Current File : /home/vacivi36/.trash/vacivitta/node_modules/motion-dom/dist/es/animation/generators/inertia.mjs
import { spring } from './spring/index.mjs';
import { calcGeneratorVelocity } from './utils/velocity.mjs';
function inertia({ keyframes, velocity = 0.0, power = 0.8, timeConstant = 325, bounceDamping = 10, bounceStiffness = 500, modifyTarget, min, max, restDelta = 0.5, restSpeed, }) {
const origin = keyframes[0];
const state = {
done: false,
value: origin,
};
const isOutOfBounds = (v) => (min !== undefined && v < min) || (max !== undefined && v > max);
const nearestBoundary = (v) => {
if (min === undefined)
return max;
if (max === undefined)
return min;
return Math.abs(min - v) < Math.abs(max - v) ? min : max;
};
let amplitude = power * velocity;
const ideal = origin + amplitude;
const target = modifyTarget === undefined ? ideal : modifyTarget(ideal);
/**
* If the target has changed we need to re-calculate the amplitude, otherwise
* the animation will start from the wrong position.
*/
if (target !== ideal)
amplitude = target - origin;
const calcDelta = (t) => -amplitude * Math.exp(-t / timeConstant);
const calcLatest = (t) => target + calcDelta(t);
const applyFriction = (t) => {
const delta = calcDelta(t);
const latest = calcLatest(t);
state.done = Math.abs(delta) <= restDelta;
state.value = state.done ? target : latest;
};
/**
* Ideally this would resolve for t in a stateless way, we could
* do that by always precalculating the animation but as we know
* this will be done anyway we can assume that spring will
* be discovered during that.
*/
let timeReachedBoundary;
let spring$1;
const checkCatchBoundary = (t) => {
if (!isOutOfBounds(state.value))
return;
timeReachedBoundary = t;
spring$1 = spring({
keyframes: [state.value, nearestBoundary(state.value)],
velocity: calcGeneratorVelocity(calcLatest, t, state.value), // TODO: This should be passing * 1000
damping: bounceDamping,
stiffness: bounceStiffness,
restDelta,
restSpeed,
});
};
checkCatchBoundary(0);
return {
calculatedDuration: null,
next: (t) => {
/**
* We need to resolve the friction to figure out if we need a
* spring but we don't want to do this twice per frame. So here
* we flag if we updated for this frame and later if we did
* we can skip doing it again.
*/
let hasUpdatedFrame = false;
if (!spring$1 && timeReachedBoundary === undefined) {
hasUpdatedFrame = true;
applyFriction(t);
checkCatchBoundary(t);
}
/**
* If we have a spring and the provided t is beyond the moment the friction
* animation crossed the min/max boundary, use the spring.
*/
if (timeReachedBoundary !== undefined && t >= timeReachedBoundary) {
return spring$1.next(t - timeReachedBoundary);
}
else {
!hasUpdatedFrame && applyFriction(t);
return state;
}
},
};
}
export { inertia };
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