add basic projectile

obj/game/Player.lua

@@ -27,8 +27,10 @@ function Player:new(area, x, y, opts)
     self.max_v = 100
     -- player acceleration
     self.a = 100
+    -- attack rate
+    self.ar = 0.24
 
-    self.timer:every(4, function() self:shoot() end)
+    self.timer:every(self.ar, function() self:shoot() end)
 end
 
 function Player:update(dt)
@@ -70,6 +72,7 @@ function Player:shoot()
     local d = 1.2*self.w
     local offset_x, offset_y = self.x + d*math.cos(self.r), self.y + d*math.sin(self.r)
     self.area:addGameObject('ShootEffect', offset_x, offset_y, {player = self, d = d})
+    self.area:addGameObject('Projectile', offset_x, offset_y, {r = self.r})
 end
 
 return Player

obj/game/Projectile.lua

@@ -0,0 +1,46 @@
+---@class Projectile:GameObject
+---@field r number
+---@field s number|nil
+---@field v number|nil
+local Projectile = GameObject:extend()
+
+function Projectile:new(area, x, y, opts)
+    Projectile.super.new(self, area, x, y, opts)
+
+    -- radius of collider
+    self.s = opts.s or 2.5
+    -- velocity
+    self.v = opts.v or 200
+    self.collider = self.area.world:circle(self.x, self.y, self.s)
+end
+
+---Updates Projectile
+---@param dt number delta time
+function Projectile:update(dt)
+    Projectile.super.update(self, dt)
+
+    -- update velocity
+    --self.v = math.min(self.v + self.a*dt, self.max_v)
+
+    -- update position
+    local vx = self.v * math.cos(self.r)  -- velocity X
+    local vy = self.v * math.sin(self.r)  -- velocity Y
+    self.x = self.x + vx * dt             -- update position X
+    self.y = self.y + vy * dt             -- update position Y
+
+    -- move collision area
+    self.collider:moveTo(self.x, self.y)
+end
+
+---Draws Projectile
+function Projectile:draw()
+    Projectile.super.draw(self)
+    if DEBUG then
+        love.graphics.setColor(1, 0, 0)
+        self.collider:draw()
+    end
+    love.graphics.setColor(1, 1, 1)
+    love.graphics.circle('fill', self.x, self.y, self.s)
+end
+
+return Projectile

obj/game/ShootEffect.lua

@@ -23,7 +23,7 @@ end
 function ShootEffect:draw()
     ShootEffect.super.draw(self)
     pushRotateScale(self.x, self.y, self.player.r+math.pi/4)
-    love.graphics.setColor(0.6, 0.5, 0.1)
+    love.graphics.setColor(1,1,1)
     love.graphics.rectangle('fill', self.x - self.w/2, self.y - self.w/2, self.w, self.w)
     love.graphics.pop()
 end