feat: experimental support for compounds

src/lib/assets/keymaps/chara-chorder.yml

@@ -104,6 +104,26 @@ actions:
     <<: *tertiary_keymap
     id: "KM_3_R"
     variant: right
+  558:
+    id: HOLD_COMPOUND
+    title: Activate Chord Library
+    icon: layers
+    description: |
+      When used in a chord includes that chord as a base 
+      compound chord for all subsequent chords.
+      This is effectively a library switch.
+      Since library activations can be nested, you
+      usually add a "Reset Chord Library" before this action.
+  559:
+    id: RELEASE_COMPOUND
+    title: Reset Chord Library
+    icon: layers_clear
+    description: |
+      Releases the active compound state, returning
+      to the default library.
+      While "Activate Chord Library" can only be used
+      as an output of a chord, this action can be assigned
+      to switches directly.
   576:
     id: ACTION_DELAY_1000
     icon: clock_loader_90

src/lib/serial/chord.ts

@@ -55,3 +55,19 @@ export function deserializeActions(native: bigint): number[] {
 
   return actions;
 }
+
+/**
+ * Hashes a chord input the same way as CCOS
+ */
+export function hashChord(actions: number[]) {
+  const chord = new Uint8Array(16);
+  const view = new DataView(chord.buffer);
+  const serialized = serializeActions(actions);
+  view.setBigUint64(0, serialized & 0xffff_ffff_ffff_ffffn, true);
+  view.setBigUint64(8, serialized >> 64n, true);
+  let hash = 2166136261;
+  for (let i = 0; i < 16; i++) {
+    hash = Math.imul(hash ^ view.getUint8(i), 16777619);
+  }
+  return hash & 0x3fff_ffff;
+}

src/lib/undo-redo.ts

@@ -1,6 +1,6 @@
 import { persistentWritable } from "$lib/storage";
 import { derived } from "svelte/store";
-import type { Chord } from "$lib/serial/chord";
+import { hashChord, type Chord } from "$lib/serial/chord";
 import {
   deviceChords,
   deviceLayout,
@@ -158,3 +158,9 @@ export const chords = derived([overlay, deviceChords], ([overlay, chords]) => {
     a.localeCompare(b),
   );
 });
+
+export const chordHashes = derived(
+  chords,
+  (chords) =>
+    new Map(chords.map((chord) => [hashChord(chord.actions), chord] as const)),
+);