How to make a bullet shoot towards the mouse?

[Jacob Pickens]

The title explains it all.

[BurntPizza]

Apply force in direction of mouse. Integrate.

EDIT: That's for "homing missile" behavior. Unless you mean, "how to make gun point in direction of mouse"

[Jacob Pickens]

What if I'm not using a physics engine?

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[Drenius]

http://www.java-gaming.org/index.php/topic,26757.

[BurntPizza]

What if I'm not using a physics engine?

Don't need one. The code to do that is ~10 lines.

[Jacob Pickens]

Well then, if it isn't too big of a deal, could i have that code?

[BurntPizza]

I still can't tell (and you haven't clarified) if you mean you want "point gun at mouse position" or "mouse-following homing missile bullets."

[Jacob Pickens]

Basically, When you click the mouse, I want the bullet to move in that direction. When you move the mouse, the bullets direction will never change.

[Drenius]

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vec.x = mouse.x-gun.x; vec.y = mouse.y-gun.y;

Is the vector to the mouse. Normalize it and you have the direction as a vector.

[BurntPizza]

Basically, When you click the mouse, I want the bullet to move in that direction. When you move the mouse, the bullets direction will never change.

So that would be gun aiming, more or less.

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class Bullet {     float velocityX, velocityY, positionX, positionY; } /**     Sets Bullet [b] to fly towards [x, y] from it's current location at [speed]. */ private void directBulletToPoint(Bullet b, float x, float y, float speed) {     float dx = x - b.positionX;     float dy = y - b.positionY;     float len = Math.sqrt(dx*dx+dy*dy);     b.velocityX = dx / len * speed;     b.velocityY = dy / len * speed; }

Simple vector stuff:
Get displacement vector
Normalize
Multiply by speed

Programmed in post, may contain errors.
Also somebody correct me if I screwed something up.

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[jonjava]

<a href="http://www.youtube.com/v/xp6ibuI8UuQ?version=3&amp;hl=en_US&amp;start=" target="_blank">http://www.youtube.com/v/xp6ibuI8UuQ?version=3&amp;hl=en_US&amp;start=</a>

[Gibbo3771]

Tutorial

This is for Cocos2D but the code is easy enough to translate.

[trollwarrior1]

I'm pretty sure I already answered exact same topic a lot of times already in the past.. I remember at least 2 of these topics..

[Jimmt]

Yeah this is one of the more asked questions, the corresponding inquiries being "rotate arm" and "get angle".

[ags1]

Shooting towards cursor position I can understand, but shooting toward mouse position seems insoluble to me... :-)

[GNecro1]

I do it like this.

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// your game tick    public void tick() {       if (Clicked) {          int targetX2 = mse.x;          int targetY2 = mse.y;          double xDistance = mse.x - x;          double yDistance = mse.y - y;          int targetX = (mse.x - width / 2);          int targetY = (mse.y - height / 2);       }       int pathX = (int) (game.planet.x + game.planet.width / 2 - width / 2 - x);       int pathY = (int) (game.planet.y + game.planet.height / 2 - height / 2 - y);       double distance = Math.sqrt(pathX * pathX + pathY * pathY);       double directionX = pathX / distance;       double directionY = pathY / distance;       double movementX = directionX * 3;       double movementY = directionY * 3;       x += (int) movementX;       y += (int) movementY;    }    // MouseListener (something that extends MouseListener)    public void mousePressed(MouseEvent e) {       if (e.getButton() == 1) {          Clicked = true;       }    }    public void mouseReleased(MouseEvent e) {       if (e.getButton() == 1) {          Clicked = false;       }    }    // MouseMotionListener (something that extends MouseMotionListener)    public void mouseDragged(MouseEvent e) {       mse = new Point(e.getX(), e.getY());    }    public void mouseMoved(MouseEvent e) {       mse = new Point(e.getX(), e.getY());    }

Did it help?