From 7e49db5ddefe8c515b5f3931a5c701efaac33d91 Mon Sep 17 00:00:00 2001 From: David Luevano Alvarado Date: Fri, 16 Dec 2022 17:45:03 -0600 Subject: change structure for new pyssg version --- src/blog/g/flappybird_godot_devlog_1.md | 684 ++++++++++++++++++++++++++++++ src/blog/g/godot_project_structure.md | 87 ++++ src/blog/g/gogodot_jam3_devlog_1.md | 724 ++++++++++++++++++++++++++++++++ src/blog/g/starting_gamedev_blogging.md | 14 + 4 files changed, 1509 insertions(+) create mode 100644 src/blog/g/flappybird_godot_devlog_1.md create mode 100644 src/blog/g/godot_project_structure.md create mode 100644 src/blog/g/gogodot_jam3_devlog_1.md create mode 100644 src/blog/g/starting_gamedev_blogging.md (limited to 'src/blog/g') diff --git a/src/blog/g/flappybird_godot_devlog_1.md b/src/blog/g/flappybird_godot_devlog_1.md new file mode 100644 index 0000000..44a5f36 --- /dev/null +++ b/src/blog/g/flappybird_godot_devlog_1.md @@ -0,0 +1,684 @@ +title: Creating a FlappyBird clone in Godot 3.5 devlog 1 +author: David Luévano +lang: en +summary: Since I'm starting to get more into gamedev stuff, I'll start blogging about it just to keep consistent. This shows as "devlog 1" just in case I want to include more parts for extra stuff. +tags: gamedev + godot + english + +I just have a bit of experience with Godot and with gamedev in general, so I started with this game as it is pretty straight forward. On a high level the main characteristics of the game are: + +- Literally just one sprite going up and down. +- Constant horizontal move of the world/player. +- If you go through the gap in the pipes you score a point. +- If you touch the pipes, the ground or go past the "ceiling" you lose. + +The game was originally developed with *Godot 4.0 alpha 8*, but it didn't support HTML5 (webassembly) export... so I backported to *Godot 3.5 rc1*. + +Not going to specify all the details, only the needed parts and what could be confusing, as the source code is available and can be inspected; also this assumes minimal knowledge of *Godot* in general. Usually when I mention that a set/change of something it usually it's a property and it can be found under the *Inspector* on the relevant node, unless stated otherwise; also, all scripts attached have the same name as the scenes, but in *snake_case* (scenes/nodes in *PascalCase*). + +One thing to note, is that I started writing this when I finished the game, so it's hard to go part by part, and it will be hard to test individual parts when going through this as everything is depending on each other. For the next devlog, I'll do it as I go and it will include all the changes to the nodes/scripts as I was finding them, probably better idea and easier to follow. + +The source code can be found in my GitHub [here](https://github.com/luevano/flappybird_godot), it also contains the exported versions for HTML5, Windows and Linux (be aware that the sound might be too high and I'm too lazy to make it configurable, it was the last thing I added), or you could also go to the itch.io page I setup where it's playable in the browser: + +

+ +## Initial project setup + +### Directory structure + +I'm basically going with what I wrote on [Godot project structure](https://blog.luevano.xyz/g/godot_project_structure.html) recently, and probably with minor changes depending on the situation. + +### Config + +#### Default import settings + +Since this is just pixel art, the importing settings for textures needs to be adjusted so the sprites don't look blurry. Go to *Project -> Project settings... -> Import defaults* and on the drop down select `Texture`, untick everything and make sure *Compress/Mode* is set to `Lossless`. + +![Project settings - Import defaults - Texture settings](images/g/flappybird_godot/project_settings_import_texture.png "Project settings - Import defaults - Texture settings") + +#### General settings + +It's also a good idea to setup some config variables project-wide. To do so, go to *Project -> Project settings... -> General*, select *Application/config* and add a new property (there is a text box at the top of the project settings window) for game scale: `application/config/game_scale` for the type use `float` and then click on add; configure the new property to `3.0`; On the same window, also add `application/config/version` as a `string`, and make it `1.0.0` (or whatever number you want). + +![Project settings - General - Game scale and version properties](images/g/flappybird_godot/project_settings_config_properties.png "Project settings - General - Game scale and version properties") + +For my personal preferences, also disable some of the *GDScript* debug warnings that are annoying, this is done at *Project -> Project settings... -> General*, select *Debug/GDScript* and toggle off "Unused arguments", "Unused signal" and "Return value discarded", and any other that might come up too often and don't want to see. + +![Project settings - General - GDScript debug warnings](images/g/flappybird_godot/project_settings_debug_gdscript.png "Project settings - General - GDScript debug warnings") + +Finally, set the initial window size in *Project -> Project settings... -> General*, select *Display/Window* and set *Size/Width* and *Size/Height* to `600` and `800`, respectively. As well as the *Stretch/Mode* to "viewport", and *Stretch/Aspect* to "keep": + +![Project settings - General - Initial window size](images/g/flappybird_godot/project_settings_window_settings.png "Project settings - General - Initial window size") + +#### Keybindings + +I only used 3 actions (keybindings): jump, restart and toggle_debug (optional). To add custom keybindings (so that the `Input.something()` API can be used), go to *Project -> Project settings... -> Input Map* and on the text box write "jump" and click add, then it will be added to the list and it's just a matter of clicking the `+` sign to add a "Physical key", press any key you want to be used to jump and click ok. Do the same for the rest of the actions. + +![Project settings - Input Map - Adding necessary keybindings](images/g/flappybird_godot/project_settings_input_map.png "Project settings - Input Map - Adding necessary keybindings") + +#### Layers + +Finally, rename the physics layers so we don't lose track of which layer is which. Go to *Project -> Layer Names -> 2d Physics* and change the first 5 layer names to (in order): "player", "ground", "pipe", "ceiling" and "score". + +![Project settings - Layer Names - 2D Physics](images/g/flappybird_godot/project_settings_layer_names_2d_physics.png "Project settings - Layer Names - 2D Physics") + +## Assets + +For the assets I found out about a pack that contains just what I need: [flappy-bird-assets](https://megacrash.itch.io/flappy-bird-assets) by [MegaCrash](https://megacrash.itch.io/); I just did some minor modifications on the naming of the files. For the font I used [Silver](https://poppyworks.itch.io/silver), and for the sound the resources from [FlappyBird-N64](https://github.com/meeq/FlappyBird-N64) (which seems to be taken from [101soundboards.com](https://www.101soundboards.com/boards/10178-flappy-bird-sounds) which the orignal copyright holder is [.Gears](https://dotgears.com/) anyways). + +### Importing + +Create the necessary directories to hold the respective assets and it's just a matter of dragging and dropping, I used directories: `res://entities/actors/player/sprites/`, `res://fonts/`, `res://levels/world/background/sprites/`, `res://levels/world/ground/sprites/`, `res://levels/world/pipe/sprites/`, `res://sfx/`. For the player sprites, the "FileSystem" window looks like this (`entities/actor` directories are really not necessary): + +![FileSystem - Player sprite imports](images/g/flappybird_godot/player_sprite_imports.png "FileSystem - Player sprite imports") + +It should look similar for other directories, except maybe for the file extensions. For example, for the sfx: + +![FileSystem - SFX imports](images/g/flappybird_godot/sfx_imports.png "FileSystem - SFX imports") + +## Scenes + +Now it's time to actually create the game, by creating the basic scenes that will make up the game. The hardest part and the most confusing is going to be the *TileMaps*, so that goes first. + +### TileMaps + +I'm using a scene called "WorldTiles" with a *Node2D* node as root called the same. With 2 different *TileMap* nodes as children named "GroundTileMap" and "PipeTileMap" (these are their own scene); yes 2 different *TileMaps* because we need 2 different physics colliders (In Godot 4.0 you can have a single *TileMap* with different physics colliders in it). Each node has its own script. It should look something like this: + +![Scene - WorldTiles (TileMaps)](images/g/flappybird_godot/scene_world_tiles.png "Scene - WorldTiles (TileMaps)") + +I used the following directory structure: + +![Scene - WorldTiles - Directory structure](images/g/flappybird_godot/scene_world_tiles_directory_structure.png "Scene - WorldTiles - Directory structure") + +To configure the GroundTileMap, select the node and click on "(empty)" on the *TileMap/Tile set* property and then click on "New TileSet", then click where the "(empty)" used to be, a new window should open on the bottom: + +![TileSet - Configuration window](images/g/flappybird_godot/tile_set_config_window.png "TileSet - Configuration window") + +Click on the plus on the bottom left and you can now select the specific tile set to use. Now click on the yellow "+ New Single Tile", activate the grid and select any of the tiles. Should look like this: + +![TileSet - New single tile](images/g/flappybird_godot/tile_set_new_single_tile.png "TileSet - New single tile") + +We need to do this because for some reason we can't change the snap options before selecting a tile. After selecting a random tile, set up the *Snap Options/Step* (in the *Inspector*) and set it to 16x16 (or if using a different tile set, to it's tile