Files
OpenSpace/data/assets/util/lua_state_machine_helper.asset
2021-12-28 23:40:09 +01:00

62 lines
1.9 KiB
Lua

-- Contains the required functions to create a simple Lua state machine, that can step
-- forwards and backwards through a list of states.
--
-- A state is given as a table with a Title string, and two functions: Play and Rewind
-- (see example asset)
local goToNextStateFunction = function (machine)
if (machine.currentStateIndex >= #machine.states) then
machine.currentStateIndex = #machine.states
return
end
if (machine.currentStateIndex == 0) then
openspace.printInfo("Starting state machine with " ..
machine.states[machine.currentStateIndex + 1].Title)
elseif (machine.currentStateIndex == #machine.states) then
openspace.printInfo("Proceed from " ..
machine.states[machine.currentStateIndex].Title
)
else
openspace.printInfo("Proceed from " ..
machine.states[machine.currentStateIndex].Title .. " to " ..
machine.states[machine.currentStateIndex + 1].Title
)
end
machine.currentStateIndex = machine.currentStateIndex + 1
machine.states[machine.currentStateIndex].Play()
end
local goToPreviousStateFunction = function (machine)
if (machine.currentStateIndex < 1) then
machine.currentStateIndex = 0
return
end
if (machine.currentStateIndex == 1) then
openspace.printInfo("Rewind from " .. machine.states[machine.currentStateIndex].Title)
else
openspace.printInfo("Rewind from " ..
machine.states[machine.currentStateIndex].Title .. " to " ..
machine.states[machine.currentStateIndex - 1].Title
)
end
machine.states[machine.currentStateIndex].Rewind()
machine.currentStateIndex = machine.currentStateIndex - 1
end
local createStateMachine = function (states)
local machine = {
states = states,
currentStateIndex = 0
}
machine.goToNextState = function () goToNextStateFunction(machine) end
machine.goToPreviousState = function () goToPreviousStateFunction(machine) end
return machine
end
asset.export("createStateMachine", createStateMachine)