cx
,cy
)到鼠标位置(mouseX
,mouseY
)的向量。分别使用p5.Vector
和createVector()
来表示向量,并通过setMag()
将向量的大小更改为圆的半径radius
。let v = createVector(mouseX - cx, mouseY - cy).setMag(radius);
let px = v.x + cx;
let py = v.y + cy;
let cpt = createVector(cx, cy);
let pt = createVector(mouseX, mouseY).sub(cpt).setMag(radius).add(cpt);
let px = pt.x;
let py = pt.y;