Support for per-pixel negative lights. Added BLEND_SUBTRACT & BLEND_SUBTRACTALPHA blend modes. Light code cleanup.
For Travis CI - automate housekeeping of old snapshots.
[ci package]
Travis CI: API documentation update at 2014-03-12 02:39:20 UTC.
[ci skip]
For Travis CI - setup digital key earlier for housekeeping to work.
[ci package]
For Travis CI - fix non uniq revision deletion list for housekeeping.
[ci package]
Added .tga to the editor's file picker for textures/images, as it is supported by stb_image.
Add fixed pixel size (user don't need change the value).
Add 2D physics class.
Add Lua and AngelScript binding.
Add Urho2D Physics sample.
Add attribute accessor in Physics2D classes..
Guard LuaScript subsystem against unsubscribing internally listened events.
Clean up Batch code. Give larger sorting priority to negative lights so that they are applied right after ambient, followed by additive lights.
Fix Lua binding of PhysicsWorld2D. Closes #250.
Exposed IsPowerOfTwo(), NextPowerOfTwo() and SDBMHash() to script.
Merge branch 'track'