refactor(entities): shorten component getters/checkers for entities

1 files changed, 98 insertions, 91 deletions

diff --git a/raccoon.lua b/raccoon.lua
index 0ada342..c0fec2f 100644
--- a/raccoon.lua
+++ b/raccoon.lua
@@ -104,41 +104,51 @@ end
 -- Entities keep track of components using a table indexed by component
 -- class.
 -- @usage
--- Given an entity `e`,  a component `c` of class `C`
+-- Given an entity `e`,  a component `c1` of class `C`
 -- ```
---      e:with_component(c)
---      e.has_component[C]      -- true
---      e.get_component[C]      -- c
+--      e:with(c1)
+--      e:has_c() == e:components[c1.__index] == true
+--      e:get_c() == e:components[c1.__index] == c1
 -- ```
+--
+-- @return this entity.
 function Entity:init()
     self.id = Entity.get_id()
-    self.has_component = {}
-    self.get_component = {}
+    self.components = {}
     return self
 end
 --- Add component to this entity.
--- @param c the component to be added to this entity.
+-- @param t the component(s) to be added to this entity.
 -- @return this entity.
 --
 -- @note the modified entity is returned to allow chains of multiple calls to this method.
+--
 -- @usage
 -- ```
---     entity
---       :with_component(c1)
---       :with_component(c2)
---       :with_component(c3)
+--     entity:with(c1):with(c2):with(c3)
+--     entity:with({c1,c2,c3})
 -- ```
-function Entity:with_component(c)
-    self.has_component[c.__index] = true
-    self.get_component[c.__index] = c
+function Entity:with(t)
+    if t.meta then
+        self.components[t.__index] = t
+    else
+        for _,c in ipairs(t) do
+            self.components[c.__index] = c
+        end
+    end
     return self
 end
 --- Remove component from this entity.
--- @param c the component to be removed from this entity.
+-- @param t the component(s) to be removed from this entity.
 -- @return this entity.
-function Entity:remove_component(c)
-    self.has_component[c.__index] = false
-    self.get_component[c.__index] = nil    -- possibly triggers GC
+function Entity:without(t)
+    if t.meta then
+        self.components[t.__index] = nil    -- possibly triggers GC
+    else
+        for _,c in ipairs(t) do
+            self.components[c.__index] = nil
+        end
+    end
     return self
 end
 
@@ -147,12 +157,20 @@ end
 -- component. Components are what make entities interesting and
 -- different from each other.
 --
--- @note at the moment this is simply a wrapper to create a new class.
--- Component-specific functions can be added in the wrapper, if
--- necessary.
+-- The new component keeps track of its name in a `meta` table inside of it.
+-- @note for `t` table, you can use `t.meta` as a boolean check for whether `t`
+-- is a component.
+--
+-- Given a component "Comp", functions `has_comp` and `get_comp` are added to `Entity`.
 local Component = util.new_class()
-function Component:init()
-    return util.new_class()
+function Component:init(name)
+    local component = util.new_class()
+    component.meta = { name = name or "" } -- NOTE use meta as "component check"
+    if name then
+        Entity["has_"..name:lower()] = function(self) return self.components[_G[name].__index] end
+        Entity["get_"..name:lower()] = function(self) return self.components[_G[name].__index] end
+    end
+    return component
 end
 
 --- Systems.
@@ -188,7 +206,7 @@ function System:init(...)
             -- @todo is there a better way?
             local selected = true
             for _, component in ipairs(self.components) do
-                if not entity.has_component[component] then
+                if not Entity["has_"..component.meta.name:lower()](entity) then
                     selected = false
                     break
                 end
@@ -199,7 +217,7 @@ function System:init(...)
                     if cmps then
                         -- Remove components from entity
                         for _,c in ipairs(cmps) do
-                            entity:remove_component(c)
+                            entity:without(c)
                         end
                     else
                         -- Remove entity
@@ -212,7 +230,7 @@ function System:init(...)
     return cls
 end
 
-local Pos = Component()
+Pos = Component("Pos")
 function Pos:init(x,y)
     self.x = x or 0
     self.y = y or 0
@@ -235,7 +253,7 @@ function Pos:to_screen(lpos)
     return self.x - lpos.x, self.y - lpos.y
 end
 
-local Movement = Component()
+Movement = Component("Movement")
 function Movement:init(accel, max)
     -- direction facing
     self.dir = true -- true: right, false: left
@@ -250,19 +268,19 @@ function Movement:is_moving()
     return self.cur.x ~= 0 or self.cur.y ~= 0
 end
 
-local Pixel = Component()
+Pixel = Component("Pixel")
 function Pixel:init(c)
     self.color = c
     return self
 end
 
-local Sprite = Component()
+Sprite = Component("Sprite")
 function Sprite:init(i)
     self.i = i
     return self
 end
 
-local Jump = Component()
+Jump = Component("Jump")
 function Jump:init(pwr)
     self.jumping = false
     self.cur = 0
@@ -270,7 +288,7 @@ function Jump:init(pwr)
     return self
 end
 
