godot/demos/2d/platformer/player.gd

263 lines
5.9 KiB
GDScript

extends RigidBody2D
# Character Demo, written by Juan Linietsky.
#
# Implementation of a 2D Character controller.
# This implementation uses the physics engine for
# controlling a character, in a very similar way
# than a 3D character controller would be implemented.
#
# Using the physics engine for this has the main
# advantages:
# -Easy to write.
# -Interaction with other physics-based objects is free
# -Only have to deal with the object linear velocity, not position
# -All collision/area framework available
#
# But also has the following disadvantages:
#
# -Objects may bounce a little bit sometimes
# -Going up ramps sends the chracter flying up, small hack is needed.
# -A ray collider is needed to avoid sliding down on ramps and
# undesiderd bumps, small steps and rare numerical precision errors.
# (another alternative may be to turn on friction when the character is not moving).
# -Friction cant be used, so floor velocity must be considered
# for moving platforms.
var anim=""
var siding_left=false
var jumping=false
var stopping_jump=false
var shooting=false
var WALK_ACCEL = 800.0
var WALK_DEACCEL= 800.0
var WALK_MAX_VELOCITY= 200.0
var GRAVITY = 700.0
var AIR_ACCEL = 200.0
var AIR_DEACCEL= 200.0
var JUMP_VELOCITY=460
var STOP_JUMP_FORCE=900.0
var MAX_FLOOR_AIRBORNE_TIME = 0.15
var airborne_time=1e20
var shoot_time=1e20
var MAX_SHOOT_POSE_TIME = 0.3
var bullet = preload("res://bullet.xml")
var floor_h_velocity=0.0
var enemy
func _integrate_forces(s):
var lv = s.get_linear_velocity()
var step = s.get_step()
var new_anim=anim
var new_siding_left=siding_left
# Get the controls
var move_left = Input.is_action_pressed("move_left")
var move_right = Input.is_action_pressed("move_right")
var jump = Input.is_action_pressed("jump")
var shoot = Input.is_action_pressed("shoot")
var spawn = Input.is_action_pressed("spawn")
if spawn:
var e = enemy.instance()
var p = get_pos()
p.y = p.y - 100
e.set_pos(p)
get_parent().add_child(e)
#deapply prev floor velocity
lv.x-=floor_h_velocity
floor_h_velocity=0.0
# Find the floor (a contact with upwards facing collision normal)
var found_floor=false
var floor_index=-1
for x in range(s.get_contact_count()):
var ci = s.get_contact_local_normal(x)
if (ci.dot(Vector2(0,-1))>0.6):
found_floor=true
floor_index=x
# A good idea when impementing characters of all kinds,
# Compensates for physics imprecission, as well as human
# reaction delay.
if (shoot and not shooting):
shoot_time=0
var bi = bullet.instance()
var ss
if (siding_left):
ss=-1.0
else:
ss=1.0
var pos = get_pos() + get_node("bullet_shoot").get_pos()*Vector2(ss,1.0)
bi.set_pos(pos)
get_parent().add_child(bi)
bi.set_linear_velocity( Vector2(800.0*ss,-80) )
get_node("sprite/smoke").set_emitting(true)
get_node("sound").play("shoot")
PS2D.body_add_collision_exception(bi.get_rid(),get_rid()) # make bullet and this not collide
else:
shoot_time+=step
if (found_floor):
airborne_time=0.0
else:
airborne_time+=step #time it spent in the air
var on_floor = airborne_time < MAX_FLOOR_AIRBORNE_TIME
# Process jump
if (jumping):
if (lv.y>0):
#set off the jumping flag if going down
jumping=false
elif (not jump):
stopping_jump=true
if (stopping_jump):
lv.y+=STOP_JUMP_FORCE*step
if (on_floor):
# Process logic when character is on floor
if (move_left and not move_right):
if (lv.x > -WALK_MAX_VELOCITY):
lv.x-=WALK_ACCEL*step
elif (move_right and not move_left):
if (lv.x < WALK_MAX_VELOCITY):
lv.x+=WALK_ACCEL*step
else:
var xv = abs(lv.x)
xv-=WALK_DEACCEL*step
if (xv<0):
xv=0
lv.x=sign(lv.x)*xv
#Check jump
if (not jumping and jump):
lv.y=-JUMP_VELOCITY
jumping=true
stopping_jump=false
get_node("sound").play("jump")
#check siding
if (lv.x < 0 and move_left):
new_siding_left=true
elif (lv.x > 0 and move_right):
new_siding_left=false
if (jumping):
new_anim="jumping"
elif (abs(lv.x)<0.1):
if (shoot_time<MAX_SHOOT_POSE_TIME):
new_anim="idle_weapon"
else:
new_anim="idle"
else:
if (shoot_time<MAX_SHOOT_POSE_TIME):
new_anim="run_weapon"
else:
new_anim="run"
else:
# Process logic when the character is in the air
if (move_left and not move_right):
if (lv.x > -WALK_MAX_VELOCITY):
lv.x-=AIR_ACCEL*step
elif (move_right and not move_left):
if (lv.x < WALK_MAX_VELOCITY):
lv.x+=AIR_ACCEL*step
else:
var xv = abs(lv.x)
xv-=AIR_DEACCEL*step
if (xv<0):
xv=0
lv.x=sign(lv.x)*xv
if (lv.y<0):
if (shoot_time<MAX_SHOOT_POSE_TIME):
new_anim="jumping_weapon"
else:
new_anim="jumping"
else:
if (shoot_time<MAX_SHOOT_POSE_TIME):
new_anim="falling_weapon"
else:
new_anim="falling"
#Update siding
if (new_siding_left!=siding_left):
if (new_siding_left):
get_node("sprite").set_scale( Vector2(-1,1) )
else:
get_node("sprite").set_scale( Vector2(1,1) )
siding_left=new_siding_left
#Change animation
if (new_anim!=anim):
anim=new_anim
get_node("anim").play(anim)
shooting=shoot
# Apply floor velocity
if (found_floor):
floor_h_velocity=s.get_contact_collider_velocity_at_pos(floor_index).x
lv.x+=floor_h_velocity
#Finally, apply gravity and set back the linear velocity
lv+=s.get_total_gravity()*step
s.set_linear_velocity(lv)
func _ready():
# Initalization here
# if !Globals.has_singleton("Facebook"):
# return
# var Facebook = Globals.get_singleton("Facebook")
# var link = Globals.get("facebook/link")
# var icon = Globals.get("facebook/icon")
# var msg = "I just sneezed on your wall! Beat my score and Stop the Running nose!"
# var title = "I just sneezed on your wall!"
# Facebook.post("feed", msg, title, link, icon)
enemy = ResourceLoader.load("res://enemy.xml")
pass