snapshot of https://github.com/excalidraw/excalidraw.git (master, 2026-09-16; blobs > 131072B omitted)

packages/excalidraw/subset/harfbuzz/harfbuzz-bindings.ts

@@ -0,0 +1,202 @@
+/**
+ * Modified version of hb-subset bindings from "subset-font" package https://github.com/papandreou/subset-font/blob/3f711c8aa29a426c7f22655861abfb976950f527/index.js
+ * 
+ * CHANGELOG:
+ * - removed dependency on node APIs to work inside the browser
+ * - removed dependency on font fontverter for brotli compression
+ * - removed dependencies on lodash and p-limit
+ * - removed options for preserveNameIds, variationAxes, noLayoutClosure (not needed for now)
+ * - replaced text input with codepoints
+ * - rewritten in typescript and with esm modules
+
+Copyright (c) 2012, Andreas Lind Petersen
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+  * Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+  * Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+  * Neither the name of the author nor the names of contributors may
+    be used to endorse or promote products derived from this
+    software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// function HB_TAG(str) {
+//   return str.split("").reduce((a, ch) => {
+//     return (a << 8) + ch.charCodeAt(0);
+//   }, 0);
+// }
+
+function subset(
+  hbSubsetWasm: any,
+  heapu8: Uint8Array,
+  font: ArrayBuffer,
+  codePoints: ReadonlySet<number>,
+) {
+  const input = hbSubsetWasm.hb_subset_input_create_or_fail();
+  if (input === 0) {
+    throw new Error(
+      "hb_subset_input_create_or_fail (harfbuzz) returned zero, indicating failure",
+    );
+  }
+
+  const fontBuffer = hbSubsetWasm.malloc(font.byteLength);
+  heapu8.set(new Uint8Array(font), fontBuffer);
+
+  // Create the face
+  const blob = hbSubsetWasm.hb_blob_create(
+    fontBuffer,
+    font.byteLength,
+    2, // HB_MEMORY_MODE_WRITABLE
+    0,
+    0,
+  );
+  const face = hbSubsetWasm.hb_face_create(blob, 0);
+  hbSubsetWasm.hb_blob_destroy(blob);
+
+  // Do the equivalent of --font-features=*
+  const layoutFeatures = hbSubsetWasm.hb_subset_input_set(
+    input,
+    6, // HB_SUBSET_SETS_LAYOUT_FEATURE_TAG
+  );
+  hbSubsetWasm.hb_set_clear(layoutFeatures);
+  hbSubsetWasm.hb_set_invert(layoutFeatures);
+
+  // if (preserveNameIds) {
+  //   const inputNameIds = harfbuzzJsWasm.hb_subset_input_set(
+  //     input,
+  //     4, // HB_SUBSET_SETS_NAME_ID
+  //   );
+  //   for (const nameId of preserveNameIds) {
+  //     harfbuzzJsWasm.hb_set_add(inputNameIds, nameId);
+  //   }
+  // }
+
+  // if (noLayoutClosure) {
+  //   harfbuzzJsWasm.hb_subset_input_set_flags(
+  //     input,
+  //     harfbuzzJsWasm.hb_subset_input_get_flags(input) | 0x00000200, // HB_SUBSET_FLAGS_NO_LAYOUT_CLOSURE
+  //   );
+  // }
+
+  // Add unicodes indices
+  const inputUnicodes = hbSubsetWasm.hb_subset_input_unicode_set(input);
+  for (const c of codePoints) {
+    hbSubsetWasm.hb_set_add(inputUnicodes, c);
+  }
+
+  // if (variationAxes) {
+  //   for (const [axisName, value] of Object.entries(variationAxes)) {
+  //     if (typeof value === "number") {
+  //       // Simple case: Pin/instance the variation axis to a single value
+  //       if (
+  //         !harfbuzzJsWasm.hb_subset_input_pin_axis_location(
+  //           input,
+  //           face,
+  //           HB_TAG(axisName),
+  //           value,
+  //         )
+  //       ) {
+  //         harfbuzzJsWasm.hb_face_destroy(face);
+  //         harfbuzzJsWasm.free(fontBuffer);
+  //         throw new Error(
+  //           `hb_subset_input_pin_axis_location (harfbuzz) returned zero when pinning ${axisName} to ${value}, indicating failure. Maybe the axis does not exist in the font?`,
+  //         );
+  //       }
+  //     } else if (value && typeof value === "object") {
+  //       // Complex case: Reduce the variation space of the axis
+  //       if (
+  //         typeof value.min === "undefined" ||
+  //         typeof value.max === "undefined"
+  //       ) {
+  //         harfbuzzJsWasm.hb_face_destroy(face);
+  //         harfbuzzJsWasm.free(fontBuffer);
+  //         throw new Error(
+  //           `${axisName}: You must provide both a min and a max value when setting the axis range`,
+  //         );
+  //       }
+  //       if (
+  //         !harfbuzzJsWasm.hb_subset_input_set_axis_range(
+  //           input,
+  //           face,
+  //           HB_TAG(axisName),
+  //           value.min,
+  //           value.max,
+  //           // An explicit NaN makes harfbuzz use the existing default value, clamping to the new range if necessary
+  //           value.default ?? NaN,
+  //         )
+  //       ) {
+  //         harfbuzzJsWasm.hb_face_destroy(face);
+  //         harfbuzzJsWasm.free(fontBuffer);
+  //         throw new Error(
+  //           `hb_subset_input_set_axis_range (harfbuzz) returned zero when setting the range of ${axisName} to [${value.min}; ${value.max}] and a default value of ${value.default}, indicating failure. Maybe the axis does not exist in the font?`,
+  //         );
+  //       }
+  //     }
+  //   }
+  // }
+
+  let subset;
+  try {
+    subset = hbSubsetWasm.hb_subset_or_fail(face, input);
+    if (subset === 0) {
+      hbSubsetWasm.hb_face_destroy(face);
+      hbSubsetWasm.free(fontBuffer);
+      throw new Error(
+        "hb_subset_or_fail (harfbuzz) returned zero, indicating failure. Maybe the input file is corrupted?",
+      );
+    }
+  } finally {
+    // Clean up
+    hbSubsetWasm.hb_subset_input_destroy(input);
+  }
+
+  // Get result blob
+  const result = hbSubsetWasm.hb_face_reference_blob(subset);
+
+  const offset = hbSubsetWasm.hb_blob_get_data(result, 0);
+  const subsetByteLength = hbSubsetWasm.hb_blob_get_length(result);
+  if (subsetByteLength === 0) {
+    hbSubsetWasm.hb_blob_destroy(result);
+    hbSubsetWasm.hb_face_destroy(subset);
+    hbSubsetWasm.hb_face_destroy(face);
+    hbSubsetWasm.free(fontBuffer);
+    throw new Error(
+      "Failed to create subset font, maybe the input file is corrupted?",
+    );
+  }
+
+  const subsetFont = new Uint8Array(
+    heapu8.subarray(offset, offset + subsetByteLength),
+  );
+
+  // Clean up
+  hbSubsetWasm.hb_blob_destroy(result);
+  hbSubsetWasm.hb_face_destroy(subset);
+  hbSubsetWasm.hb_face_destroy(face);
+  hbSubsetWasm.free(fontBuffer);
+
+  return subsetFont;
+}
+
+export default {
+  subset,
+};