-local Input = Component()
+Input = Component("Input")
 function Input:init(up, down, left, right, a, b)
     self.btns = { up or 0, down or 1, left or 2, right or 3, a or 4, b or 5 }
     self.raw = { false, false, false, false, false, false }
@@ -278,14 +296,14 @@ function Input:init(up, down, left, right, a, b)
     return self
 end
 
-local Level = Component()
+Level = Component("Level")
 function Level:init(id, screens)
     self.id = id
     self.screens = screens
     return self
 end
 
-local Entities = Component()
+Entities = Component("Entities")
 function Entities:init(list)
     for i,v in pairs(list) do
         self[i] = v
@@ -300,7 +318,7 @@ function Action:init(a,b)
     return self
 end
 
-local CircleEffect = Component()
+CircleEffect = Component("CircleEffect")
 function CircleEffect:init(r2, r1, time, color)
     self.r2 = r2
     self.r1 = r1 or 1
@@ -312,7 +330,7 @@ function CircleEffect:draw(x,y)
     circb(x,y,self.r1,self.color)
 end
 
-local PosAnim = Component()
+PosAnim = Component("PosAnim")
 function PosAnim:init(f,d)
     self.t = 0
     self.d = d
@@ -320,7 +338,7 @@ function PosAnim:init(f,d)
     return self
 end
 
-local Particles = Component()
+Particles = Component("Particles")
 function Particles:init(d)
     self.t = 0
     self.d = d
@@ -332,21 +350,21 @@ function Particles:spawn(pos, entities)
         local offset = math.random(7) -- TODO change to pos.width once implemented
         local speed = 0.2 + math.random()
         table.insert(entities,
-            Entity():with_component(Pixel(12))
-                    :with_component(Pos(pos.x + offset,pos.y))
-                    :with_component(PosAnim(function(t,p) p.y = p.y - speed end, 10)))
+            Entity():with(Pixel(12))
+                    :with(Pos(pos.x + offset,pos.y))
+                    :with(PosAnim(function(t,p) p.y = p.y - speed end, 10)))
     end
 end
 
-local ForceField = Component()
 function ForceField:init(force,range,instant)
+ForceField = Component("ForceField")
     self.force = force or 1
     self.range = range or 1
     self.instant = instant
     return self
 end
 
-local Metadata = Component()
+Metadata = Component("Metadata")
 function Metadata:init(name)
     self.name = name or "Unnamed"
     return self
@@ -354,12 +372,11 @@ end
 
 local ForceFieldSystem = System(Pos,ForceField)
 function ForceFieldSystem:exec(entity,enemies)
-    local pos = entity.get_component[Pos]
-    local ff = entity.get_component[ForceField]
+    local pos = entity:get_pos()
+    local ff = entity:get_forcefield()
     for _,e in pairs(enemies) do
-        if e.has_component[Pos] and e.has_component[Movement] then
-            local pos1 = e.get_component[Pos]
-            local mov = e.get_component[Movement]
+        if e:has_pos() and ff.is_target(e) then
+            local pos1 = e:get_pos()
             local dist,vec = util.distance(pos,pos1)
             if dist < ff.range then
                 if e.has_component[Metadata] then
@@ -380,7 +397,7 @@ end
 
 local InputSystem = System(Input)
 function InputSystem:exec(entity)
-    local input = entity.get_component[Input]
+    local input = entity:get_input()
     for i = 1,6 do
         input.raw[i] = btn(input.btns[i])
         input.rawp[i] = btnp(input.btns[i])
@@ -520,25 +537,25 @@ function DrawingSystem:exec(entity,level)
 end
 function DrawingSystem:draw(game)
     local level = game.levels[game.level]
-    local info = level.get_component[Level]
-    local pos = level.get_component[Pos]
+    local info = level:get_level()
+    local pos = level:get_pos()
     map(pos.x//8,pos.y//8,31,18,-(pos.x%8),-(pos.y%8),-1)
     DrawingSystem:run(game.entities,pos)
 end
 
 local LevelSystem = System(Level)
 function LevelSystem:exec(level, game)
-    local info = level.get_component[Level]
-    local lpos = level.get_component[Pos]
-    local entities = level.get_component[Entities]
-    local ppos = game.player.get_component[Pos]
+    local info = level:get_level()
+    local lpos = level:get_pos()
+    local entities = level:get_entities()
+    local ppos = game.player:get_pos()
     lpos.x = math.min(
         math.max(0, ppos.x - util.screen.width // 2),
         (info.screens - 1) * 240
     )
     for i,e in pairs(entities) do
-         if e.has_component[Pos] then
-             local pos = e.get_component[Pos]
+         if e:has_pos() then
+             local pos = e:get_pos()
              if pos.x >= lpos.x and pos.x < lpos.x + 240 and
                 pos.y >= lpos.y and pos.y < lpos.y + 134 then
                 table.insert(game.entities, e)
@@ -550,9 +567,9 @@ end
 
