LÖVE

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...
menu.update
menu.draw
menu.update
menu.draw
menu.update
assault.update
assault.draw
assault.update
assault.draw
...

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	-- call function only if at least one 'update' was called beforehand
	-- (see issue #46)
	if not state_is_dirty or func == 'update' then
		...

Code: Select all

--[[
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.

(c) Copyright 2020 Pedro Gimeno Fortea

Permissions to use, to copy, to modify and to distribute this software for any
purpose are hereby granted, provided that the above copyright notice and this
permission notice appear in all copies. This software comes with no implied
warranty.

]]--

local function __NULL__() end

 -- default gamestate produces error on every callback
local state_init = setmetatable({leave = __NULL__},
		{__index = function() error("Gamestate not initialized. Use Gamestate.switch()") end})
local stack = {state_init}
local initialized_states = setmetatable({}, {__mode = "k"})
local state_to_key = setmetatable({}, {__mode = "k"})
local key_to_state = setmetatable({}, {__mode = "v"})

local GS = {}
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
	if not initialized_states[to] then
		initialized_states[to] = true
		;(to.init or __NULL__)(to)
	end

	stack[#stack+stack_offset] = to
	return (to.enter or __NULL__)(to, pre, ...)
end

function love.handlers.gsswitch(to, ...)
	to = key_to_state[to]
	;(stack[#stack].leave or __NULL__)(stack[#stack])
	return change_state(0, to, ...)
end

function love.handlers.gspush(to, ...)
	to = key_to_state[to]
	return change_state(1, to, ...)
end

function love.handlers.gspop(...)
	assert(#stack > 1, "No more states to pop!")
	local pre, to = stack[#stack], stack[#stack-1]
	stack[#stack] = nil
	;(pre.leave or __NULL__)(pre)
	return (to.resume or __NULL__)(to, pre, ...)
end

function GS.switch(to, ...)
	assert(to, "Missing argument: Gamestate to switch to")
	assert(to ~= GS, "Can't call switch with colon operator")
	local k = state_to_key[to]
	if not k then
		k = tostring(to)
		state_to_key[to] = k
		key_to_state[k] = to
	end
	love.event.push("gsswitch", k, ...)
end

function GS.push(to, ...)
	assert(to, "Missing argument: Gamestate to switch to")
	assert(to ~= GS, "Can't call push with colon operator")
	local k = state_to_key[to]
	if not k then
		k = tostring(to)
		state_to_key[to] = k
		key_to_state[k] = to
	end
	love.event.push("gspush", k, ...)
end

function GS.pop(...)
	love.event.push("gspop", ...)
end

function GS.current()
	return stack[#stack]
end

-- XXX: don't overwrite love.errorhandler by default:
--      this callback is different than the other callbacks
--      (see http://love2d.org/wiki/love.errorhandler)
--      overwriting thi callback can result in random crashes (issue #95)
local all_callbacks = { 'draw', 'update' }

-- fetch event callbacks from love.handlers
for k in pairs(love.handlers) do
	all_callbacks[#all_callbacks+1] = k
end

function GS.registerEvents(callbacks)
	local registry = {}
	callbacks = callbacks or all_callbacks
	for _, f in ipairs(callbacks) do
		registry[f] = love[f] or __NULL__
		love[f] = function(...)
			registry[f](...)
			return GS[f](...)
		end
	end
end

-- forward any undefined functions
setmetatable(GS, {__index = function(_, func)
	return function(...)
		return (stack[#stack][func] or __NULL__)(stack[#stack], ...)
	end
end})

return GS

Code: Select all

...
menu.update
menu.draw
menu.update
menu.draw
assault.update
assault.draw
assault.update
assault.draw
...