====== Getting Started with Godot ======
This event runs monthly on the **2nd Monday** of the month.  See the [[start|home page]] for the date of our next monthly event.

For our regular monthly tutorial nights, we're basing our teaching on the wonderful series by [[https://www.youtube.com/@AJsLearningLab|AJ's Learning Lab]], [[https://www.youtube.com/playlist?list=PL4vjw0qHwNZIQZScBFaON0WGkz-BMyoCh|Godot FPS Tutorial - Learn Godot by making Wolfenstein 3D]].

He has made the assets he uses freely available (please consider donating) here: https://ajslearninglab.itch.io/boganstein-3d-learn-godot-4-with-wolfenstein-3d/

All the code we use is available on AJ's Learning Lab github - https://github.com/AJsLearningLab/GodotFPS

Glasgow Social Game Dev Chatroom Link (Matrix): https://glasgow.social/matrix

===== First Steps =====
  * Download Godot from https://godotengine.org/download/ and install it (it's available on all platforms)
  * Download the assets from AJ's Learning Lab here: https://ajslearninglab.itch.io/boganstein-3d-learn-godot-4-with-wolfenstein-3d/


==== Part 1 ====
**Goal: Learn about Godot, create a world/room (floor and walls)**
  * New scene: click 3D Scene, rename to 'world'
  * Create floor.  Add MeshInstance3D to scene
  * Set Mesh type to 'New PlaneMesh'
  * Change size.  Transform -> scale to 20
  * Create collision mesh.  Using the 'Mesh' top button, choose 'Trimesh Static Body'.  That automatically creates a StaticBody3D of the correct type, and then adds a CollisionShape3D.
  * New wall.  Create another new mesh.  This time the Mesh should be New BoxMesh'.  Move walls to edge, set z to 20
  * Tweak the wall height, 'y to the sky', set to 10
  * Duplicate for the other three walls

==== Part 2 ====
**Goal: Create a player character that can be controlled by the keyboard**
  * New scene.  Click + next to the world scene.  Other node.  Search for CharacterBody3D.  Name it 'player'.
  * Add subnode.  Click +, search for MeshInstance3D.  Set Mesh shape to Capsule shape.
  * Fix the height.  Transform, adjust Y to 1m.
  * Select player node, add new node, Camera3D.
  * Adjust Camera height to eye height.
  * Create script.  Select player node.  Use script+/scroll button.  Select a template for Basic movement.
  * Add new variable.  ''const TURN_SPEED = 0.05''
  * Add new code
<code>
if Input.is_action_pressed("ui_left"):
  self.rotate_y(TURN_SPEED)
if Input.is_action_pressed("ui_right"):
  self.rotate_y(-TURN_SPEED)
</code>
  * Comment out the jump code
  * In the world scene, drag the player scene into the world
  * In the three dot menu (world scene), use 'Add Sun to scene', 'add environment to scene'
  * In the player scene, use the Mesh button to add a 'Simplified Convex Collision Sibling' mesh to the player's MeshInstance3D (not 'Single', that'll cause performance issues - why?)
  * Set up WASD controls in the Project Settings

==== Part 3 ====
**Goal: Add textures to the walls and floor**
  * Import a texture by dragging it into the file system.
  * Select a wall.  Use Geometry -> Material Override.  Select New StandardMaterial3D.  Click the sphere.  Expand Albedo.  Drag the texture to the 'Texture' input.
  * Find UV1, experiment with the sizing, approx 30 x 10
  * Apply to floor/other walls.

==== Part 4 ====
**Goal: Add a UI/HUD and a knife**
  * Create new scene, other node: 'CanvasLayer', rename to 'ui'
  * Create new node, AnimatedSprite2D
  * Create new node, ColorRect
  * In 2D view, size the ColorRect.  Layout -> Anchors -> Bottom Wide.  Set the colour to dark blue.
  * Import wolfweapons.png
  * Select Animated Sprite.  Expand Animation -> Sprite Frame.  Click New SpriteFrames.  Click it again to view the animation frame at the bottom.
  * Rename default to 'knife_idle', set as default.
  * Click grid, adjust, set up idle frame.
  * Adjust position of animatedspirteframe in 2D view, use Transform->Scale to size up to 5
  * Create new animation called 'stab'
  * Add new stab animations, disable loop, set FPS to 16
  * Click UI root node, add script. Enter the following code:
<code file ui.gd>
extends CanvasLayer

var ammo = 0
var current_weapon = "knife"

func _ready():
	$AnimatedSprite2D.animation_finished.connect(_on_AnimatedSprite2D_animation_finished)

func _process(delta):
	if Input.is_action_just_pressed("ui_select"):
		if current_weapon == "knife":
			$AnimatedSprite2D.play("stab")
		elif current_weapon == "gun":
			if ammo > 0:
				$AnimatedSprite2D.play("shoot")
				ammo -= 1

func _on_AnimatedSprite2D_animation_finished():
	if current_weapon == "knife":
		$AnimatedSprite2D.play("knife_idle")
	elif current_weapon == "gun":
		$AnimatedSprite2D.play("gun_idle")


