Add thang sound panning for #454

app/lib/AudioPlayer.coffee

@@ -38,6 +38,7 @@ class AudioPlayer extends CocoClass
   constructor: () ->
     super()
     @ext = if createjs.Sound.getCapability('mp3') then '.mp3' else '.ogg'
+    @camera = null
     @listenToSound()
     @createNewManifest()
     @soundsToPlayWhenLoaded = {}
@@ -51,6 +52,13 @@ class AudioPlayer extends CocoClass
     # So for now, we'll just load through SoundJS instead.
     createjs.Sound.on 'fileload', @onSoundLoaded
 
+  applyPanning: (options, pos) ->
+    sup = @camera.worldToSurface pos
+    svp = @camera.surfaceViewport
+    pan = Math.max -1, Math.min 1, ((sup.x - svp.x) - svp.width / 2) / svp.width * 2
+    # TODO: derive new volume from old one and distance ratio
+    volume: options.volume, delay: options.delay, pan: pan
+
   # PUBLIC LOADING METHODS
 
   soundForDialogue: (message, soundTriggers) ->
@@ -78,8 +86,11 @@ class AudioPlayer extends CocoClass
       @preloadInterfaceSounds [name] unless filename of cache
       @soundsToPlayWhenLoaded[name] = volume
 
-  playSound: (name, volume=1, delay=0) ->
-    instance = createjs.Sound.play name, {volume: (me.get('volume') ? 1) * volume, delay: delay}
+  playSound: (name, volume=1, delay=0, pos=null) ->
+    audioOptions = {volume: (me.get('volume') ? 1) * volume, delay: delay}
+    unless @camera is null or pos is null
+      audioOptions = @applyPanning audioOptions, pos
+    instance = createjs.Sound.play name, audioOptions
     instance
 
 #  # TODO: load Interface sounds somehow, somewhere, somewhen

app/lib/surface/CocoSprite.coffee

@@ -188,6 +188,13 @@ module.exports = CocoSprite = class CocoSprite extends CocoClass
     return 0 unless @thang.bobHeight
     @thang.bobHeight * (1 + Math.sin(@age * Math.PI / @thang.bobTime))
 
+  getWorldPosition: ->
+    p1 = @thang.pos
+    if bobOffset = @getBobOffset()
+      p1 = p1.copy?() or _.clone(p1)
+      p1.z += bobOffset
+    x: p1.x, y: p1.y, z: if @thang.isLand then 0 else p1.z - @thang.depth / 2
+
   updatePosition: ->
     return unless @thang?.pos and @options.camera?
     [p0, p1] = [@lastPos, @thang.pos]
@@ -477,6 +484,6 @@ module.exports = CocoSprite = class CocoSprite extends CocoClass
     return null unless sound
     delay = if withDelay and sound.delay then 1000 * sound.delay / createjs.Ticker.getFPS() else 0
     name = AudioPlayer.nameForSoundReference sound
-    instance = AudioPlayer.playSound name, volume, delay
+    instance = AudioPlayer.playSound name, volume, delay, @getWorldPosition()
 #    console.log @thang?.id, "played sound", name, "with delay", delay, "volume", volume, "and got sound instance", instance
     instance

app/lib/surface/Surface.coffee

@@ -360,6 +360,7 @@ module.exports = Surface = class Surface extends CocoClass
     canvasHeight = parseInt(@canvas.attr('height'), 10)
     @camera?.destroy()
     @camera = new Camera canvasWidth, canvasHeight
+    AudioPlayer.camera = @camera
     @layers.push @surfaceLayer = new Layer name: "Surface", layerPriority: 0, transform: Layer.TRANSFORM_SURFACE, camera: @camera
     @layers.push @surfaceTextLayer = new Layer name: "Surface Text", layerPriority: 1, transform: Layer.TRANSFORM_SURFACE_TEXT, camera: @camera
     @layers.push @screenLayer = new Layer name: "Screen", layerPriority: 2, transform: Layer.TRANSFORM_SCREEN, camera: @camera