meat_madness_redux/godot/player/OnFootPhysics.gd

extends KinematicBody

onready var util = get_node("/root/Util")

export var gravity: float = 2.5
"public" var velocity: Vector3 = Vector3.ZERO
export var velocity_acceleration: float = 5
export var velocity_friction: float = 5
export var jump_power: float = 125
export var sprint_factor: float = 1.07

var velocity_factor: Vector3 = Vector3.ONE

var target_velocity: Vector3 = Vector3.ZERO
var is_jumping: bool = false
var jump_permission: float = 1.0

func get_terminal_falling_velocity():
	return -gravity * .5

func is_falling_velocity_terminal():
	return velocity.y <= get_terminal_falling_velocity()


func process_velocity(delta: float):
	# Uses the input from MovementInput to compute and update this node's velocity
	# velocity_acceleration controls gradual speedup whereas velocity_friction
	# controls gradual slowdown
	
	# Gravity
	# You can buffer jumps by pressing releaseing the space bar and then pressing it again
	if not is_on_floor():
		target_velocity.y = -gravity
	else:
		velocity.y = max(0.0, velocity.y)
		target_velocity.y = max(0.0, max(target_velocity.y, jump_power * $"../MovementInput".jump_intent * jump_permission))
	if not is_jumping and $"../MovementInput".jump_intent != 0.0 and is_on_floor():
		jump_permission = 0.0
		is_jumping = true
	elif is_jumping and $"../MovementInput".jump_intent == 0.0:
		jump_permission = 1.0
		is_jumping = false
	
	
	var target_velocity_xz = $"../MovementInput".input_xz 
	target_velocity = util.vec2_xz_to_vec3(target_velocity_xz, target_velocity.y)
	
	var velocity_xz = util.vec3_xz(velocity)

	var xz_weight = velocity_acceleration * delta
	if target_velocity_xz.length() < velocity_xz.length():
		xz_weight = velocity_friction * delta

	var target_xz_length = lerp(velocity_xz.length(), target_velocity_xz.length(), xz_weight)
	if target_velocity_xz != Vector2.ZERO:
		velocity_xz = target_velocity_xz.normalized() * target_xz_length
	elif velocity_xz != Vector2.ZERO:
		velocity_xz = velocity_xz.normalized() * target_xz_length
		
	if (target_velocity_xz - velocity_xz).length() <= 0.025:
		velocity_xz = target_velocity_xz
	
	var y_weight = velocity_acceleration * delta
	if target_velocity.y < velocity.y:
		y_weight = velocity_friction * delta
	
	var velocity_y = lerp(velocity.y, target_velocity.y, y_weight)
	if abs(target_velocity.y - velocity_y) <= 0.025:
		velocity_y = target_velocity.y

	if $"../MovementInput".sprinting:
		velocity_xz *= sprint_factor

	velocity = util.vec2_xz_to_vec3(velocity_xz, velocity_y) * velocity_factor

func increase_velocity_factor(by: Vector3):
	velocity_factor *= by
	
func decrease_velocity_factor(by: Vector3):
	velocity_factor /= by

func _physics_process(delta):
	process_velocity(delta)
	velocity = move_and_slide(velocity, Vector3.UP)