Support the Tiled Terrain Tool and Subrectangles / Polygons

[pmer]

http://doc.mapeditor.org/manual/using-the-terrain-tool/

The Tiled terrain tool looks useful for game developers as it automates the repetitive process of placing terrain transition files.

The tool supports transitions between two different terrain types within the same tile layer, which, funnily enough, Driftwood will support pretty well right now. Driftwood supports it well right now because it allows players to move ½ a tile over the bounds of the current tile. (Look at the pictures in the link. Notice how terrain transition tiles change terrain at the half-way point within a tile.) The plans for redoing the engine's entities (#91) might mess with this. This issue is to figure out how to support the terrain tool with the new entity movement schema.

[pmer]

If a transitionary tile contains a wall (as several of the examples in the docs show) then a map author will probably mark the tile as no-walk.

Then pixel-mode entities cannot enter the tile, which will look weird. To fix this, we can allow authors to specify sub-tile rectangles that are no-walk. That will allow pixel-mode entities to walk up to the wall edges.

Tile- and turn-based entities can never enter into Tiled's transitionary tiles if they contain walls.

[pmer]

Oh yeah, supporting subrectangles & polygons is #110. I should have linked that here. @seisatsu Should we add #110 to 0.0.8?

[seisatsu]

Sure we can add it, but tile entities will treat any amount of nowalk on a tile as the entire tile being nowalk, since they only think in whole tiles when deciding whether or not to move. They do the same thing with other entities. So, I don't think #110 is actually a prerequisite.

[pmer]

Oh man, you're right. I was confused and thought #110 was for pixel entities.

[pmer]

Let's not add it. I'll revert its milestone.