Change Util.applyInverseTransform to use the point-argument as an in/out parameter

This will help reduce the total number of Array allocations, which cannot hurt.

Author: Snuffleupagus

src/display/display_utils.js

@@ -287,7 +287,9 @@ class PageViewport {
    * @see {@link convertToViewportPoint}
    */
   convertToPdfPoint(x, y) {
-    return Util.applyInverseTransform([x, y], this.transform);
+    const p = [x, y];
+    Util.applyInverseTransform(p, this.transform);
+    return p;
   }
 }
 

src/shared/util.js

@@ -758,10 +758,10 @@ class Util {
   }
 
   static applyInverseTransform(p, m) {
+    const [p0, p1] = p;
     const d = m[0] * m[3] - m[1] * m[2];
-    const xt = (p[0] * m[3] - p[1] * m[2] + m[2] * m[5] - m[4] * m[3]) / d;
-    const yt = (-p[0] * m[1] + p[1] * m[0] + m[4] * m[1] - m[5] * m[0]) / d;
-    return [xt, yt];
+    p[0] = (p0 * m[3] - p1 * m[2] + m[2] * m[5] - m[4] * m[3]) / d;
+    p[1] = (-p0 * m[1] + p1 * m[0] + m[4] * m[1] - m[5] * m[0]) / d;
   }
 
   // Applies the transform to the rectangle and finds the minimum axially