geometry-circles.js 10.7 KB
/* *
 *
 *  !!!!!!! SOURCE GETS TRANSPILED BY TYPESCRIPT. EDIT TS FILE ONLY. !!!!!!!
 *
 * */
import geometry from './geometry.js';
var getAngleBetweenPoints = geometry.getAngleBetweenPoints, getCenterOfPoints = geometry.getCenterOfPoints, getDistanceBetweenPoints = geometry.getDistanceBetweenPoints;
/**
 * @private
 * @param {number} x
 *        Number to round
 * @param {number} decimals
 *        Number of decimals to round to
 * @return {number}
 *         Rounded number
 */
var round = function round(x, decimals) {
    var a = Math.pow(10, decimals);
    return Math.round(x * a) / a;
};
/**
 * Calculates the area of a circle based on its radius.
 * @private
 * @param {number} r
 *        The radius of the circle.
 * @return {number}
 *         Returns the area of the circle.
 */
var getAreaOfCircle = function (r) {
    if (r <= 0) {
        throw new Error('radius of circle must be a positive number.');
    }
    return Math.PI * r * r;
};
/**
 * Calculates the area of a circular segment based on the radius of the circle
 * and the height of the segment.
 * See http://mathworld.wolfram.com/CircularSegment.html
 * @private
 * @param {number} r
 *        The radius of the circle.
 * @param {number} h
 *        The height of the circular segment.
 * @return {number}
 *         Returns the area of the circular segment.
 */
var getCircularSegmentArea = function getCircularSegmentArea(r, h) {
    return r * r * Math.acos(1 - h / r) - (r - h) * Math.sqrt(h * (2 * r - h));
};
/**
 * Calculates the area of overlap between two circles based on their radiuses
 * and the distance between them.
 * See http://mathworld.wolfram.com/Circle-CircleIntersection.html
 * @private
 * @param {number} r1
 *        Radius of the first circle.
 * @param {number} r2
 *        Radius of the second circle.
 * @param {number} d
 *        The distance between the two circles.
 * @return {number}
 *         Returns the area of overlap between the two circles.
 */
var getOverlapBetweenCircles = function getOverlapBetweenCircles(r1, r2, d) {
    var overlap = 0;
    // If the distance is larger than the sum of the radiuses then the circles
    // does not overlap.
    if (d < r1 + r2) {
        if (d <= Math.abs(r2 - r1)) {
            // If the circles are completely overlapping, then the overlap
            // equals the area of the smallest circle.
            overlap = getAreaOfCircle(r1 < r2 ? r1 : r2);
        }
        else {
            // Height of first triangle segment.
            var d1 = (r1 * r1 - r2 * r2 + d * d) / (2 * d), 
            // Height of second triangle segment.
            d2 = d - d1;
            overlap = (getCircularSegmentArea(r1, r1 - d1) +
                getCircularSegmentArea(r2, r2 - d2));
        }
        // Round the result to two decimals.
        overlap = round(overlap, 14);
    }
    return overlap;
};
/**
 * Calculates the intersection points of two circles.
 *
 * NOTE: does not handle floating errors well.
 * @private
 * @param {Highcharts.CircleObject} c1
 *        The first circle.
 * @param {Highcharts.CircleObject} c2
 *        The second sircle.
 * @return {Array<Highcharts.PositionObject>}
 *         Returns the resulting intersection points.
 */
var getCircleCircleIntersection = function getCircleCircleIntersection(c1, c2) {
    var d = getDistanceBetweenPoints(c1, c2), r1 = c1.r, r2 = c2.r, points = [];
    if (d < r1 + r2 && d > Math.abs(r1 - r2)) {
        // If the circles are overlapping, but not completely overlapping, then
        // it exists intersecting points.
        var r1Square = r1 * r1, r2Square = r2 * r2, 
        // d^2 - r^2 + R^2 / 2d
        x = (r1Square - r2Square + d * d) / (2 * d), 
        // y^2 = R^2 - x^2
        y = Math.sqrt(r1Square - x * x), x1 = c1.x, x2 = c2.x, y1 = c1.y, y2 = c2.y, x0 = x1 + x * (x2 - x1) / d, y0 = y1 + x * (y2 - y1) / d, rx = -(y2 - y1) * (y / d), ry = -(x2 - x1) * (y / d);
        points = [
            { x: round(x0 + rx, 14), y: round(y0 - ry, 14) },
            { x: round(x0 - rx, 14), y: round(y0 + ry, 14) }
        ];
    }
    return points;
};
/**
 * Calculates all the intersection points for between a list of circles.
 * @private
 * @param {Array<Highcharts.CircleObject>} circles
 *        The circles to calculate the points from.
 * @return {Array<Highcharts.GeometryObject>}
 *         Returns a list of intersection points.
 */
var getCirclesIntersectionPoints = function getIntersectionPoints(circles) {
    return circles.reduce(function (points, c1, i, arr) {
        var additional = arr.slice(i + 1)
            .reduce(function (points, c2, j) {
            var indexes = [i, j + i + 1];
            return points.concat(getCircleCircleIntersection(c1, c2)
                .map(function (p) {
                p.indexes = indexes;
                return p;
            }));
        }, []);
        return points.concat(additional);
    }, []);
};
/**
 * Tests wether a point lies within a given circle.
 * @private
 * @param {Highcharts.PositionObject} point
 *        The point to test for.
