both, so that it can be static for both games.
Previously, valptridx used PREFIX for allow-invalid+mutable, c#PREFIX
for allow-invalid+const, v#PREFIX for require-valid+mutable, vc#PREFIX
for require-valid+const. Convert the types, factories, and all usage
sites to specify a qualifier for all four combinations:
im#PREFIX -> allow-invalid+mutable
ic#PREFIX -> allow-invalid+const
vm#PREFIX -> require-valid+mutable
vc#PREFIX -> require-valid+const
Changes to common/include/valptridx.h and common/include/fwd-valptridx.h
are manual. All other changes are generated by:
git grep -lz -e '\(obj\|seg\|clwall\|wall\|actdoor\|trg\)\(ptridx\|ptr\|idx\)\(_t\)\?\>' | xargs -0 sed -i -e 's/\<\(v\?\)\(\(obj\|seg\|clwall\|wall\|actdoor\|trg\)\(ptridx\|ptr\|idx\)\(_t\)\?\)\>/\1m\2/g'
for the 'm' prefix and:
git grep -lz -e '\(obj\|seg\|clwall\|wall\|actdoor\|trg\)\(ptridx\|ptr\|idx\)\(_t\)\?\>' | xargs -0 sed -i -e 's/\<\([cm]\(obj\|seg\|clwall\|wall\|actdoor\|trg\)\(ptridx\|ptr\|idx\)\(_t\)\?\)\>/i&/g'
for the 'i' prefix.
