Modified randomSuppies API

getRng now returns a 32 bit random Number
getIndexRng returns a random index in a range
getBitRng returns a random bit
getValueRng is the old getRng which alters the provided value

lib/modifiedAPI.js

@@ -124,7 +124,7 @@
 		var data2 = imageData2.data;
 		var l = data1.length;
 		if (l === data2.length){
-			var rng = randomSupply.getRng(l, window);
+			var rng = randomSupply.getValueRng(l, window);
 			
 			for (var i = 0; i < l; i += 1){
 				if (data1[i] > data2[i]){
@@ -314,7 +314,7 @@
 			object: "CanvasRenderingContext2D",
 			fakeGenerator: function(prefs, notify, window, original){
 				return function isPointInPath(x, y){
-					var rng = randomSupply.getRng(1, window);
+					var rng = randomSupply.getValueRng(1, window);
 					var originalValue = original.apply(this, window.Array.from(arguments));
 					if ((typeof originalValue) === "boolean"){
 						notify.call(this, "fakedReadout");
@@ -337,7 +337,7 @@
 			object: "CanvasRenderingContext2D",
 			fakeGenerator: function(prefs, notify, window, original){
 				return function isPointInStroke(x, y){
-					var rng = randomSupply.getRng(1, window);
+					var rng = randomSupply.getValueRng(1, window);
 					var originalValue = original.apply(this, window.Array.from(arguments));
 					if ((typeof originalValue) === "boolean"){
 						notify.call(this, "fakedReadout");

lib/randomSupplies.js

@@ -13,6 +13,56 @@
 		scope = window.scope.randomSupplies;
 	}
 	
+	const rngTemplate = {
+		getBitRng: function(length, window){
+			const rng = this.getRng(Math.ceil(length / 32), window);
+			let bitIndex = 32;
+			let rnd = 0;
+			let mask = 0xffffffff * 2;
+			return function(value, i){
+				if (mask > 0xffffffff){
+					mask = 1;
+					rnd = rng(i / 32);
+				}
+				let bit = 1 * (!!(rnd & mask));
+				mask *= 2;
+				return bit;
+			};
+		},
+		getIndexRng: function(length, maxIndex, window){
+			const rng = this.getRng(length, window);
+			
+			return function(i){
+				return Math.floor(rng(i) / 0xffffffff * maxIndex);
+			};
+		},
+		getValueRng: function(length, window){
+			const rng = this.getBitRng(length, window);
+			return function(value, i){
+				var rnd = rng(value, i);
+				
+				// XOR the last bit to alter it... or not
+				return value ^ (rnd & 0x01);
+			};
+		},
+		getPixelRng: function(length, window, ignoredColors){
+			var rng = this.getValueRng(length, window);
+			return function(r, g, b, a, i){ // eslint-disable-line max-params
+				var index = String.fromCharCode(r, g, b, a);
+				if (ignoredColors[index]){
+					return [r, g, b, a];
+				}
+				var baseIndex = i * 4;
+				return [
+					rng(r, baseIndex + 0),
+					rng(g, baseIndex + 1),
+					rng(b, baseIndex + 2),
+					rng(a, baseIndex + 3)
+				];
+			};
+		}
+	};
+
 	const settings = require("./settings");
 	
 	function getDomain(window){
@@ -40,7 +90,7 @@
 						return typeof value === "number" && value >= 0 && value < 256;
 					})
 				){
-					persistentRnd[domain] = value;
+					persistentRnd[domain] = new Uint8Array(value);
 				}
 			}
 		}
@@ -73,12 +123,20 @@
 			return persistentRnd[domain];
 		};
 	}());
-	scope.persistent = {
+	
-		name: "persistent",
+	scope.persistent = Object.create(rngTemplate);
-		setDomainRnd: function(domain, rnd){
+	scope.persistent.name = "persistent";
+	scope.persistent.setDomainRnd = function(domain, rnd){
 		persistentRnd[domain] = new Uint8Array(rnd);
-		},
+	};
-		getRng: function(length, window){
+	scope.persistent.getRng = function(length, window){
+		var bitSet = new Uint32Array(getPersistentRnd(window).buffer);
+		var bitSetLength = bitSet.length;
+		return function(i){
+			return bitSet[i % bitSetLength];
+		};
+	};
+	scope.persistent.getBitRng = function(length, window){
 		var bitSet = getPersistentRnd(window);
 		
 		return function(value, i){
@@ -93,37 +151,19 @@
 			// extract the bit
 			var bit = (bitSet[index] >>> bitIndex) & 0x01;
 			
