Rotate Sprite to Mouse Position

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

How d开发者_如何学Gooes one rotate a sprite so it always turns toward where the mouse is located on screen?

Thanks.

(SFML specific code is preferred)

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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