Moving a point on a rotating sprite

Question

I've been trying to get sprites to stay on a set point on another rotating sprite. At the moment, it's very inaccurate, the original position is wrong, and when the rotation is applied the sprite drifts away from the point its intended to stay in. The code I'm currently using is as follows, and I'm pretty sure there's something wrong with it, I just don't know what it is.

rad = sqrt((x-originx)^2 + (y-originy)^2)
x = originx + cos(cameraangle+asin(x-originx)) * rad)
y = originy + (sin(cameraangle+acos(y-originy)) * rad)

Answer 1

Based on the notation i'm assuming this is in GameMaker. If you're not using Gamemaker, you could derive a similar solution from this code. Anyways, a much simpler way to do this would be to use lengthdir. I'm not sure about your exact situation, but if obj_a is your rotating object, then run this code in object b:

var len = 10;//length in pixels

x = obj_a.x + lengthdir_x(obj.x,obj.y,len);

y = obh_a.y + lengthdir_y(obj.x,obj.y,len);