for common.glMatrix equals method added optional param tolerance by default equal to EPSILON

Author: psnet

CONTRIBUTING.md

@@ -6,5 +6,5 @@ When adding new functionality, please explain why and when the functionality is
 
 Please provide unit tests for new functionality. (See [TESTING.md](./TESTING.md) for details)  
 
-Also, avoid commiting [rebuilt docs](https://github.com/toji/gl-matrix/tree/master/dist) and [files in the dist folder](https://github.com/toji/gl-matrix/tree/master/dist)
+Also, avoid commiting [rebuilt docs](https://github.com/toji/gl-matrix/tree/master/docs) and [files in the dist folder](https://github.com/toji/gl-matrix/tree/master/dist)
 to prevent merge conflicts.

spec/gl-matrix/common-spec.js

@@ -14,15 +14,19 @@ describe("common", function(){
   });
 
   describe("equals", function() {
-    let r0, r1, r2;
+    let r0, r1, r2, r3, r4;
     beforeEach(function() {
       r0 = glMatrix.equals(1.0, 0.0);
       r1 = glMatrix.equals(1.0, 1.0);
       r2 = glMatrix.equals(1.0+glMatrix.EPSILON/2, 1.0);
+      r3 = glMatrix.equals(1.0+glMatrix.EPSILON/2, 1.0, 0.001);
+      r4 = glMatrix.equals(100.5, 100.7, 0.2);
     });
     it("should return false for different numbers", function() { expect(r0).toBe(false); });
     it("should return true for the same number", function() { expect(r1).toBe(true); });
     it("should return true for numbers that are close", function() { expect(r2).toBe(true); });
+    it("should return false for numbers that are close but tolerance is set to smaller value", function() { expect(r3).toBe(false); });
+    it("should return true for numbers that are close with tolerance is set to bigger value", function() { expect(r4).toBe(true); });
   });
 
 });

src/common.js

@@ -59,10 +59,11 @@ export function toDegree(a) {
  * or relative tolerance of glMatrix.EPSILON (an absolute tolerance is used for values less
  * than or equal to 1.0, and a relative tolerance is used for larger values)
  *
- * @param {Number} a The first number to test.
- * @param {Number} b The second number to test.
+ * @param {Number} a          The first number to test.
+ * @param {Number} b          The second number to test.
+ * @param {Number} tolerance  Absolute or relative tolerance (default glMatrix.EPSILON)
  * @returns {Boolean} True if the numbers are approximately equal, false otherwise.
  */
-export function equals(a, b) {
-  return Math.abs(a - b) <= EPSILON * Math.max(1.0, Math.abs(a), Math.abs(b));
+export function equals(a, b, tolerance = EPSILON) {
+  return Math.abs(a - b) <= tolerance * Math.max(1, Math.abs(a), Math.abs(b));
 }