Add random waviness to the squares using Perlin noise

app/Main.hs

@@ -88,15 +88,36 @@ renderQuad Quad{..} = renderClosedPath [quadA, quadB, quadC, quadD]
 darkGunmetal :: Double -> Render ()
 darkGunmetal = hsva 170 0.30 0.16
 
+quadAddNoise :: Quad -> Generate Quad
+quadAddNoise Quad{..} = do
+  perlinSeed <- fromIntegral <$> asks worldSeed
+
+  let
+    perlinOctaves = 5
+    perlinScale = 0.1
+    perlinPersistance = 0.5
+    perlinNoise
+      = P.perlin (round perlinSeed) perlinOctaves perlinScale perlinPersistance
+    perlin2d (V2 x y)
+      = P.noiseValue perlinNoise (x + perlinSeed, y + perlinSeed, perlinSeed) - 0.5
+    addNoise v = let noise = perlin2d v in v ^+^ V2 (noise / 5) (noise / 8)
+
+  pure $ Quad
+    (addNoise quadA)
+    (addNoise quadB)
+    (addNoise quadC)
+    (addNoise quadD)
+
 renderSketch :: Generate ()
 renderSketch = do
   fillScreen eggshell 1
 
   cairo $ setLineWidth 0.15
 
   quads <- genQuadGrid
+  noisyQuads <- traverse quadAddNoise quads
 
-  cairo $ for_ quads $ \quad -> do
+  cairo $ for_ noisyQuads $ \quad -> do
     renderQuad quad
     darkGunmetal 1 *> stroke