hump/timer.lua
headchant 95f07233b9 Punctation change
Unifies instance and default timer object access of functions to '.' for example: timer.clear(). For instances you had to use ':' until now.
2014-11-13 16:00:20 +01:00

192 lines
6.1 KiB
Lua

--[[
Copyright (c) 2010-2013 Matthias Richter
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
Except as contained in this notice, the name(s) of the above copyright holders
shall not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
]]--
local Timer = {}
Timer.__index = Timer
local function _nothing_() end
local function new()
local timer = setmetatable({functions = {}, tween = Timer.tween}, Timer)
return setmetatable({
new = new,
update = function(...) return timer:update(...) end,
do_for = function(...) return timer:do_for(...) end,
add = function(...) return timer:add(...) end,
addPeriodic = function(...) return timer:addPeriodic(...) end,
cancel = function(...) return timer:cancel(...) end,
clear = function(...) return timer:clear(...) end,
tween = setmetatable({}, {
__index = Timer.tween,
__newindex = function(_,k,v) Timer.tween[k] = v end,
__call = function(t,...) return timer:tween(...) end,
})
}, {__call = new})
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
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)
end
end
function Timer:do_for(delay, func, after)
local handle = {func = func, after = after or _nothing_}
self.functions[handle] = delay
return handle
end
function Timer:add(delay, func)
return self:do_for(delay, _nothing_, func)
end
function Timer:addPeriodic(delay, func, count)
local count, handle = count or math.huge -- exploit below: math.huge - 1 = math.huge
handle = self:add(delay, function(f)
if func(func) == false then return end
count = count - 1
if count > 0 then
self.functions[handle] = delay
end
end)
return handle
end
function Timer:cancel(handle)
self.functions[handle] = nil
end
function Timer:clear()
self.functions = {}
end
Timer.tween = setmetatable({
-- helper functions
out = function(f) -- 'rotates' a function
return function(s, ...) return 1 - f(1-s, ...) end
end,
chain = function(f1, f2) -- concatenates two functions
return function(s, ...) return (s < .5 and f1(2*s, ...) or 1 + f2(2*s-1, ...)) * .5 end
end,
-- useful tweening functions
linear = function(s) return s end,
quad = function(s) return s*s end,
cubic = function(s) return s*s*s end,
quart = function(s) return s*s*s*s end,
quint = function(s) return s*s*s*s*s end,
sine = function(s) return 1-math.cos(s*math.pi/2) end,
expo = function(s) return 2^(10*(s-1)) end,
circ = function(s) return 1 - math.sqrt(1-s*s) end,
back = function(s,bounciness)
bounciness = bounciness or 1.70158
return s*s*((bounciness+1)*s - bounciness)
end,
bounce = function(s) -- magic numbers ahead
local a,b = 7.5625, 1/2.75
return math.min(a*s^2, a*(s-1.5*b)^2 + .75, a*(s-2.25*b)^2 + .9375, a*(s-2.625*b)^2 + .984375)
end,
elastic = function(s, amp, period)
amp, period = amp and math.max(1, amp) or 1, period or .3
return (-amp * math.sin(2*math.pi/period * (s-1) - math.asin(1/amp))) * 2^(10*(s-1))
end,
}, {
-- register new tween
__call = function(tween, self, len, subject, target, method, after, ...)
-- recursively collects fields that are defined in both subject and target into a flat list
local function tween_collect_payload(subject, target, out)
for k,v in pairs(target) do
local ref = subject[k]
assert(type(v) == type(ref), 'Type mismatch in field "'..k..'".')
if type(v) == 'table' then
tween_collect_payload(ref, v, out)
else
local ok, delta = pcall(function() return (v-ref)*1 end)
assert(ok, 'Field "'..k..'" does not support arithmetic operations')
out[#out+1] = {subject, k, delta}
end
end
return out
end
method = tween[method or 'linear'] -- see __index
local payload, t, args = tween_collect_payload(subject, target, {}), 0, {...}
local last_s = 0
return self:do_for(len, function(dt)
t = t + dt
local s = method(math.min(1, t/len), unpack(args))
local ds = s - last_s
last_s = s
for _, info in ipairs(payload) do
local ref, key, delta = unpack(info)
ref[key] = ref[key] + delta * ds
end
end, after)
end,
-- fetches function and generated compositions for method `key`
__index = function(tweens, key)
if type(key) == 'function' then return key end
assert(type(key) == 'string', 'Method must be function or string.')
if rawget(tweens, key) then return rawget(tweens, key) end
local function construct(pattern, f)
local method = rawget(tweens, key:match(pattern))
if method then return f(method) end
return nil
end
local out, chain = rawget(tweens,'out'), rawget(tweens,'chain')
return construct('^in%-([^-]+)$', function(...) return ... end)
or construct('^out%-([^-]+)$', out)
or construct('^in%-out%-([^-]+)$', function(f) return chain(f, out(f)) end)
or construct('^out%-in%-([^-]+)$', function(f) return chain(out(f), f) end)
or error('Unknown interpolation method: ' .. key)
end})
-- default timer
local default = new()
-- the module
return default