问记录Paper.js路径对象并稍后重新绘制

EN

var mousePosition = null;
function onMouseMove(event) {
    if (mousePosition != null) {
        var path = new Path();
        path.strokeColor = 'black';
        path.moveTo(mousePosition);
        path.lineTo(event.point);
    }
    mousePosition = event.point;
}

var recordedPositions = [];
var delayFrames = 60;
function onFrame(event) {
    if (mousePosition != null) {
        recordedPositions.push(mousePosition);
        if (recordedPositions.length > delayFrames) {
            var path = new Path();
            path.strokeColor = 'red';
            delayedPositionIndex = recordedPositions.length - delayFrames;
            path.moveTo(recordedPositions[delayedPositionIndex - 1]);
            path.lineTo(recordedPositions[delayedPositionIndex]);
        }
    }
}