Implement first enemy, bullet damage and collision.

src/kani.lua

@@ -3,6 +3,7 @@ import "CoreLibs/object"
 import "CoreLibs/graphics"
 import "CoreLibs/sprites"
 import "CoreLibs/timer"
+import "entity"
 import "bullet"
 import "ui"
 
@@ -19,19 +20,16 @@ local WEAPON_CHARGE_LOOKUP <const> = {
    [3]=50
 }
 
-class("Kani").extends(gfx.sprite)
+class("Kani").extends(Entity)
 
 function Kani:init(ui)
    local img = gfx.image.new("images/kani.png")
-   Kani.super.init(self, img)
+   Kani.super.init(self, img, 100)
 
-   self:setCollideRect(0, 0, self:getSize())
    self.vector = {x=0,y=0} -- movement direction
    self:setGroupMask(0x2)
    self:setCollidesWithGroupsMask(0x19)
 
-   -- stats
-   self.health = 100
    self.reserveCharge = 100
 
    -- controls the speed the crank recharges the player's reserves. A lower number allows faster charging.
@@ -106,12 +104,12 @@ function Kani:fire()
 end
 
 function Kani:damage(amount)
-   self.health = math.max(self.health - amount, 0)
-
-   if self.health <= 0 then
-      -- TODO: destroy ship
-   end
+   Kani.super.damage(self, amount)
    self.ui.healthMeter:setValue(self.health)
+
+   if self.health == 0 then
+      -- TODO: end game here
+   end
 end
 
 function Kani:addInputHandlers()