Negate masks for a small code size reduction

Author: davidje13

docs/integrity.txt

@@ -1,6 +1,6 @@
-index.mjs:              sha384-t+94URBG0X4n9UfMx4w+QAFX9G5Y8+sQvj2nlz5/7vgweO7sAhX2e1wk7txC16Cj
-index.js:               sha384-sBqXcYWazfHB7xekYG3pcTE62PVw4Kl4DAS71zhVPwESkFJejqoVwhKX3YiaWA1D
-nano.mjs:               sha384-4Ws+pC9t1jZdJyS4XRFsLI8NQrlUL/bk+6sGUIT4I98XlDPBx/ga682gAmemIMTw
+index.mjs:              sha384-6Uu0RYalZ7Zv802Ew4mdhp8Hzq4Kl/hDwjQowRN3ws0N566c/cVzWa0Mp6/0JhD0
+index.js:               sha384-9tErxRWXMXhzGgUPF4/Mo3uQ9QsatQWR3at3hDrX5DXkkhGoFT6uh/iE1nAtyDa0
+nano.mjs:               sha384-v8pAURUCvIAHRMAtQgbuZoaevbsskAKM7SN3ZVpoITG+8bVtwPDsQNos1U9Xm109
 extras/svg.mjs:         sha384-3pkh2mVqJfcbY5hcEp4KTGcaWZN1EeJfqKCr6Xnz9qUkgXb54ocau/pBlClVACyL
 extras/svg.js:          sha384-FElcxc5DxhRR9QjjMNlQ/0C1dTlVogFRx7Fj/sgOeUR0oKA2yvVXMqaSX6vDQsVo
 extras/node_export.mjs: sha384-l3U32OuSe/3qIQkqn4i0VGLdCeJCpTBUd+bqIbNX7Z1HSC4iEz10feCrWIyi2PqB
@@ -9,4 +9,4 @@ extras/react.mjs:       sha384-WMj3wD5sIRcxHYWdj7j7SYJ/tVJuJ/capEy+UhnivNhCfU56Z
 extras/react.js:        sha384-io/wo5e3Zc4sweQDtStRLvuuj98pZa/LG2rD1H+3ylDd7K/pWSoRrRojmZgubP2S
 extras/errors.mjs:      sha384-LaUpr3MpI+ZWjDG8L54lwBzgymdm+C1fijP3Z3HukZOFOn3nmRUtgK5aTmOSVm/q
 extras/errors.js:       sha384-lpwl8zlB1GwhvS1ftgUv4mCvOhlixuRa8fRag2aZ2PEEPKQ++l+IjhZL8lhbZMVe
-webcomponent.mjs:       sha384-K3p+YoLK5MrGTZX0UnO6siMZJzIilHuW1Sje0euI6Kr2NWYWQ7YVU2ynSF0RhM72
+webcomponent.mjs:       sha384-QX0gJO6xHh49Ad63YR4Hhfb0I3E4+gxZ+2GwA09TmxXM24yb52dHpdNHHGVXZfhm

docs/stats.txt

@@ -1,6 +1,6 @@
-index.mjs:                  6908 bytes /     3637 bytes (compressed)
-index.js:                   6924 bytes /     3630 bytes (compressed)
-nano.mjs:                   3792 bytes /     2159 bytes (compressed)
+index.mjs:                  6877 bytes /     3635 bytes (compressed)
+index.js:                   6893 bytes /     3629 bytes (compressed)
+nano.mjs:                   3761 bytes /     2157 bytes (compressed)
 extras/svg.mjs:             1348 bytes /      953 bytes (compressed)
 extras/svg.js:              1365 bytes /      951 bytes (compressed)
 extras/node_export.mjs:     1072 bytes /      785 bytes (compressed)
@@ -9,4 +9,4 @@ extras/react.mjs:            961 bytes /      661 bytes (compressed)
 extras/react.js:             968 bytes /      660 bytes (compressed)
 extras/errors.mjs:           287 bytes /      342 bytes (compressed)
 extras/errors.js:            287 bytes /      340 bytes (compressed)
-webcomponent.mjs:           8654 bytes /     4417 bytes (compressed)
+webcomponent.mjs:           8623 bytes /     4417 bytes (compressed)