size): + +![TileSet - Tile - Step snap options](images/g/flappybird_godot/tile_set_tile_step_snap_options.png "TileSet - Tile - Step snap options") + +Now you can select the actual single tile. Once selected click on "Collision", use the rectangle tool and draw the rectangle corresponding to that tile's collision: + +![TileSet - Tile - Selection and collision](images/g/flappybird_godot/tile_set_tile_selection_collision.png "TileSet - Tile - Selection and collision") + +Do the same for the other 3 tiles. If you select the *TileMap* itself again, it should look like this on the right (on default layout it's on the left of the *Inspector*): + +![TileSet - Available tiles](images/g/flappybird_godot/tile_set_available_tiles.png "TileSet - Available tiles") + +The ordering is important only for the "underground tile", which is the filler ground, it should be at the end (index 3); if this is not the case, repeat the process (it's possible to rearrange them but it's hard to explain as it's pretty weird). + +At this point the tilemap doesn't have any physics and the cell size is wrong. Select the "GroundTileMap", set the *TileMap/Cell/Size* to 16x16, the *TileMap/Collision/Layer* set to `bit 2` only (ground layer) and disable any *TileMap/Collision/Mask* bits. Should look something like this: + +![TileMap - Cell size and collision configuration](images/g/flappybird_godot/tile_map_cell_collision_configuration.png "TileMap - Cell size and collision configuration") + +Now it's just a matter of repeating the same for the pipes ("PipeTileMap"), only difference is that when selecting the tiles you need to select 2 tiles, as the pipe is 2 tiles wide, or just set the *Snap Options/Step* to 32x16, for example, just keep the cell size to 16x16. + +#### Default ground tiles + +I added few default ground tiles to the scene, just for testing purposes but I left them there. These could be place programatically, but I was too lazy to change things. On the "WorldTiles" scene, while selecting the "GroundTileMap", you can select the tiles you want to paint with, and left click in the grid to paint with the selected tile. Need to place tiles from `(-8, 7)` to `(10, 7)` as well as the tile below with the filler ground (the tile position/coordinates show at the bottom left, refer to the image below): + +![Scene - WorldTiles - Default ground tiles](images/g/flappybird_godot/world_tiles_default_tiles.png "Scene - WorldTiles - Default ground tiles") + +### Player + +On a new scene called "Player" with a *KinematicBody2D* node named "Player" as the root of the scene, then for the children: *AnimatedSprite* as "Sprite", *CollisionShape2D* as "Collision" (with a circle shape) and 3 *AudioStreamPlayers* for "JumpSound", "DeadSound" and "HitSound". Not sure if it's a good practice to have the audio here, since I did that at the end, pretty lazy. Then, attach a script to the "Player" node and then it should look like this: + +![Scene - Player - Node setup](images/g/flappybird_godot/scene_player_node_setup.png "Scene - Player - Node setup") + +Select the "Player" node and set the *CollisionShape2D/Collision/Layer* to 1 and the *CollisionObject2D/Collision/Mask* to 2 and 3 (ground and pipe). + +For the "Sprite" node, when selecting it click on the "(empty)" for the *AnimatedSprite/Frames* property and click "New SpriteFrames", click again where the "(empty)" used to be and ane window should open on the bottom: + +![Scene - Player - SpriteFrames window](images/g/flappybird_godot/scene_player_spriteframes_window.png "Scene - Player - SpriteFrames window") + +Right off the bat, set the "Speed" to `10 FPS` (bottom left) and rename "default" to "bird_1". With the "bird_1" selected, click on the "Add frames from a Sprite Sheet", which is the second button under "Animation Frames:" which looks has an icon of a small grid (next to the folder icon), a new window will popup where you need to select the respective sprite sheet to use and configure it for importing. On the "Select Frames" window, change the "Vertical" to 1, and then select all 4 frames (*Ctrl + Scroll* wheel to zoom in): + +![Scene - Player - Sprite sheet importer](images/g/flappybird_godot/scene_player_sprite_sheet_importer.png "Scene - Player - Sprite sheet importer") + +After that, the *SpriteFrames* window should look like this: + +![Scene - Player - SpriteFrames window with sprite sheet configured](images/g/flappybird_godot/scene_player_spriteframes_window_with_sprite_sheet.png "Scene - Player - SpriteFrames window with sprite sheet configured") + +Finally, make sure the "Sprite" node has the *AnimatedSprite/Animation* is set to "bird_1" and that the "Collision" node is configured correctly for its size and position (I just have it as a radius of 7). As well as dropping the SFX files into the corresponding *AudioStreamPlayer* (into the *AudioStreamPlayer/Stream* property). + +### Other + +These are really simple scenes that don't require much setup: + +- "CeilingDetector": just an *Area2D* node with a *CollisionShape2D* in the form of a rectangle (*CollisionShape2D/Shape/extents* to `(120, 10)`), stretched horizontally so it fits the whole screen. *CollisionObject2D/Collision/Layer* set to `bit 4` (ceiling) and *CollisionObject2D/Collision/Mask* set to bit 1 (player). +- "ScoreDetector": similar to the "CeilingDetector", but vertical (*CollisionShape2D/Shape/extents* to `(2.5, 128)`) and *CollisionObject2D/Collision/Layer* set to `bit 1` (player). +- "WorldDetector": *Node2D* with a script attached, and 3 *RayCast2D* as children: + - "NewTile": *Raycast2D/Enabled* to true (checked), *Raycast2D/Cast To* `(0, 400)`, *Raycast2D/Collision Mask* to `bit 2` (ground) and *Node2D/Transform/Position* to `(152, -200)` + - "OldTile": same as "NewTile", except for the *Node2D/Transform/Position*, set it to `(-152, -200)`. + - "OldPipe": same as "OldTile", except for the *Raycast2D/Collision Mask*, set it to `bit 3` (pipe). + +### Game + +This is the actual "Game" scene that holds all the playable stuff, here we will drop in all the previous scenes; the root node is a *Node2D* and also has an attached script. Also need to add 2 additional *AudioStreamPlayers* for the "start" and "score" sounds, as well as a *Sprite* for the background (*Sprite/Offset/Offset* set to `(0, 10)`) and a *Camera2D* (*Camera2D/Current* set to true (checked)). It should look something like this: + +![Scene - Game - Node setup](images/g/flappybird_godot/scene_game_node_setup.png "Scene - Game - Node setup") + +The scene viewport should look something like the following: + +![Scene - Game - Viewport](images/g/flappybird_godot/scene_game_viewport.png "Scene - Game - Viewport") + +### UI + +#### Fonts + +We need some font "Resources" to style the *Label* fonts. Under the *FileSystem* window, right click on the fonts directory (create one if needed) and click on "New Resource..." and select *DynamicFontData*, save it in the "fonts" directory as "SilverDynamicFontData.tres" ("Silver" as it is the font I'm using) then double click the just created resource and set the *DynamicFontData/Font Path* to the actual "Silver.ttf" font (or whatever you want). + +Then create a new resource and this time select *DynamicFont*, name it "SilverDynamicFont.tres", then double click to edit and add the "SilverDynamicFontData.tres" to the *DynamicFont/Font/Font Data* property (and I personally toggled off the *DynamicFont/Font/Antialiased* property), now just set the *DynamicFont/Settings/(Size, Outline Size, Outline Color)* to 32, 1 and black, respectively (or any other values you want). It should look something like this: + +![Resource - DynamicFont - Default font](images/g/flappybird_godot/resource_dynamic_font.png "Resource - DynamicFont - Default font") + +Do the same for another *DynamicFont* which will be used for the score label, named "SilverScoreDynamicFont.tres". Only changes are *Dynamic/Settings/(Size, Outline Size)* which are set to 128 and 2, respectively. The final files for the fonts should look something like this: + +![Resource - Dynamicfont - Directory structure](images/g/flappybird_godot/resource_dynamic_font_directory_structure.png "Resource - Dynamicfont - Directory structure") + +#### Scene setup + +This has a bunch of nested nodes, so I'll try to be concise here. The root node is a *CanvasLayer* named "UI" with its own script attached, and for the children: + +- "MarginContainer": *MarginContainer* with *Control/Margin/(Left, Top)* set to `10` and *Control/Margin/(Right, Bottom)* set to `-10`. + - "InfoContainer": *VBoxContainer* with *Control/Theme Overrides/Constants/Separation* set to `250`. + - "ScoreContainer": *VBoxContainer*. + - "Score": *Label* with *Label/Align* set to "Center", *Control/Theme Overrides/Fonts/Font* to the "SilverScoreDynamicFont.tres", if needed adjust the *DynamicFont* settings. + - "HighScore: same as "Score", escept for the *Control/Theme Overrides/Fonts/Font* which is set to "SilverDynamicFont.tres". + - "StartGame": Same as "HighScore". + - "DebugContainer": *VBoxContainer*. + - "FPS": *Label*. + - "VersionContainer": *VBoxContainer* with *BoxContainer/Alignment* set to "Begin". + - "Version": *Label* with *Label/Align* set to "Right". + +The scene ends up looking like this: + +![Scene - UI - Node setup](images/g/flappybird_godot/scene_ui.png "Scene - UI - Node setup") + +### Main + +This is the final scene where we connect the Game and the UI. It's made of a *Node2D* with it's own script attached and an instance of "Game" and "UI" as it's children. + +This is a good time to set the default scene when we run the game by going to *Project -> Project settings... -> General* and in *Application/Run* set the *Main Scene* to the "Main.tscn" scene. + +## Scripting + +I'm going to keep this scripting part to the most basic code blocks, as it's too much code, for a complete view you can head to the [source code](https://github.com/luevano/flappybird_godot). + +As