« on: April 27, 2015, 10:19:53 pm »
I'm curious about the mechanics of it.
There are two aspects to it. Doorway tiles (those between door bubbles) trigger a room transition. We can use invisible tiles that have the same behavior to have doorless room transitions.
To stop the screen from scrolling beyond the edge of a scrolling region (and I'm not sure that this is used in Rogue Dawn, at least not everywhere), you can use a screen-load routine. The game has a variable that is set when a door is present to stop scrolling. The screen-load routine simply sets this variable.
This isn't from Rogue Dawn, but the same tricks are used here. In my case, the doorway tiles are visible for development and debugging. The StopLeftScroll routine is called from the screen-load routine for the selected room.