allow field offsets, stub for worley noise

Author: tayloraswift

Package.swift

@@ -15,10 +15,11 @@ let package = Package(
     targets: [
         .target(
             name: "Noise",
-            dependencies: ["MaxPNG"], 
-            path: "Sources/noise"), 
+            dependencies: ["MaxPNG"],
+            path: "sources/noise"),
         .testTarget(
             name: "NoiseTests",
-            dependencies: ["Noise"]),
+            dependencies: ["Noise"], 
+            path: "tests/noise"),
     ]
 )

sources/noise/cell.swift

@@ -0,0 +1,33 @@
+public
+struct Cell2D:HashedNoise
+{
+    let perm1024:[Int],
+        hashes:[Int]
+
+    static
+    var n_hashes:Int = 1024
+
+    public
+    init(amplitude:Double, frequency:Double, seed:Int = 0)
+    {
+        (self.perm1024, self.hashes) = SuperSimplex2D.table(seed: seed)
+    }
+
+    public
+    func evaluate(_ x:Double, _ y:Double) -> Double
+    {
+        return 0
+    }
+
+    public
+    func evaluate(_ x:Double, _ y:Double, _:Double) -> Double
+    {
+        return self.evaluate(x, y)
+    }
+
+    public
+    func evaluate(_ x:Double, _ y:Double, _:Double, _:Double) -> Double
+    {
+        return self.evaluate(x, y)
+    }
+}

Sources/noise/noise.swift renamed to sources/noise/noise.swift

@@ -20,24 +20,35 @@ public
 extension Noise
 {
     public
-    func noise2d(width:Int, height:Int) -> [Double]
+    func sample_area(width:Int, height:Int) -> [(x:Double, y:Double, z:Double)]
     {
-        var samples:[Double] = []
+        var samples:[(x:Double, y:Double, z:Double)] = []
             samples.reserveCapacity(width * height)
-        for y in 0 ..< height
+        for i in 0 ..< height
         {
-            for x in 0 ..< width
+            for j in 0 ..< width
             {
-                samples.append(self.evaluate(Double(x), Double(y)))
+                let x:Double = Double(i) + 0.5,
+                    y:Double = Double(j) + 0.5
+                samples.append((x: x, y: y, z: self.evaluate(x, y)))
             }
         }
         return samples
     }
 
     public
-    func noise2d_u8(width:Int, height:Int) -> [UInt8]
+    func sample_area_saturated_to_u8(width:Int, height:Int, offset:Double = 0.5) -> [UInt8]
     {
-        return self.noise2d(width: width, height: height).map{ UInt8(max(0, min(255, $0 + 127.5))) }
+        var samples:[UInt8] = []
+            samples.reserveCapacity(width * height)
+        for y in 0 ..< height
+        {
+            for x in 0 ..< width
+            {
+                samples.append(UInt8(max(0, min(255, self.evaluate(Double(x), Double(y)) + offset))))
+            }
+        }
+        return samples
     }
 }
 

Sources/noise/opensimplex.swift renamed to sources/noise/opensimplex.swift

@@ -39,19 +39,19 @@ try png_encode(path: "poisson.png", raw_data: pixbuf, properties: png_properties
 
 let S:fBm<Simplex2D> = fBm<Simplex2D>(amplitude: 1, frequency: 0.00083429273, octaves: 10)
 t0 = clock()
-pixbuf = S.noise2d_u8(width: viewer_size, height: viewer_size)
+pixbuf = S.sample_area_saturated_to_u8(width: viewer_size, height: viewer_size, offset: 127.5)
 print(clock() - t0)
 try png_encode(path: "simplex.png", raw_data: pixbuf, properties: png_properties)
 
 
 let SS:fBm<SuperSimplex2D> = fBm<SuperSimplex2D>(amplitude: 1, frequency: 0.00083429273, octaves: 10)
 t0 = clock()
-pixbuf = SS.noise2d_u8(width: viewer_size, height: viewer_size)
+pixbuf = SS.sample_area_saturated_to_u8(width: viewer_size, height: viewer_size, offset: 127.5)
 print(clock() - t0)
 try png_encode(path: "super_simplex.png", raw_data: pixbuf, properties: png_properties)
 
 let SS3D:fBm<SuperSimplex3D> = fBm<SuperSimplex3D>(amplitude: 1, frequency: 0.00083429273, octaves: 10)
 t0 = clock()
-pixbuf = SS3D.noise2d_u8(width: viewer_size, height: viewer_size)
+pixbuf = SS3D.sample_area_saturated_to_u8(width: viewer_size, height: viewer_size, offset: 127.5)
 print(clock() - t0)
 try png_encode(path: "super_simplex3D.png", raw_data: pixbuf, properties: png_properties)