Fix defend state, add animation tables (not used quite yet), and add onExit functions to the state machine.

src/entity.lua

@@ -16,6 +16,10 @@ function Entity:init(img, health, armor)
    self.armor = armor or 0
    self.introAnimator = nil
 
+   -- For imagetable-based animation
+   self.animationIndex = nil
+   self.animationTimer = nil
+
    -- movement direction, every update() the entity will move along this vector and return
    -- collision data to the subclass
    self.vector = geom.vector2D.new(0, 0)
@@ -32,15 +36,15 @@ function Entity:init(img, health, armor)
    local states = {
       ["INIT"] = {
          main=self.runInit,
-         transition=self.onInit
+         incoming=self.onInit
       },
       ["INTRO"] = {
          main=self.runIntro,
-         transition=self.onIntro,
+         incoming=self.onIntro,
       },
       ["READY"] = {
          main=self.runReady,
-         transition=self.onReady,
+         incoming=self.onReady,
       },
    }
    self.fsm = StateMachine.new({self}, states)
@@ -68,6 +72,26 @@ end
 function Entity:update()
    -- update state machine
    self.fsm:execute()
+
+   if self.animationTimer then
+      local targetIndex = math.floor(self.animationTimer.value)
+      if self.animationIndex ~= targetIndex then
+         self:setImage(self.animationTable:getImage(targetIndex))
+      end
+   end
+end
+
+-- animate the entity based on the passed in imageTable. If reverse is true, play the
+-- animation backwards. duration is how long the animation should be in total
+function Entity:animate(imgTable, duration, reverse)
+   self.animationTable = imgTable
+   local startValue = 1
+   local endValue = #imgTable
+   if reverse then
+      startValue = #imgTable
+      endValue = 1
+   end
+   self.animationTimer = playdate.timer.new(duration, startValue, endValue)
 end
 
 -- State machine-controlled functions

src/kani.lua

@@ -69,25 +69,7 @@ function Kani:init(ui)
    -- the UI gets passed in to Kani so that we can update pieces of it easily.
    self.ui = ui
 
-   self.inputHandlers = {
+   self.fsm:addState("DEFEND", self.runDefend, self.onDefend, self.onDefendExit)
-      upButtonDown =    function() self.vector.dy = -3 end,
-      downButtonDown =  function() self.vector.dy = 3 end,
-      leftButtonDown =  function() self.vector.dx = -3 end,
-      rightButtonDown = function() self.vector.dx = 3 end,
-      upButtonUp =      function() self.vector.dy = 0 end,
-      downButtonUp =    function() self.vector.dy = 0 end,
-      leftButtonUp =    function() self.vector.dx = 0 end,
-      rightButtonUp =   function() self.vector.dx = 0 end,
-      cranked = function(change, accelChange) self:chargeReserve(change) end,
-      AButtonDown = function()
-         self.firingTimer = playdate.timer.keyRepeatTimerWithDelay(self.weaponChargeSpeed / 2,
-                                                                   self.weaponChargeSpeed,
-                                                                   self.chargeShot, self)
-      end,
-      AButtonUp = function() self:fire() end,
-   }
-
-   self.fsm:changeState("READY")
 end
 
 function Kani:chargeReserve(change)
@@ -138,24 +120,65 @@ end
 function Kani:damage(amount)
    Kani.super.damage(self, amount)
    self.ui.healthMeter:setValue(self.health)
-
+   print("Kani health now at " .. self.health) -- debug
    if self.health == 0 then
       -- TODO: end game here
    end
 end
 
