Rotate Sprite to Mouse Position

Question

I've been using the SFML 1.6 library, and I'd like to know.

How does one rotate a sprite so it always turns toward where the mouse is located on screen?

Thanks.

(SFML specific code is preferred)

Answer 1

If you have the position of the sprite : S = (Sx, Sy) and the position of the cursor C = (Cx, Cy)

You can calculate the angle between the vector = (Cx - Sx, Cy - Sy) and a unit vector for example = (1, 0, 0).

To calculate the angle you can use the cross product :

And then :

then you calculate the angle :

Finally You rotate your sprite :

Sprite.SetRotation(alpha); //alpha in degree