WebGLLayer now recycles previous sprite sheets, speeding up rendering additional thang types or animations.

app/lib/surface/Layer.coffee

@@ -34,7 +34,6 @@ layerProperties = {
     @layerPriority = options.layerPriority ? 0
     @transformStyle = options.transform ? layerClassProperties.TRANSFORM_CHILD
     @camera = options.camera
-    console.debug @toString(), 'needs a camera.' unless @camera
     @updateLayerOrder = _.bind(@updateLayerOrder, @) 
     @updateLayerOrder = _.throttle @updateLayerOrder, 1000 / 30  # Don't call multiple times in one frame; 30 FPS is probably good enough
     Backbone.Mediator.subscribe(channel, @[func], @) for channel, func of @subscriptions

app/lib/surface/WebGLLayer.coffee

@@ -146,6 +146,7 @@ module.exports = class WebGLLayer extends CocoClass
       return
     
     @spriteSheet = builder.spriteSheet
+    @spriteSheet.resolutionFactor = @resolutionFactor
     oldLayer = @spriteContainer 
     @spriteContainer = new SpriteContainerLayer(@spriteSheet, @layerOptions)
     for cocoSprite in @cocoSprites
@@ -178,8 +179,13 @@ module.exports = class WebGLLayer extends CocoClass
     spriteBuilder = new SpriteBuilder(thangType, {colorConfig: colorConfig})
     for containerGlobalName in _.keys(containersToRender)
       containerKey = @renderGroupingKey(thangType, containerGlobalName, colorConfig)
-      container = spriteBuilder.buildContainerFromStore(containerGlobalName)
-      frame = spriteSheetBuilder.addFrame(container, null, @resolutionFactor * (thangType.get('scale') or 1))
+      if @spriteSheet?.resolutionFactor is @resolutionFactor and containerKey in @spriteSheet.getAnimations()
+        container = new createjs.Sprite(@spriteSheet)
+        container.gotoAndStop(containerKey)
+        frame = spriteSheetBuilder.addFrame(container)
+      else
+        container = spriteBuilder.buildContainerFromStore(containerGlobalName)
+        frame = spriteSheetBuilder.addFrame(container, null, @resolutionFactor * (thangType.get('scale') or 1))
       spriteSheetBuilder.addAnimation(containerKey, [frame], false)
 
   getContainersForAnimation: (thangType, animation) ->
@@ -202,6 +208,22 @@ module.exports = class WebGLLayer extends CocoClass
     for animationName, actions of animationGroups
       renderAll = _.any actions, (action) -> action.frames is undefined
       scale = actions[0].scale or thangType.get('scale') or 1
+      
+      actionKeys = (@renderGroupingKey(thangType, action.name, colorConfig) for action in actions)
+      if @spriteSheet?.resolutionFactor is @resolutionFactor and _.all(actionKeys, (key) => key in @spriteSheet.getAnimations())
+        framesNeeded = _.uniq(_.flatten((@spriteSheet.getAnimation(key)).frames for key in actionKeys))
+        framesMap = {}
+        for frame in framesNeeded
+          sprite = new createjs.Sprite(@spriteSheet)
+          sprite.gotoAndStop(frame)
+          framesMap[frame] = spriteSheetBuilder.addFrame(sprite)
+        for key, index in actionKeys
+          action = actions[index]
+          frames = (framesMap[f] for f in @spriteSheet.getAnimation(key).frames)
+          next = @nextForAction(action)
+          spriteSheetBuilder.addAnimation(key, frames, next)
+        continue
+      
       mc = spriteBuilder.buildMovieClip(animationName, null, null, null, {'temp':0})
       
       if renderAll
@@ -223,11 +245,7 @@ module.exports = class WebGLLayer extends CocoClass
           frames = (framesMap[parseInt(frame)] for frame in action.frames.split(','))
         else
           frames = _.values(framesMap).sort()
-          
-        next = true
-        next = action.goesTo if action.goesTo
-        next = false if action.loops is false
-
+        next = @nextForAction(action)
         spriteSheetBuilder.addAnimation(name, frames, next) 
         
     containerActions = []
@@ -245,6 +263,12 @@ module.exports = class WebGLLayer extends CocoClass
         name = @renderGroupingKey(thangType, action.name, colorConfig)
         spriteSheetBuilder.addAnimation(name, [frame], false)      
     
