feat: add a finite state machine to actors

sonic-radiance.love/birb/classes/states/init.lua

@@ -0,0 +1,102 @@
+-- classes/states :: a finite state machine for objects
+
+--[[
+  Copyright © 2022 Kazhnuz
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy of
+  this software and associated documentation files (the "Software"), to deal in
+  the Software without restriction, including without limitation the rights to
+  use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+  the Software, and to permit persons to whom the Software is furnished to do so,
+  subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in all
+  copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+  FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+  COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+  IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+]]
+
+local StateMachine = Object:extend()
+
+function StateMachine.addState(self, name, state, isDefault)
+    if (self.states == nil) then
+        self.states = {}
+        self.states.list = {}
+    end
+
+	self.states.list[name] = state
+    
+    if (isDefault == true) then
+    	self.states.default = name
+	end
+end
+
+function StateMachine.addStates(self, statesPath, default)
+    local states = require(statesPath)
+    for i, stateName in ipairs(states) do
+        local state = require(statesPath .. "." .. stateName)
+        self:addState(stateName, state)
+    end
+    self.states.default = default
+end
+
+function StateMachine:initStates()
+    if (self.states == nil) then
+        self.states = {}
+        self.states.list = {}
+    end
+	self.currentState = self.states.default or "none"
+end
+
+function StateMachine:updateState(dt)
+    self:playStateFunc("update", dt)
+end
+
+function StateMachine:haveState(state)
+    return (self.states.list[state] ~= nil)
+end
+
+function StateMachine:setState(state)
+    if (not self:haveState(state)) then
+        return self.currentState
+    end
+    self:playStateFunc("stop", state)
+    local currentState = self.currentState
+    self.currentState = state
+    self:playStateFunc("start", currentState)
+    return state
+end
+
+function StateMachine:getState()
+	return self.states.list[self.currentState]
+end
+
+function StateMachine:getStateVar(varName, default)
+	local state = self:getState()
+    if (state == nil) then
+        return nil
+    end
+    local var = state[varName]
+    if (var == nil) then
+        return default
+    end
+    return var
+end
+
+function StateMachine:playStateFunc(funcName, ...)
+	local state = self:getState()
+    if (state == nil) then
+        return
+    end
+    local func = state[funcName]
+    if (func ~= nil) then
+        func(self, ...)
+    end
+end
+
+return StateMachine

sonic-radiance.love/birb/modules/world/actors/actor2D.lua

@@ -29,6 +29,8 @@ local TimedActor = require("birb.modules.world.actors.mixins.timers")
 local InputActor = require("birb.modules.world.actors.mixins.inputs")
 local PhysicalActor = require("birb.modules.world.actors.mixins.physics")
 
+local StateMachine = require("birb.classes.states")
+
 local Actor2D = Rect:extend()
 Actor2D:implement(BaseActor)
 Actor2D:implement(SpritedActor)
@@ -36,6 +38,8 @@ Actor2D:implement(TimedActor)
 Actor2D:implement(InputActor)
 Actor2D:implement(PhysicalActor)
 
+Actor2D:implement(StateMachine)
+
 local Hitbox  = require "birb.modules.world.actors.utils.hitbox2D"
 
 -- INIT FUNCTIONS
@@ -49,6 +53,7 @@ function Actor2D:new(world, type, x, y, w, h, isSolid)
   self:initTimers()
   self:initSprite()
   self:initKeys()
+  self:initStates()
 end
 
 function Actor2D:destroy()

sonic-radiance.love/birb/modules/world/actors/actor3D.lua

@@ -33,6 +33,8 @@ local InputActor = require("birb.modules.world.actors.mixins.inputs")
 local PhysicalActor = require("birb.modules.world.actors.mixins.physics")
 local Shape3DActor = require("birb.modules.world.actors.mixins.shapes")
 
+local StateMachine = require("birb.classes.states")
+
 local Actor3D = BasicBox:extend()
 Actor3D:implement(BaseActor)
 Actor3D:implement(SpritedActor)
@@ -41,6 +43,8 @@ Actor3D:implement(InputActor)
 Actor3D:implement(PhysicalActor)
 Actor3D:implement(Shape3DActor)
 
+Actor3D:implement(StateMachine)
+
 -- INIT FUNCTIONS
 -- Initialise the actor and its base functions
 
@@ -52,6 +56,7 @@ function Actor3D:new(world, type, x, y, z, w, h, d, isSolid)
   self:initSprite()
   self:initKeys()
   self:initShape(Boxes, true)
+  self:initStates()
 end
 
 function Actor3D:destroy()

sonic-radiance.love/birb/modules/world/actors/mixins/base.lua

@@ -88,6 +88,7 @@ end
 function BaseActor:update(dt)
   self:updateStart(dt)
   self:applyUpdateFunctions(dt)
+  self:updateState(dt)
   self:updateEnd(dt)
 end