FRP.Rhine.Gloss.Pure.Combined

A pure gloss backend for Rhine, with separated event and simulation loop.

To run pure Rhine apps with gloss, write a signal network (SN) in the GlossCombinedClock and use flowGlossCombined. As an easy starter, you can use the helper function buildGlossRhine.

Documentation

type GlossCombinedClock a = SequentialClock (GlossEventClock a) GlossSimulationClock

The overall clock of a pure rhine SN that can be run by gloss. It is combined of two subsystems, the event part and the simulation part. a is the type of subevents that are selected.

Events

type GlossEventClock a = SelectClock GlossClock a

The clock that ticks whenever a specific gloss event occurs.

glossEventSelectClock :: (Event -> Maybe a) -> GlossEventClock a

Select the relevant events by converting them to Just a, and the irrelevant ones to Nothing.

glossEventClock :: GlossEventClock Event

Tick on every event.

Simulation

type GlossSimulationClock = SelectClock GlossClock ()

The clock that ticks for every gloss simulation step.

glossSimulationClock :: GlossSimulationClock

Signal networks

type GlossRhine a = Rhine GlossM (GlossCombinedClock a) () ()

The type of a valid Rhine that can be run by gloss, if you chose to separate events and simulation into two subsystems. a is the type of subevents that are selected.

All painting has to be done in GlossM, e.g. via the paint method.

Typically, such a Rhine is built something like this:

-- | Select only key press events
myEventClock :: GlossEventClock Key
myEventClock = glossEventSelectClock selector
  where
    selector (EventKey key _ _ _) = Just key
    selector _ = Nothing

myEventSubsystem :: ClSF GlossM GlossEventClock () MyType
myEventSubsystem = ...

mySim :: ClSF GlossM GlossSimulationClock [MyType] ()
mySim = ...

myGlossRhine :: GlossRhine a
myGlossRhine
  = myEventSubsystem @ myEventClock >-- collect --> mySim @ glossSimulationClock

buildGlossRhine

Arguments

:: (Event -> Maybe a)

The event selector

-> ClSF GlossM GlossSimulationClock [a] ()

The ClSF representing the game loop.

-> GlossRhine a

For most applications, it is sufficient to implement a single signal function that is called with a list of all relevant events that occurred in the last tick.