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Asked By | linklight2 |
Hello. In my project, I have an array of my custom class, SnakeInfo, shown here.
class SnakeInfo:
var x : float
var y : float
var dir : int
var type : int
var curve : int
func toVector2() -> Vector2 : return Vector2(x, y)
and the array
var bodyPositions : Array
Every element of the array is assigned with the type SnakeInfo, so, you can expect to access individual elements of my class snake info. bodyPositions[0] should return a value of type’SnakeInfo, which I can then edit the values of by using the . operator.
Like so: bodyPositions[0].curve = 15 or something like that.
The problem I’m having is this. In one of my functions, when I assign a variable of bodyPositions[0], I am also editing the value of bodyPositions[1] Tried and tested below:
bodyPositions[0].dir = direction
bodyPositions[0].type = TYPE.head
bodyPositions[0].curve = CURVE.noCurve
var beforeBug0 = bodyPositions[0].toVector2()
var beforeBug1 = bodyPositions[1].toVector2()
match direction:
DIRECTION.up:
bodyPositions[0].y -= Global_Vars.sector
DIRECTION.down:
bodyPositions[0].y += Global_Vars.sector
DIRECTION.right:
bodyPositions[0].x += Global_Vars.sector
DIRECTION.left:
bodyPositions[0].x -= Global_Vars.sector
if bodyPositions[0].toVector2() == beforeBug0:
# This branch doesn't execute
print("bodyPositions[0] didnt change?")
if bodyPositions[1].toVector2() != beforeBug1:
# This branch executes
print("bodyPositions[1] changed???")
Here I only change the values of bodyPositions[0], but the values of bodyPositions[1] and bodyPositions[0] change at the same time. This was a nightmare to figure out where in my code this went wrong, and the result doesn’t make any sense to me.
I wish to know why this happens, and how I can prevent this kind of bug from happening. Thanks for your time and help in advance
did you initialize array? like var bodyPositions : Array = []
volzhs | 2019-05-22 22:29
I did. In my initialization function, i initialize it, and I call that function from _ready(): Here it is below:
func _ready():
initialize()
func initialize() -> void:
# Reset the snake body
while bodyPositions.size() > 0:
bodyPositions.remove(0)
direction = DIRECTION.stopped
bodyPositions.append(setRandHeadPos())
bodyPositions.append(SnakeInfo(bodyPositions[0].x, bodyPositions[0].y + Global_Vars.sector))
bodyPositions.append(SnakeInfo(bodyPositions[1].x, bodyPositions[1].y + Global_Vars.sector, DIRECTION.up, TYPE.tail))
The setRandHeadPos() function returns a new object of type SnakeInfo and is listed below
func setRandHeadPos() -> SnakeInfo:
# Set the x and y pos to a point on the game grid
var randX : int = rand.randi_range(leftR, rightR) * Global_Vars.sector
var randY : int = rand.randi_range(topR, bottomR) * Global_Vars.sector
# Return the random position
return SnakeInfo(randX, randY, DIRECTION.stopped, TYPE.head, CURVE.noCurve)
And here is the constructor that returns an object of type SnakeInfo
func SnakeInfo(x : float = 0, y : float = 0, dir : int = DIRECTION.up, type : int = TYPE.body, curve : int = CURVE.noCurve) -> SnakeInfo:
var snake = SnakeInfo.new()
snake.x = x
snake.y = y
snake.dir = dir
snake.type = type
snake.curve = curve
return snake
linklight2 | 2019-05-22 23:12
Additionally, initializing the array like you said var bodyPositions : Array = [] did not change the incorrect behavior at all
linklight2 | 2019-05-22 23:39