+  nextForAction: (action) ->
+    next = true
+    next = action.goesTo if action.goesTo
+    next = false if action.loops is false
+    return next
+        
   renderRasterImage: (thangType, spriteSheetBuilder) ->
     unless thangType.rasterImage
       console.error("Cannot render the WebGLLayer SpriteSheet until the raster image for <#{thangType.get('name')}> is loaded.")

test/app/lib/surface/WebGLLayer.spec.coffee

@@ -3,6 +3,7 @@ CocoSprite = require 'lib/surface/CocoSprite'
 ThangType = require 'models/ThangType'
 treeThangType = new ThangType(require 'test/app/fixtures/tree1.thang.type')
 ogreMunchkinThangType = new ThangType(require 'test/app/fixtures/ogre-munchkin-m.thang.type')
+SpriteBuilder = require 'lib/sprites/SpriteBuilder'
 
 describe 'WebGLLayer', ->
   layer = null
@@ -118,3 +119,49 @@ describe 'WebGLLayer', ->
     thangType2.trigger('raster-image-loaded', thangType2)
     expect(layer.numThingsLoading).toBe(0)
     expect(layer._renderNewSpriteSheet).toHaveBeenCalled()
+
+  it 'recycles *containers* from previous sprite sheets, rather than building repeatedly from raw vector data', ->
+    treeThangType.set('renderStrategy', 'container')
+    sprite = new CocoSprite(treeThangType)
+    layer.addCocoSprite(sprite)
+    spyOn(SpriteBuilder.prototype, 'buildContainerFromStore').and.callThrough()
+    for i in _.range(2)
+      sheet = layer.renderNewSpriteSheet()
+    expect(SpriteBuilder.prototype.buildContainerFromStore.calls.count()).toBe(1)
+
+  it '*does not* recycle *containers* from previous sprite sheets when the resolutionFactor has changed', ->
+    treeThangType.set('renderStrategy', 'container')
+    sprite = new CocoSprite(treeThangType)
+    layer.addCocoSprite(sprite)
+    spyOn(SpriteBuilder.prototype, 'buildContainerFromStore').and.callThrough()
+    for i in _.range(2)
+      layer.resolutionFactor *= 1.1
+      sheet = layer.renderNewSpriteSheet()
+    expect(SpriteBuilder.prototype.buildContainerFromStore.calls.count()).toBe(2)
+
+  it 'recycles *animations* from previous sprite sheets, rather than building repeatedly from raw vector data', ->
+    ogreMunchkinThangType.set('renderStrategy', 'spriteSheet')
+    sprite = new CocoSprite(ogreMunchkinThangType)
+    layer.addCocoSprite(sprite)
+    numFrameses = []
+    spyOn(SpriteBuilder.prototype, 'buildMovieClip').and.callThrough()
+    for i in _.range(2)
+      sheet = layer.renderNewSpriteSheet()
+      numFrameses.push(sheet.getNumFrames())
+
+    # this process should not have created any new frames
+    expect(numFrameses[0]).toBe(numFrameses[1])
+
+    # one movie clip made for each raw animation: move (3), attack, die
+    expect(SpriteBuilder.prototype.buildMovieClip.calls.count()).toBe(5)
+
+  it '*does not* recycles *animations* from previous sprite sheets when the resolutionFactor has changed', ->
+    ogreMunchkinThangType.set('renderStrategy', 'spriteSheet')
+    sprite = new CocoSprite(ogreMunchkinThangType)
+    layer.addCocoSprite(sprite)
+    spyOn(SpriteBuilder.prototype, 'buildMovieClip').and.callThrough()
+    for i in _.range(2)
+      layer.resolutionFactor *= 1.1
+      sheet = layer.renderNewSpriteSheet()
+
+    expect(SpriteBuilder.prototype.buildMovieClip.calls.count()).toBe(10)