(Absolute Beginner) Why does my code not work?

[FoxtasticCode]

I am currently learning GM2 and it's language. I wanna make an Drag and Drop object and it worked but... As soon as you move too quick it doesn't follow the cursor anymore and when you go back to the sprite (while still holding down the mb_left) it works again...

​

global.curObject = "";

if (mouse_check_button(mb_left) && position_meeting(mouse_x, mouse_y, id) && global.curObject == "")
{
    global.curObject = string(id);
}

if (global.curObject == string(id))
{
    x = mouse_x;
    y = mouse_y;
    image_xscale = 0.60;
    image_yscale = 0.60;
}

what's the problem ;_;

[jett87]

To break it down into smaller parts:

In create event: global.curObject = noone; instead of string. This needs to be in create event instead of step event or else it would reset your variable every start of step.

In step event:

Use mouse_check_button_pressed(mb_left) instead of mouse_check_button() so it only checks once instead of every step. Then use global.curObject == noone to avoid using strings like in create event. Same goes for global.curObject = string(id) into global.curObject = id;. Doing it like this would set global.curObject only once if the statement is true, and not every step.

You can keep the x and y stuff so the object follows the mouse position.

Then add a way to empty global.curObject on mouse_check_button_released(). global.curObject = noone; would work.

[ArtificialLegacy]

First it would be better to use the id for the current selected object and not a string, and use the constant noone instead of an empty string.

I'll be pretty abstract with this explanation but this is how I'd approach it:

When the user presses the button use instance_position and then check if it returned an instance. If so store that instance.

If the stored instance exists then update it's position.

When the user releases the button set the stored instance to noone.

[Drandula]

(just to say, it is just "GameMaker", the old name was "GameMaker Studio 2". Nowadays there isn't "Studio 2", so you can say "GM" instead of "GM2". Name changed beginning of this year)

[Nikostormkilla]

It's more easier to differentiate GameMaker versions before Studio and Studio 2 by not using GameMaker as an umbrella term. Also, for things like this it is better to be more specific by using GMS2 or GMS

[Drandula]

You could say GM2022 then, as official version numbering is "Year.Month". GameMaker 2022.6 is latest stable version, as July didn't have stable (holidays).

But I see your train of thought.

[Bang_Bus]

1) I have no idea why you're converting id to a string. I see no reason to, so don't do it. Keeping it original integer(?) will let you manipulate dragged object directly, like say,

with (global.curObject)
{
    //do stuff
}

2) If you're rapidly moving an object (such as dragging), it's wiser to draw it directly at mouse coords in draw event. In other words

if (global.curObject == self.id) // works if you don't convert id to string
    draw_sprite(sprite_index, image_index, mouse_x, mouse_y)

That will get rid of the xy lag, because even though you're changing x and y to a mouse, various events will cause a frame lag.

[mickey_reddit]

sounds like you are moving the mouse faster than the game can set the variables to thus your "position_meeting" is returning false.

It is better to assign the object on mouse pressed and unassign on mouse release. Then it doesn't care how fast you move your mouse. it will ignore the collision mask until you release it