tiling noise protocols

Author: tayloraswift

sources/noise/cell.swift

@@ -3,14 +3,17 @@ protocol _CellNoise2D
 {
     var frequency:Double { get }
     var amplitude:Double { get }
-    func distance2(from sample_point:Math.DoubleV2, generating_point:Math.IntV2) -> Double
+
+    func hash(point:Math.IntV2) -> Int
 }
 
 extension _CellNoise2D
 {
     @inline(__always)
-    func _distance2(hash:Int, sample_point:Math.DoubleV2, generating_point:Math.IntV2) -> Double
+    private
+    func distance2(from sample_point:Math.DoubleV2, generating_point:Math.IntV2) -> Double
     {
+        let hash:Int = self.hash(point: generating_point)
         // hash is within 0 ... 255, take it to 0 ... 0.5
 
         // Notice that we have 256 possible hashes, and therefore 8 bits of entropy,
@@ -25,35 +28,6 @@ extension _CellNoise2D
         let dv:Math.DoubleV2 = Math.sub(Math.add(Math.cast_double(generating_point), dp), sample_point)
         return Math.dot(dv, dv)
     }
-}
-
-public
-struct CellNoise2D:_CellNoise2D, HashedNoise
-{
-    let permutation_table:PermutationTable,
-        amplitude:Double,
-        frequency:Double
-
-    init(amplitude:Double, frequency:Double, permutation_table:PermutationTable)
-    {
-        self.amplitude = amplitude
-        self.frequency = frequency
-        self.permutation_table = permutation_table
-    }
-
-    public
-    init(amplitude:Double, frequency:Double, seed:Int = 0)
-    {
-        self.amplitude = amplitude * 1/2
-        self.frequency = frequency
-        self.permutation_table = PermutationTable(seed: seed)
-    }
-
-    fileprivate
-    func distance2(from sample_point:Math.DoubleV2, generating_point:Math.IntV2) -> Double
-    {
-        return self._distance2(hash: self.permutation_table.hash(generating_point), sample_point: sample_point, generating_point: generating_point)
-    }
 
     // still here to make tests run, because of a linker bug in the Swift compiler
     public
@@ -211,6 +185,35 @@ struct CellNoise2D:_CellNoise2D, HashedNoise
     }
 }
 
+public
+struct CellNoise2D:_CellNoise2D, HashedNoise
+{
+    let permutation_table:PermutationTable,
+        amplitude:Double,
+        frequency:Double
+
+    init(amplitude:Double, frequency:Double, permutation_table:PermutationTable)
+    {
+        self.amplitude = amplitude
+        self.frequency = frequency
+        self.permutation_table = permutation_table
+    }
+
+    public
+    init(amplitude:Double, frequency:Double, seed:Int = 0)
+    {
+        self.amplitude = amplitude * 1/2
+        self.frequency = frequency
+        self.permutation_table = PermutationTable(seed: seed)
+    }
+
+    fileprivate
+    func hash(point:Math.IntV2) -> Int
+    {
+        return self.permutation_table.hash(point)
+    }
+}
+
 public
 struct CellNoise3D:HashedNoise
 {

sources/noise/gradient.swift

@@ -11,16 +11,18 @@ protocol _ClassicNoise3D
 {
     var frequency:Double { get }
     var amplitude:Double { get }
-    func gradient(from point:Math.IntV3, at offset:Math.DoubleV3) -> Double
+
+    func hash(point:Math.IntV3) -> Int
 }
 
 extension _ClassicNoise3D
 {
     @inline(__always)
-    func _gradient(hash:Int, offset:Math.DoubleV3) -> Double
+    private
+    func gradient(from generating_point:Math.IntV3, at offset:Math.DoubleV3) -> Double
     {
         // use vectors to the edge of a cube
-        let h:Int     = hash & 15,
+        let h:Int     = self.hash(point: generating_point) & 15,
             u:Double  = h < 8              ? offset.x : offset.y,
             vt:Double = h == 12 || h == 14 ? offset.x : offset.z,
             v:Double  = h < 4              ? offset.y : vt
@@ -94,9 +96,9 @@ struct ClassicNoise3D:_ClassicNoise3D, HashedNoise
     }
 
     fileprivate
-    func gradient(from point:Math.IntV3, at offset:Math.DoubleV3) -> Double
+    func hash(point:Math.IntV3) -> Int
     {
-        return self._gradient(hash: self.permutation_table.hash(point), offset: offset)
+        return self.permutation_table.hash(point)
     }
 }
 
@@ -137,9 +139,9 @@ struct ClassicTilingNoise3D:_ClassicNoise3D, HashedTilingNoise
     }
 
     fileprivate
-    func gradient(from point:Math.IntV3, at offset:Math.DoubleV3) -> Double
+    func hash(point:Math.IntV3) -> Int
     {
-        return self._gradient(hash: self.permutation_table.hash(Math.mod(point, self.wavelengths)), offset: offset)
+        return self.permutation_table.hash(Math.mod(point, self.wavelengths))
     }
 }
 

tests/noise/tests.swift

@@ -79,6 +79,7 @@ func banner_classic3d(width:Int, height:Int, seed:Int)
                     path: "tests/banner_classic3d.png")
 }
 
+/*
 func banner_simplex2d(width:Int, height:Int, seed:Int)
 {
     color_noise_png(r_noise: SimplexNoise2D(amplitude: 0.5*255, frequency: 0.015, seed: seed),
@@ -89,6 +90,7 @@ func banner_simplex2d(width:Int, height:Int, seed:Int)
                     value_offset: (0.65*255, 0.65*255, 0.65*255),
                     path: "tests/banner_simplex2d.png")
 }
+*/
 
 func banner_supersimplex2d(width:Int, height:Int, seed:Int)
 {
@@ -260,7 +262,7 @@ func banners(width:Int, ratio:Double)
 {
     let height:Int = Int(Double(width) / ratio)
     banner_classic3d     (width: width, height: height, seed: 6)
-    banner_simplex2d     (width: width, height: height, seed: 6)
+    //banner_simplex2d     (width: width, height: height, seed: 6)
     banner_supersimplex2d(width: width, height: height, seed: 8)
     banner_supersimplex3d(width: width, height: height, seed: 2)
     banner_cell2d        (width: width, height: height, seed: 0)