gloss-examples-1.2.0.0: Eden/World.hs

module World where

import Graphics.Gloss
import Graphics.Gloss.Interface.Simulate
import System.Random
import Community
import Cell

maxSteps	= 30

-- The World consists of a Community and a random number generator.
-- (The RNG is a model of chaos or hand-of-god.)
data World 
	= World Community StdGen Int
	deriving (Show)

-- The initial world
genesis :: World
genesis 
	= World [Cell (0,0) 30 0] (mkStdGen 1023) 0

-- Seeding the prng means every run is identical.
-- To get different runs, need to use gen <- getStdGen in main :: IO()
-- and pass gen in as an argument.  Edit Main.hs accordingly.
genesis' :: StdGen -> World
genesis' gen 
	= World [Cell (0,0) 30 0] gen 0


-- Consume some random numbers to advance the simulation
evolve :: ViewPort -> Float -> World -> World
evolve vp step world@(World comm gen steps) 
	| steps < maxSteps	
	= let	(genThis, genNext) = split gen
          	(genA, genS)       = split genThis
          	angles             = randomRs (0.0, 2*pi) genA
          	scales             = randomRs (0.7, 0.9) genS
    	  in  	World (generation comm angles scales) genNext (steps + 1)

	| otherwise
	= world

-- Converting the world to a picture is just converting the community component
render :: World -> Picture
render (World comm gen steps) 
	= Color (makeColor 0.3 0.3 0.6 1.0)
	$ Community.render comm