crystal-bit / angry-aliens

Angry Birds like mobile game. Used for tutorials on how to create a mobile game with Godot 3

Angry Aliens

Angry Aliens is an open source game made with Godot Engine 3.2.1.

Source code is MIT licensed. Feel free to read it, modify it and reuse it in your projects.

Gameplay is definitely inspired by Angry Birds.

Disclaimer

This project is used as a base for video tutorials in Italian. All the source code and documentation is in English. If you are interested, videos are released on my Crystal Bit YouTube channel.

Table of Contents

• Angry Aliens
  • Disclaimer
  • Table of Contents
  • Branches: master, develop and video
  • Prerequisites
  • Tutorial Contents
    • 1. Introduction
    • 2. Configure Godot and Android SDK
    • 3. Testing performances on the smartphone
    • 4. Slingshot
    • 5. Level (for multiple resolutions)
    • 6. Enemies
    • 7. Obstacles
    • [EXTRA] Possible improvements / future topics
  • Credits
  • Thanks
  • Support me

Branches: master, develop and video

• develop branch contains the complete project.Some advanced features may not be included in the master branch.
• master branch will be in sync with video tutorials releases on my YouTube channel.
• videoX/start branches contains the code to follow the tutorial number X. Example:
  • video5/start contains the code to follow the video tutorial 5 on YouTube.

Prerequisites

The tutorials require basic Godot understanding about Scenes, GDScript, 2D Nodes such as Sprite2D, CollisionShape2D, Area2D.

You can learn these topics by:

• reading the official documentation
• following my video tutorial series on Godot 3 basics (only in Italian)

Tutorial Contents

1. Introduction

• 🎥 YouTube - #1 - Introduzione

This tutorial series will focus on creating a simple mobile game using Godot 3.2.

I choose to make an Angry Birds clone because:

1. it is short to recreate (without adding polish)
2. it allows to stress Godot performances on the worst case scenario: intense game (physics based) on a low-power device (smartphone)

I'm creating these tutorials using Manjaro Linux (Arch Linux derivative), but similar steps can be done on other operating systems as well.

Currently I don't have an Apple device and I cannot develop/test iOS/OSX games. I'll try to provide instructions for other OSs, but help here is really appreciated (especially if you are a Debian, Ubuntu, Windows or OSX user).

2. Configure Godot and Android SDK

• 🎥 YouTube - #2 - Configurare Linux
• 🎥 YouTube - #3 - Configurare Windows

How do I configure my computer for Android development?

• android-tools and jdk-openjdk
• debug keystore
• Godot configuration
• Export templates
• APK creation
• APK one click installation

3. Testing performances on the smartphone

• 🎥 YouTube - #4 - Creare il livello
• 🎥 YouTube - #5 - Creare la scena StressTest (pt1)
• 🎥 YouTube - #6 - Stress test (pt.2) - Debugger e profiler
• 🎥 YouTube - #7 - Stress test (pt.3) - Debugging su Android con Remote Debugger

If we include all the physics elements and we create hundreds of game objects, is the game playable?

4. Slingshot

• 🎥 YouTube - #8 - Lancio Proiettili (Pt.1)
• 🎥 YouTube - #9 - TouchScreen Input: Press, Release e Drag - Lancio Proiettili (Pt.2)
• 🎥 YouTube - #10 - input e unhandled_input

How to create a slingshot that reacts on touchscreen and mouse input

• Create a projectile
• Create a simple slingshot
• Input handling for mouse and touchscreen
• Projectile launch
• Load new projectile

5. Level (for multiple resolutions)

• 🎥 #11 - Risoluzioni Multiple (pt1)
• 🎥 #12 - Risoluzioni Multiple (pt2)

• Mobile Layout
• Multiple resolutions handling

6. Enemies

• 🎥 #13 - Quantità di moto e gestione delle collisioni (pt1)

• 🎥 #14 - _integrate_forces: gestione collisioni (pt2)

• Rigid bodies with collision detection

• Enemies destruction

• enemy destroyed signal

7. Obstacles

• 🎥 #15 - Aggiungere ostacoli e generalizzare le collisioni

• Obstacle scene

• Obstacle destruction

• CollisionHandler node to generalize collision physics

[EXTRA] Possible improvements / future topics

Extra topics are available in the develop branch.

They are not tutorialized, but the code should be simple to understand.

More than that, there are still a lot of areas that can be explored like:

• Camera handling (pan, focus, zoom, ...)
• Publishing on a game store
  • Fdroid
  • Play Store
• Managing audio sfx
• Improve the slingshot elastic animation
• Parallax background
• Moving clouds
• Particle effects
• Android modules
• Double tap, drag 'n drop, pinch to zoom,...
• Using Sensors (GPS, accelerometer, light sensor, bluetooth,...)

Credits

• