Borked Lighting System on Rougelike Map

[mikewesthad]

There's something wrong about how we are approaching lighting. I don't know if this is an issue we have always had or something new introduced by some of the more recent lighting system updates (or, more likely, a combination of the two).

Current algorithm:

• Light rays are only being cast at walls that face away from the light ("back walls")
• The cast light rays are then used to mask a shadow layer - only leaving shadow where there is no light

Problems:

• Light rays are not hitting walls that face towards the light ("front walls"). The _getWallIntersection function is being run only using back walls, so essentially the front walls are completely ignored in lighting.
• If we use the front walls in the lighting calculation, then the wall tiles themselves will appear in shadow. To fix that, we'd need to draw the lighting in a layered way. E.g. draw tilemap background layer, draw masked shadows, draw tilemap walls layer, draw lighting?

[mikewesthad]

https://github.com/byronknoll/visibility-polygon-js
http://www.redblobgames.com/articles/visibility/

[mikewesthad]

For posterity: http://archive.gamedev.net/archive/reference/programming/features/2dsoftshadow/index.html