minor tidy up

src/motion/spring.js

@@ -117,20 +117,18 @@ export function spring(value, opts = {}) {
 			last_time = window.performance.now();
 			settled = false;
 
-			task = loop(() => {
+			task = loop(now=> {
-				const time = window.performance.now();
-
 				({ value, settled } = tick_spring(
 					velocity,
 					value,
 					target_value,
 					spring.stiffness,
 					spring.damping,
-					(time - last_time) * 60 / 1000,
+					(now - last_time) * 60 / 1000,
 					threshold
 				));
 
-				last_time = time;
+				last_time = now;
 
 				if (settled) {
 					value = target_value;

src/motion/tweened.js

@@ -76,9 +76,8 @@ export function tweened(value, defaults = {}) {
 		const start = window.performance.now() + delay;
 		let fn;
 
-		task = loop(() => {
+		task = loop(now => {
-			const time = window.performance.now();
+			if (now < start) return true;
-			if (time < start) return true;
 
 			if (!started) {
 				fn = interpolate(value, new_value);
@@ -91,7 +90,7 @@ export function tweened(value, defaults = {}) {
 				previous_task = null;
 			}
 
-			const elapsed = time - start;
+			const elapsed = now - start;
 
 			if (elapsed > duration) {
 				store.set(value = new_value);