first commit

external/qcms/qcms_utils.js

@@ -0,0 +1,84 @@
+/* Copyright 2025 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+class QCMS {
+  static #memoryArray = null;
+
+  static _memory = null;
+
+  static _mustAddAlpha = false;
+
+  static _destBuffer = null;
+
+  static _destOffset = 0;
+
+  static _destLength = 0;
+
+  static _cssColor = "";
+
+  static _makeHexColor = null;
+
+  static get _memoryArray() {
+    const array = this.#memoryArray;
+    if (array?.byteLength) {
+      return array;
+    }
+    return (this.#memoryArray = new Uint8Array(this._memory.buffer));
+  }
+}
+
+function copy_result(ptr, len) {
+  // This function is called from the wasm module (it's an external
+  // "C" function). Its goal is to copy the result from the wasm memory
+  // to the destination buffer without any intermediate copies.
+  const { _mustAddAlpha, _destBuffer, _destOffset, _destLength, _memoryArray } =
+    QCMS;
+  if (len === _destLength) {
+    _destBuffer.set(_memoryArray.subarray(ptr, ptr + len), _destOffset);
+    return;
+  }
+  if (_mustAddAlpha) {
+    for (let i = ptr, ii = ptr + len, j = _destOffset; i < ii; i += 3, j += 4) {
+      _destBuffer[j] = _memoryArray[i];
+      _destBuffer[j + 1] = _memoryArray[i + 1];
+      _destBuffer[j + 2] = _memoryArray[i + 2];
+      _destBuffer[j + 3] = 255;
+    }
+  } else {
+    for (let i = ptr, ii = ptr + len, j = _destOffset; i < ii; i += 3, j += 4) {
+      _destBuffer[j] = _memoryArray[i];
+      _destBuffer[j + 1] = _memoryArray[i + 1];
+      _destBuffer[j + 2] = _memoryArray[i + 2];
+    }
+  }
+}
+
+function copy_rgb(ptr) {
+  const { _destBuffer, _destOffset, _memoryArray } = QCMS;
+  _destBuffer[_destOffset] = _memoryArray[ptr];
+  _destBuffer[_destOffset + 1] = _memoryArray[ptr + 1];
+  _destBuffer[_destOffset + 2] = _memoryArray[ptr + 2];
+}
+
+function make_cssRGB(ptr) {
+  const { _memoryArray } = QCMS;
+  QCMS._cssColor = QCMS._makeHexColor(
+    _memoryArray[ptr],
+    _memoryArray[ptr + 1],
+    _memoryArray[ptr + 2]
+  );
+}
+
+export { copy_result, copy_rgb, make_cssRGB, QCMS };