36 lines
1.1 KiB
JavaScript
36 lines
1.1 KiB
JavaScript
import { useMotionValueEvent } from '../utils/use-motion-value-event.mjs';
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import { useMotionValue } from './use-motion-value.mjs';
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import { frame } from '../frameloop/frame.mjs';
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/**
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* Creates a `MotionValue` that updates when the velocity of the provided `MotionValue` changes.
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*
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* ```javascript
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* const x = useMotionValue(0)
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* const xVelocity = useVelocity(x)
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* const xAcceleration = useVelocity(xVelocity)
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* ```
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*
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* @public
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*/
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function useVelocity(value) {
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const velocity = useMotionValue(value.getVelocity());
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const updateVelocity = () => {
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const latest = value.getVelocity();
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velocity.set(latest);
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/**
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* If we still have velocity, schedule an update for the next frame
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* to keep checking until it is zero.
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*/
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if (latest)
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frame.update(updateVelocity);
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};
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useMotionValueEvent(value, "change", () => {
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// Schedule an update to this value at the end of the current frame.
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frame.update(updateVelocity, false, true);
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});
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return velocity;
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}
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export { useVelocity };
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