1 files changed, 218 insertions, 0 deletions
diff --git a/script/timer.lua b/script/timer.lua
new file mode 100644
index 00000000..1d4343f1
--- /dev/null
+++ b/script/timer.lua
@@ -0,0 +1,218 @@
+local setmetatable = setmetatable
+local mathMax      = math.max
+local mathFloor    = math.floor
+local osClock      = os.clock
+
+_ENV = nil
+
+local curFrame = 0
+local maxFrame = 0
+local curIndex = 0
+local freeQueue = {}
+local timer = {}
+
+local function allocQueue()
+    local n = #freeQueue
+    if n > 0 then
+        local r = freeQueue[n]
+        freeQueue[n] = nil
+        return r
+    else
+        return {}
+    end
+end
+
+local function mTimeout(self, timeout)
+    if self._pauseRemaining or self._running then
+        return
+    end
+    local ti = curFrame + timeout
+    local q = timer[ti]
+    if q == nil then
+        q = allocQueue()
+        timer[ti] = q
+    end
+    self._timeoutFrame = ti
+    self._running = true
+    q[#q + 1] = self
+end
+
+local function mWakeup(self)
+    if self._removed then
+        return
+    end
+    self._running = false
+    if self._onTimer then
+        self:_onTimer()
+    end
+    if self._removed then
+        return
+    end
+    if self._timerCount then
+        if self._timerCount > 1 then
+            self._timerCount = self._timerCount - 1
+            mTimeout(self, self._timeout)
+        else
+            self._removed = true
+        end
+    else
+        mTimeout(self, self._timeout)
+    end
+end
+
+local function getRemaining(self)
+    if self._removed then
+        return 0
+    end
+    if self._pauseRemaining then
+        return self._pauseRemaining
+    end
+    if self._timeoutFrame == curFrame then
+        return self._timeout or 0
+    end
+    return self._timeoutFrame - curFrame
+end
+
+local function onTick()
+    local q = timer[curFrame]
+    if q == nil then
+        curIndex = 0
+        return
+    end
+    for i = curIndex + 1, #q do
+        local callback = q[i]
+        curIndex = i
+        q[i] = nil
+        if callback then
+            mWakeup(callback)
+        end
+    end
+    curIndex = 0
+    timer[curFrame] = nil
+    freeQueue[#freeQueue + 1] = q
+end
+
+local m = {}
+local mt = {}
+mt.__index = mt
+mt.type = 'timer'
+
+function mt:__tostring()
+    return '[table:timer]'
+end
+
+function mt:__call()
+    if self._onTimer then
+        self:_onTimer()
+    end
+end
+
+function mt:remove()
+    self._removed = true
+end
+
+function mt:pause()
+    if self._removed or self._pauseRemaining then
+        return
+    end
+    self._pauseRemaining = getRemaining(self)
+    self._running = false
+    local ti = self._timeoutFrame
+    local q = timer[ti]
+    if q then
+        for i = #q, 1, -1 do
+            if q[i] == self then
+                q[i] = false
+                return
+            end
+        end
+    end
+end
+
+function mt:resume()
+    if self._removed or not self._pauseRemaining then
+        return
+    end
+    local timeout = self._pauseRemaining
+    self._pauseRemaining = nil
+    mTimeout(self, timeout)
+end
+
+function mt:restart()
+    if self._removed or self._pauseRemaining or not self._running then
+        return
+    end
+    local ti = self._timeoutFrame
+    local q = timer[ti]
+    if q then
+        for i = #q, 1, -1 do
+            if q[i] == self then
+                q[i] = false
+                break
+            end
+        end
+    end
+    self._running = false
+    mTimeout(self, self._timeout)
+end
+
+function mt:remaining()
+    return getRemaining(self) / 1000.0
+end
+
+function mt:onTimer()
+    self:_onTimer()
+end
+
+function m.wait(timeout, onTimer)
+    local t = setmetatable({
+        ['_timeout'] = mathMax(mathFloor(timeout * 1000.0), 1),
+        ['_onTimer'] = onTimer,
+        ['_timerCount'] = 1,
+    }, mt)
+    mTimeout(t, t._timeout)
+    return t
+end
+
+function m.loop(timeout, onTimer)
+    local t = setmetatable({
+        ['_timeout'] = mathFloor(timeout * 1000.0),
+        ['_onTimer'] = onTimer,
+    }, mt)
+    mTimeout(t, t._timeout)
+    return t
+end
+
+function m.timer(timeout, count, onTimer)
+    if count == 0 then
+        return m.loop(timeout, onTimer)
+    end
+    local t = setmetatable({
+        ['_timeout'] = mathFloor(timeout * 1000.0),
+        ['_onTimer'] = onTimer,
+        ['_timerCount'] = count,
+    }, mt)
+    mTimeout(t, t._timeout)
+    return t
+end
+
+function m.clock()
+    return curFrame / 1000.0
+end
+
+local lastClock = osClock()
+function m.update()
+    local currentClock = osClock()
+    local delta = currentClock - lastClock
+    lastClock = currentClock
+    if curIndex ~= 0 then
+        curFrame = curFrame - 1
+    end
+    maxFrame = maxFrame + delta * 1000.0
+    while curFrame < maxFrame do
+        curFrame = curFrame + 1
+        onTick()
+    end
+end
+
+return m