of now, the game itself doesn't do anything if we hit play. The first thing to do so we have something going on is to do the minimal player scripting. + +### Player + +The most basic code needed so the bird goes up and down is to just detect "jump" key presses and add a negative jump velocity so it goes up (`y` coordinate is reversed in godot...), we also check the velocity sign of the `y` coordinate to decide if the animation is playing or not. + +```gdscript +class_name Player +extends KinematicBody2D + +export(float, 1.0, 1000.0, 1.0) var JUMP_VELOCITY: float = 380.0 + +onready var sprite: AnimatedSprite = $Sprite + +var gravity: float = 10 * ProjectSettings.get_setting("physics/2d/default_gravity") +var velocity: Vector2 = Vector2.ZERO + + +func _physics_process(delta: float) -> void: + velocity.y += gravity * delta + + if Input.is_action_just_pressed("jump"): + velocity.y = -JUMP_VELOCITY + + if velocity.y < 0.0: + sprite.play() + else: + sprite.stop() + + velocity = move_and_slide(velocity) +``` + +You can play it now and you should be able to jump up and down, and the bird should stop on the ground (although you can keep jumping). One thing to notice is that when doing `sprite.stop()` it stays on the last frame, we can fix that using the code below (and then change `sprite.stop()` for `_stop_sprite()`): + +```gdscript +func _stop_sprite() -> void: + if sprite.playing: + sprite.stop() + if sprite.frame != 0: + sprite.frame = 0 +``` + +Where we just check that the last frame has to be the frame 0. + +Now just a matter of adding other needed code for moving horizontally, add sound by getting a reference to the *AudioStreamPlayers* and doing `sound.play()` when needed, as well as handling death scenarios by adding a `signal died` at the beginning of the script and handle any type of death scenario using the below function: + +```gdscript +func _emit_player_died() -> void: + # bit 2 corresponds to pipe (starts from 0) + set_collision_mask_bit(2, false) + dead = true + SPEED = 0.0 + emit_signal("died") + # play the sounds after, because yield will take a bit of time, + # this way the camera stops when the player "dies" + velocity.y = -DEATH_JUMP_VELOCITY + velocity = move_and_slide(velocity) + hit_sound.play() + yield(hit_sound, "finished") + dead_sound.play() +``` + +Finally need to add the actual checks for when the player dies (like collision with ground or pipe) as well as a function that listens to a signal for when the player goes to the ceiling. + +### WorldDetector + +The code is pretty simple, we just need a way of detecting if we ran out of ground and send a signal, as well as sending as signal when we start detecting ground/pipes behind us (to remove it) because the world is being generated as we move. The most basic functions needed are: + +```gdscript +func _was_colliding(detector: RayCast2D, flag: bool, signal_name: String) -> bool: + if detector.is_colliding(): + return true + if flag: + emit_signal(signal_name) + return false + return true + + +func _now_colliding(detector: RayCast2D, flag: bool, signal_name: String) -> bool: + if detector.is_colliding(): + if not flag: + emit_signal(signal_name) + return true + return false +``` + +We need to keep track of 3 "flags": `ground_was_colliding`, `ground_now_colliding` and `pipe_now_colliding` (and their respective signals), which are going to be used to do the checks inside `_physics_process`. For example for checking for new ground: `ground_now_colliding = _now_colliding(old_ground, ground_now_colliding, "ground_started_colliding")`. + +### WorldTiles + +This script is what handles the "GroundTileMap" as well as the "PipeTileMap" and just basically functions as a "Signal bus" connecting a bunch of signals from the "WorldDetector" with the *TileMaps* and just tracking how many pipes have been placed: + +```gdscript +export(int, 2, 20, 2) var PIPE_SEP: int = 6 +var tiles_since_last_pipe: int = PIPE_SEP - 1 + + +func _on_WorldDetector_ground_stopped_colliding() -> void: + emit_signal("place_ground") + + tiles_since_last_pipe += 1 + if tiles_since_last_pipe == PIPE_SEP: + emit_signal("place_pipe") + tiles_since_last_pipe = 0 + + +func _on_WorldDetector_ground_started_colliding() -> void: + emit_signal("remove_ground") + + +func _on_WorldDetector_pipe_started_colliding() -> void: + emit_signal("remove_pipe") +``` + +#### GroundTileMap + +This is the node that actually places the ground tiles upong receiving a signal. In general, what you want is to keep track of the newest tile that you need to place (empty spot) as well as the last tile that is in the tilemap (technically the first one if you count from left to right). I was experimenting with `enum`s so I used them to define the possible `Ground` tiles: + +```gdscript +enum Ground { + TILE_1, + TILE_2, + TILE_3, + TILE_DOWN_1, +} +``` + +This way you can just select the tile by doing `Ground.TILE_1`, which will correspond to the `int` value of `0`. So most of the code is just: + +```gdscript +# old_tile is the actual first tile, whereas the new_tile_position +# is the the next empty tile; these also correspond to the top tile +const _ground_level: int = 7 +const _initial_old_tile_x: int = -8 +const _initial_new_tile_x: int = 11 +var old_tile_position: Vector2 = Vector2(_initial_old_tile_x, _ground_level) +var new_tile_position: Vector2 = Vector2(_initial_new_tile_x, _ground_level) + + +func _place_new_ground() -> void: + set_cellv(new_tile_position, _get_random_ground()) + set_cellv(new_tile_position + Vector2.DOWN, Ground.TILE_DOWN_1) + new_tile_position += Vector2.RIGHT + + +func _remove_first_ground() -> void: + set_cellv(old_tile_position, -1) + set_cellv(old_tile_position + Vector2.DOWN, -1) + old_tile_position += Vector2.RIGHT +``` + +Where you might notice that the `_initial_new_tile_x` is `11`, instead of `10`, refer to [Default ground tiles](#default-ground-tiles) where we placed tiles from `-8` to `10`, so the next empty one is `11`. These `_place_new_ground` and `_remove_first_ground` functions are called upon receiving the signal. + +#### PipeTileMap + +This is really similar to the "GroundTileMap" code, instead of defining an `enum` for the ground tiles, we define it for the pipe patterns (because each pipe is composed of multiple pipe tiles). If your pipe tile set looks like this (notice the index): + +![PipeTileMap - Tile set indexes](images/g/flappybird_godot/tile_set_pipes_indexes.png "PipeTileMap - Tile set indexes") + +Then you can use the following "pipe patterns": + +```gdscript +var pipe: Dictionary = { + PipePattern.PIPE_1: [0, 1, 2, 2, 2, 2, 2, 2, 3, 4, -1, -1, -1, 0, 1, 2], + PipePattern.PIPE_2: [0, 1, 2, 2, 2, 2, 2, 3, 4, -1, -1, -1, 0, 1, 2, 2], + PipePattern.PIPE_3: [0, 1, 2, 2, 2, 2, 3, 4, -1, -1, -1, 0, 1, 2, 2, 2], + PipePattern.PIPE_4: [0, 1, 2, 2, 2, 3, 4, -1, -1, -1, 0, 1, 2, 2, 2, 2], + PipePattern.PIPE_5: [0, 1, 2, 2, 3, 4, -1, -1, -1, 0, 1, 2, 2, 2, 2, 2], + PipePattern.PIPE_6: [0, 1, 2, 3, 4, -1, -1, -1, 0, 1, 2, 2, 2, 2, 2, 2] +} +``` + +Now, the pipe system requires a bit more of tracking as we need to instantiate a "ScoreDetector" here, too. I ended up keeping track of the placed pipes/detectors by using a "pipe stack" (and "detector stack") which is just an array of placed objects from which I pop the first when deleting them: + +```gdscript +onready var _pipe_sep: int = get_parent().PIPE_SEP +const _pipe_size: int = 16 +const _ground_level: int = 7 +const _pipe_level_y: int = _ground_level - 1 +const _initial_new_pipe_x: int = 11 +var new_pipe_starting_position: Vector2 = Vector2(_initial_new_pipe_x, _pipe_level_y) +var pipe_stack: Array + +# don't specify type for game, as it results in cyclic dependency, +# as stated here: https://godotengine.org/qa/39973/cyclic-dependency-error-between-actor-and-actor-controller +onready var game = get_parent().get_parent() +var detector_scene: PackedScene = preload("res://levels/detectors/score_detector/ScoreDetector.tscn") +var detector_offset: Vector2 = Vector2(16.0, -(_pipe_size / 2.0) * 16.0) +var detector_stack: Array +``` + +The `detector_offset` is just me being picky. For placing a new pipe, we get the starting position (bottom pipe tile) and build upwards, then instantiate a new "ScoreDetector" (`detector_scene`) and set it's position to the pipe starting position plus the offset, so it's centered in the pipe, then just need to connect the "body_entered" signal from the detector with the game, so we keep track of the scoring. Finally just add the placed pipe and detector to their corresponding stacks: + +```gdscript +func _place_new_pipe() -> void: + var current_pipe: Vector2 = new_pipe_starting_position + for tile in pipe[_get_random_pipe()]: + set_cellv(current_pipe, tile) + current_pipe += Vector2.UP + + var detector: Area2D = detector_scene.instance() + detector.position = map_to_world(new_pipe_starting_position) + detector_offset + detector.connect("body_entered", game, "_on_ScoreDetector_body_entered") + detector_stack.append(detector) + add_child(detector) + + pipe_stack.append(new_pipe_starting_position) + new_pipe_starting_position += _pipe_sep * Vector2.RIGHT +``` + +For removing pipes, it's really similar but instead of getting the position from the next tile, we pop the first element from the (pipe/detector) stack and work with that. To remove the cells we just set the index to `-1`: + +```gdscript +func _remove_old_pipe() -> void: + var current_pipe: Vector2 = pipe_stack.pop_front() + var c: int = 0 + while c < _pipe_size: + set_cellv(current_pipe, -1) + current_pipe += Vector2.UP + c += 1 + + var detector: Area2D = detector_stack.pop_front() + remove_child(detector) + detector.queue_free() +``` + +These functions are called when receiving the signal to place/remove pipes. + +### Saved data + +Before proceeding, we require a way to save/load data (for the high scores). We're going to use the *ConfigFile* node that uses a custom