有人可以帮助我更好地理解此错误吗？我试图使用p5.js和firebase / firestore创建一个站点，您可以在画布上绘制一些东西，然后将图形保存到firestore，但是当我单击save时，出现此错误：

  

error.ts：166未捕获的FirebaseError：函数DocumentReference.set（）用无效数据调用。不支持嵌套数组

var drawing = [];
var currentPath = [];
var isDrawing = false;

function setup() {
    canvas = createCanvas(400,400);
    canvas.mousepressed(startPath);
    canvas.parent('canvas');
    canvas.mouseReleased(endPath);
    var saveButton = select('#saveButton');
    saveButton.mousepressed(saveDrawing);
}

function startPath() {
    isDrawing = true;
    currentPath = [];
    drawing.push(currentPath);
}

function endPath() {
    isDrawing = false;
}

function draw() {
    background(0);

    if (isDrawing){
        var point = {
        x: mouseX,y: mouseY
        }
    currentPath.push(point);
    }

    stroke(255);
    strokeWeight(7);
    noFill();
    for (var i = 0; i < drawing.length; i++) {
        var path = drawing[i];
        beginShape();
        for (var k = 0; k < path.length; k++) {
            vertex(path[k].x,path[k].y)
        }
        endShape();
    }
}

function saveDrawing(){
    db.collection('joonistused').add({
        drawing: drawing
    });
    var result = ref.push(data,dataSent);
    console.log(result.key)

    function dataSent(status) {
        console.log(status);
    }
}

edit：如何将图形坐标存储到Firestore中？像将绘图保存到Firestore中一样？