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.
The existing code checks that w.m_ptr is not nullptr before using it.
clang's flow analysis is unable to prove that w.m_ptr does not become
nullptr after it was first checked, even though `w` is const. This
causes clang to include calls to null_pointer_exception::report, which
is not instantiated for wall. That in turn causes a link error.
Rewrite the code to let clang see that the value tested is the value
used, and that no nullptr dereference can happen here.
Add a helper to deduce the enum type of a value, and use an appropriate
std::underlying_type<T> expression for that enum type. This avoids the
need to repeat the type of the enum at the site of each cast, and moves
the casts into the helper to make the callers easier to read.
Every user now uses inheritance and a virtual function override. Make
callback_handler pure virtual, delete its body, and then delete the
member variables that existed only for use in that body. Remove the
constructor parameters that initialized those variables, and update all
derived classes accordingly.
The requirement to call send_creation_events from outside the
constructor makes the presence of a helper function convenient. Rename
ui_create_dialog to window_create, and move it to window.h.
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.
Use an enum class to prevent implicit conversion between trigger
behavior flags and other integers. Fix up various resulting breaks,
which look like bugs:
- Descent 2 editor mode could modify trigger::flags, but used
TRIGGER_FLAG_* values, which specify the actions for a Descent 1
trigger when it executes, not the behavior properties for a trigger.
- Adding a trigger set its flags to 0, then cleared all flags except
TRIGGER_ON. Since the flags were just set to 0, the mask operation is
useless. Remove it.
- trigger_turn_all_ON cleared all flags except TRIGGER_ON. This seems
to be completely wrong. Change it to remove
trigger_behavior_flags::disabled. Descent 1 has no (working) support
for disabling triggers, so make trigger_turn_all_ON exclusive to
Descent 2.
- wall_restore_all would enable TRIGGER_ON in both games. Descent 1
never reads TRIGGER_ON. Descent 2 uses this field for trigger
behavior flags, and TRIGGER_ON is not a behavior flag.
- For Descent 1 builds, remove the modification of the field.
- For Descent 2 builds, change it to clear
trigger_behavior_flags::disabled.
