gloss-examples-1.0.0.0: Eden/Cell.hs

module Cell where

import Graphics.Gloss

data Cell 
	= Cell	Point    -- centre
             	Float    -- radius
		Int	
              	deriving Show

-- Produce a new cell of a certain relative radius at a certain angle.
-- 	The factor argument is in the range [0..1] so spawned cells are
-- 	smaller than their parent.
-- The check whether it fits in the community is elsewhere.
offspring :: Cell -> Float -> Float -> Cell
offspring (Cell (x,y) r gen) alpha factor 
	= Cell 	(x + (childR+r) * cos alpha, y + (childR+r) * sin alpha) 
		childR 
		(gen + 1)

    	where childR = factor * r

-- Do two cells overlap?         
-- Used to decide if newly spawned cells can join the community.
overlap :: Cell -> Cell -> Bool
overlap (Cell (x1,y1) r1 _) (Cell (x2,y2) r2 _) 
	= centreDist < (r1 + r2) * 0.999
    	where 	centreDist = sqrt(xdiff*xdiff + ydiff*ydiff)
          	xdiff = x1 - x2
          	ydiff = y1 - y2

render :: Cell -> Picture
render (Cell (x,y) r gen) 
 = let 	z	= fromIntegral gen * 0.1
	color	= makeColor 0.0 z 0.5 1.0
   in	Color color
		$ Translate x y
		$ Circle r