* export d2asset singleton
* add *d2asset.AssetManager to d2app
- d2app now has a reference to an asset manager which it will use for loading
- added asset loader methods to the asset manager
- functions in d2asset are now wrappers for asset manager methods
* add asset manager reference to audio provider
- d2app asset manager reference is now passed to audio provider
- asset manager is created in main.go for now to pass into audio provider
- CreateSoundEffect is now a method, no longer exported, uses the asset manager reference
* d2app passes asset manager refence to map engine test
* in d2asset, all calls to LoadFile replaced with call to Singleton.Loadfile
* blizzard intro and credits screen
- d2app passes reference to the asset manager to these screens
* asset manager for d2map
- adding MapStampFactory, takes an asset manager reference
- embedded MapStampFactory into the MapEngine
- LoadStamp is now a method of the MapStampFactory
* d2asset: removed LoadFileStream, LoadFile, and FileExists
* d2gui changes
- singleton now has an asset manager reference
- calls to d2asset loader functions removed
- createButton is now a method of LayoutManager
- moved LayoutEntry to its own file
* map entity factory
- Map engine has an embedded map entity factory
- Map stamp factory gets a reference to the map engine's entity factory
- Stamps are given a reference to the map engine entity factory when created
- Character select gets a map entity factory
- Embedded the stamp factory into the MapEngine
* asset manager for d2ui
- d2ui is passed an asset manager reference when created
- all calls to d2asset loader functions in d2ui now refer to the asset manager
- d2gamescreen gets a ui manager when created
- help overlay is now passed a ui manager when created
* d2gamescreen + d2player: asset manager references
added an asset manager reference to
- inventory panel + inventory grid
- mini panel
- game controls
- help overlay
- character select
- main menu
- select hero class
- hero stats panel
* Removed d2asset.LoadAnimation
all references to this function have been replaced with calls to the asset manager method
* adding asset to help overlay, bugfix for 4d59c91
* Removed d2asset.LoadFont and d2asset.LoadAnimationWithEffect
all references to these have been replaced with calls to the asset manager methods
* MapRenderer now gets an asset manager reference
* removed d2asset.LoadPalette
all references have been replaced with calls to an asset manager instance
* merged d2object with d2mapentity
d2object was only being used to create objects in the map, so the provider
function is now a method of the map entity factory. calls to d2asset have
been removed.
* removed d2asset.LoadComposite
all calls are now made to the asset manager method
* removed d2asset singleton
all singleton references have been removed, a single instance of the
asset manager is passed around the entire app
* rename Initialize to NewAssetManager
* lint fixes for the game.go
* lint fixes for the gui_testing.go
* lint fixes for the blizzard_intro.go, map_engine_testing.go and select_hero_class.go
* added package comment for the d2gamescreen package
* fixes after merge
