Refactor light animation in regenerateMana spell using easing

lib/spellbook.lua

@@ -11,6 +11,7 @@ local task       = require 'lib.utils.task'
 local spell      = require 'lib.spell.spell'
 local targetTest = require 'lib.spell.target_test'
 local Query      = require "lib.spell.target_query"
+local easing     = require "lib.utils.easing"
 
 local walk       = setmetatable({
     --- @type Deque
@@ -89,17 +90,12 @@ local regenerateMana = spell.new {
             Tree.behaviors.positioned.new(caster:has(Tree.behaviors.positioned).position + Vec3 { 0.5, 0.5 }),
         }
 
-        local flash = function(callback)
-            light:has(Tree.behaviors.light):animateColor(Vec3 {})(
-                function()
-                    light:die()
-                    callback()
-                end
-            )
-        end
-
         return task.wait {
-            flash,
+            task.chain(task.tween(light:has(Tree.behaviors.light) --[[@as LightBehavior]],
+                { intensity = 1, color = Vec3 {} }, 1000, easing.easeInCubic), function()
+                light:die()
+                return task.fromValue()
+            end),
             sprite:animate("hurt")
         }
     end