version of the "ini" file format. Need to define where to save the data: + +```gdscript +const DATA_PATH: String = "user://data.cfg" +const SCORE_SECTION: String = "score" +var _data: ConfigFile +``` + +Note that `user://` is a OS specific path in which the data can be stored on a per user basis, for more: [File paths](https://docs.godotengine.org/en/stable/tutorials/io/data_paths.html). Then, a way to load the save file: + +```gdscript +func _load_data() -> void: + # create an empty file if not present to avoid error while loading settings + var file: File = File.new() + if not file.file_exists(DATA_PATH): + file.open(DATA_PATH, file.WRITE) + file.close() + + _data = ConfigFile.new() + var err: int = _data.load(DATA_PATH) + if err != OK: + print("[ERROR] Cannot load data.") +``` + +A way to save the data: + +```gdscript +func save_data() -> void: + var err: int = _data.save(DATA_PATH) + if err != OK: + print("[ERROR] Cannot save data.") +``` + +And of course, a way to get and set the high score: + +```gdscript +func set_new_high_score(high_score: int) -> void: + _data.set_value(SCORE_SECTION, "high_score", high_score) + + +func get_high_score() -> int: + return _data.get_value(SCORE_SECTION, "high_score") +``` + +Then, whenever this script is loaded we load the data and if it's a new file, then add the default high score of 0: + +```gdscript +func _ready() -> void: + _load_data() + + if not _data.has_section(SCORE_SECTION): + set_new_high_score(0) + save_data() +``` + +Now, this script in particular will need to be a [Singleton (AutoLoad)](https://docs.godotengine.org/en/stable/tutorials/scripting/singletons_autoload.html), which means that there will be only one instance and will be available across all scripts. To do so, go to *Project -> Project settings... -> AutoLoad* and select this script in the "Path:" and add a "Node Name:" (I used "SavedData", if you use something else, be careful while following this devlog) which will be the name we'll use to access the singleton. Toggle on "Enable" if needed, it should look like this: + +![Project settings - AutoLoad - SavedData singleton](images/g/flappybird_godot/project_settings_autoload_saved_data.png "Project settings - AutoLoad - SavedData singleton") + +### Game + +The game script it's also like a "Signal bus" in the sense that it connects all its childs' signals together, and also has the job of starting/stopping the `_process` and `_physics_process` methods from the childs as needed. First, we need to define the signals and and references to all child nodes: + +```gdscript +signal game_started +signal game_over +signal new_score(score, high_score) + +onready var player: Player = $Player +onready var background: Sprite= $Background +onready var world_tiles: WorldTiles = $WorldTiles +onready var ceiling_detector: Area2D = $CeilingDetector +onready var world_detector: Node2D = $WorldDetector +onready var camera: Camera2D = $Camera +onready var start_sound: AudioStreamPlayer = $StartSound +onready var score_sound: AudioStreamPlayer = $ScoreSound +``` + +It's important to get the actual "player speed", as we're using a scale to make the game look bigger (remember, pixel art), to do so we need a reference to the "game_scale" we setup at the beginning and compute the `player_speed`: + +```gdscript +var _game_scale: float = ProjectSettings.get_setting("application/config/game_scale") +var player_speed: float + + +func _ready() -> void: + scale = Vector2(_game_scale, _game_scale) + # so we move at the actual speed of the player + player_speed = player.SPEED / _game_scale +``` + +This `player_speed` will be needed as we need to move all the nodes ("Background", "Camera", etc.) in the `x` axis as the player is moving. This is done in the `_physics_process`: + +```gdscript +func _physics_process(delta: float) -> void: + ceiling_detector.move_local_x(player_speed * delta) + world_detector.move_local_x(player_speed * delta) + background.move_local_x(player_speed * delta) + camera.move_local_x(player_speed * delta) +``` + +We also need a way to start and stop the processing of all the nodes: + +```gdscript +func _set_processing_to(on_off: bool, include_player: bool = true) -> void: + set_process(on_off) + set_physics_process(on_off) + if include_player: + player.set_process(on_off) + player.set_physics_process(on_off) + world_tiles.set_process(on_off) + world_tiles.set_physics_process(on_off) + ceiling_detector.set_process(on_off) + ceiling_detector.set_physics_process(on_off) +``` + +Where the `player` is a special case, as when the player dies, it should still move (only down), else it would just freeze in place. In `_ready` we connect all the necessary signals as well as initially set the processing to `false` using the last function. To start/restart the game we need to keep a flag called `is_game_running` initially set to `false` and then handle the (re)startability in `_input`: + +```gdscript +func _input(event: InputEvent) -> void: + if not is_game_running and event.is_action_pressed("jump"): + _set_processing_to(true) + is_game_running = true + emit_signal("game_started") + start_sound.play() + + if event.is_action_pressed("restart"): + get_tree().reload_current_scene() +``` + +Then we handle two specific signals: + +```gdscript +func _on_Player_died() -> void: + _set_processing_to(false, false) + emit_signal("game_over") + + +func _on_ScoreDetector_body_entered(body: Node2D) -> void: + score += 1 + if score > high_score: + high_score = score + SavedData.set_new_high_score(high_score) + SavedData.save_data() + emit_signal("new_score", score, high_score) + score_sound.play() +``` + +When the `player` dies, we set all processing to `false`, except for the player itself (so it can drop all the way to the ground). Also, when receiving a "scoring" signal, we manage the current score, as well as saving the new high score when applicable, note that we need to read the `high_score` at the beginning by calling `SavedData.get_high_score()`. This signal we emit will be received by the UI so it updates accordingly. + +### UI + +First thing is to get a reference to all the child *Labels*, an initial reference to the high score as well as the version defined in the project settings: + +```gdscript +onready var fps_label: Label = $MarginContainer/DebugContainer/FPS +onready var version_label: Label = $MarginContainer/VersionContainer/Version +onready var score_label: Label = $MarginContainer/InfoContainer/ScoreContainer/Score +onready var high_score_label: Label = $MarginContainer/InfoContainer/ScoreContainer/HighScore +onready var start_game_label: Label = $MarginContainer/InfoContainer/StartGame + +onready var _initial_high_score: int = SavedData.get_high_score() + +var _version: String = ProjectSettings.get_setting("application/config/version") +``` + +Then set the initial *Label* values as well as making the `fps_label` invisible: + +```gdscript +func _ready() -> void: + fps_label.visible = false + version_label.set_text("v%s" % _version) + high_score_label.set_text("High score: %s" % _initial_high_score) +``` + +Now we need to handle the `fps_label` update and toggle: + +```gdscript +func _input(event: InputEvent) -> void: + if event.is_action_pressed("toggle_debug"): + fps_label.visible = !fps_label.visible + + +func _process(delta: float) -> void: + if fps_label.visible: + fps_label.set_text("FPS: %d" % Performance.get_monitor(Performance.TIME_FPS)) +``` + +Finally the signal receiver handlers which are straight forward: + +```gdscript +func _on_Game_game_started() -> void: + start_game_label.visible = false + high_score_label.visible = false + + +func _on_Game_game_over() -> void: + start_game_label.set_text("Press R to restart") + start_game_label.visible = true + high_score_label.visible = true + + +func _on_Game_new_score(score: int, high_score: int) -> void: + score_label.set_text(String(score)) + high_score_label.set_text("High score: %s" % high_score) +``` + +### Main + +This is the shortest script, it just connects the signals between the "Game" and the "UI": + +```gdscript +onready var game: Game = $Game +onready var ui: UI = $UI + +var _game_over: bool = false + + +func _ready() -> void: + game.connect("game_started", ui, "_on_Game_game_started") + game.connect("game_over", ui, "_on_Game_game_over") + game.connect("new_score", ui, "_on_Game_new_score") +``` + +## Final notes and exporting + +At this point the game should be fully playable (if any detail missing feel free to look into the source code linked at the beginning). Only thing missing is an icon for the game; I did one pretty quicly with the assets I had. + +### Preparing the files + +If you followed the directory structure I used, then only thing needed is to transform the icon to a native Windows `ico` format (if exporting to Windows, else ignore this part). For this you need [ImageMagick](https://imagemagick.org/index.php) or some other program that can transform `png` (or whatever file format you used for the icon) to `ico`. I used [Chocolatey][https://chocolatey.org/] to install `imagemagick`, then to convert the icon itself used: `magick convert icon.png -define icon:auto-resize=256,128,64,48,32,16 icon.ico` as detailed in *Godot*'s [Changing application icon for Windows](https://docs.godotengine.org/en/stable/tutorials/export/changing_application_icon_for_windows.html). + +### Exporting + +You need to download the templates for exporting as detailed in *Godot*'s [Exporting projects](https://docs.godotengine.org/en/stable/tutorials/export/exporting_projects.html). Basically you go to *Editor -> Manage Export Templates...* and download the latest one specific to your *Godot* version by clicking on "Download and Install". + +If exporting for Windows then you also need to download `rcedit` from [here](https://github.com/electron/rcedit/releases/latest). Just place it wherever you want (I put it next to the *Godot* executable). + +Then go to *Project -> Export...