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extends RigidBody2D
var velocity #How fast car is moving
var velVector #What direction the car is moving
var velUnitVector #Direction vector, but in a single unit(no magnitude)
var velAngle #The angle of the velocity(relative to world)
var carAngle #The angle to car is facing(relative to world)
#Skidmarks on floor
onready var skidObj = preload("res://4WheelCar/Skid/Skidmark.tscn")
#Reduces steering strength when braking
var steerDampBase = 1
var steerDamp = 1
#Steering Curve Vars
var steerSplitA = 20
var steerSplitB = 40
var steerHeight = 2.6
var steerLimit = 73
var steerMinimum = 1
var gripDelay = 0
var wheelSlip = Vector2(0,0)
var isSkid = false #this one is used when user presses shift. Initially called in this function
var isSkidOverride = false #this one is used when driving over sand, initially called in carbody
signal slip
signal end
var elapsed = 0
var isForward = true
# Called when the node enters the scene tree for the first time.
func _ready():
pass
# Called every frame. 'delta' is the elapsed time since the previous frame.
func _process(delta):
#Variable Setup
#---
velocity = measure_velocity()
velVector = get_node("../../../CarBody").get_linear_velocity()
velUnitVector = velVector.normalized()
velAngle = atan2(velVector.y,velVector.x)
carAngle = get_node("../../../CarBody").get_transform().get_rotation()
isForward = is_forward()
#---
set_rotation(carAngle)
# gripDelay = has_grip(0.4,delta)
isSlip(delta)
if(!isSkidOverride):
isSkid = Input.is_action_pressed("grip")
#Determines if drifting
if Input.is_action_pressed("grip") || Input.is_action_pressed("brake"):
null_slide(max(5,velocity/7),delta)
else:
null_slide(1,delta)
#Braking
if Input.is_action_pressed("brake"):
if velocity > 20:
linear_damp = 3
steerDamp = 0.7
else:
linear_damp = 6
steerDamp = 0.4
else:
linear_damp = 0.01
steerDamp = 1
#Steering
if Input.is_action_pressed("steer_left"):
apply_central_impulse(steerDamp*Vector2(0,steer_curve(steerSplitA, steerSplitB, steerHeight, steerLimit,steerMinimum)).rotated(steer_angle())*delta*5000)
if Input.is_action_pressed("steer_right"):
apply_central_impulse(steerDamp*Vector2(0,-steer_curve(steerSplitA, steerSplitB, steerHeight, steerLimit,steerMinimum)).rotated(steer_angle())*delta*5000)
func null_slide(var strength, var delta):
#strength is how strong you would like the nullify to be
#higher is less sliding/drifting
var movementUnitVector = get_linear_velocity().normalized()#the direction of the velocity
var directionAngle = carAngle + (PI/2.0)#the angle the car is facing(relative to the world)
var directionUnitVector = Vector2(cos(directionAngle),sin(directionAngle)).normalized()#the direction the car is facing
var nullify = directionUnitVector * movementUnitVector.dot(directionUnitVector)
wheelSlip = (-(movementUnitVector - nullify))*strength
apply_central_impulse(wheelSlip*delta*5000)
#func has_grip(var tractionDelay, var delta):
# var movementUnitVector = get_linear_velocity().normalized()#the direction of the velocity
# var directionAngle = carAngle#the angle the car is facing(relative to the world)
# var directionUnitVector = Vector2(cos(directionAngle),sin(directionAngle)).normalized()#the direction the car is facing
# if velocity > 10:
# if Input.is_action_pressed("grip"):##if pressing shift
# gripDelay = tractionDelay
# elif (gripDelay <= 0 && abs(movementUnitVector.dot(directionUnitVector)) > 0.4):#if not drifting but past steering point
# gripDelay = tractionDelay
# elif gripDelay > 0 && abs(movementUnitVector.dot(directionUnitVector)) > 0.3:#if drifting and past steering point
# gripDelay = tractionDelay
# elif gripDelay > 0:#if at recovery point and drifting
# gripDelay -= delta
# else:
# gripDelay = 0
# return gripDelay
#Determines if skidmarks should be creted, or stopped
func isSlip(time):
if (wheelSlip.length() > 0.6):
if(elapsed/4 > time):
emit_signal("end")
elapsed = 0
else:
emit_signal("slip")
else:
elapsed += time
func measure_velocity():
return floor(sqrt(get_linear_velocity().dot(get_linear_velocity()))/12)
#determines if the car is driving forward, or backward
func is_forward():
var carVector = Vector2(cos(carAngle + PI/2),sin(carAngle + PI/2))
if velVector == Vector2(0,0) || carVector == Vector2(0,0):
return true
if velVector.dot(carVector) <= 0:
return true
else:
return false
#returns the angle the car is facing, relative to the direction it is moving
func steer_angle():
if isForward:
return carAngle + (PI/2.0)
else:
return carAngle - (PI/2.0)
#Determines strength of steering as a function of the speed
func steer_curve(var splitA, splitB, var height, var limit, var minimum):
#Rules:
# splitA < splitB < limit
# height > 0, limit >= 0
# ---
#Desmos: SteerCurve
#Link: https://www.desmos.com/calculator/jkrd8zzoj9
# splitA = a
# splitB = b
# height = h
# limit = f
#note: minimum is not in the graph, it is simply the minimum y value you want when x > splitB
# ---
if(velocity >= splitB):
return max((-pow((velocity-splitB)/((limit-splitB)/sqrt(height)),2)+height)*abs(cos(abs(velAngle-carAngle)+PI/2)),minimum)
elif velocity >= splitA:
return height
else:
return max((-pow((velocity/(splitA/sqrt(height)))-sqrt(height),2)+height)*abs(cos(abs(velAngle-carAngle)+PI/2)),0)
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