In pondering how to learn video game programming, I just came up with this concept: Think Like a Speedrunner<\/p>\n\n\n\n
In short, learn a development task, and the repeat it. Keep repeating it so often you can do it very quickly. The first attempt may take a very long time. You’ll need to research it, there will be issues, you may need to reach out to the programming community for help, etc. And after you get it all sorted out though, it still may not all fit inside your head. So, do it again. Repeat it so many times you can do it from scratch and without needing to look at any guides.<\/p>\n\n\n\n
So that’s what I’m going to do next with learning Godot. I’m going to keep doing the tutorial from the documentation until I can do it like a speedrunner.<\/p>\n\n\n\n
I don’t recall exactly how long it took me to do the first time, but it was at at least four evenings…<\/p>\n\n\n\n
Here are my notes from the second pass, a highly distilled version of the documented steps:<\/p>\n\n\n\n
PART 1: SETUP<\/p>\n\n\n\n
Step1: Create a project<\/strong><\/p>\n\n\n\n Step 2:<\/strong> Project Settings -> Window -> Viewport Width\/Height -> 480 x 720<\/p>\n\n\n\n Step 3: <\/strong>Project Settings -> Windows -> Mode = canvas items && Aspect = keep<\/p>\n\n\n\n PART 2: PLAYER SCENE<\/p>\n\n\n\n Step 1<\/strong>: Create a Player root node as Area2D and enable Group Select<\/p>\n\n\n\n Step 2:<\/strong> Create child node AnimatedSprite2D<\/p>\n\n\n\n Step 3:<\/strong> Sprite Frames -> New SpriteFrames<\/p>\n\n\n\n Step 4:<\/strong> rename default animation to “walk” and a new one called “up”<\/p>\n\n\n\n Step 5:<\/strong> Drag in two images for each animation<\/p>\n\n\n\n Step 6:<\/strong> Player -> AnimatedSprite2D -> Node2D -> Transform -> Scale -> 0.5, 0.5<\/p>\n\n\n\n Step 7:<\/strong> Create child node of Player -> CollisionShape2D -> CapsuleShape2D<\/p>\n\n\n\n Part 3: CODING PLAYER<\/p>\n\n\n\n Step 1:<\/strong> Player -> Attach Script<\/p>\n\n\n\n Step 2:<\/strong> Declare member variables:<\/p>\n\n\n\n Step 3:<\/strong> _ready<\/p>\n\n\n\n _ready is called when a node enters the scene tree, which is a good time to find the size of the game window<\/p>\n\n\n\n Step4:<\/strong> _process<\/p>\n\n\n\n Use the Step 4a<\/strong>: Map Input Keys<\/p>\n\n\n\n Project -> Project Settings -> Input Map -> type “move_right” -> click Add -> + Add Event -> <press right arrow><\/p>\n\n\n\n Repeat for left, up, down<\/p>\n\n\n\n Step 4b:<\/strong><\/p>\n\n\n\n If you hold Step 5:<\/strong><\/p>\n\n\n\n Now that we have a movement direction, we can update the player’s position. We can also use The delta parameter in the _process() function refers to the frame length<\/em> – the amount of time that the previous frame took to complete. Using this value ensures that your movement will remain consistent even if the frame rate changes.<\/p>\n\n\n\n Step 6:<\/strong> Choosing which animation is playing based on player direction<\/p>\n\n\n\n Step 7.<\/strong> When you’re sure the movement is working correctly, add this line to Step 8<\/strong>. Preparing for collisions<\/p>\n\n\n\n We want This defines a custom signal called “hit” that we will have our player emit (send out) when it collides with an enemy. We will use Notice our custom “hit” signal is there as well! Since our enemies are going to be Next add this code to the func:<\/p>\n\n\n\n
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\n\n\n\nextends Area2D\n\n@export var speed = 400 # How fast the player will move (pixels\/sec).\nvar screen_size # Size of the game window.<\/code><\/pre>\n\n\n\n\n
func _ready():\n\tscreen_size = get_viewport_rect().size<\/code><\/pre>\n\n\n\n_process()<\/code> function to define what the player will do. _process()<\/code> is called every frame, so we’ll use it to update elements of our game, which we expect will change often. For the player, we need to do the following:<\/p>\n\n\n\n\n
func _process(delta):\n\tvar velocity = Vector2.ZERO # The player's movement vector.\n\tif Input.is_action_pressed(\"move_right\"):\n\t\tvelocity.x += 1\n\tif Input.is_action_pressed(\"move_left\"):\n\t\tvelocity.x -= 1\n\tif Input.is_action_pressed(\"move_down\"):\n\t\tvelocity.y += 1\n\tif Input.is_action_pressed(\"move_up\"):\n\t\tvelocity.y -= 1\n\n\tif velocity.length() > 0:\n\t\tvelocity = velocity.normalized() * speed\n\t\t$AnimatedSprite2D.play()\n\telse:\n\t\t$AnimatedSprite2D.stop()<\/code><\/pre>\n\n\n\nright<\/code> and down<\/code> at the same time, the resulting velocity<\/code> vector will be (1, 1)<\/code>. In this case, since we’re adding a horizontal and a vertical movement, the player would move faster<\/em> diagonally than if it just moved horizontally. We can prevent that if we normalize<\/em> the velocity, which means we set its length<\/em> to 1<\/code>, then multiply by the desired speed. This means no more fast diagonal movement.<\/p>\n\n\n\n$<\/code> returns the node at the relative path from the current node<\/p>\n\n\n\nclamp()<\/code> to prevent it from leaving the screen. Clamping<\/em> a value means restricting it to a given range. Add the following to the bottom of the _process<\/code> function<\/p>\n\n\n\nposition += velocity * delta\nposition = position.clamp(Vector2.ZERO, screen_size)\n<\/code><\/pre>\n\n\n\nif velocity.x != 0:\n\t$AnimatedSprite2D.animation = \"walk\"\n\t$AnimatedSprite2D.flip_v = false\n\t# See the note below about the following boolean assignment.\n\t$AnimatedSprite2D.flip_h = velocity.x < 0\nelif velocity.y != 0:\n\t$AnimatedSprite2D.animation = \"up\"\n\t$AnimatedSprite2D.flip_v = velocity.y > 0<\/code><\/pre>\n\n\n\n_ready()<\/code>, so the player will be hidden when the game starts: <\/p>\n\n\n\nhide()<\/code><\/pre>\n\n\n\nPlayer<\/code> to detect when it’s hit by an enemy, but we haven’t made any enemies yet! That’s OK, because we’re going to use Godot’s signal<\/em> functionality to make it work. Add the following at the top of the script. If you’re using GDScript, add it after extends Area2D<\/code>: <\/p>\n\n\n\nsignal hit<\/code><\/pre>\n\n\n\nArea2D<\/code> to detect the collision. Select the Player<\/code> node and click the “Node” tab next to the Inspector tab to see the list of signals the player can emit.<\/p>\n\n\n\nRigidBody2D<\/code> nodes, we want the body_entered(body: Node2D)<\/code> signal. This signal will be emitted when a body contacts the player. Click “Connect..” and the “Connect a Signal” window appears.<\/p>\n\n\n\nfunc _on_body_entered(body):\n\thide() # Player disappears after being hit.\n\thit.emit()\n\t# Must be deferred as we can't change physics properties on a physics callback.\n\t$CollisionShape2D.set_deferred(\"disabled\", true)<\/code><\/pre>\n\n\n\n