* and the Window should be empty, add a new template by clicking on "Add..." at the top and then select the template you want. I used HTML5, Windows Desktop and Linux/X11. Really the only thing you need to set is the "Export Path" for each template, which is te location of where the executable will be written to, and in the case of the Windows Desktop template you could also setup stuff like "Company Name", "Product Name", "File/Product Version", etc.. + +Once the templates are setup, select any and click on "Export Project" at the bottom, and make sure to untoggle "Export With Debug" in the window that pops up, this checkbox should be at the bottom of the new window. diff --git a/src/blog/g/godot_project_structure.md b/src/blog/g/godot_project_structure.md new file mode 100644 index 0000000..3f013cc --- /dev/null +++ b/src/blog/g/godot_project_structure.md @@ -0,0 +1,87 @@ +title: General Godot project structure +author: David Luévano +lang: en +summary: Details on the project structure I'm using for Godot, based on preference and some research I did. +tags: gamedev + short + english + +One of my first issues when starting a project is how to structure everything. So I had to spend some time researching best practices and go with what I like the most and after trying some of them I wanted to write down somewhere what I'm sticking with. + +The first place to look for is, of course, the official *Godot* documentation on [Project organization](https://docs.godotengine.org/en/stable/tutorials/best_practices/project_organization.html); along with project structure discussion, also comes with best practices for code style and what-not. I don't like this project/directory structure that much, just because it tells you to bundle everything under the same directory but it's a really good starting point, for example it tells you to use: + +- /models/town/house/ + - house.dae + - window.png + - door.png + +Where I would prefer to have more modularity, for example: + +- /levels/structures/town/house (or /levels/town/structures/house) + - window/ + - window.x + - window.y + - window.z + - door/ + - ... + - house.x + - house.y + - house.z + +It might look like it's more work, but I prefer it like this. I wish [this site](https://www.braindead.bzh/entry/creating-a-game-with-godot-engine-ep-2-project-organization) was still available, as I got most of my ideas from there and was a pretty good resource, but apparently the owner is not maintaining his site anymore; but there is [this excelent comment on reddit](https://www.reddit.com/r/godot/comments/7786ee/comment/dojuzuf/?utm_source=share&utm_medium=web2x&context=3) which shows a project/directory structure more in line with what I'm currently using (and similr to the site that is down that I liked). I ended up with: + +- /.git +- /assets (raw assets/editable assets/asset packs) +- /releases (executables ready to publish) +- /src (the actual godot project) + - .godot/ + - actors/ (or entities) + - player/ + - sprites/ + - player.x + - ... + - enemy/ (this could be a dir with subdirectories for each type of enemy for example...) + - sprites/ + - enemy.x + - ... + - actor.x + - ... + - levels/ (or scenes) + - common/ + - sprites/ + - ... + - main/ + - ... + - overworld/ + - ... + - dugeon/ + - ... + - Game.tscn (I'm considering the "Game" as a level/scene) + - game.gd + - objects/ + - box/ + - ... + - ... + - screens/ + - main_menu/ + - ... + - ... + - globals/ (singletons/autoloads) + - ui/ + - menus/ + - ... + - ... + - sfx/ + - ... + - vfx/ + - ... + - etc/ + - ... + - Main.tscn (the entry point of the game) + - main.gd + - icon.png (could also be on a separate "icons" directory) + - project.godot + - ... +- \ + +And so on, I hope the idea is clear. I'll probably change my mind on the long run, but for now this has been working fine. \ No newline at end of file diff --git a/src/blog/g/gogodot_jam3_devlog_1.md b/src/blog/g/gogodot_jam3_devlog_1.md new file mode 100644 index 0000000..9e836b1 --- /dev/null +++ b/src/blog/g/gogodot_jam3_devlog_1.md @@ -0,0 +1,724 @@ +title: Creating my Go Godot Jam 3 entry using Godot 3.5 devlog 1 +author: David Luévano +lang: en +summary: Details on the implementation for the game I created for the Go Godot Jam 3, which theme is Evolution. +tags: gamedev + godot + gamejam + english + +The jam's theme is Evolution and all the details are listed [here](https://itch.io/jam/go-godot-jam-3). ~~This time I'm logging as I go, so there might be some changes to the script or scenes along the way~~ ^^I couldn't actually do this, as I was running out of time.^^. Note that I'm not going to go into much details, the obvious will be ommitted. + +I wanted to do a *Snake* clone, and I'm using this jam as an excuse to do it and add something to it. The features include: + +- Snakes will pass their stats in some form to the next snakes. +- Non-grid snake movement. I just hate the grid constraint, so I wanted to make it move in any direction. +- Depending on the food you eat, you'll gain new mutations/abilities ~~and the more you eat the more that mutation develops.~~ ^^didn't have time to add this feature, sad.^^ +- Procedural map creation. + +I created this game using *Godot 3.5-rc3*. You can find the source code in my GitHub [here](https://github.com/luevano/gogodot_jam3) which at the time of writing this it doesn't contain any exported files, for that you can go ahead and play it in your browser at itch.io, which you can find below: + +

+ +You can also find the jam entry [here](https://itch.io/jam/go-godot-jam-3/rate/1562701). + +Similarly with the my FlappyBird clone, I plan to update this to a better state. + +## Initial setup + +Again, similar to the [FlappyBird](https://blog.luevano.xyz/g/flappybird_godot_devlog_1.html) clone I developed, I'm using the directory structure I wrote about on [Godot project structure](https://blog.luevano.xyz/g/godot_project_structure.html) with slight modifications to test things out. Also using similar *Project settings* as those from the *FlappyBird* clone like the pixel art texture imports, keybindings, layers, etc.. + +I've also setup [GifMaker](https://github.com/bram-dingelstad/godot-gifmaker), with slight modifications as the *AssetLib* doesn't install it correctly and contains unnecessry stuff: moved necessary files to the `res://addons` directory, deleted test scenes and files in general, and copied the license to the `res://docs` directory. Setting this up was a bit annoying because the tutorial it's bad (with all due respect). I might do a separate entry just to explain how to set it up, because I couldn't find it anywhere other than by inspecting some of the code/scenes.^^I ended up not leaving this enabled in the game as it lagged the game out, but it's an option I'll end up researching more.^^ + +This time I'm also going to be using an [Event bus](https://www.gdquest.com/docs/guidelines/best-practices/godot-gdscript/event-bus/) singleton (which I'm going to just call *Event*) as managing signals was pretty annoying on my last project; as well as a *Global* singleton for essential stuff so I don't have to do as many cross references between nodes/scenes. + +## Assets + +This time I'll be creating my own assets in [Aseprite](https://www.aseprite.org/), wont be that good, but enough to prototype and get things going. + +Other than that I used few key sprites from [vryell](https://vryell.itch.io/): [Controller & Keyboard Icons](https://vryell.itch.io/controller-keyboard-icons) and a font from [datagoblin](https://datagoblin.itch.io/): [Monogram](https://datagoblin.itch.io/monogram). + +## The snake + +This is the most challenging part in my opinion as making all the body parts follow the head in a user defined path it's kinda hard. I tried with like 4-5 options and the one I'm detailing here is the only one that worked as I wanted for me. This time the directory structure I'm using is the following: + +![FileSystem - Snake dir structure](images/g/gogodot_jam3/file_system_snake_dir_structure.png "FileSystem - Snake dir structure") + +### Basic movement + +The most basic thing is to move the head, this is what we have control of. Create a scene called `Head.tscn` and setup the basic *KinematicBody2D* with it's own *Sprite* and *CollisionShape2D* (I used a small circle for the tip of the head), and set the *Collision Layer/Mask* accordingly, for now just `layer = bit 1`. And all we need to do, is keep moving the snake forwards and be able to rotate left or right. Created a new script called `head.gd` attached to the root (*KinematicBody2D*) and added: + +```gdscript +extends KinematicBody2D + +enum { + LEFT=-1, + RIGHT=1 +} + +var velocity: Vector2 = Vector2.ZERO +var _direction: Vector2 = Vector2.UP + + +func _physics_process(delta: float) -> void: + if Input.is_action_pressed("move_left"): + _rotate_to(LEFT) + if Input.is_action_pressed("move_right"): + _rotate_to(RIGHT) + + velocity = _direction * Global.SNAKE_SPEED + + velocity = move_and_slide(velocity) + _handle_time_elapsed(delta) + + +func _rotate_to(direction: int) -> void: + rotate(deg2rad(direction * Global.SNAKE_ROT_SPEED * get_physics_process_delta_time())) + _direction = _direction.rotated(deg2rad(direction * Global.SNAKE_ROT_SPEED * get_physics_process_delta_time())) +``` + +After tunning all the necessary parameters you should get something like this: + +![Snake - Basic movement (left and right controls)](images/g/gogodot_jam3/snake_basic_movement.gif "Snake - Basic movement (left and right controls)") + +### Setting up path following + +To move other snake parts by following the snake head the only solution I found was to use the *Path2D* and *PathFollow2D* nodes. *Path2D* basically just handles the curve/path that *PathFollow2D* will use to move its child node; and I say "child node" in singular... as *PathFollow2D* can only handle one damn child, all the other