simplify-path/radial-distance.js

simplify 2D polyline

function getSqDist(p1, p2) {
    var dx = p1[0] - p2[0],
        dy = p1[1] - p2[1];

    return dx * dx + dy * dy;
}

// basic distance-based simplification
module.exports = function simplifyRadialDist(points, tolerance) {
    if (points.length<=1)
        return points;
    tolerance = typeof tolerance === 'number' ? tolerance : 1;
    var sqTolerance = tolerance * tolerance;
    
    var prevPoint = points[0],
        newPoints = [prevPoint],
        point;

    for (var i = 1, len = points.length; i < len; i++) {
        point = points[i];

        if (getSqDist(point, prevPoint) > sqTolerance) {
            newPoints.push(point);
            prevPoint = point;
        }
    }

    if (prevPoint !== point) newPoints.push(point);

    return newPoints;
}