feat: added tempo detection with auto-align beats feature

2026-05-26 22:45:54 -07:00
parent e82c3cbfc2
commit 7fc5ac1590
21 changed files with 1504 additions and 36 deletions
@@ -0,0 +1,114 @@
+import { KGCore } from '../core/KGCore';
+import { CreateTempoRegionCommand } from '../core/commands/global-region/CreateTempoRegionCommand';
+import { UpdateTempoRegionCommand } from '../core/commands/global-region/UpdateTempoRegionCommand';
+import { MoveRegionCommand } from '../core/commands/region/MoveRegionCommand';
+import type { KGProject } from '../core/KGProject';
+import {
+  findTempoRegionAtBar,
+  findTempoRegionAtBeat,
+} from './globalTrackUtil';
+
+export const DETECTED_TEMPO_ACTION_UPDATE_CURRENT = 'update-current-tempo';
+export const DETECTED_TEMPO_ACTION_INSERT_REGION = 'insert-tempo-change';
+
+export type DetectedTempoAction =
+  | typeof DETECTED_TEMPO_ACTION_UPDATE_CURRENT
+  | typeof DETECTED_TEMPO_ACTION_INSERT_REGION;
+
+export function buildDetectedTempoChoiceMessage(bpm: number): string {
+  return `Detected tempo: ${bpm} BPM. Choose how to apply it.\n\nUpdate Current Tempo changes the active tempo at this clip location. Insert Tempo Change adds a new tempo region at the nearest bar before the clip starts.`;
+}
+
+const ALIGNMENT_EPSILON = 1e-6;
+
+interface ApplyDetectedTempoActionParams {
+  action: DetectedTempoAction;
+  detectedBpm: number;
+  detectedTempo: number;
+  detectedOffsetSeconds: number;
+  autoAlignRegionToBeat: boolean;
+  project: KGProject;
+  regionId: string;
+  regionStartBeat: number;
+  regionTrackId: string;
+  regionTrackIndex: number;
+  refreshProjectState: () => void;
+  setBpm: (bpm: number) => void;
+}
+
+export function getRightwardBeatAlignmentShiftBeats(
+  detectedTempo: number,
+  offsetSeconds: number,
+): number {
+  if (!Number.isFinite(detectedTempo) || detectedTempo <= 0 || !Number.isFinite(offsetSeconds) || offsetSeconds <= 0) {
+    return 0;
+  }
+
+  const secondsPerBeat = 60 / detectedTempo;
+  const offsetWithinBeat = offsetSeconds % secondsPerBeat;
+  if (offsetWithinBeat <= ALIGNMENT_EPSILON || secondsPerBeat - offsetWithinBeat <= ALIGNMENT_EPSILON) {
+    return 0;
+  }
+
+  return (secondsPerBeat - offsetWithinBeat) / secondsPerBeat;
+}
+
+export function applyDetectedTempoAction({
+  action,
+  detectedBpm,
+  detectedTempo,
+  detectedOffsetSeconds,
+  autoAlignRegionToBeat,
+  project,
+  regionId,
+  regionStartBeat,
+  regionTrackId,
+  regionTrackIndex,
+  refreshProjectState,
+  setBpm,
+}: ApplyDetectedTempoActionParams): void {
+  const core = KGCore.instance();
+
+  if (action === DETECTED_TEMPO_ACTION_UPDATE_CURRENT) {
+    const targetRegion = findTempoRegionAtBeat(project, regionStartBeat);
+    if (targetRegion) {
+      core.executeCommand(new UpdateTempoRegionCommand(targetRegion.getId(), detectedBpm), { rethrow: true });
+    } else {
+      setBpm(detectedBpm);
+    }
+  } else {
+    const beatsPerBar = project.getTimeSignature().numerator;
+    const targetBar = Math.max(0, Math.floor(regionStartBeat / beatsPerBar));
+    const existingRegionAtBar = findTempoRegionAtBar(project, targetBar);
+
+    if (existingRegionAtBar && existingRegionAtBar.getStartBar() === targetBar) {
+      core.executeCommand(new UpdateTempoRegionCommand(existingRegionAtBar.getId(), detectedBpm), { rethrow: true });
+    } else {
+      const createTempoRegionCommand = new CreateTempoRegionCommand(targetBar);
+      core.executeCommand(createTempoRegionCommand, { rethrow: true });
+
+      const createdRegion = createTempoRegionCommand.getCreatedRegion();
+      if (!createdRegion) {
+        throw new Error(`Failed to create tempo region at bar ${targetBar + 1}`);
+      }
+
+      core.executeCommand(new UpdateTempoRegionCommand(createdRegion.getId(), detectedBpm), { rethrow: true });
+    }
+  }
+
+  if (autoAlignRegionToBeat) {
+    const shiftBeats = getRightwardBeatAlignmentShiftBeats(detectedTempo, detectedOffsetSeconds);
+    if (shiftBeats > 0) {
+      core.executeCommand(
+        MoveRegionCommand.createPositionOnlyMove(
+          regionId,
+          regionStartBeat + shiftBeats,
+          regionTrackId,
+          regionTrackIndex,
+        ),
+        { rethrow: true },
+      );
+    }
+  }
+  refreshProjectState();
+}