Add support for tile registration points (alignment offsets)

[zytoblast]

Add support for tile registration points (alignment offsets)

[bjorn]

I fully agree. For some use cases it may be enough or better to center-align the tiles horizontally, but as that screenshot shows you may also want your tiles to drop down below the grid. So a configurable tile offset is certainly necessary, and I would indeed do this on the tileset level for now.

[stefanbeller]

When doing a solution on tileset level as suggested by bjorn, keep the per tile based solution in mind.
( maybe in combination with work of @biouxtai at biouxtai@13ddc36 ) This maybe faces the same direction, since the tile based offset is just a special property, as in the given commit.

[bjorn]

@stefanbeller Supporting offsets on Cells is not a scenario I'm interested in supporting, that functionality is entirely covered by the object layer. If you're rather talking about offsets on Tile instances, this would be feasible to add later.

[tompave]

Hi, I've just sent a pull request to cocos2d-iphone to add support for this feature:
cocos2d/cocos2d-objc#302

I've referenced the TMX format, and I'd appreciate if you could doublecheck, please :-)

Cheers

[bjorn]

@tompave It looks fine to me, you're doing good work! :-)