README

This package provides a simple wrapper for the gloss library, or rather the function Graphics.Gloss.play, enabling you to write gloss applications as synchronous signal functions. An example "gears" program, which you can run as cabal run gloss-gears, now becomes as simple as:

import FRP.Rhine.Gloss


-- | Calculate a gear wheel rotated by a certain angle.
gears :: Float -> Picture
gears angle = color green $ pictures
  $ circleSolid 60
  : map (rotate angle) [ rotate (45 * n) $ rectangleSolid 20 150 | n <- [0..3] ]

-- | Rotate the gear with a constant angular velocity.
mainSyncSF :: GlossSyncSF a
mainSyncSF = timeInfoOf sinceStart >>> arr (* 50) >>> arr gears

main :: IO ()
main = flowGloss (InWindow "rhine-gloss-gears" (400, 400) (10, 10)) (greyN 0.3) 30
     $ buildGlossRhine Just mainSyncSF