Smooth out weapon usage and movement, add health bar.

src/kani.lua

@@ -13,7 +13,7 @@ local WEAPON_CHARGE_LOOKUP <const> = {
    [0]=5,
    [1]=15,
    [2]=30,
-   [3]=49
+   [3]=50
 }
 
 -- maximum value the reserve charge can reach
@@ -24,7 +24,7 @@ class("Kani").extends(gfx.sprite)
 function Kani:init(ui)
    local img = gfx.image.new("images/kani.png")
    Kani.super.init(self, img)
-   print(self)
+
    self:setCollideRect(0, 0, self:getSize())
    self.vector = {x=0,y=0} -- movement direction
    self:setGroupMask(0x2)
@@ -39,10 +39,10 @@ function Kani:init(ui)
 
    -- input handlers
    self.inputHandlers = {
-      upButtonDown =    function() self.vector.y = -1 end,
-      downButtonDown =  function() self.vector.y = 1 end,
-      leftButtonDown =  function() self.vector.x = -1 end,
-      rightButtonDown = function() self.vector.x = 1 end,
+      upButtonDown =    function() self.vector.y = -3 end,
+      downButtonDown =  function() self.vector.y = 3 end,
+      leftButtonDown =  function() self.vector.x = -3 end,
+      rightButtonDown = function() self.vector.x = 3 end,
       upButtonUp =      function() self.vector.y = 0 end,
       downButtonUp =    function() self.vector.y = 0 end,
       leftButtonUp =    function() self.vector.x = 0 end,
@@ -56,7 +56,7 @@ function Kani:init(ui)
 end
 
 function Kani:chargeReserve(change)
-   if change < 0 then return end
+   if change <= 0 then return end
    self.reserveCharge = math.min(self.reserveCharge + change / 15, 100)
    self.ui.chargeMeter:setValue(self.reserveCharge)
 end
@@ -65,9 +65,16 @@ function Kani:chargeShot()
    if self.weaponPower >= 4 then
       return -- weapon is fully charged
    end
+
    local requiredPower = WEAPON_CHARGE_LOOKUP[self.weaponPower]
-   if self.reserveCharge > requiredPower then
-      self.reserveCharge -= requiredPower
+
+   -- We use math.ceil here so that any fractional charge rounds up.
+   -- This ensures we can always use our last bit of juice for a level 1 shot,
+   -- and smooths out play experience around fully charged values.
+   local effectiveCharge = math.ceil(self.reserveCharge)
+
+   if effectiveCharge >= requiredPower then
+      self.reserveCharge = effectiveCharge - requiredPower
       self.weaponPower += 1
       print("Shot charged to size " .. self.weaponPower)
       self.ui.chargeMeter:setValue(self.reserveCharge)