add feed obj

data/scripts/classes/feed.lua

@@ -0,0 +1,41 @@
+local Vector3 = require "types.vector3"
+local util    = require "util"
+
+local TEXTURE = "images/tongue.png"
+
+local Feed = {
+  position = {},
+  direction = {},
+  velocity = {},
+  landed = false,
+
+  speed = 0.15,
+}
+
+Feed.__index = Feed
+
+function Feed.new(p_position, p_direction)
+  local f = util.shallow_copy(Feed)
+  f.position = p_position:copy()
+  f.direction = p_direction:copy()
+  f.velocity = f.direction * f.speed
+  f.velocity.y = 0.1
+
+  return setmetatable(f, Feed)
+end
+
+function Feed:tick(ctx)
+  if not self.landed then
+    -- gravity
+    self.velocity.y = math.max(self.velocity.y - 0.02, -0.2)
+    self.position = self.position + self.velocity
+  end
+  
+  if self.position.y <= 0.2 and not self.landed then
+    self.position.y = 0.2
+    self.landed = true
+  end
+  draw_billboard{position = self.position, texture = TEXTURE, size = Vector3(0.2, 0.2)}
+end
+
+return Feed