packages/excalidraw/subset/harfbuzz/harfbuzz-loader.ts

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+/**
+ * DON'T depend on anything from the outside like `promiseTry`, as this module is part of a separate lazy-loaded chunk.
+ *
+ * Including anything from the main chunk would include the whole chunk by default.
+ * Even it it would be tree-shaken during build, it won't be tree-shaken in dev.
+ *
+ * In the future consider separating common utils into a separate shared chunk.
+ */
+
+import bindings from "./harfbuzz-bindings";
+import binary from "./harfbuzz-wasm";
+
+/**
+ * Lazy loads wasm and respective bindings for font subsetting based on the harfbuzzjs.
+ */
+let loadedWasm: ReturnType<typeof load> | null = null;
+
+// TODO: consider adding support for fetching the wasm from an URL (external CDN, data URL, etc.)
+const load = (): Promise<{
+  subset: (
+    fontBuffer: ArrayBuffer,
+    codePoints: ReadonlySet<number>,
+  ) => Uint8Array<ArrayBuffer>;
+}> => {
+  return new Promise(async (resolve, reject) => {
+    try {
+      const module = await WebAssembly.instantiate(binary);
+      const harfbuzzJsWasm = module.instance.exports;
+      // @ts-expect-error since `.buffer` is custom prop
+      const heapu8 = new Uint8Array(harfbuzzJsWasm.memory.buffer);
+
+      const hbSubset = {
+        subset: (fontBuffer: ArrayBuffer, codePoints: ReadonlySet<number>) => {
+          return bindings.subset(
+            harfbuzzJsWasm,
+            heapu8,
+            fontBuffer,
+            codePoints,
+          );
+        },
+      };
+
+      resolve(hbSubset);
+    } catch (e) {
+      reject(e);
+    }
+  });
+};
+
+// lazy load the default export
+export default (): ReturnType<typeof load> => {
+  if (!loadedWasm) {
+    loadedWasm = load();
+  }
+
+  return loadedWasm;
+};