ones will have weird transformations and/or rotations. So, the next thing to do is to setup a way to compute (and draw so we can validate) the snake's path/curve. + +Added the signal `snake_path_new_point(coordinates)` to the *Event* singleton and then add the following to `head.gd`: + +```gdscript +var _time_elapsed: float = 0.0 + +# using a timer is not recommended for < 0.01 +func _handle_time_elapsed(delta: float) -> void: + if _time_elapsed >= Global.SNAKE_POSITION_UPDATE_INTERVAL: + Event.emit_signal("snake_path_new_point", global_position) + _time_elapsed = 0.0 + _time_elapsed += delta +``` + +This will be pinging the current snake head position every `0.01` seconds (defined in *Global*). Now create a new scene called `Snake.tscn` which will contain a *Node2D*, a *Path2D* and an instance of *Head* as its childs. Create a new script called `snake.gd` attached to the root (*Node2D*) with the following content: + +```gdscript +class_name Snake +extends Node2D + +onready var path: Path2D = $Path + +func _ready(): + Event.connect("snake_path_new_point", self, "_on_Head_snake_path_new_point") + + +func _draw() -> void: + if path.curve.get_baked_points().size() >= 2: + draw_polyline(path.curve.get_baked_points(), Color.aquamarine, 1, true) + + +func _on_Head_snake_path_new_point(coordinates: Vector2) -> void: + path.curve.add_point(coordinates) + # update call is to draw curve as there are new points to the path's curve + update() +``` + +With this, we're now populating the *Path2D* curve points with the position of the snake head. You should be able to see it because of the `_draw` call. If you run it you should see something like this: + +![Snake - Basic movement with path](images/g/gogodot_jam3/snake_basic_movement_with_path.gif "Snake - Basic movement with path") + +### Define body parts for the snake + +At this point the only thing to do is to add the corresponding next body parts and tail of the snake. To do so, we need a *PathFollow2D* to use the live-generating *Path2D*, the only caveat is that we need one of these per body part/tail (this took me hours to figure out, *thanks documentation*). + +Create a new scene called `Body.tscn` with a *PathFollow2D* as its root and an *Area2D* as its child, then just add the necessary *Sprite* and *CollisionShap2D* for the *Area2D*, I'm using `layer = bit 2` for its collision. Create a new script called `generic_segment.gd` with the following code: + +```gdscript +extends PathFollow2D + +export(String, "body", "tail") var TYPE: String = "body" + + +func _physics_process(delta: float) -> void: + offset += Global.SNAKE_SPEED * delta +``` + +And this can be attached to the *Body*'s root node (*PathFollow2D*), no extra setup needed. Repeat the same steps for creating the `Tail.tscn` scene and when attaching the `generic_segment.gd` script just configure the `Type` parameter to `tail` in the GUI (by selecting the node with the script attached and editing in the *Inspector*). + +### Adding body parts + +Now it's just a matter of handling when to add new body parts in the `snake.gd` script. For now I've only setup for adding body parts to fulfill the initial length of the snake (this doesn't include the head or tail). The extra code needed is the following: + +```gdscript +export(PackedScene) var BODY_SEGMENT_NP: PackedScene +export(PackedScene) var TAIL_SEGMENT_NP: PackedScene + +var current_body_segments: int = 0 +var max_body_segments: int = 1 + + +func _add_initial_segment(type: PackedScene) -> void: + if path.curve.get_baked_length() >= (current_body_segments + 1.0) * Global.SNAKE_SEGMENT_SIZE: + var _temp_body_segment: PathFollow2D = type.instance() + path.add_child(_temp_body_segment) + current_body_segments += 1 + + +func _on_Head_snake_path_new_point(coordinates: Vector2) -> void: + path.curve.add_point(coordinates) + # update call is to draw curve as there are new points to the path's curve + update() + + # add the following lines + if current_body_segments < max_body_segments: + _add_initial_segment(BODY_SEGMENT_NP) + elif current_body_segments == max_body_segments: + _add_initial_segment(TAIL_SEGMENT_NP) +``` + +Select the *Snake* node and add the *Body* and *Tail* scene to the parameters, respectively. Then when running you should see something like this: + +![Snake - Basic movement with all body parts](images/g/gogodot_jam3/snake_basic_movement_added_body_parts.gif "Snake - Basic movement with all body parts") + +Now, we need to handle adding body parts after the snake is complete and already moved for a bit, this will require a queue so we can add part by part in the case that we eat multiple pieces of food in a short period of time. For this we need to add some signals: `snake_adding_new_segment(type)`, `snake_added_new_segment(type)`, `snake_added_initial_segments` and use them when makes sense. Now we need to add the following: + +```gdscript +var body_segment_stack: Array +var tail_segment: PathFollow2D +# didn't konw how to name this, basically holds the current path lenght +# whenever the add body segment, and we use this stack to add body parts +var body_segment_queue: Array +``` + +As well as updating `_add_initial_segment` with the following so it adds the new segment on the specific variable: + +```gdscript +if _temp_body_segment.TYPE == "body": + body_segment_stack.append(_temp_body_segment) +else: + tail_segment = _temp_body_segment +``` + +Now that it's just a matter of creating the segment queue whenever a new segment is needed, as well as adding each segment in a loop whenever we have items in the queue and it's a good distance to place the segment on. These two things can be achieved with the following code: + +```gdscript +# this will be called in _physics_process +func _add_new_segment() -> void: + var _path_length_threshold: float = body_segment_queue[0] + Global.SNAKE_SEGMENT_SIZE + if path.curve.get_baked_length() >= _path_length_threshold: + var _removed_from_queue: float = body_segment_queue.pop_front() + var _temp_body_segment: PathFollow2D = BODY_SEGMENT_NP.instance() + var _new_body_offset: float = body_segment_stack.back().offset - Global.SNAKE_SEGMENT_SIZE + + _temp_body_segment.offset = _new_body_offset + body_segment_stack.append(_temp_body_segment) + path.add_child(_temp_body_segment) + tail_segment.offset = body_segment_stack.back().offset - Global.SNAKE_SEGMENT_SIZE + + current_body_segments += 1 + + +func _add_segment_to_queue() -> void: + # need to have the queues in a fixed separation, else if the eating functionality + # gets spammed, all next bodyparts will be spawned almost at the same spot + if body_segment_queue.size() == 0: + body_segment_queue.append(path.curve.get_baked_length()) + else: + body_segment_queue.append(body_segment_queue.back() + Global.SNAKE_SEGMENT_SIZE) +``` + +With everything implemented and connected accordingly then we can add segments on demand (for testing I'm adding with a keystroke), it should look like this: + +![Snake - Basic movement with dynamic addition of new segments](images/g/gogodot_jam3/snake_basic_movement_with_dynamic_segments.gif "Snake - Basic movement with dynamic addition of new segments") + +For now, this should be enough, I'll add more stuff as needed as I go. Last thing is that after finished testing that the movement felt ok, I just added a way to stop the snake whenever it collides with itself by using the following code (and the signal `snake_segment_body_entered(body)`) in a `main.gd` script that is the entry point for the game: + +```gdscript +func _snake_disabled(on_off: bool) -> void: + _snake.propagate_call("set_process", [on_off]) + _snake.propagate_call("set_process_internal", [on_off]) + _snake.propagate_call("set_physics_process", [on_off]) + _snake.propagate_call("set_physics_process_internal", [on_off]) + _snake.propagate_call("set_process_input", [on_off]) +``` + +Which will stop the snake node and all children. + +### Fix on body segments following head + +After a while of testing and developing, I noticed that sometimes the head "detaches" from the body when a lot of rotations happen (moving the snake left or right), because of how imprecise the *Curve2D* is. To do this I just send a signal (`snake_rotated`) whenever the snake rotates and make a small correction (in `generic_segment.gd`): + +```gdscript +func _on_snake_rotated() -> void: + offset -= 0.75 * Global.SNAKE_SPEED * pow(get_physics_process_delta_time(), 2) +``` + +This is completely random, I tweaked it manually after a lot of iterations. + +## The food + +For now I just decided to setup a simple system to see everything works fine. The idea is to make some kind of generic food node/scene and a "food manager" to spawn them, for now in totally random locations. For this I added the following signals: `food_placing_new_food(type)`, `food_placed_new_food(type)` and `food_eaten(type)`. + +First thing is creating the `Food.tscn` which is just an *Area2D* with its necessary children with an attached script called `food.gd`. The script is really simple: + +```gdscript +class_name Food # needed to access Type enum outside of the script, this registers this script as a node +extends Area2D + +enum Type { + APPLE +} + +var _type_texture: Dictionary = { + Type.APPLE: preload("res://entities/food/sprites/apple.png") +} + +export(Type) var TYPE +onready var _sprite: Sprite = $Sprite + + +func _ready(): + connect("body_entered", self, "_on_body_entered") + _sprite.texture = _type_texture[TYPE] + + +func _on_body_entered(body: Node) -> void: + Event.emit_signal("food_eaten", TYPE) + queue_free() +``` + +Then this `food_eaten` signal is received in `snake.gd` to add a new segment to the queue. + +Finally, for the food manager I just created a `FoodManager.tscn` with a *Node2D* with an attached script called `food_manager.gd`. To get a random position: + +```gdscript +func _get_random_pos() -> Vector2: + var screen_size: Vector2 = get_viewport().get_visible_rect().size + var temp_x: float = randf() * screen_size.x - screen_size.x / 2.0 + var temp_y: float = randf() * screen_size.y - screen_size.y / 2.0 + + return Vector2(temp_x, temp_y) +``` + +Which gets the job done, but later I'll have to add a way to check that the position is valid. And to actually place the food: + +```gdscript +func _place_new_food() -> void: + var food: Area2D = FOOD.instance() + var position: Vector2 = _get_random_pos() + food.global_position = position + add_child(food) +``` + +And this is used in `_process` to place new food whenever needed. For now I added a condition to add food until 10 pieces are in place, and keep adding whenever the food is is lower than 10. After setting everything up, this is the result: + +![Snake - Food basic interaction](images/g/gogodot_jam3/snake_food_basic_interaction.gif "Snake - Food basic interaction") + +## Za warudo! (The world) + +It just happend that I saw a video to create random maps by using a method called [random walks](https://www.mit.edu/~kardar/teaching/projects/chemotaxis(AndreaSchmidt)/random.htm), this video was made by [NAD LABS](https://www.youtube.com/c/NADLABS): [Nuclear Throne Like Map Generation In Godot](https://www.youtube.com/watch?v=ppP2Doq3p7s). It's a pretty simple but powerful script, he provided the source code from which I based my random walker, just tweaked a few things and added others. Some of the maps than can be generated with this method (already aded some random sprites): + +![World map generator - Random map 1](images/g/gogodot_jam3/world_generator_1.png "World map generator - Random map 1") + +![World map generator - Random map 2](images/g/gogodot_jam3/world_generator_2.png "World map generator - Random map 2") + +![World map generator - Random map 3](images/g/gogodot_jam3/world_generator_3.png "World map generator - Random map 3") + +It started with just black and white tiles, but I ended up adding some sprites as it was really harsh to the eyes. My implementation is basically the same as *NAD LABS*' with few changes, most importantly: I separated the generation in 2 diferent tilemaps (floor and wall) to have better control as well as wrapped everything in a single scene with a "main" script with the following important functions: + +```gdscript +func get_valid_map_coords() -> Array: + var safe_area: Array = walker_head.get_cells_around() + var cells_used: Array = ground_tilemap.get_used_cells() + for location in safe_area: + cells_used.erase(location) + return cells_used + + +func get_centered_world_position(location: Vector2) -> Vector2: + return ground_tilemap.map_to_world(location) + Vector2.ONE * Global.TILE_SIZE / 2.0 +``` + +Where `get_cells_around` is just a function that gets the safe cells around the origin. And this `get_valid_map_coords` just returns used cells minus the safe cells, to place food. `get_centered_world_position` is so we can center the food in the tiles. + +Some signals I used for the world gen: `world_gen_walker_started(id)`, `world_gen_walker_finished(id)`, `world_gen_walker_died(id)` and `world_gen_spawn_walker_unit(location)`. + +### Food placement + +The last food algorithm doesn't check anything related to the world, and thus the food could spawn in the walls and outside the map. + +First thing is I generalized the food into a single script and added basic food and special food which inherit from base food. The most important stuff for the base food is to be able to set all necessary properties at first: + +```gdscript +func update_texture() -> void: + _sprite.texture = texture[properties["type"]] + + +func set_properties(pos: Vector2, loc: Vector2, special: bool, type: int, points: int=1, special_points: int=1, ttl: float = -1.0) -> void: + properties["global_position"] = pos + global_position = pos + properties["location"] = loc + properties["special"] = special + properties["type"] = type + + properties["points"] = points + properties["special_points"] = special_points + properties["ttl"] = ttl + if properties["ttl"] != -1.0: + timer.wait_time = properties["ttl"] + timer.start() +``` + +Where the `update_texture` needs to be a separate function, because we need to create the food first, set properties, add as a child and then update the sprite; we also need to keep track of the global position, location (in tilemap coordinates) and identifiers for the type of food. + +Then basic/special food just extend base food, define a `Type` enum and preloads the necessary textures, for example: + +```gdscript +enum Type { + APPLE, + BANANA, + RAT +} + + +func _ready(): + texture[Type.APPLE] = preload("res://entities/food/sprites/apple.png") + texture[Type.BANANA] = preload("res://entities/food/sprites/banana.png") + texture[Type.RAT] = preload("res://entities/food/sprites/rat.png") +``` + +Now, some of the most important change to `food_manager.gd` is to get an actual random valid position: + +```gdscript +func _get_random_pos() -> Array: + var found_valid_loc: bool = false + var index: int + var location: Vector2 + + while not found_valid_loc: + index = randi() % possible_food_locations.size() + location = possible_food_locations[index] + if current_basic_food.find(location) == -1 and current_special_food.find(location) == -1: + found_valid_loc = true + + return [world_generator.get_centered_world_position(location), location] +``` + +Other than that, there are some differences between placing normal and special food (specially the signal they send, and if an extra "special points" property is set). Some of the signals that I used that might be important: `food_placing_new_food(type)`, `food_placed_new_food(type, location)` and `food_eaten(type, location)`. + +## Stats clas and loading/saving data + +I got the idea of saving the current stats (points, max body segments, etc.) in a separate *Stats* class for easier load/save data. This option I went with didn't work as I would liked it to work, as it was a pain in the ass to setup and each time a new property is added you have to manually setup the load/save helper functions... so not the best option. This option I used was json but saving a Node directly could work better or using resources (saving `tres` files). + +### Stats class + +The *Stats* "class" is just a script that extends from *Node* called `stats.gd`. It needs to define the `class_name` as `Stats`. The main content: + +```gdscript +# main +var points: int = 0 +var segments: int = 0 + +# track of trait points +var dash_points: int = 0 +var slow_points: int = 0 +var jump_points: int = 0 + +# times trait achieved +var dash_segments: int = 0 +var slow_segments: int = 0 +var jump_segments: int = 0 + +# trait properties +var dash_percentage: float = 0.0 +var slow_percentage: float = 0.0 +var jump_lenght: float = 0.0 + +# trait active +var trait_dash: bool = false +var trait_slow: bool = false +var trait_jump: bool = false +``` + +And with the ugliest functions: + +```gdscript +func get_stats() -> Dictionary: + return { + "points": points, + "segments": segments, + "dash_points": dash_points, + "dash_segments": dash_segments, + "dash_percentage": dash_percentage, + "slow_points": slow_points, + "slow_segments": slow_segments, + "slow_percentage": slow_percentage, + "jump_points": jump_points, + "jump_segments": jump_segments, + "jump_lenght": jump_lenght, + "trait_dash": trait_dash, + "trait_slow": trait_slow, + "trait_jump": trait_jump + } + + +func set_stats(stats: Dictionary) -> void: + points = stats["points"] + segments = stats["segments"] + dash_points = stats["dash_points"] + slow_points = stats["slow_points"] + jump_points = stats["jump_points"] + dash_segments = stats["dash_segments"] + slow_segments = stats["slow_segments"] + jump_segments = stats["jump_segments"] + dash_percentage = stats["dash_percentage"] + slow_percentage = stats["slow_percentage"] + jump_lenght = stats["jump_lenght"] + trait_dash = stats["trait_dash"] + trait_slow = stats["trait_slow"] + trait_jump = stats["trait_jump"] +``` + +And this is not scalable at all, but I had to do this at the end of the jam so no way of optimizing and/or doing it correctly, sadly. + +### Load/save data + +The load/save function is pretty standard. It's a singleton/autoload called *SavedData* with a script that extends from *Node* called `save_data.gd`: + +```gdscript +const DATA_PATH: String = "user://data.save" + +var _stats: Stats + + +func _ready() -> void: + _load_data() + + +# called when setting "stats" and thus saving +func save_data(stats: Stats) -> void: + _stats = stats + var file: File = File.new() + file.open(DATA_PATH, File.WRITE) + file.store_line(to_json(_stats.get_stats())) + file.close() + + +func get_stats() -> Stats: + return _stats + + +func _load_data() -> void: + # create an empty file if not present to avoid error while loading settings + _handle_new_file() + + var file = File.new() + file.open(DATA_PATH, File.READ) + _stats = Stats.new() + _stats.set_stats(parse_json(file.get_line())) + file.close() + + +func _handle_new_file() -> void: + var file: File = File.new() + if not file.file_exists(DATA_PATH): + file.open(DATA_PATH, File.WRITE) + _stats = Stats.new() + file.store_line(to_json(_stats.get_stats())) + file.close() +``` + +It uses json as the file format, but I might end up changing this in the future to something else more reliable and easier to use (*Stats* class related issues). + +## Scoring + +For this I created a scoring mechanisms and just called it *ScoreManager* (`score_manager.gd`) which just basically listens to `food_eaten` signal and adds points accordingly to the current *Stats* object loaded. The main function is: + +```gdscript +func _on_food_eaten(properties: Dictionary) -> void: + var is_special: bool = properties["special"] + var type: int = properties["type"] + var points: int = properties["points"] + var special_points: int = properties["special_points"] + var location: Vector2 = properties["global_position"] + var