sonic-bluestreak/sonic-bluestreak.love/libs/hump/timer.lua

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2019-02-03 20:22:25 +01:00
--[[
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
function Timer:update(dt)
local to_remove = {}
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
end
for i = 1, #to_remove do
self.functions[to_remove[i]] = nil
end
end
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
function Timer:after(delay, func)
return self:during(delay, _nothing_, func)
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
function Timer:cancel(handle)
self.functions[handle] = nil
end
function Timer:clear()
self.functions = {}
end
function Timer:script(f)
local co = coroutine.wrap(f)
co(function(t)
self:after(t, co)
coroutine.yield()
end)
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:during(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})
-- Timer instancing
function Timer.new()
return setmetatable({functions = {}, tween = Timer.tween}, Timer)
end
-- default instance
local default = Timer.new()
-- module forwards calls to default instance
local module = {}
for k in pairs(Timer) do
if k ~= "__index" then
module[k] = function(...) return default[k](default, ...) end
end
end
module.tween = setmetatable({}, {
__index = Timer.tween,
__newindex = function(k,v) Timer.tween[k] = v end,
__call = function(t, ...) return default:tween(...) end,
})
return setmetatable(module, {__call = Timer.new})