问题描述

我正在尝试将 java 中的二维点围绕另一个具有指定度数的点旋转，在这种情况下，只是围绕点 (0, 0) 旋转 90 度.

I am trying to rotate a 2D Point in java around another with a specified degree value, in this case simply around Point (0, 0) at 90 degrees.

方法:

public void rotateAround(Point center, double angle) {
    x = center.x + (Math.cos(Math.toRadians(angle)) * (x - center.x) - Math.sin(Math.toRadians(angle)) * (y - center.y));
    y = center.y + (Math.sin(Math.toRadians(angle)) * (x - center.x) + Math.cos(Math.toRadians(angle)) * (y - center.y));
}

期望 (3, 0):X = 0，Y = -3

Expected for (3, 0): X = 0, Y = -3

为 (3, 0) 返回:X = 1.8369701987210297E-16，Y = 1.8369701987210297E-16

Returned for (3, 0): X = 1.8369701987210297E-16, Y = 1.8369701987210297E-16

期望 (0, -10):X = -10, Y = 0

Expected for (0, -10): X = -10, Y = 0

返回 (0, -10):X = 10.0, Y = 10.0

Returned for (0, -10): X = 10.0, Y = 10.0

方法本身有问题吗?我将函数从 (Rotating A Point In 2D In Lua - GPWiki) 移植到 Java.

Is something wrong with the method itself? I ported the function from (Rotating A Point In 2D In Lua - GPWiki) to Java.

做了一些性能测试.没想到，矢量解赢了，所以我就用这个.

Did some performance tests. I wouldn't have thought so, but the vector solution won, so I'll use this one.

推荐答案

如果你可以访问java.awt，这只是

If you have access to java.awt, this is just

double[] pt = {x, y};
AffineTransform.getRotateInstance(Math.toRadians(angle), center.x, center.y)
  .transform(pt, 0, pt, 0, 1); // specifying to use this double[] to hold coords
double newX = pt[0];
double newY = pt[1];

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