amount_to_grow: int + var special_amount_to_grow: int + + amount_to_grow = _process_points(points) + _spawn_added_score_text(points, location) + _spawn_added_segment_text(amount_to_grow) + + if is_special: + special_amount_to_grow = _process_special_points(special_points, type) + # _spawn_added_score_text(points, location) + _spawn_added_special_segment_text(special_amount_to_grow, type) + _check_if_unlocked(type) +``` + +Where the most important function is: + +```gdscript +func _process_points(points: int) -> int: + var score_to_grow: int = (stats.segments + 1) * Global.POINTS_TO_GROW - stats.points + var amount_to_grow: int = 0 + var growth_progress: int + stats.points += points + if points >= score_to_grow: + amount_to_grow += 1 + points -= score_to_grow + # maybe be careful with this + amount_to_grow += points / Global.POINTS_TO_GROW + stats.segments += amount_to_grow + Event.emit_signal("snake_add_new_segment", amount_to_grow) + + growth_progress = Global.POINTS_TO_GROW - ((stats.segments + 1) * Global.POINTS_TO_GROW - stats.points) + Event.emit_signal("snake_growth_progress", growth_progress) + return amount_to_grow +``` + +Which will add the necessary points to `Stats.points` and return the amount of new snake segments to grow. After this `_spawn_added_score_segment` and `_spawn_added_segment_text` just spawn a *Label* with the info on the points/segments gained; this is custom UI I created, nothing fancy. + +Last thing is taht in `_process_points` there is a check at the end, where if the food eaten is "special" then a custom variation of the last 3 functions are executed. These are really similar, just specific to each kind of food. + +This *ScoreManager* also handles the calculation for the `game_over` signal, to calculte progress, set necessary *Stats* values and save the data: + +```gdscript +func _on_game_over() -> void: + var max_stats: Stats = _get_max_stats() + SaveData.save_data(max_stats) + Event.emit_signal("display_stats", initial_stats, stats, mutation_stats) + + +func _get_max_stats() -> Stats: + var old_stats_dict: Dictionary = initial_stats.get_stats() + var new_stats_dict: Dictionary = stats.get_stats() + var max_stats: Stats = Stats.new() + var max_stats_dict: Dictionary = max_stats.get_stats() + var bool_stats: Array = [ + "trait_dash", + "trait_slow", + "trait_jump" + ] + + for i in old_stats_dict: + if bool_stats.has(i): + max_stats_dict[i] = old_stats_dict[i] or new_stats_dict[i] + else: + max_stats_dict[i] = max(old_stats_dict[i], new_stats_dict[i]) + max_stats.set_stats(max_stats_dict) + return max_stats +``` + +Then this sends a signal `display_stats` to activate UI elements that shows the progression. + +Naturally, the saved *Stats* are loaded whenever needed. For example, for the *Snake*, we load the stats and setup any value needed from there (like a flag to know if any ability is enabled), and since we're saving the new *Stats* at the end, then on restart we load the updated one. + +## Snake redesigned with the state machine pattern + +I redesigned the snake code (the head, actually) to use the state machine pattern by following [this guide](https://gdscript.com/solutions/godot-state-machine/) which is definitely a great guide, straight to the point and easy to implement. + +Other than what is shown in the guide, I implemented some important functions in the `state_machine.gd` script itself, to be used by each of the states as needed: + +```gdscript +func rotate_on_input() -> void: + if Input.is_action_pressed("move_left"): + player.rotate_to(player.LEFT) + if Input.is_action_pressed("move_right"): + player.rotate_to(player.RIGHT) + + +func slow_down_on_collisions(speed_backup: float): + if player.get_last_slide_collision(): + Global.SNAKE_SPEED = player.velocity.length() + else: + Global.SNAKE_SPEED = speed_backup + + +func handle_slow_speeds() -> void: + if Global.SNAKE_SPEED <= Global.SNAKE_SPEED_BACKUP / 4.0: + Global.SNAKE_SPEED = Global.SNAKE_SPEED_BACKUP + Event.emit_signal("game_over") +``` + +And then in the *StateMachine*'s `_process`: + +```gdscript +func _physics_process(delta: float) -> void: + # state specific code, move_and_slide is called here + if state.has_method("physics_process"): + state.physics_process(delta) + + handle_slow_speeds() + player.handle_time_elapsed(delta) +``` + +And now it's just a matter of implementing the necessary states. I used 4: `normal_stage.gd`, `slow_state.gd`, `dash_state.gd` and `jump_state.gd`. + +The `normal_state.gd` contains what the original `head.gd` code contained: + +```gdscript +func physics_process(delta: float) -> void: + fsm.rotate_on_input() + fsm.player.velocity = fsm.player.direction * Global.SNAKE_SPEED + fsm.player.velocity = fsm.player.move_and_slide(fsm.player.velocity) + + fsm.slow_down_on_collisions(Global.SNAKE_SPEED_BACKUP) + + +func input(event: InputEvent) -> void: + if fsm.player.can_dash and event.is_action_pressed("dash"): + exit("DashState") + if fsm.player.can_slow and event.is_action_pressed("slow"): + exit("SlowState") + if fsm.player.can_jump and event.is_action_pressed("jump"): + exit("JumpState") +``` + +Here, the `exit` method is basically to change to the next state. And lastly, I'm only gonna show the `dash_state.gd` as the other ones are pretty similar: + +```gdscript +func enter(): + if fsm.DEBUG: + print("Got inside %s." % name) + Event.emit_signal("snake_started_dash") + Global.SNAKE_SPEED = Global.SNAKE_DASH_SPEED + yield(get_tree().create_timer(Global.SNAKE_DASH_TIME), "timeout") + exit() + + +func exit(): + Event.emit_signal("snake_finished_dash") + Global.SNAKE_SPEED = Global.SNAKE_SPEED_BACKUP + fsm.back() + + +func physics_process(delta: float) -> void: + fsm.rotate_on_input() + fsm.player.velocity = fsm.player.direction * Global.SNAKE_SPEED + fsm.player.velocity = fsm.player.move_and_slide(fsm.player.velocity) + + fsm.slow_down_on_collisions(Global.SNAKE_DASH_SPEED) +``` + +Where the important parts happen in the `enter` and `exit` functions. We need to change the `Global.SNAKE_SPEED` with the `Global.SNAKE_DASH_SPEED` on `start`and start the timer for how long should the dash last. And on the `exit` we reset the `Global.SNAKE_SPEED` back to normal. There is probably a better way of updating the `Global.SNAKE_SPEED` but this works just fine. + +For the other ones is the same. Only difference with the `jump_state.gd` is that the collision from head to body is disabled, and no rotation is allowed (by not calling the `rotate_on_input` function). + +## Other minor stuff + +Not as important but worth mentioning: + +- Added restartability function. +- Added signals for game control: `game_over` and `game_start`, but ended not using them. +- Fixed issue where the *Curve2D* stayed the same even when restarting by just setting an empty curve on starting the node. +- Added a debug mode for drawing of the *Curve2D* instead of always drawing. +- Tweaked the tracking of the snake size. +- Tweaked the food system to contain more attributes and use a base food node. +- Added a HUD with mini snake sprites. +- Added a HUD for growth progress on snake body segments and abilities. +- Refactored the nodes to make it work with `change_scene_to`, and added a main menu. +- Added GUI for dead screen, showing the progress. + +## Final notes + +I actually didn't finish this game (as how I visualized it), but I got it in a playable state which is good. My big learning during this jam is the time management that it requires to plan and design a game. I lost a lot of time trying to implement some mechanics because I was facing many issues, because of my lack of practice (which was expected) as well as trying to blog and create the necessary sprites myself. Next time I should just get an asset pack and do something with it, as well as keeping the scope of my game shorter. + +For exporting and everything else, I went with what I did for my [FlappyBird Godot clone](https://blog.luevano.xyz/g/flappybird_godot_devlog_1#final-notes-and-exporting) \ No newline at end of file diff --git a/src/blog/g/starting_gamedev_blogging.md b/src/blog/g/starting_gamedev_blogging.md new file mode 100644 index 0000000..6fc518c --- /dev/null +++ b/src/blog/g/starting_gamedev_blogging.md @@ -0,0 +1,14 @@ +title: Will start blogging about gamedev +author: David Luévano +lang: en +summary: Since I'm starting to get more into gamedev stuff, I'll start blogging about it just to keep consistent. +tags: gamedev + update + short + english + +I've been wanting to get into gamedev for a while now, but it's always a pain to stay consistent. I just recently started to get into gamedev again, and this time I'm trying to actually do stuff. + +So, the plan is to blog about my progress and clone some simple games just to get started. I'm thinking on sticking with [Godot](https://godotengine.org/) just because I like that it's open source, it's getting better and better overtime (big rewrite happening right now) and I already like how the engine works. ~~Specifically I'll start using *Godot 4* even though it's not done yet, to get used to the new features, specifically pumped for [GDScript 2.0](https://godotengine.org/article/gdscript-progress-report-feature-complete-40).~~ ^^Actually... (for the small clones/ripoffs) I'll need to use *Godot 3.X* (probably 3.5), as *Godot 4* doesn't have support to export to webassembly (HTML5) yet, and I want that to publish to [itch.io](https://itch.io/) and my website. I'll continue to use *Godot 4* for bigger projects, as they will take longer and I hope that by the time I need to publish, there's no issues to export.^^ + +For a moment I almost started a new subdomain just for gamedev stuff, but decided to just use a different directory for subtleness; this directory and use of tags should be enough. I'll be posting the entry about the first rip-off I'm *developing* (FlappyBird L O L) shortly. \ No newline at end of file -- cgit v1.2.3-70-g09d2