Add HashNode (mrdoob#26663)

sunag · web-flow · commit acf97d01d26e · 2023-08-28T16:27:44.000-03:00
diff --git a/examples/jsm/nodes/Nodes.js b/examples/jsm/nodes/Nodes.js
@@ -38,6 +38,7 @@ export { NodeUtils };
 export { default as MathNode, EPSILON, INFINITY, radians, degrees, exp, exp2, log, log2, sqrt, inverseSqrt, floor, ceil, normalize, fract, sin, cos, tan, asin, acos, atan, abs, sign, length, negate, oneMinus, dFdx, dFdy, round, reciprocal, trunc, fwidth, atan2, min, max, mod, step, reflect, distance, difference, dot, cross, pow, pow2, pow3, pow4, transformDirection, mix, clamp, saturate, refract, smoothstep, faceForward } from './math/MathNode.js';
 export { default as OperatorNode, add, sub, mul, div, remainder, equal, assign, lessThan, greaterThan, lessThanEqual, greaterThanEqual, and, or, xor, bitAnd, bitOr, bitXor, shiftLeft, shiftRight } from './math/OperatorNode.js';
 export { default as CondNode, cond } from './math/CondNode.js';
+export { default as HashNode, hash } from './math/HashNode.js';
 
 // utils
 export { default as ArrayElementNode } from './utils/ArrayElementNode.js';
diff --git a/examples/jsm/nodes/math/HashNode.js b/examples/jsm/nodes/math/HashNode.js
@@ -0,0 +1,35 @@
+import Node, { addNodeClass } from '../core/Node.js';
+import { add, mul, bitXor, shiftRight } from './OperatorNode.js';
+import { addNodeElement, nodeProxy, uint } from '../shadernode/ShaderNode.js';
+
+class HashNode extends Node {
+
+	constructor( seedNode ) {
+
+		super();
+
+		this.seedNode = seedNode;
+
+	}
+
+	construct( /*builder*/ ) {
+
+		const seed = this.seedNode;
+
+		const state = add( mul( uint( seed ), 747796405 ), 2891336453 );
+		const word = mul( bitXor( shiftRight( state, add( shiftRight( state, 28 ), 4 ) ), state ), 277803737 );
+		const uintResult = bitXor( shiftRight( word, 22 ), word );
+
+		return mul( 1 / 2 ** 32, uintResult ); // Convert to range [0, 1)
+
+	}
+
+}
+
+export default HashNode;
+
+export const hash = nodeProxy( HashNode );
+
+addNodeElement( 'hash', hash );
+
+addNodeClass( HashNode );
