svelte-motion/src/utils/geometry/delta-calc.js

Svelte animation library based on the React library framer-motion.

/** 
based on framer-motion@4.1.15,
Copyright (c) 2018 Framer B.V.
*/
import {fixed} from '../../utils/fix-process-env';
import { mix, distance, clamp, progress } from 'popmotion';

var clampProgress = function (v) { return clamp(0, 1, v); };
/**
 * Returns true if the provided value is within maxDistance of the provided target
 */
function isNear(value, target, maxDistance) {
    if (target === void 0) { target = 0; }
    if (maxDistance === void 0) { maxDistance = 0.01; }
    return distance(value, target) < maxDistance;
}
function calcLength(axis) {
    return axis.max - axis.min;
}
/**
 * Calculate a transform origin relative to the source axis, between 0-1, that results
 * in an asthetically pleasing scale/transform needed to project from source to target.
 */
function calcOrigin(source, target) {
    var origin = 0.5;
    var sourceLength = calcLength(source);
    var targetLength = calcLength(target);
    if (targetLength > sourceLength) {
        origin = progress(target.min, target.max - sourceLength, source.min);
    }
    else if (sourceLength > targetLength) {
        origin = progress(source.min, source.max - targetLength, target.min);
    }
    return clampProgress(origin);
}
/**
 * Update the AxisDelta with a transform that projects source into target.
 *
 * The transform `origin` is optional. If not provided, it'll be automatically
 * calculated based on the relative positions of the two bounding boxes.
 */
function updateAxisDelta(delta, source, target, origin) {
    if (origin === void 0) { origin = 0.5; }
    delta.origin = origin;
    delta.originPoint = mix(source.min, source.max, delta.origin);
    delta.scale = calcLength(target) / calcLength(source);
    if (isNear(delta.scale, 1, 0.0001))
        delta.scale = 1;
    delta.translate =
        mix(target.min, target.max, delta.origin) - delta.originPoint;
    if (isNear(delta.translate))
        delta.translate = 0;
}
/**
 * Update the BoxDelta with a transform that projects the source into the target.
 *
 * The transform `origin` is optional. If not provided, it'll be automatically
 * calculated based on the relative positions of the two bounding boxes.
 */
function updateBoxDelta(delta, source, target, origin) {
    updateAxisDelta(delta.x, source.x, target.x, defaultOrigin(origin.originX));
    updateAxisDelta(delta.y, source.y, target.y, defaultOrigin(origin.originY));
}
/**
 * Currently this only accepts numerical origins, measured as 0-1, but could
 * accept pixel values by comparing to the target axis.
 */
function defaultOrigin(origin) {
    return typeof origin === "number" ? origin : 0.5;
}
function calcRelativeAxis(target, relative, parent) {
    target.min = parent.min + relative.min;
    target.max = target.min + calcLength(relative);
}
function calcRelativeBox(projection, parentProjection) {
    calcRelativeAxis(projection.target.x, projection.relativeTarget.x, parentProjection.target.x);
    calcRelativeAxis(projection.target.y, projection.relativeTarget.y, parentProjection.target.y);
}

export { calcOrigin, calcRelativeAxis, calcRelativeBox, isNear, updateAxisDelta, updateBoxDelta };