-				// XOR the bit and the value to alter the last bit of it... or not
+			return bit;
-				return value ^ bit;
 		};
-		},
-		getPixelRng: function(length, window, ignoredColors){
-			var rng = this.getRng(length, window);
-			return function(r, g, b, a, i){ // eslint-disable-line max-params
-				var index = String.fromCharCode(r, g, b, a);
-				if (ignoredColors[index]){
-					return [r, g, b, a];
-				}
-				var baseIndex = i * 4;
-				return [
-					rng(r, baseIndex + 0),
-					rng(g, baseIndex + 1),
-					rng(b, baseIndex + 2),
-					rng(a, baseIndex + 3)
-				];
-			};
-		}
 	};
 	
-	scope.constant = {
+	scope.constant = Object.create(rngTemplate);
-		name: "constant",
+	scope.constant.name = "constant";
-		getRng: function(length, window){
+	scope.constant.getRng = function(length, window){
 		return scope.nonPersistent.getRng(length, window);
-		},
+	};
-		getPixelRng: (function(){
+	scope.constant.getPixelRng = (function(){
 		var colors = Object.create(null);
 		return function getConstantPixelRng(length, window, ignoredColors){
-				var rng = scope.nonPersistent.getRng(1024, window);
+			var rng = scope.nonPersistent.getValueRng(1024, window);
 			
 			return function(r, g, b, a, i){ // eslint-disable-line max-params
 				var index = String.fromCharCode(r, g, b, a);
@@ -143,48 +183,28 @@
 				return color;
 			};
 		};
-		}())
+	}());
-	};
 	
-	scope.nonPersistent = {
+	scope.nonPersistent = Object.create(rngTemplate);
-		name: "nonPersistent",
+	scope.nonPersistent.name = "nonPersistent";
-		getRng: function(length, window){
+	scope.nonPersistent.getRng = function(length, window){
-			// Initialize the random number batch creation
+		const maxLength = 0x4000;
-			var randomI = 65536;
+		var randomI = maxLength;
-			var randomNumbers = new Uint8Array(Math.min(65536, length));
+		var randomNumbers = new Uint32Array(Math.min(maxLength, length));
-			
+		return function(i){
-			return function(value, i){
 			if (randomI >= randomNumbers.length){
 				// refill the random number bucket if empty
 				randomI = 0;
-					if (length - i < 65536){
+				if (length - i < maxLength){
-						randomNumbers = new Uint8Array(length - i);
+					randomNumbers = new Uint32Array(Math.max(1, length - i));
 				}
 				window.crypto.getRandomValues(randomNumbers);
 			}
 			var rnd = randomNumbers[randomI];
 			randomI += 1;
 			
-				// XOR the last bit to alter it... or not
+			return rnd;
-				return value ^ (rnd & 0x01);
 		};
-		},
-		getPixelRng: function(length, window, ignoredColors){
-			var rng = this.getRng(length, window);
-			return function(r, g, b, a, i){ // eslint-disable-line max-params
-				var index = String.fromCharCode(r, g, b, a);
-				if (ignoredColors[index]){
-					return [r, g, b, a];
-				}
-				var baseIndex = i * 4;
-				return [
-					rng(r, baseIndex + 0),
-					rng(g, baseIndex + 1),
-					rng(b, baseIndex + 2),
-					rng(a, baseIndex + 3)
-				];
-			};
-		}
 	};
 	
 	scope.white = {
@@ -194,6 +214,19 @@
 				return 255;
 			};
 		},
+		getBitRng: function(){
+			return function(){
+				return 1;
+			};
+		},
+		getIndex: function(){
+			return function(){
+				return 0;
+			};
+		},
+		getValueRng: function(){
+			return this.getRng();
+		},
 		getPixelRng: function(){
 			return function(){
 				return [255, 255, 255, 255];