 * @param {Highcharts.CircleObject} circle
 *        The circle to test if the point is within.
 * @return {boolean}
 *         Returns true if the point is inside, false if outside.
 */
var isPointInsideCircle = function isPointInsideCircle(point, circle) {
    return getDistanceBetweenPoints(point, circle) <= circle.r + 1e-10;
};
/**
 * Tests wether a point lies within a set of circles.
 * @private
 * @param {Highcharts.PositionObject} point
 *        The point to test.
 * @param {Array<Highcharts.CircleObject>} circles
 *        The list of circles to test against.
 * @return {boolean}
 *         Returns true if the point is inside all the circles, false if not.
 */
var isPointInsideAllCircles = function isPointInsideAllCircles(point, circles) {
    return !circles.some(function (circle) {
        return !isPointInsideCircle(point, circle);
    });
};
/**
 * Tests wether a point lies outside a set of circles.
 *
 * TODO: add unit tests.
 * @private
 * @param {Highcharts.PositionObject} point
 *        The point to test.
 * @param {Array<Highcharts.CircleObject>} circles
 *        The list of circles to test against.
 * @return {boolean}
 *         Returns true if the point is outside all the circles, false if not.
 */
var isPointOutsideAllCircles = function isPointOutsideAllCircles(point, circles) {
    return !circles.some(function (circle) {
        return isPointInsideCircle(point, circle);
    });
};
/**
 * Calculate the path for the area of overlap between a set of circles.
 * @todo handle cases with only 1 or 0 arcs.
 * @private
 * @param {Array<Highcharts.CircleObject>} circles
 *        List of circles to calculate area of.
 * @return {Highcharts.GeometryIntersectionObject|undefined}
 *         Returns the path for the area of overlap. Returns an empty string if
 *         there are no intersection between all the circles.
 */
var getAreaOfIntersectionBetweenCircles = function getAreaOfIntersectionBetweenCircles(circles) {
    var intersectionPoints = (getCirclesIntersectionPoints(circles)
        .filter(function (p) {
        return isPointInsideAllCircles(p, circles);
    })), result;
    if (intersectionPoints.length > 1) {
        // Calculate the center of the intersection points.
        var center = getCenterOfPoints(intersectionPoints);
        intersectionPoints = intersectionPoints
            // Calculate the angle between the center and the points.
            .map(function (p) {
            p.angle = getAngleBetweenPoints(center, p);
            return p;
        })
            // Sort the points by the angle to the center.
            .sort(function (a, b) {
            return b.angle - a.angle;
        });
        var startPoint = intersectionPoints[intersectionPoints.length - 1];
        var arcs = intersectionPoints
            .reduce(function (data, p1) {
            var startPoint = data.startPoint, midPoint = getCenterOfPoints([startPoint, p1]);
            // Calculate the arc from the intersection points and their
            // circles.
            var arc = p1.indexes
                // Filter out circles that are not included in both
                // intersection points.
                .filter(function (index) {
                return startPoint.indexes.indexOf(index) > -1;
            })
                // Iterate the circles of the intersection points and
                // calculate arcs.
                .reduce(function (arc, index) {
                var circle = circles[index], angle1 = getAngleBetweenPoints(circle, p1), angle2 = getAngleBetweenPoints(circle, startPoint), angleDiff = angle2 - angle1 +
                    (angle2 < angle1 ? 2 * Math.PI : 0), angle = angle2 - angleDiff / 2, width = getDistanceBetweenPoints(midPoint, {
                    x: circle.x + circle.r * Math.sin(angle),
                    y: circle.y + circle.r * Math.cos(angle)
                }), r = circle.r;
                // Width can sometimes become to large due to floating
                // point errors
                if (width > r * 2) {
                    width = r * 2;
                }
                // Get the arc with the smallest width.
                if (!arc || arc.width > width) {
                    arc = {
                        r: r,
                        largeArc: width > r ? 1 : 0,
                        width: width,
                        x: p1.x,
                        y: p1.y
                    };
                }
                // Return the chosen arc.
                return arc;
            }, null);
            // If we find an arc then add it to the list and update p2.
            if (arc) {
                var r = arc.r;
                data.arcs.push(['A', r, r, 0, arc.largeArc, 1, arc.x, arc.y]);
                data.startPoint = p1;
            }
            return data;
        }, {
            startPoint: startPoint,
            arcs: []
        }).arcs;
        if (arcs.length === 0) {
            // empty
        }
        else if (arcs.length === 1) {
            // empty
        }
        else {
            arcs.unshift(['M', startPoint.x, startPoint.y]);
            result = {
                center: center,
                d: arcs
            };
        }
    }
    return result;
};
var geometryCircles = {
    getAreaOfCircle: getAreaOfCircle,
    getAreaOfIntersectionBetweenCircles: getAreaOfIntersectionBetweenCircles,
    getCircleCircleIntersection: getCircleCircleIntersection,
    getCirclesIntersectionPoints: getCirclesIntersectionPoints,
    getCircularSegmentArea: getCircularSegmentArea,
    getOverlapBetweenCircles: getOverlapBetweenCircles,
    isPointInsideCircle: isPointInsideCircle,
    isPointInsideAllCircles: isPointInsideAllCircles,
    isPointOutsideAllCircles: isPointOutsideAllCircles,
    round: round
};
export default geometryCircles;