The Random Dungeon That Isn't So Random pt. 2

A tile can have any number of doors, in any position in the tile -- they shouldn't be limited to the outside edges of a tile. This means that when other tiles are attached, simply having a door of the same width is not sufficient. The algorithm will have to handle:

1. There are no tiles that have a door of the same width.
2. There are no tiles that could be added that do not overlap an already placed tile.

The first way to handle these exceptions is to evaluate a different door in the dungeon. This means that the "bad" door will have to be marked as so, and can't be evaluated again. If there are no good doors available in the rest of the dungeon, there are two options:

1. Create a random door of a random width in a random location in the dungeon.
2. "Finish" the dungeon and place the exits and entrances.

Right now, I'm leaning toward option two, which leaves more up to the user to create good tiles. Perhaps display a message that tells the user the dungeon level was ended prematurely.

Doors

Doors are the crux of the dungeon, and there are still a few things about them that will be tricky.
Determining a door's width is straightforward:

1. Iterate through all the Tile's Blocks until youyou hit a "Door" block.
2. Mark this block as "evaluated"
3. Evaluate the blocks to the right and under the current block. Find where the door "continues" and count how many door blocks are reached in that direction until a non-door block is hit.
4. Do the same evaluation in the opposite direction. This will be the true width. Mark each door block as "evaluated" as they are evaluated.
5. When a non-door block is reached, the position of this block will be the door's position within the tile.
6. Add the door, with it's position and width, to the Tile's list of Doors.

So, when a tile is up for being placed, the door widths can be easily compared. It may also be useful to store the orientation of the door -- horizontal or vertical -- in order to easily know if the tile needs to be rotated. If the tile attempts to be placed and cannot fit without overlapping, the tile can be flipped horizontally or vertically, respectively. If the door is one pixel wide, it can be rotated 90, 180, or 270 degrees and placed if/when it fits.

However, this algorithm does not say what to do if the door shares a corner with another door...