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Mini Shell
Mini Shell
import { progress, velocityPerSecond } from 'motion-utils';
/**
* A time in milliseconds, beyond which we consider the scroll velocity to be 0.
*/
const maxElapsed = 50;
const createAxisInfo = () => ({
current: 0,
offset: [],
progress: 0,
scrollLength: 0,
targetOffset: 0,
targetLength: 0,
containerLength: 0,
velocity: 0,
});
const createScrollInfo = () => ({
time: 0,
x: createAxisInfo(),
y: createAxisInfo(),
});
const keys = {
x: {
length: "Width",
position: "Left",
},
y: {
length: "Height",
position: "Top",
},
};
function updateAxisInfo(element, axisName, info, time) {
const axis = info[axisName];
const { length, position } = keys[axisName];
const prev = axis.current;
const prevTime = info.time;
axis.current = element[`scroll${position}`];
axis.scrollLength = element[`scroll${length}`] - element[`client${length}`];
axis.offset.length = 0;
axis.offset[0] = 0;
axis.offset[1] = axis.scrollLength;
axis.progress = progress(0, axis.scrollLength, axis.current);
const elapsed = time - prevTime;
axis.velocity =
elapsed > maxElapsed
? 0
: velocityPerSecond(axis.current - prev, elapsed);
}
function updateScrollInfo(element, info, time) {
updateAxisInfo(element, "x", info, time);
updateAxisInfo(element, "y", info, time);
info.time = time;
}
export { createScrollInfo, updateScrollInfo };
Zerion Mini Shell 1.0