godot/demos/2d/kinematic_char/player.gd
2015-12-09 08:39:12 +01:00

124 lines
3.4 KiB
GDScript

extends KinematicBody2D
# This is a simple collision demo showing how
# the kinematic controller works.
# move() will allow to move the node, and will
# always move it to a non-colliding spot,
# as long as it starts from a non-colliding spot too.
# Member variables
const GRAVITY = 500.0 # Pixels/second
# Angle in degrees towards either side that the player can consider "floor"
const FLOOR_ANGLE_TOLERANCE = 40
const WALK_FORCE = 600
const WALK_MIN_SPEED = 10
const WALK_MAX_SPEED = 200
const STOP_FORCE = 1300
const JUMP_SPEED = 200
const JUMP_MAX_AIRBORNE_TIME = 0.2
const SLIDE_STOP_VELOCITY = 1.0 # One pixel per second
const SLIDE_STOP_MIN_TRAVEL = 1.0 # One pixel
var velocity = Vector2()
var on_air_time = 100
var jumping = false
var prev_jump_pressed = false
func _fixed_process(delta):
# Create forces
var force = Vector2(0, GRAVITY)
var walk_left = Input.is_action_pressed("move_left")
var walk_right = Input.is_action_pressed("move_right")
var jump = Input.is_action_pressed("jump")
var stop = true
if (walk_left):
if (velocity.x <= WALK_MIN_SPEED and velocity.x > -WALK_MAX_SPEED):
force.x -= WALK_FORCE
stop = false
elif (walk_right):
if (velocity.x >= -WALK_MIN_SPEED and velocity.x < WALK_MAX_SPEED):
force.x += WALK_FORCE
stop = false
if (stop):
var vsign = sign(velocity.x)
var vlen = abs(velocity.x)
vlen -= STOP_FORCE*delta
if (vlen < 0):
vlen = 0
velocity.x = vlen*vsign
# Integrate forces to velocity
velocity += force*delta
# Integrate velocity into motion and move
var motion = velocity*delta
# Move and consume motion
motion = move(motion)
var floor_velocity = Vector2()
if (is_colliding()):
# You can check which tile was collision against with this
# print(get_collider_metadata())
# Ran against something, is it the floor? Get normal
var n = get_collision_normal()
if (rad2deg(acos(n.dot(Vector2(0, -1)))) < FLOOR_ANGLE_TOLERANCE):
# If angle to the "up" vectors is < angle tolerance
# char is on floor
on_air_time = 0
floor_velocity = get_collider_velocity()
if (on_air_time == 0 and force.x == 0 and get_travel().length() < SLIDE_STOP_MIN_TRAVEL and abs(velocity.x) < SLIDE_STOP_VELOCITY and get_collider_velocity() == Vector2()):
# Since this formula will always slide the character around,
# a special case must be considered to to stop it from moving
# if standing on an inclined floor. Conditions are:
# 1) Standing on floor (on_air_time == 0)
# 2) Did not move more than one pixel (get_travel().length() < SLIDE_STOP_MIN_TRAVEL)
# 3) Not moving horizontally (abs(velocity.x) < SLIDE_STOP_VELOCITY)
# 4) Collider is not moving
revert_motion()
velocity.y = 0.0
else:
# For every other case of motion, our motion was interrupted.
# Try to complete the motion by "sliding" by the normal
motion = n.slide(motion)
velocity = n.slide(velocity)
# Then move again
move(motion)
if (floor_velocity != Vector2()):
# If floor moves, move with floor
move(floor_velocity*delta)
if (jumping and velocity.y > 0):
# If falling, no longer jumping
jumping = false
if (on_air_time < JUMP_MAX_AIRBORNE_TIME and jump and not prev_jump_pressed and not jumping):
# Jump must also be allowed to happen if the character left the floor a little bit ago.
# Makes controls more snappy.
velocity.y = -JUMP_SPEED
jumping = true
on_air_time += delta
prev_jump_pressed = jump
func _ready():
set_fixed_process(true)