src/qr/draw.mjs

@@ -96,7 +96,7 @@ export const applyMask = ({ size, _data }, mask, maskId, ecLevel) => {
   for (let j = 0; j < size; ++j) {
     for (let i = 0; i < size; ++i) {
       const p = j * size + i;
-      _data[p] ^= mask(i, j) & ((_data[p] >> 1) ^ 1);
+      _data[p] ^= !(mask(i, j) || _data[p] & 2);
     }
   }
   const info = ((ecLevel ^ 1) << 3) | maskId;

src/qr/options/masks.mjs

@@ -1,10 +1,10 @@
 export const masks = [
-  (x, y) => !((x ^ y) & 1),
-  (x, y) => !(y & 1),
-  (x) => !(x % 3),
-  (x, y) => !((x + y) % 3),
-  (x, y) => !((((x / 3) | 0) ^ (y >> 1)) & 1),
-  (x, y) => !((x & y & 1) + ((x * y) % 3)),
-  (x, y) => !(((x & y & 1) + ((x * y) % 3)) & 1),
-  (x, y) => !((((x ^ y) & 1) + ((x * y) % 3)) & 1),
+  (x, y) => (x ^ y) & 1,
+  (x, y) => y & 1,
+  (x) => x % 3,
+  (x, y) => (x + y) % 3,
+  (x, y) => ((x / 3) ^ (y >> 1)) & 1,
+  (x, y) => (x & y & 1) + ((x * y) % 3),
+  (x, y) => ((x & y) + ((x * y) % 3)) & 1,
+  (x, y) => ((x ^ y) + ((x * y) % 3)) & 1,
 ];

src/qr/options/masks.test.mjs

@@ -76,22 +76,13 @@ describe('masks', () => {
       const dimX = 6;
       const dimY = id === 4 ? 4 : 6;
 
-      it('returns true or false for any given pixel location', () => {
-        for (let y = 0; y < 10; ++y) {
-          for (let x = 0; x < 10; ++x) {
-            const value = mask(x, y);
-            expect(typeof value).toEqual('boolean');
-          }
-        }
-      });
-
       it(`defines a repeating ${dimX}x${dimY} pattern`, () => {
         for (let y = 0; y < dimY; ++y) {
           for (let x = 0; x < dimX; ++x) {
-            const value = mask(x, y);
-            expect(value).toEqual(mask(x + dimX, y));
-            expect(value).toEqual(mask(x, y + dimY));
-            expect(value).toEqual(mask(x + dimX, y + dimY));
+            const value = Boolean(mask(x, y));
+            expect(value).toEqual(Boolean(mask(x + dimX, y)));
+            expect(value).toEqual(Boolean(mask(x, y + dimY)));
+            expect(value).toEqual(Boolean(mask(x + dimX, y + dimY)));
           }
         }
       });
@@ -100,7 +91,7 @@ describe('masks', () => {
         let actual = '';
         for (let y = 0; y < dimY; ++y) {
           for (let x = 0; x < dimX; ++x) {
-            actual += mask(x, y) ? '#' : ' ';
+            actual += mask(x, y) ? ' ' : '#';
           }
           actual += '\n';
         }

tools/mask-preview-gen.mjs

@@ -23,6 +23,6 @@ for (let i = 0; i < masks.length; ++i) {
 
   await writeFile(
     path,
-    toPngBuffer({ size, get: (x, y) => !masks[i](x, y) }, options),
+    toPngBuffer({ size, get: (x, y) => Boolean(masks[i](x, y)) }, options),
   );
 }