Merge pull request #68 from Kingdaro/kingdaro-timer-fix

Timer now accounts for "lateness" and repetition

gamestate.lua

@@ -38,7 +38,7 @@ function GS.new(t) return t or {} end -- constructor - deprecated!
 
 local function change_state(stack_offset, to, ...)
 	local pre = stack[#stack]
-	
+
 	-- initialize only on first call
 	;(initialized_states[to] or to.init or __NULL__)(to)
 	initialized_states[to] = __NULL__

spec/timer_spec.lua

@@ -0,0 +1,73 @@
+local timer = require 'timer'()
+
+describe('hump.timer', function()
+  it('runs a function during a specified time', function()
+    local delta, remaining
+
+    timer:during(10, function(...) delta, remaining = ... end)
+
+    timer:update(2)
+    assert.are.equal(delta, 2)
+    assert.are.equal(8, remaining)
+
+    timer:update(5)
+    assert.are.equal(delta, 5)
+    assert.are.equal(3, remaining)
+
+    timer:update(10)
+    assert.are.equal(delta, 10)
+    assert.are.equal(0, remaining)
+  end)
+
+  it('runs a function after a specified time', function()
+    local finished1 = false
+    local finished2 = false
+
+    timer:after(3, function(...) finished1 = true end)
+    timer:after(5, function(...) finished2 = true end)
+
+    timer:update(4)
+    assert.are.equal(true, finished1)
+    assert.are.equal(false, finished2)
+
+    timer:update(4)
+    assert.are.equal(true, finished1)
+    assert.are.equal(true, finished2)
+  end)
+
+  it('runs a function every so often', function()
+    local count = 0
+
+    timer:every(1, function(...) count = count + 1 end)
+
+    timer:update(3)
+    assert.are.equal(3, count)
+
+    timer:update(7)
+    assert.are.equal(10, count)
+  end)
+
+  it('can script timed events', function()
+    local state
+
+    timer:script(function(wait)
+      state = 'foo'
+      wait(1)
+      state = 'bar'
+    end)
+
+    assert.are.equal('foo', state)
+    timer:update(0.5)
+    assert.are.equal('foo', state)
+    timer:update(1)
+    assert.are.equal('bar', state)
+  end)
+
+  it('cancels and clears timer functions', function()
+    pending('to be tested...')
+  end)
+
+  it('tweens', function()
+    pending('to be tested...')
+  end)
+end)

timer.lua

@@ -31,23 +31,41 @@ local function _nothing_() end
 
 function Timer:update(dt)
 	local to_remove = {}
-	for handle, delay in pairs(self.functions) do
-		delay = delay - dt
-		if delay <= 0 then
-			to_remove[#to_remove+1] = handle
+
+	for handle in pairs(self.functions) do
+		-- handle: {
+		--   time = <number>,
+		--   after = <function>,
+		--   during = <function>,
+		--   limit = <number>,
+		--   count = <number>,
+		-- }
+
+		handle.time = handle.time + dt
+		handle.during(dt, math.max(handle.limit - handle.time, 0))
+
+		while handle.time >= handle.limit and handle.count > 0 do
+			if handle.after(handle.after) == false then
+				handle.count = 0
+				break
+			end
+			handle.time = handle.time - handle.limit
+			handle.count = handle.count - 1
+		end
+
+		if handle.count == 0 then
+			table.insert(to_remove, handle)
 		end
-		self.functions[handle] = delay
-		handle.func(dt, delay)
 	end
-	for _,handle in ipairs(to_remove) do
-		self.functions[handle] = nil
-		handle.after(handle.after)
+
+	for i = 1, #to_remove do
+		self.functions[to_remove[i]] = nil
 	end
 end
 
-function Timer:during(delay, func, after)
-	local handle = {func = func, after = after or _nothing_}
-	self.functions[handle] = delay
+function Timer:during(delay, during, after)
+	local handle = { time = 0, during = during, after = after or _nothing_, limit = delay, count = 1 }
+	self.functions[handle] = true
 	return handle
 end
 
@@ -55,16 +73,10 @@ function Timer:after(delay, func)
 	return self:during(delay, _nothing_, func)
 end
 
-function Timer:every(delay, func, count)
-	local count, handle = count or math.huge -- exploit below: math.huge - 1 = math.huge
-
-	handle = self:after(delay, function(f)
-		if func(func) == false then return end
-		count = count - 1
-		if count > 0 then
-			self.functions[handle] = delay
-		end
-	end)
+function Timer:every(delay, after, count)
+	local count = count or math.huge -- exploit below: math.huge - 1 = math.huge
+	local handle = { time = 0, during = _nothing_, after = after, limit = delay, count = count }
+	self.functions[handle] = true
 	return handle
 end