+ +

Final improvements to the FlappyBird clone and Android support devlog 3

+ +

Decided to conclude my FlappyBird journey with one last set of improvements, following up on devlogs 1 and 2. Focusing on refactoring, better UI, sprite selection and Android support.

I missed some features that I really wanted to get in but I’m already tired of working on this toy project and already eager to move to another one. Most of the features I wanted to add are just QoL UI enhancements and extra buttons basically.

The source code can be found at luevano/flappybirdgodot. Playable at itch.io:

<a href="https://lorentzeus.itch.io/flappybirdgodot">FlappyBirdGodot by Lorentzeus</a>

+ +

Table of contents¶

Table of contents
Refactoring
Improvements
- Background parallax
- Sprite switcher
- Save data
+
Android
Misc

Refactoring¶

The first part for my refactor was to move everything out of the src/ directory into the root directory of the git repository, organizing it a tiny bit better, personal preference from what I’ve learned so far. I also decided to place all the raw aseprite assets next to the imported one, this way its easier to make modifications and then save directly in the same directory. Also, a list of other refactoring done:

The way I handled the gameplay means that I needed to make the camera, background and the (ceiling and tiles) “detectors” move along with the player, while restricting their movement in the x axis, really hacky. Instead, I did what I should’ve done from the beginning… just let the tiles move backwards and keep everything static with the player only moving up an down (as how I stated at the beginning of FlappyBirdgodot devlog 1 but didn’t actually follow).
Moved the set_process methodology to their own scripts, instead of handling everything in main.gd while also taking advantage of how signals work now. Instead of doing:

func _ready():
+    Event.game_pause.connect(_on_game_pause)
+
+func _on_game_pause(pause: bool):
+    set_process(pause)
+

Just connecting to set_process is enough:

func _ready():
+    Event.game_pause.connect(set_process)
+    # and when the signal doesn't send anything:
+    Event.game_start.connect(set_process.bind(true))
+    Event.game_over.connect(set_process.bind(false))
+

Improvements¶

Background parallax¶

First thing was to add a moving background functionality, by adding 2 of the same Sprite2D‘s one after another and everytime the first sprite moves out of the screen, position it right after the second sprite. Some sample code to accomplish this:

func _ready():
+   # Sprite2D and CompressedTexture2D nodes
+   background_orig.texture = background_texture
+   texture_size = background_orig.texture.get_size()
+
+   backgrounds.append(background_orig.duplicate())
+   backgrounds.append(background_orig.duplicate())
+   backgrounds[1].position = background_orig.position + Vector2(texture_size.x, 0.0)
+
+   add_child(backgrounds[0])
+   add_child(backgrounds[1])
+   background_orig.visible = false
+
+# ifirst (index first) it's a boolean value starting with false and
+#   its a hacky way of tracking the first sprites
+#   (the one closest to the left of the screen) in the array
+func _process(delta: float):
+    for background in backgrounds:
+        background.move_local_x(- SPEED * delta)
+
+    # moves the sprite that just exited the screen to the right of the upcoming sprite
+    if backgrounds[int(ifirst)].position.x <= - background_orig.position.x:
+        backgrounds[int(ifirst)].position.x = backgrounds[int(!ifirst)].position.x + texture_size.x
+        ifirst = !ifirst
+

Then I added background parallax by separating the background sprites in two: background and “foreground” (the buildings in the original sprites). And to move them separately just applied the same logic described above with 2 different speeds.

Sprite switcher¶

Also added a way to select between the bird sprites and the backgrounds, currently pretty primitive but functional. Accomplished this by holding textures in an exported array, then added a bit of logic to cycle between them (example for the background):

func _get_new_sprite_index(index: int) -> int:
+    return clampi(index, 0, background_textures.size() - 1)
+
+
+func _set_sprites_index(index: int) -> int:
+    var new_index: int = _get_new_sprite_index(index)
+    if new_index == itexture:
+        return new_index
+    for bg in backgrounds:
+        bg.texture = background_textures[new_index]
+    for fg in foregrounds:
+        fg.texture = foreground_textures[new_index]
+    itexture = new_index
+    return new_index
+

Then, in custom signals I just call _set_sprites_index with a texture_index +/- 1.

Save data¶

Moved from manual ConfigFile (which is an .ini file basically) to Resource which is easier to work with and faster to implement.

Accomplished by defining a new data_resource.gd:

class_name DataResource
+extends Resource
+
+@export var high_score: int
+@export var volume: float
+@export var mute: bool
+@export var bird: int
+@export var background: int
+
+func _init():
+    high_score = 0
+    volume = 0.5
+    mute = false
+    bird = 0
+    background = 0
+

Where the @exports are not needed unless you need to manage the .tres resource files for testing in-editor.

Then, the data.gd script needs to be changed accordingly, most notably:

The file extension is .tres instead of .cfg.
No need for “config sections”.
Saving changes to:

func save():
+    var err: int = ResourceSaver.save(_data, DATA_PATH)
+    if err != OK:
+        print("[ERROR] Couldn't save data.")
+

The loader gets simplified (mostly because the default values are set in the _init() function of the data_resource.gd) to:

func _load_data():
+    if ResourceLoader.exists(DATA_PATH):
+        _data = load(DATA_PATH)
+    else:
+        _data = DataResource.new()
+        save()
+

The attributes/config/saved data can be retrieved directly by the data_resource.gd variable name, for example: instead of _data.get_value(SCORE_SECTION, "high_score") it’s now simply _data.high_score. And similar for setting the values.

Compared to the 3.x version it is a lot more simple. Though I still have setters and getters for each attribute/config (I’ll se how to change this in the future).

Android¶

I did add android support but it’s been so long since I did it that I actually don’t remember (this entry has been sitting in a draft for months). In general I followed the official guide for Exporting for Android, setting up Android studio and remotely debugging with my personal phone; it does take a while to setup but after that it’s as simple as doing “one click deploys”.

Most notably, I had to enable touch screen support and make the buttons clickable either by an actual mouse click or touch input. Some of the Project Settings that I remember that needs changes are:

display/window/handheld/orientation set to Portrait.
input_devices/pointing/emulate_touch_from_mouse and input_devices/pointing/emulate_mouse_from_touch both set to on.

Misc¶

Found a bug on the ScoreDetector where it would collide with the Ceiling. While this is really not a problem outside of me doing tests I fixed it by applying the correct layer/mask.

+ +

+ + + + + Index + + + + + + + Previous + + +

+ + +

By David Luévano

Created: Fri, Mar 01, 2024 @ 10:00 UTC

Modified: Fri, Mar 01, 2024 @ 10:11 UTC

Tags: +english, gamedev, gdscript, godot

+ +

While the complete answer is the first, as that is how layers work, the second can be used like a rule: 1) the layer is where the object lives, while 2) the mask is what the object will detect.

2023

Table of contents¶

Refactoring¶

Improvements¶

Background parallax¶

Sprite switcher¶

Save data¶

Android¶

Misc¶

Articles

2023

2024

2023

Articles

2023

2024

2023

2022

Articles

2023

2024

2023

2022

Articles

2023

2024

2023

2022

Final improvements to the FlappyBird clone and Android support devlog 3

Table of contents¶

Refactoring¶

Improvements¶

Background parallax¶

Sprite switcher¶

Save data¶

Android¶

Misc¶

Articles

2023

2024