Rotating sprite to face cursor

Question

Given the sprites X and Y values, and the mouses X and Y values, how can I make the sprite face the mouse cursor?

I tried doing this in my move method which I found in another SO question:

    private function move(mousePosX:Number, mousePosY:Number) {
        if(key.isDown(Keyboard.A))
            this.vx -= this.speed;
        else
            this.vx *= this.friction;
        if(key.isDown(Keyboard.D))
            this.vx += this.speed;
        else
            this.vx *= this.friction;
        if(key.isDown(Keyboard.W))
            this.vy -= this.speed;
        else
            this.vy *= this.friction;
        if(key.isDown(Keyboard.S))
            this.vy += this.speed;
        else
            this.vy *= this.friction;

        this.x += vx;
        this.y += vy;

        // Make the player face the cursor
        this.rotation = Math.atan2(this.x - mousePosX, this.y - mousePosY);
    }

And rotation does happen, but it's of one or two pixels. this.x and this.y are the sprite X and Y values.

Cheers!

EDIT: Got it. here's the final calculation:

this.rotation = -(Math.atan2(this.x - mousePosX, this.y - mousePosY) * 180 / Math.PI);

Answer 1

Trying to speed answer your question,

I guess you are halfway there, you probably are getting the rotation in radians from Math.atan2() call, and you're graphics library deals with degrees!

degree_angle = rotation * 180 / 3.1415926 (PI);

Anyway, as a bonus, if you actually need movement in the mouse direction, the direction vector would be such as v(cos(rotation), sin(rotation)). Then multiply that for the desired movement "speed", and there it goes, following the mouse.

Please correct me if i'm wrong :)