 local ActionSystem = System(Pos,Input,Action)
 function ActionSystem:exec(entity,game)
-    local pos = entity.get_component[Pos]
-    local input = entity.get_component[Input]
-    local action = entity.get_component[Action]
+    local pos = entity:get_pos()
+    local input = entity:get_input()
+    local action = entity:get_action()
     if input.rawp[5] and action.a then
         action.a(entity,game)
     end
@@ -563,8 +580,8 @@ end
 
 local EffectSystem = System()
 function EffectSystem:exec(entity)
-     if entity.has_component[CircleEffect] then
-         local effect = entity.get_component[CircleEffect]
+     if entity:has_circleeffect() then
+         local effect = entity:get_circleeffect()
          effect.r1 = effect.r1 + effect.step
          if effect.r1 > effect.r2 then
              return true
@@ -574,8 +591,8 @@ end
 
 local PosAnimSystem = System(Pos, PosAnim)
 function PosAnimSystem:exec(entity)
-    local pos = entity.get_component[Pos]
-    local anim = entity.get_component[PosAnim]
+    local pos = entity:get_pos()
+    local anim = entity:get_posanim()
     anim.f(anim.t, pos)
     anim.t = anim.t + 1
     if anim.d and anim.t > anim.d then
@@ -585,8 +602,8 @@ end
 
 local ParticlesSystem = System(Pos, Particles)
 function ParticlesSystem:exec(entity, game)
-    local pos = entity.get_component[Pos]
-    local parts = entity.get_component[Particles]
+    local pos = entity:get_pos()
+    local parts = entity:get_particles()
     parts:spawn(pos,game.entities)
     parts.t = parts.t + 1
     if parts.d and parts.t > parts.d then
@@ -594,34 +611,24 @@ function ParticlesSystem:exec(entity, game)
     end
 end
 
-local player = Entity()
-    :with_component(Metadata("Giulia"))
-    :with_component(Pos(100,10))
-    :with_component(Movement())
-    :with_component(Jump(10))
-    :with_component(Sprite(256))
-    :with_component(Input(0,1,2,3,4,5))
-    :with_component(Action(
-        function(entity,game)
-            --local lpos = game.levels[game.level].get_component[Pos]
-            local pos = entity.get_component[Pos]--:to_screen(lpos)
-            table.insert(
-                game.entities,
-                Entity():with_component(Pos(pos.x,pos.y)):with_component(ForceField(5,10,true)):with_component(CircleEffect(20)))
-        end,
-        nil))
+local player = Entity():with({
+    Metadata("Giulia"), Sprite(256),
+    Pos(100,10), Health(100), Status(),
+    Movement(), Jump(10),
+    Input(0,1,2,3,4,5), Action(Action.forcefield,nil)
+})
 
 local level1_entities = {
     -- Turists
-    Entity():with_component(Metadata("Tourist1")):with_component(Pos(16*8,11*8)):with_component(Sprite(272)):with_component(Movement()),
-    Entity():with_component(Metadata("Tourist2")):with_component(Pos(47*8, 8*8)):with_component(Sprite(272)):with_component(Movement()),
-    Entity():with_component(Metadata("Tourist3")):with_component(Pos(85*8, 7*8)):with_component(Sprite(272)):with_component(Movement()),
+    Entity():with({Metadata("Tourist1"), Sprite(272), Pos(16*8,11*8), Health(5), Status(), Movement(), MovementAI(), Target(player:get_pos())}),
+    Entity():with({Metadata("Tourist2"), Sprite(272), Pos(47*8, 8*8), Health(5), Status(), Movement(), MovementAI()}),
+    Entity():with({Metadata("Tourist3"), Sprite(272), Pos(85*8, 7*8), Health(5), Status(), Movement(), MovementAI()}),
     -- Waypoints
-    Entity():with_component(Pos(15*8,11*8)):with_component(Sprite(288))
-            :with_component(PosAnim(function(t,p) p.y = p.y - math.sin(t/6)/3 end))
-            :with_component(Particles()),
-    Entity():with_component(Pos(48*8, 8*8)):with_component(Sprite(288))
-            :with_component(PosAnim(function(t,p) p.y = p.y - math.sin(t/6)/3 end)),
+    Entity():with(Pos(15*8,11*8)):with(Sprite(288))
+            :with(PosAnim(function(t,p) p.y = p.y - math.sin(t/6)/3 end))
+            :with(Particles()),
+    Entity():with(Pos(48*8, 8*8)):with(Sprite(288))
+            :with(PosAnim(function(t,p) p.y = p.y - math.sin(t/6)/3 end)),
 }
 
 -- TODO turn this into something more structured, containing everything related
@@ -632,9 +639,9 @@ local game = {
     level = 1,
     levels = {
         Entity()
-            :with_component(Level(0,3))
-            :with_component(Pos(0,0))
-            :with_component(Entities(level1_entities))
+            :with(Level(0,3))
+            :with(Pos(0,0))
+            :with(Entities(level1_entities))
     }
 }