Use permutation table, some test cleanup

Author: jwagner

.jshintrc

@@ -1,5 +1,6 @@
 {
     "predef": [
+        "define",
         "describe",
         "it",
         "beforeEach"

package.json

@@ -6,6 +6,7 @@
   "author": "Jonas Wagner <[email protected]> (http://29a.ch/)",
   "main": "./simplex-noise",
   "devDependencies": {
+    "alea": "0.0.9",
     "benchmark": "~2.1.0",
     "chai": "^3.5.0",
     "mocha": "^3.2.0"
@@ -19,6 +20,7 @@
     "simplex",
     "plasma",
     "procedural",
+    "generation",
     "gfx",
     "generative"
   ],
@@ -28,6 +30,7 @@
     "url": "https://github.com/jwagner/simplex-noise.js.git"
   },
   "scripts": {
-    "test": "mocha"
+    "test": "jscs simplex-noise.js && jshint simplex-noise.js && mocha",
+    "benchmark": "node ./perf/benchmark.js"
   }
 }

perf/benchmark.js

@@ -1,52 +1,56 @@
-var Benchmark = this.Benchmark || require('benchmark') ,
-    SimplexNoise = this.SimplexNoise || require('../simplex-noise'),
-    simplex = new SimplexNoise();
+var Benchmark = this.Benchmark || require('benchmark');
+var SimplexNoise = this.SimplexNoise || require('../simplex-noise');
+var simplex = new SimplexNoise();
 
 var suite = new Benchmark.Suite('simplex-noise')
-    .add('init', function() {
-        var simplex = new SimplexNoise();
-    })
-    .add('noise2D', function() {
-        for(var x = 0; x < 8; x++){
-              for(var y = 0; y < 8; y++){
-                      for(var z = 0; z < 8; z++){
-                          simplex.noise2D(x/8, y/8);
-                      }
-              }
+  .add('init', function() {
+    var simplex = new SimplexNoise();
+  })
+  .add('noise2D', function() {
+    for (var x = 0; x < 8; x++) {
+      for (var y = 0; y < 8; y++) {
+        for (var z = 0; z < 8; z++) {
+          simplex.noise2D(x / 8, y / 8);
         }
-    })
-    .add('noise3D', function() {
-         for(var x = 0; x < 8; x++){
-              for(var y = 0; y < 8; y++){
-                      for(var z = 0; z < 8; z++){
-                          simplex.noise3D(x/8, y/8, z/8);
-                      }
-              }
+      }
+    }
+  })
+  .add('noise3D', function() {
+    for (var x = 0; x < 8; x++) {
+      for (var y = 0; y < 8; y++) {
+        for (var z = 0; z < 8; z++) {
+          simplex.noise3D(x / 8, y / 8, z / 8);
         }
-    })
-    .add('noise3D2', function() {
-         for(var x = 0; x < 8; x++){
-              for(var y = 0; y < 8; y++){
-                      for(var z = 0; z < 8; z++){
-                          simplex.noise3D(x/8, y/8, z/8);
-                      }
-              }
+      }
+    }
+  })
+  .add('noise3D2', function() {
+    for (var x = 0; x < 8; x++) {
+      for (var y = 0; y < 8; y++) {
+        for (var z = 0; z < 8; z++) {
+          simplex.noise3D(x / 8, y / 8, z / 8);
         }
-    })
-    .add('noise4D', function() {
-          for(var x = 0; x < 8; x++){
-              for(var y = 0; y < 8; y++){
-                      for(var z = 0; z < 8; z++){
-                          simplex.noise4D(x/8, y/8, z/8, (x+y)/16);
-                      }
-              }
+      }
+    }
+  })
+  .add('noise4D', function() {
+    for (var x = 0; x < 8; x++) {
+      for (var y = 0; y < 8; y++) {
+        for (var z = 0; z < 8; z++) {
+          simplex.noise4D(x / 8, y / 8, z / 8, (x + y) / 16);
         }
-    })
-    .on('complete', function() {
-        this.forEach(function (bench) {
-            console.log(bench.name + ': ' + Benchmark.formatNumber(Math.round(1.0/bench.times.period)) + ' ops/sec ±' + Math.round(bench.stats.rme) + '%');
-            //console.log(bench.times);
-            //console.log(bench.stats);
-        });
-    }) 
-    .run();
+      }
+    }
+  })
+  .on('complete', function() {
+    this.forEach(function(bench) {
+      console.log(
+        bench.name +
+        ': ' +
+        Benchmark.formatNumber(Math.round(1.0 / bench.times.period)) +
+        ' ops/sec ±' +
+        Math.round(bench.stats.rme) + '%'
+      );
+    });
+  })
+  .run();

simplex-noise.js

@@ -41,7 +41,7 @@ var G4 = (5.0 - Math.sqrt(5.0)) / 20.0;
 
 function SimplexNoise(random) {
   if (!random) random = Math.random;
-  this.p = new Uint8Array(256);
+  this.p = buildPermutationTable(random);
   this.perm = new Uint8Array(512);
   this.permMod12 = new Uint8Array(512);
   for (var i = 0; i < 256; i++) {

test/simplex-noise-test.js

@@ -1,42 +1,44 @@
 var SimplexNoise = require('../simplex-noise');
-
+var Alea = require('alea');
 var assert = require('chai').assert;
 
-describe('simplex-noise', function() {
+describe('SimplexNoise', function() {
   function getRandom() {
-    var rnd = 0;
-    return function() {
-      return 1.0 / (rnd++);
-    };
+    return new Alea('seed');
   }
 
+  describe('buildPermutationTable', function() {
+    var table = SimplexNoise._buildPermutationTable(getRandom());
+    var aTable = Array.prototype.slice.call(table);
+    assert.lengthOf(aTable, 256);
+    for (var i = 0; i < aTable.length; i++) {
+      assert.include(aTable, i);
+    }
+  });
+
   describe('constructor', function() {
     it('should initialize with Math.random', function() {
       var simplex = new SimplexNoise();
       assert.equal(simplex.perm.length, 512);
       assert.equal(simplex.permMod12.length, 512);
       for (var i = 0; i < 512; i++) {
-        assert(simplex.perm[i] < 256);
-        assert(simplex.perm[i] >= 0);
-        assert(simplex.perm[i] >= 0);
+        assert.isBelow(simplex.perm[i], 256);
+        assert.isAtLeast(simplex.perm[i], 0);
         assert.equal(simplex.perm[i], simplex.perm[i & 255]);
         assert.equal(simplex.permMod12[i], simplex.perm[i] % 12);
       }
     });
 
     it('should initialize with a custom random function', function() {
-      var i = 2;
-      var simplex = new SimplexNoise(function() {
-        return 1.0 / i++;
-      });
+      var simplex = new SimplexNoise(getRandom());
       assert.equal(simplex.perm.length, 512);
       assert.equal(simplex.permMod12.length, 512);
-      assert.equal(simplex.perm[0], 128);
-      assert.equal(simplex.perm[1], 85);
-      assert.equal(simplex.perm[256], 128);
-      assert.equal(simplex.perm[257], 85);
-      assert.equal(simplex.permMod12[0], 128 % 12);
-      assert.equal(simplex.permMod12[1], 85 % 12);
+      for (var i = 0; i < 512; i++) {
+        assert.isBelow(simplex.perm[i], 256);
+        assert.isAtLeast(simplex.perm[i], 0);
+        assert.equal(simplex.perm[i], simplex.perm[i & 255]);
+        assert.equal(simplex.permMod12[i], simplex.perm[i] % 12);
+      }
     });
   });