1 files changed, 72 insertions, 0 deletions
diff --git a/apps/web/src/lib/animation/vector-channel.ts b/apps/web/src/lib/animation/vector-channel.ts
new file mode 100644
index 00000000..50c62e40
--- /dev/null
+++ b/apps/web/src/lib/animation/vector-channel.ts
@@ -0,0 +1,72 @@
+import type {
+	AnimationPropertyPath,
+	ElementAnimations,
+	VectorAnimationChannel,
+	VectorValue,
+} from "@/lib/animation/types";
+
+export function isVectorValue(value: unknown): value is VectorValue {
+	return (
+		typeof value === "object" &&
+		value !== null &&
+		"x" in value &&
+		"y" in value &&
+		typeof (value as VectorValue).x === "number" &&
+		typeof (value as VectorValue).y === "number"
+	);
+}
+
+export function getVectorChannelForPath({
+	animations,
+	propertyPath,
+}: {
+	animations: ElementAnimations | undefined;
+	propertyPath: AnimationPropertyPath;
+}): VectorAnimationChannel | undefined {
+	const channel = animations?.channels[propertyPath];
+	if (!channel || channel.valueKind !== "vector") {
+		return undefined;
+	}
+	return channel;
+}
+
+export function getVectorChannelValueAtTime({
+	channel,
+	time,
+	fallbackValue,
+}: {
+	channel: VectorAnimationChannel | undefined;
+	time: number;
+	fallbackValue: VectorValue;
+}): VectorValue {
+	if (!channel || channel.keyframes.length === 0) {
+		return fallbackValue;
+	}
+
+	const keyframes = [...channel.keyframes].sort((a, b) => a.time - b.time);
+	const first = keyframes[0];
+	const last = keyframes[keyframes.length - 1];
+
+	if (!first || !last) return fallbackValue;
+	if (time <= first.time) return first.value;
+	if (time >= last.time) return last.value;
+
+	for (let i = 0; i < keyframes.length - 1; i++) {
+		const left = keyframes[i];
+		const right = keyframes[i + 1];
+		if (time < left.time || time > right.time) continue;
+
+		if (left.interpolation === "hold") return left.value;
+
+		const span = right.time - left.time;
+		if (span === 0) return right.value;
+
+		const t = (time - left.time) / span;
+		return {
+			x: left.value.x + (right.value.x - left.value.x) * t,
+			y: left.value.y + (right.value.y - left.value.y) * t,
+		};
+	}
+
+	return last.value;
+}