rotation - Libgdx 两点度数计算

Question

这里我正在计算 Actor 和触摸点之间的度数，并将这个度数作为旋转角度传递给 Actor 。我希望 Actor 应该指向手指触摸或手指拖动的方向。(考虑我在路上通过手指触摸和拉公共(public)汽车拖动)

float degrees = (float) ((Math.atan2(touchPoint.x - crocodile.position.x, -(touchPoint.y - crocodile.position.y)) * 180.0d / Math.PI));

其计算度恰到好处。只是有时在两者之间它会给出不同的程度。所以当结果确实与预期不同时，我的 Actor 会波动。

我打印的结果是:

Blockquote

    degree is :: 141.93233
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 158.61426
    degree is :: 90.0
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 90.0
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 141.93057
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 141.93306
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 141.93257
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 141.93134
    degree is :: 141.93257
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 141.93134
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 141.93306
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 141.93257
    degree is :: 180.0
    degree is :: 141.93134
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 141.93257
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 141.93257
    degree is :: 180.0
    degree is :: 141.93134
    degree is :: 180.0
    degree is :: 141.93257
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 141.93008
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 141.93306
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 141.93257
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 141.93134
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 180.0
    degree is :: 180.0

现在，180 和 141 为什么会随这些值波动。考虑到我期望 141 不断或 180 不断我需要改变上面的公式。

Answer 1

第一个参数必须是y，第二个参数是x。

double atan2(double y, double x)

Atan2实际上是y/x的指定反正切函数

因为通常第一个参数取y。

有时当你交换 x 和 y 时你可以获得适当的度数，因为在某些边界如 x<0 和 y<0 中交换与否并不重要。

Look here for more explanation