小编bar*_*emo的帖子

我的代码中有这些事件监听器

canvas.addEventListener('mousemove', onMouseMove, false);
canvas.addEventListener('mousedown', onMouseDown,false);
canvas.addEventListener('mouseup', onMouseUp, false);

这些功能将帮助我平移画布.我已经宣布的一个变量onLoad叫pan,isDown,mousePostion和以前的鼠标位置.然后在INITIALISE功能被设定的pan,mousePos并且premousepos含有0,0矢量

function draw() {
    context.translate(pan.getX(), pan.getY());
    topPerson.draw(context);
    console.log(pan);
}

function onMouseDown(event) {
    var x = event.offsetX;
    var y = event.offsetY;
    var mousePosition = new vector(event.offsetX, event.offsetY);

    previousMousePosition = mousePosition;

    isDown = true;

    console.log(previousMousePosition);
    console.log("onmousedown" + "X coords: " + x + ", Y coords: " + y);
}

function onMouseUp(event) {
    isDown = false;
}


function onMouseMove(event) …