Avoid to create any subarrays when optimizing 'save, transform, constructPath, restore' (bug 1961107)

Removing those `subarray`calls helps to improve performance by a factor 6 on Linux and by a factor of 3
on Windows 11.

Author: calixteman

src/core/operator_list.js

@@ -524,11 +524,11 @@ addState(
       switch (buffer[k++]) {
         case DrawOPS.moveTo:
         case DrawOPS.lineTo:
-          Util.applyTransform(buffer.subarray(k), transform);
+          Util.applyTransformToBuffer(buffer, k, transform);
           k += 2;
           break;
         case DrawOPS.curveTo:
-          Util.applyTransformToBezier(buffer.subarray(k), transform);
+          Util.applyTransformToBezierBuffer(buffer, k, transform);
           k += 6;
           break;
       }

src/shared/util.js

@@ -737,19 +737,25 @@ class Util {
     p[1] = p0 * m[1] + p1 * m[3] + m[5];
   }
 
-  // For 2d affine transforms
-  static applyTransformToBezier(p, transform) {
+  static applyTransformToBuffer(buffer, pos, m) {
+    const p0 = buffer[pos];
+    const p1 = buffer[pos + 1];
+    buffer[pos] = p0 * m[0] + p1 * m[2] + m[4];
+    buffer[pos + 1] = p0 * m[1] + p1 * m[3] + m[5];
+  }
+
+  static applyTransformToBezierBuffer(buffer, pos, transform) {
     const m0 = transform[0];
     const m1 = transform[1];
     const m2 = transform[2];
     const m3 = transform[3];
     const m4 = transform[4];
     const m5 = transform[5];
     for (let i = 0; i < 6; i += 2) {
-      const pI = p[i];
-      const pI1 = p[i + 1];
-      p[i] = pI * m0 + pI1 * m2 + m4;
-      p[i + 1] = pI * m1 + pI1 * m3 + m5;
+      const pI = buffer[pos + i];
+      const pI1 = buffer[pos + i + 1];
+      buffer[pos + i] = pI * m0 + pI1 * m2 + m4;
+      buffer[pos + i + 1] = pI * m1 + pI1 * m3 + m5;
     }
   }