added timer

timer.lua

@@ -0,0 +1,78 @@
+local function defaultTimeout() end
+
+---@class Timer
+---@field duration number
+---@field time number
+---@field oneShot boolean
+---@field timeout function
+---@field data table
+---@field paused boolean
+Timer = {
+    duration = 1,
+    time = 1,
+    oneShot = false,
+    timeout = defaultTimeout,
+    data = {},
+    paused = true
+}
+
+---@param duration number|nil
+---@param oneShot boolean|nil
+---@param timeout function|nil
+---@param data table|nil
+---@return Timer
+function Timer:new( duration, oneShot, timeout, data )
+    local timer = {
+        duration = duration or self.duration,
+        time = duration or self.duration,
+        oneShot = oneShot or self.oneShot,
+        timeout = timeout or self.timeout,
+        data = data or self.data,
+        paused = self.paused,
+    }
+    setmetatable( timer, { __index = self } )
+
+    return timer
+end
+
+---@param dt number
+function Timer:tick( dt )
+    if self.paused then
+        return
+    end
+
+    self.time = self.time - dt
+
+    if self.time <= 0 then
+        self.timeout( self.data )
+
+        if self.oneShot then
+            self.paused = true
+            self.time = 0
+        else
+            self.time = self.duration + self.time
+        end
+    end
+end
+
+---@param duration number|nil
+function Timer:start( duration )
+    self.paused = false
+    if duration ~= nil then
+        self.duration = duration
+    end
+    self.time = self.duration
+end
+
+---@param emit boolean
+function Timer:stop( emit )
+    self.paused = true
+    self.time = 0
+    if emit then
+        self.timeout( self.data )
+    end
+end
+
+function Timer:elapsed()
+    return self.duration - self.time
+end