Setting a bullet's direction

[TheOnlyWRT]

I am trying to use just one bullet object in order to conserve the use of objects. In the step event of the different enemies when they shoot, I assumed that you could set the direction of the bullet in the step event, but that just changes the bullets direction every time the enemy changes direction. How can I set the bullets direction in the step event when it is created so that i can only use one bullet object?

Thanks!

 

[Simon Gust]

when creating the bullet you can set the direction at the start

var bullet = instance_create(x, y, obj_bullet);
bullet.direction = point_direction(x, y, mouse_x, mouse_y);

This will set direction for just the new bullet instance.

 

[TheOnlyWRT]

when creating the bullet you can set the direction at the start

var bullet = instance_create(x, y, obj_bullet);
bullet.direction = point_direction(x, y, mouse_x, mouse_y);

This will set direction for just the new bullet instance.

but i dont want to set it to the mouse direction.......... i want to set it to left or right.........

 

[BattleRifle BR55]

How do you set the enemies' direction? Whatever way you're doing it, just mimic it for the bullets.

 

[TheOnlyWRT]

but i need to set it specifically to the unique object that fired the weapon

 

[BattleRifle BR55]

What I mean is to take the id reference tip Simon Gust pointed out and set the direction with that.

 

[TheOnlyWRT]

Here is the code that I have right now:

BULLET CREATE EVENT

//variables for the bullet

dir = 0;
velocity = 20;
hsp = dir*velocity;
stability = 0;
damage = 0;

BULLET STEP EVENT

//movement
x = x + hsp;

ENEMY STEP EVENT

if((alarm[0] < 0)){
            
            attacking = true;
            alarm[0] = weapon[currentWeapon, v_reloadSpeed]; // Set the shoot alarm
            shotsFired += 1;
            var _inst = instance_create_depth((x + sign(hsp)*20), y-7, 1, objectBulletEnemy);
            _inst.damage = weapon[currentWeapon, v_damage]; // Set bullet damage
            _inst.dir = point_direction(x, y, x+dir, y);
            //set the stability
            _inst.stability = weapon[currentWeapon, v_stability] //set the stability
            
        }

I hope that this will help you find out how i could program this better. Thank you!!!!

 

[sp202]

Why use point_direction if dir already gives you the direction? Just do inst.dir=dir

 

[TheOnlyWRT]

Why use point_direction if dir already gives you the direction? Just do inst.dir=dir

because the bullet direction changes every time the enemy changes direction....... like, i remember that when i used D&D, i would just set the direction in the create event and the direction would never change. Now that I am setting the bullets direction in the step event, the direction changes. How can set it so that the bullet continues in one direction even if the player changes direction?

 

[sp202]

Well, point_direction isn't preventing that, so swap it out. I can't see how your bullet's direction can keep changing when it's only assigned a direction upon creation.

 

[IndianaBones]

Let's see.

You are updating you bullets x position using "hsp". However, you are only calculating "hsp" in the bullets Create Event.

The bullets Create Event runs the very moment you create it.

Then, you are updating the bullets "dir" variable, but as you are moving the bullet via "hsp" this will do nothing, because hsp remains as it was set in the Create Event.

Therefore, all your bullets are moving according to "hsp", which is always going to be dir * velocity as per your Create Event, your "dir" == 0.

So all bullets are going to be [shooting to the right.] EDIT: Cancel that - they won't be moving at all.

It should be more like this:

Bullet Create Event

dir = 0
velocity = 20
hsp = 0
...rest of code

Enemy Step Event (where you create the bullet)

var _inst = instance_create_depth((x + sign(hsp)*20), y-7, 1, objectBulletEnemy);
_inst.direction = dir;
_inst.speed = _inst.velocity;

Then you can delete the bullets Step Event and let Game Maker handle the movement of the bullet, because you have set the built-in variables "speed" and "direction", which Game Maker will use to move the bullet automatically.

If you must use hsp, then you will want to do this:

Enemy Step Event

var _inst = instance_create_depth((x + sign(hsp)*20), y-7, 1, objectBulletEnemy);
_inst.hsp = dir * inst.velocity;

...and leave the Enemy Bullet as "x += hsp"

 

[sp202]

@IndianaBones Given that explanation, bullets shouldn't move at all as dir*velocity would be 0.

 

[TonyCold]

I'll make it brief for you. If you are trying to make the bullet move Left and Right then you can use that code:

if (image_xscale (of player) = 1 && (shoot (Your key that shoots))){
    image_xscale(of bullet) = 1 
    x += spd
else if (image_xscale (of player) = -1 && (shoot)){
    image_xscale(of bullet) = - 1
    x -= spd
}
}

 

[sp202]

@TonyCold How does that code make any practical sense? The bullet only moves when shoot is held down? Turning the player around makes the bullet do the same?

 

[TonyCold]

@sp202 First of all this is not the whole Code but just a heads up. And Yeah. If the player is facing the Right direction and then Presses the Shoot button the Bullet will face the Right direction also and It will go The whole way right. If the player is facing the Left direction the Bullet will face the left direction also and If he presses the Shooting button it will Move the whole way left (Until if collides with something.). Briefly, obj_player.image_xscale = obj_bullet.image_xscale. That's how it works.

 

[sp202]

@TonyCold First of all your bracket was in the wrong place, so I'll assume you meant to have a working else if statement and put it before the else. Depending on whether this code is in the create event or step event it'll work partially but it's still useless in either.

In the create event, assuming you aren't quick enough to release the key before the bullet is spawned, its image_scale will be set to the player's image_scale and it will move once and never again.

In the step event, the bullet will move as long as you've held down the shoot key, let go and it'll freeze. Change the direction the player is facing and suddenly the bullet is travelling right back at the player (provided you're holding down shoot).

That's how it works.

 

[IndianaBones]

@IndianaBones Given that explanation, bullets shouldn't move at all as dir*velocity would be 0.

You're right! Didn't catch that.

Then there must be more code, or I'm missing something about the OP's logic.

 

[TheouAegis]

OP's issue: He has code inside the bullet. The bullet should not have any code in it.

 

[TheOnlyWRT]

Sooooo, how do I get this to work????

 

[TheouAegis]

with instance_create(x,y,bullet) {
direction = other.image_angle;
speed = 5;
}

 

[TheOnlyWRT]

none of these responses have worked... but thank you all for your help. Any other ideas/suggestions?

 

[TheouAegis]

Post the complete codes for your enemy and for your bullet. Because everything we've said does work -- we've all used it. Show us what you have now and we'll tell you where you messed up.

 

[TheOnlyWRT]

got it to work, i just put an if statement in the create code and now it sets the direction based on the players location. Thank you all for your help

 

[Obj_Neil]

In the bullet create event, create a variable facing = o_player.facing and then in step event, x += 3 * facing. This way the - or positive from multiplying will only happen upon the bullets creation. Just in case that is not how you fixed it, that is an easy way. -- You can also set it to enemy image_scale by creation a variable for that in enemy create.