Merge pull request #13595 from takahirox/FlattenUUID

Flatten UUID strings with .toUpperCase() to save heap memory space.

Author: mrdoob

src/math/Math.js

@@ -16,7 +16,7 @@ var _Math = {
 
 		for ( var i = 0; i < 256; i ++ ) {
 
-			lut[ i ] = ( i < 16 ? '0' : '' ) + ( i ).toString( 16 ).toUpperCase();
+			lut[ i ] = ( i < 16 ? '0' : '' ) + ( i ).toString( 16 );
 
 		}
 
@@ -26,11 +26,14 @@ var _Math = {
 			var d1 = Math.random() * 0xffffffff | 0;
 			var d2 = Math.random() * 0xffffffff | 0;
 			var d3 = Math.random() * 0xffffffff | 0;
-			return lut[ d0 & 0xff ] + lut[ d0 >> 8 & 0xff ] + lut[ d0 >> 16 & 0xff ] + lut[ d0 >> 24 & 0xff ] + '-' +
+			var uuid = lut[ d0 & 0xff ] + lut[ d0 >> 8 & 0xff ] + lut[ d0 >> 16 & 0xff ] + lut[ d0 >> 24 & 0xff ] + '-' +
 				lut[ d1 & 0xff ] + lut[ d1 >> 8 & 0xff ] + '-' + lut[ d1 >> 16 & 0x0f | 0x40 ] + lut[ d1 >> 24 & 0xff ] + '-' +
 				lut[ d2 & 0x3f | 0x80 ] + lut[ d2 >> 8 & 0xff ] + '-' + lut[ d2 >> 16 & 0xff ] + lut[ d2 >> 24 & 0xff ] +
 				lut[ d3 & 0xff ] + lut[ d3 >> 8 & 0xff ] + lut[ d3 >> 16 & 0xff ] + lut[ d3 >> 24 & 0xff ];
 
+			// .toUpperCase() here flattens concatenated strings to save heap memory space. 
+			return uuid.toUpperCase();
+
 		};
 
 	} )(),