Top Down RTS , help with rules for deploying units

ArthurR

I have a Top Down Tank project that I have been working on , it is coming along well but I am a little stumped on how to make rules for when I deploy a stationary unit.

what I have is a stationary turret , right now it is set up that I can build the unit , and it is represented in a deploy button when I click the button the unit is instanced and will follow the mouse pointer when I left click again it is dropped in place, if I hold the mouse button I can drag to rotate, it works great except for two little problems , one I can fix by either disabling the turret or making a dummy unit so it cant shoot and target while on the mouse pointer. the other problem is the one I don't have a solution for , I can drop the turret anywhere , the problem there is that I can drop it inside of walls or the HQ building or a tank. it is a static-body and during placement it is moved by directly animating the global position the position is just set to be equal to the global mouse position, and bodies don't register collisions moving that way.

the functionality for making that work was built into a control script that does things like find the map limits , move the camera by mouse pointer close to the view-port edge and box/click select, I have all controls still limited to the mouse pointer and left click so the turret is placed and rotated in { _input(event) } and I dont really see how move and collide would work with the idea of dropping the unit that way anyways.

so I am looking for some suggestions as to how I could tackle that and make it so the player cant drop stationary units in places that are already occupied.

TwistedTwigleg

Welcome to the forums @ArthurR!

I would suggest making or using an Area node that encapsulates the unit you want to place. Then you can check to see if the unit can be placed by getting all of the collision bodies in the area using the get_overlapping_bodies function (documentation). You will probably need to do a bit of processing, so the terrain and the unit you are wanting to place are ignored by the Area (or are skipped in the script), but that is what I would look into.

ArthurR

Thank you @TwistedTwigleg,

that's a good idea, maybe I can loose carrying the actual unit on the pointer and add a second fixed area to the box select node with the right collision mask, sprites to represent the different turrets, then instance using the location/rotation data. that would also solve the carrying around a shooting turret issue.

ArthurR

Thank you @TwistedTwigleg,

get_overlapping_bodies was the way to go about it, I used an area2d with collision shape added to the box select node loaded in sprites for the different turrets then sent the location rotation back to the script that instances the units, the click will not release the icon if get_overlapping_bodies returns a size greater than zero. I will be able to use the same idea to keep random dropped pickups out of walls too. thanks for the help.