-function Kani:addInputHandlers()
-   playdate.inputHandlers.push(self.inputHandlers)
-end
-
-function Kani:removeInputHandlers()
-   playdate.inputHandlers.pop()
-end
-
 -- move that crab!
 function Kani:runReady()
+   -- input handling
+   if playdate.buttonIsPressed(playdate.kButtonDown) then
+      self.vector.dy = 3
+   elseif playdate.buttonIsPressed(playdate.kButtonUp) then
+      self.vector.dy = -3
+   else
+      self.vector.dy = 0
+   end
+
+   if playdate.buttonIsPressed(playdate.kButtonLeft) then
+      self.vector.dx = -3
+   elseif playdate.buttonIsPressed(playdate.kButtonRight) then
+      self.vector.dx = 3
+   else
+      self.vector.dx = 0
+   end
+
+   local change = select(1, playdate.getCrankChange())
+   self:chargeReserve(change)
+
+   if playdate.buttonJustPressed(playdate.kButtonA) then
+      self.firingTimer = playdate.timer.keyRepeatTimerWithDelay(self.weaponChargeSpeed / 2,
+                                                                self.weaponChargeSpeed,
+                                                                self.chargeShot, self)
+   end
+   if playdate.buttonJustReleased(playdate.kButtonA) then
+      self:fire()
+   end
+
+   if playdate.buttonIsPressed(playdate.kButtonB) then
+      print("Triggering entrance to DEFEND mode")
+      self.fsm:changeState("DEFEND")
+   end
+
+   -- collision handling
    local collisions = Kani.super.runReady(self)
    for i=0, #collisions, 1 do
       -- TODO: handle player-triggered collisions
    end
 end
+
+function Kani:onDefend()
+   self.armor = 5
+end
+
+function Kani:onDefendExit()
+   self.armor = 0
+end
+
+function Kani:runDefend()
+   if not playdate.buttonIsPressed(playdate.kButtonB) then
+      self.fsm:changeState("READY")
+   end
+end

src/main.lua

@@ -23,7 +23,6 @@ function setup()
    ui = UI()
    player = Kani(ui)
    player:moveTo(16, 120)
-   player:addInputHandlers()
    player:add()
    ui:add()
    currentWave = newWave()
@@ -31,13 +30,6 @@ function setup()
 
    makeWalls()
    drawBackground()
-
-   -- debug, TODO remove this code
-   playdate.inputHandlers.push({
-         BButtonUp = function()
-            print(gfx.sprite.spriteCount())
-         end
-   })
 end
 
 function makeWalls()

src/statemachine.lua

@@ -10,24 +10,26 @@ end
 
 -- params is a table of parameters to always pass to the functions
 -- stateTable is a table of initial states. Entries should be of the form:
---   name = {main=mainFunc, transition=transFunc}
+--   name = {main=mainFunc, incoming=inFunc, outgoing=outFunc}
 --   where mainFunc and transFunc are functions that should be executed in relation to the state.
 --   the State Machine will call mainFunc on execute()
---   the State Machine will call transFunc when the state is entered
+--   the State Machine will call inFunc when the state is entered
+--   the State Machine will call outFunc when the state in exited
 function StateMachine:init(params, stateTable)
    self.currentState = nil
    self.parameters = params or {}
    self.states = stateTable or {}
 end
 
-function StateMachine:addState(name, mainFunc, transFunc)
+function StateMachine:addState(name, mainFunc, inFunc, outFunc)
-   self.states[name] = {main=mainFunc, transition=transFunc}
+   self.states[name] = {main=mainFunc, incoming=inFunc, outgoing=outFunc}
 end
 
 -- execute the main function for the current state.
 -- returns true if the function was executed, false otherwise
 function StateMachine:execute()
-   if self.currentState == nil or not self.states[self.currentState] then
+   if self.currentState == nil or not self.states[self.currentState]
+      or not self.states[self.currentState].main then
       return false
    end
 
@@ -37,11 +39,22 @@ end
 
 -- change to the specified state. returns true if the state change is successful
 function StateMachine:changeState(state)
-   if not self.states[state] then return false end
+   if not self.states[state] then
+      print("WARN (StateMachine): tried to enter nonexistent state " .. state)
+      return false
+   end
 
+   -- run the exit function for the previous state
+   if self.currentState and self.states[self.currentState].outgoing then
+      self.states[self.currentState].outgoing(table.unpack(self.parameters))
+   end
+
+   -- change state
    self.currentState = state
-   if self.states[state].transition then
+
-      self.states[state].transition(table.unpack(self.parameters))
+   -- run the entrance function for the new state
+   if self.states[state].incoming then
+      self.states[state].incoming(table.unpack(self.parameters))
    end
    return true
 end