Vertical position of map object is "artificially" modified

[tnajdek]

Hey there again!

While working with tmxlib I've noticed my map objects are position incorrectly, especially offseting y value by object's height is producing undesired effects. I'm wondering if this is done intentionally or it's a bug?

I've attached a pull request which highlights 2 pieces of code that might affect object positioning, one is the logic that offsets item's y value by it's height, second is a piece of code in mapobject.py that I can't figure out what is doing.

[encukou]

Hello,
Yes, the y has a slightly different meaning than in the TMX format. This is a controversial design decision, but I believe I have sufficient reason for deciding differently than TMX.
tmxlib's tile and object classes are designed to be as similar to each other as possible. For example, you can easily iterate over all "tile-like objects" and do common operations on them. For this reason, in tmxlib, if a tile and a tile object are at the same place, they should have identical coordinates & size. If that's not the case then it's a bug.
Tiled (the project that defines TMX) took a different approach; the reasoning is explained here: mapeditor/tiled#386

Needless to say, TMX load/save or to_dict/from_dict should give you Tiled-compatible data, and TMX/tmxlib round-trips should work fine.

This needs to be documented better so I'll keep this report open (but I'll probably only get to it after EuroPython and a vacation).

[tnajdek]

Ahh, interesting, thanks for in-depth explanation. I'll modify my implementation to work around this. Hope you're having fun @ EuroPython, cheers!