Removing a hierarchy from an entity can result in a large number of
component removes in the same pool, thus changing index of the lest
element of the pool. This *seems* to fix the memory corruption I've been
experiencing with the debug UI.
The hierarchy leak was particularly troublesome to fix, but now the
hierarchies get updated (and freed) automatically just by removing the
hierarchy reference component from the entity. I suspect there will be
issues with entities that are on multiple hierarchies, but I'll sort
that out later.
It turns out that the bsearch bug was hiding incorrect handling of
indices in the subpool beyond the last tracked subpool. In which case, a
correctly working bsearch correctly fails to find the range, but the
search can be skipped entirely.
When bubbling a component past an empty range, there's no need for any
actual movement other than adjusting the range itself, and doing so
corrupts the sparse/dense array relationship. Fixes a segfault when
hiding the deathmatch overlay (that resulted from the change to using
canvases).
I found I needed the subrange start as well as the end, but I liked that
the subpools themselves used only the end of the range, so switching to
just a unint32_t for the value and adding a function to return a tuple
made sense. I had kept the struct because I thought I might want to
store additional information (eg, the entity "owning" the subpool), but
found that I didn't need such information as the systems using subpools
that way would have access to the entity by other means.
Interestingly, the change found a bug in subpool creation: I really
don't know why things worked before, but they work better now :)
Subpools are for grouping components by some criterion. Any component
that has a rangeid callback will be grouped with other components that
return the same render id. Note that the ordering of components within a
group will be affected by adding a component into a group that comes
before that group (or removing a component).
Component pools can have multiple groups, added and removed dynamically,
but removing a group should (currently) be done only when empty.
While this does require an extra call after registering components, it
allows for multiple component sets (ie, sub-systems) to be registered
before the component pools are created. The base id for the registered
component set is returned so it can be passed to the subsystem as
needed.
There's now a main ecs.h file that includes the sub-system headers,
removing the need to explicitly include several header files, but the
sub-systems are a less cluttered.
