Function transformRing

docs/app/js/sanddance-app.js:130771–130774

(coordinates)

        coordinates.forEach(transformRing);
    }
    function transformRing(coordinates) {
        if (flip) coordinates.reverse(); // maintain winding order
        coordinates.forEach(transformPoint);
    }
    function transformPoint(coordinates) {
        coordinates[0] = (coordinates[0] - x1) * sx + tx;
        coordinates[1] = (coordinates[1] - y1) * sy + ty;