From the doc : bool test_move ( Vector2 rel_vec ) How to use it ?

Tchey

The documentation says :

bool test_move ( Vector2 rel_vec )

Return true if there would be a collision if the body moved in the given direction.

How do i actually use it to check if there is collision, and if there is not, move ? I'd like to check because my player gets stuck when it collides (can't move at all anymore), and i can't understand why.

This is my move.gd for a roguelikish topdown stuff


extends KinematicBody2D
var loc = Vector2(0,0)
var direction = Vector2(0,0)
var moving = false
var colliding = false

const SPEED = 1
const GRID = 16

func _ready():
	set_fixed_process(true)

func _fixed_process(delta):
	if !moving:
		if (Input.is_action_pressed("ui_up")):
			moving = true
			direction = Vector2(0, -1)
			loc = get_pos()
		if (Input.is_action_pressed("ui_down")):
			moving = true
			direction = Vector2(0, 1)
			loc = get_pos()
		if (Input.is_action_pressed("ui_left")):
			moving = true
			direction = Vector2(-1, 0)
			loc = get_pos()
		if (Input.is_action_pressed("ui_right")):
			moving = true
			direction = Vector2(1, 0)
			loc = get_pos()
	else:
		move_to(get_pos() +direction *SPEED)
		if get_pos() == loc + Vector2(GRID *direction.x, GRID *direction.y):
			moving = false

Ross

It's getting stuck because that final line: moving = false is never happening if it collides. It's that last 'if' statement.

Move() and move_to() already return how much movement is remaining, so you don't really need test_move(). Just check if that returns less than your move vector, if so it has hit something. But really I'm not sure what the point of that last 'if' is, after move_to() is called the body will not be moving, whether it has hit something or not.

Are you doing a traditional tile-based, turn-based roguelike?

Ross

But I didn't actually answer your question, dur.

The test_move() function returns a bool: whether it detects a collision or not. When a function returns a value, in code the function call becomes that value. So you can store it in a variable for later use, or use it directly as a bool (in this case). So you would do:

if not test_move(move_vect): move(move_vect)

Tchey

Hm, at that time it was making sense, but now i can't remember why... It's base on 2 or 3 different tutorials, i take pieces of them, try to understand, and make my code from it.

I'm doing a top down RPG adventure clan game... Looks like roguelike, with one main character, and later with kind of slaves, you cannot control them but can give orders like gather, patrol... and i want to have encounters (battle, trade...) in a kind of Fire Emblem view. I have no idea yet how to do the turn based part, and the IA part even less.

Well, i'm not there yet... Here is my progress over time : http://jeux1d100.net/forum/index.php?topic=4.0

I changed it for this and it seems to work perfectly well so far, and i the feeling is smoother too.

extends KinematicBody2D

var loc = Vector2(0,0)
var direction = Vector2(0,0)

const SPEED = 1
const GRID = 16

func _ready():
	set_fixed_process(true)

func _fixed_process(delta):

		if (Input.is_action_pressed("ui_up")):
			direction = Vector2(0, -1)
			loc = get_pos()
			move_to(get_pos() +direction *SPEED)
		if (Input.is_action_pressed("ui_down")):
			direction = Vector2(0, 1)
			loc = get_pos()
			move_to(get_pos() +direction *SPEED)			
		if (Input.is_action_pressed("ui_left")):
			direction = Vector2(-1, 0)
			loc = get_pos()
			move_to(get_pos() +direction *SPEED)
		if (Input.is_action_pressed("ui_right")):
			direction = Vector2(1, 0)
			loc = get_pos()
			move_to(get_pos() +direction *SPEED)

Ross

I see, cool. You might be interested in this site, it has some pretty good information about all aspects of roguelikes. There's a couple examples of turn-based time systems.

A couple little tweaks I would make to your code: 1. You might as well use move() instead of move_to(). Move() uses a relative position, so you don't have to do get_pos() every time, just direction * SPEED. 2. You should also multiply by delta, so the movement speed is not frame rate dependent.

Tchey

Thanks, now it looks like this

if (Input.is_action_pressed("ui_up")):
	direction = Vector2(0, -1)
	move(direction*SPEED)*delta