</code>
  * Add the ui scene to the player scene (Drag drop from file system onto player node)

==== Part 5 ====
**Goal:Add a hand gun, firing, add a global script**
  * Add new handfun sprite animations ('gun_idle' and 'shoot').  Disable looping. (Adjust to 5x4 for grid)
  * Edit the ui code, after the ''ammo -= 1'' line, add:
<code>
else:
  current_weapon = "knife"
  $AnimatedSprite2D.play("knife_idle")
</code>
  * Set the ammo to '3' and current_weapon to 'gun'.  Test.
  * Create a global script.  File -> New Script (based on Node).  Name it global.
  * Move the ammo and current weapon variables from the ui script to the global script.
  * Open the project settings, in Autoload, add the global script and mark it global
  * Tweak the project setting page, allow fullscreen too
  * Edit the ui.gd script and change all references to current_weapon and ammo to be Global.current_weapon and Global.ammo
  * Test everything still works

==== Part 7 ====
**Goal: Add enemies**
  * Create new scene.  Other node->CharacterBody3D.  Name it guard.
  * Add two children to the enemy node.  A CollisionShape3D (set to capsule), and a AnimatedSprite3D.
  * Set the Y to 1, to make it on the floor.  Adjust the capsule size to be 2m.
  * Import the guard sprite to the file system.
  * Select the AnimatedSprite3D, Click Sprite Frame-> New Sprite Frame.  Click it again to set a default animation using the grid, set to 7x2
  * Adjust the eize, choose AnimatedSprite3D.  Transform -> y =1, scale = 4 ish.
  * A new animations, 'die' and 'shoot'
  * Select the AnimatedSprite3D, in the inspector find 'Flags', enable 'Billboard - Y:Billboard'
  * Edit the player script and add this line to the _ready() function:
<code>
add_to_group("player")
</code>
  * Select the guard root node.  Create a new script, use the code below:
<code guard.gd>
extends CharacterBody3D

@onready var player : CharacterBody3D = get_tree().get_first_node_in_group("player")

const SPEED = 5.0
var gravity = ProjectSettings.get_setting("physics/3d/default_gravity")  # Get the gravity from the project settings to be synced with RigidBody nodes.
var dead = false
var is_attacking = false  
var attack_range = 5

func _ready():
	add_to_group("enemy")

func _physics_process(delta):
	if dead or is_attacking:  # Check if the enemy is dead or attacking
		return

	if player == null:
		return
		
	var dir = player.global_position - global_position
	dir.y = 0.0
	dir = dir.normalized()
	
	velocity = dir * SPEED
	# Add the gravity.
	if not is_on_floor():
		velocity.y -= gravity * delta

	move_and_slide()
	attack()

func attack():
	var dist_to_player = global_position.distance_to(player.global_position)
	if dist_to_player > attack_range:
		return
	else:
		is_attacking = true  # Set the attacking flag
		$AnimatedSprite3D.play("shoot")
		await $AnimatedSprite3D.animation_finished  # Wait for the animation to finish
		is_attacking = false  # Reset the attacking flag


func die():
	dead = true  # Corrected variable scope
	$AnimatedSprite3D.play("die")
	$CollisionShape3D.disabled = true

</code>


==== Part 6 ====
**Goal: More weapons**
  * Edit the ui AnimatedSprite2D, add new animations/sprites
  * Rename 'shoot' to gun_shoot
  * Add new variables to ui.gd script
<code>
var time_since_last_shot = 0.0
var fire_rate = 1.0
</code>
  * Add a line to the _ready() function
<code>
$AnimatedSprite2D.play(Global.current_weapon + "_idle")
</code>
  * Add some lines to the start of the _process() function
<code>
time_since_last_shot += delta
var can_shoot = time_since_last_shot >= (1.0 / fire_rate)

if Global.current_weapon != "knife" and Global.ammo <= 0:
  Global.current_weapon = "knife"
  $AnimatedSprite2D.play("knife_idle")
</code>
  * Tweak first if statement, change to:
<code>
if Input.is_action_pressed("ui_select") and can_shoot:
</code>
  * Remove everything after the stab line, and add
<code>
else:
  $AnimatedSprite2D.play(Global.current_weapon + "_shoot")
  
time_since_last_shot = 0.0

if Global.current_weapon != "knife":
  if Global.ammo > 0:
    Global.ammo -= 1
    
match Global.current_weapon:
  "gun":
    fire_rate = 3.0
  "machine":
    fire_rate = 6.0
  "mini":
    fire_rate = 10.0
  "knife":
    fire_rate = 2.0
  _:
    fire_rate = 1.0

func _on_AnimatedSprite2D_animation_finished():
  $AnimatedSprite2D.play(Global.current_weapon + "_idle")
</code>

