This has two benefits:
(1) The game uses less resources when it is asked to gotoroom to the
same room because it is no longer redrawing the warp background
every single frame, which is very wasteful.
(2) The warp background no longer freezes or flickers if the player is
standing inside a gotoroom script box (which calls gotoroom every
frame or every other frame, because every time the gotoroom happens
the script box gets reloaded).
When the game enter towermode, it adjusts player amd camera x/y depending
on what screen the player entered it from (The Tower) or the loadlevel
mode ("minitowers"; Panic Room and The Final Challenge). This code didn't
account for respawning to checkpoints. This is unlikely to matter in most
circumstances, but can cause problems in some corner cases, or with R abuse.
This could cause a player to die, respawn outside camera edges and then
immediately die again due to the edge spikes, repositioning the camera
properly. Invincibility would cause further issues, but that's Invincibility
Mode for you -- if this was the only problem I wouldn't bother.
I added a check that repositions the tower camera appropriately if a player
enter a tower as part of the respawn process.
The game makes sure that the player entity is never destroyed, but in
doing so, it doesn't destroy any duplicate player entities that might
have been created via strange means e.g. a custom level doing a
createentity with t=0.
Duplicate player entities are, in a sense, not the "real" player entity.
For one, they can take damage and die, but when they do they'll still be
stuck inside the hazard, which can result in a softlock. For another,
their position isn't updated when going between rooms. It's better to
just destroy them when we can.
