EDIT : Since there is an angle change at every 22.5 degrees, the direction should swap hands after 11.25 degrees. Therefore: 349-360//0-11 = N 12-33 = NNE 34-56 = NE Using values from 327-348 (The entire NNW spectrum) failed to produce a result for eudoxos’ answer. After giving it some thought I could not find … Read more
you could add the following: public float getAngle(Point target) { float angle = (float) Math.toDegrees(Math.atan2(target.y – y, target.x – x)); if(angle < 0){ angle += 360; } return angle; } by the way, why do you want to not use a double here?
If you rotate point (px, py) around point (ox, oy) by angle theta you’ll get: p’x = cos(theta) * (px-ox) – sin(theta) * (py-oy) + ox p’y = sin(theta) * (px-ox) + cos(theta) * (py-oy) + oy
You want the arctangent: dy = ey – cy dx = ex – cx theta = arctan(dy/dx) theta *= 180/pi // rads to degs Erm, note that the above is obviously not compiling Javascript code. You’ll have to look through documentation for the arctangent function. Edit: Using Math.atan2(y,x) will handle all of the special cases … Read more
Because normal people are more used to calculating degrees — OpenGL is meant to be used simple. Note that all the functions that operate on degrees are “high level” functions. For OpenGL itself, it’s no difference whether it receives radians or degrees — they are internally converted to transformation matrices anyway, so there’s no computational … Read more
2D case Just like the dot product is proportional to the cosine of the angle, the determinant is proprortional to its sine. So you can compute the angle like this: dot = x1*x2 + y1*y2 # dot product between [x1, y1] and [x2, y2] det = x1*y2 – y1*x2 # determinant angle = atan2(det, dot) … Read more
This gives a signed angle for any angles: a = targetA – sourceA a = (a + 180) % 360 – 180 Beware in many languages the modulo operation returns a value with the same sign as the dividend (like C, C++, C#, JavaScript, full list here). This requires a custom mod function like so: … Read more