The full code for ui.gd should now be:
<code file ui.gd>
extends CanvasLayer

var time_since_last_shot = 0.0
var fire_rate = 1.0


func _ready():
	$AnimatedSprite2D.animation_finished.connect(_on_AnimatedSprite2D_animation_finished)
	$AnimatedSprite2D.play(Global.current_weapon + "_idle")

func _process(delta):
	time_since_last_shot += delta
	var can_shoot = time_since_last_shot >= (1.0 / fire_rate)
	
	if Global.current_weapon != "knife" and Global.ammo <= 0:
		Global.current_weapon = "knife"
		$AnimatedSprite2D.play("knife_idle")
	
	if Input.is_action_pressed("ui_select") and can_shoot:
		
		if Global.current_weapon == "knife":
			$AnimatedSprite2D.play("stab")
		else:
			$AnimatedSprite2D.play(Global.current_weapon + "_shoot")
			
		time_since_last_shot = 0.0
		
		if Global.current_weapon != "knife":
			if Global.ammo > 0:
				Global.ammo -= 1
				
	match Global.current_weapon:
		"gun":
			fire_rate = 3.0
		"machine":
			fire_rate = 6.0
		"mini":
			fire_rate = 10.0
		"knife":
			fire_rate = 2.0
		_:
			fire_rate = 1.0
			
func _on_AnimatedSprite2D_animation_finished():
	$AnimatedSprite2D.play(Global.current_weapon + "_idle")


</code>

==== Part 8 ====
**Goal: Enemy Death and Raycasting**
  * Edit the ui.gd script.  Tweak the can_shoot variable, set it in the object scope (top) and remove "var" from "var can_shoot" from the _process()
  * Access the 3D view of the player.  Add a new node as a child of the camera 3D, type: RayCast3D
  * Set the target position to y:0, z: -20
  * Make sure the raycast has access to collision mask layers 1+2
  * Check the guard scene, collision should be on layer 2, mask 1+2
  * Check Player is layer 1, mask is 1+2
  * Edit the player script, add new const at the top
<code>
@onready var ui_script = $ui
@onready var ray = $Camera3D/RayCast3D
</code>
  * At the bottom, just above move_and_slide(), add the following code:
<code>
if Input.is_action_just_pressed("ui_accept"):
  if ui_script.can_shoot:
    shoot()
</code>
  * Add the shoot function
<code bash>
func shoot():
  if ray.is_colliding() and ray.get_collider().has_method("die"):
    ray.get_collider().die()
</code>
  * To allow strafing, change the ''If Input.is_action_just_pressed("ui_accept"):'' to
<code>
if Input.is_action_pressed("ui_accept"):
</code>

===== Part 9 =====
**Goal: HUD labels and player death**
  * Add a player health variable to the player.gd script
<code>
var player_health = 100
</code>
  * Create two new Label nodes as a child of the UI, name one 'health'.
  * Create a new function in the ui.gd script
<code>
function update_player_health():
  $health.text = str(get_parent().player_health)
</code>
  * Add the function to the bottom of the _process() function in the ui.gd script
<code>
update_player_health()
</code>
  * Edit the player script and add a new function:
<code>
func damage():
  player_health -= 10
  print(player_health)
  if player_health <= 0:
    queue_free()
</code>
  * Add a RayCast3D to the guard scene
  * Set Y = 0, Z = 5
  * After the ''play(shoot)'' line in the attack() function, add:
<code>
if $RayCast3D.is_colliding() and $RayCast3D.get_collider().has_method('damage'):
  $RayCast3D.get_collider().damage()
</code>

===== Part 10 =====
**Goal: Ammo pickups**


===== Next Steps =====
**Goal: Add sound effects**
  * Import the sound effect files (gun.ogg, machine.ogg, mini.ogg)
  * In the player scene, add a new node, AudioStreamPlayer.
  * Add the following code to the player shoot() function:
<code>
var sound_player = $AudioStreamPlayer
match Global.current_weapon:
  "gun":
    sound_player.stream = preload("res://gun.ogg")
  "machine":
    sound_player.stream = preload("res://machine.ogg")
  "mini":
    sound_player.stream = preload("res://mini.ogg")
sound_player.play()
</code>