5 replies to this topic

[spicydeath82]

this doesn't want to work...

/*
    Created by SpicyDeath82 / Opposing Forces Studios
    this script allows you to have an object orbit another object
    you place this in a step event(best in end step)
    orbit_object(object,dist,orbitspeed);

*/

object=argument0; // the object to orbit
dist=argument1; // this gets multiplied against the sprite's dimensions
orbitspeed=argument3; // use a negative value for reverse direction

x=object.x+lengthdir_x(object.sprite_width*dist,orbitspeed)
y=object.y+lengthdir_y(object.sprite_height*dist,orbitspeed)

all the orbiting object does is jump to the right of the object it's supposed to orbit.
how ever doing code snippets with this:
CREATE
orbitspeed=0;

STEP(end event)
orbitspeed=10;

x=object.x+lengthdir_x(object.sprite_width*dist,orbitspeed)
y=object.y+lengthdir_y(object.sprite_height*dist,orbitspeed)

the above works but isn't ideal as i want to use it as a simple script... any ides folks?

Edited by spicydeath82, 07 July 2010 - 08:50 PM.

[treacheroust]

Should be like this. Good luck!

angle = point_direction(object.x, object.y, x, y);
angle += orbitspeed;
x=object.x+lengthdir_x(dist, angle);
y=object.y+lengthdir_y(dist, angle);

[NakedPaulToast]

orbitspeed=argument3; // use a negative value for reverse direction

orbitspeed=argument2; // use a negative value for reverse direction



And by the way if you're going to use a script, then you'd be wise to declare object, dist and orbitspeed as vars.

Edited by NakedPaulToast, 08 July 2010 - 12:04 AM.

[ragarnak]

this doesn't want to work... <snip code>

Well, thats quite easy to explain : you have a variable named "orbitspeed", but you are providing it as the "direction" argument in the "lengthdir_?(...)" commands.

In other words : you are not providing a speed, but an angle.

If you want to use speed you must also have a position somewhere (in this case an angle or direction) and update that position in every step.

Maybe like this :

//Create event
orbitAngle=0;   //Current position in the orbit
orbitSpeed=10;  //Rotation-speed (in degrees per step)

//step event
orbitAngle+=orbitspeed

x=object.x+lengthdir_x(object.sprite_width*dist,orbitAngle)
y=object.y+lengthdir_y(object.sprite_height*dist,orbitAngle)

Hope that helps.

[spicydeath82]

i understand that lengthdir_? takes a direction as an argument.
but then why does the below code work perfectly fine?

CREATE
orbitspeed+=0;// or negative number

STEP(end event)
orbitspeed=10;

x=object.x+lengthdir_x(object.sprite_width*dist,orbitspeed)
y=object.y+lengthdir_y(object.sprite_height*dist,orbitspeed)

[ragarnak]

but then why does the below code work perfectly fine?

It doesn't.

You should get an error in the create-event (unknown variable), and the object will not move (you set it to 10 in every step).

Now if you would put the step-events contents in the create-event and the create-events contents in the step-event (swapping the contents) than it certainly would work.

I than have a single question remaining : why are you naming the variable "orbitspeed" when you are using it as an "orbitangle" (the actual "orbitspeed" is that "10" you are adding to it) ?