module Apecs.Physics.Geometry where import Apecs.Physics.Types import Linear vertices :: Convex -> [BVec] vertices (Convex s _) = s -- | Map a function over all vertices mapVertices :: (BVec -> BVec) -> Convex -> Convex mapVertices f (Convex s r) = Convex (f <\$> s) r -- | Translates all vertices. The name shift is to prevent collisions with gloss shift :: BVec -> Convex -> Convex shift = mapVertices . (+) getRadius :: Convex -> Double getRadius (Convex _ r) = r setRadius :: Double -> Convex -> Convex setRadius r (Convex s _) = Convex s r cCircle, zCircle :: Double -> Convex cCircle r = oCircle 0 r zCircle = cCircle oCircle :: BVec -> Double -> Convex oCircle o r = Convex [o] r hLine, vLine :: Double -> Convex hLine l = Convex [V2 (-l/2) 0, V2 (l/2) 0] 0 vLine l = Convex [V2 0 (l/2), V2 0 (-l/2)] 0 -- | Centered rectangle with a given size cRectangle :: BVec -> Convex cRectangle s = oRectangle (-s*0.5) s -- | Rectangle with a given origin and size oRectangle :: BVec -> BVec -> Convex oRectangle (V2 x y) (V2 w h) = Convex [V2 x y, V2 x (y+h), V2 (x+w) (y+h), V2 (x+w) y] 0 -- | Rectangle with origin 0 and given size zRectangle :: BVec -> Convex zRectangle s = oRectangle 0 s -- | Split a shape into its edges. Will return no edges for points, but returns 2 for a line (in opposite directions) toEdges :: Convex -> [Convex] toEdges (Convex [] _) = [] toEdges (Convex [_] _) = [] toEdges (Convex vs r) = zipWith (\h t -> Convex [h,t] r) vs (tail . cycle \$ vs) -- | A set of lines forming a grid. Returns (r + c + 2) segments. gridLines :: Vec -> Int -> Int -> [Convex] gridLines size c r = [ shift (V2 x 0) (vLine h) | x <- xs ] ++ [ shift (V2 0 y) (hLine w) | y <- ys ] where V2 w h = size V2 x y = -size*0.5 dx = w/fromIntegral c dy = h/fromIntegral r xs = [x + fromIntegral n * dx | n <- [0..c]] ys = [y + fromIntegral n * dy | n <- [0..r]]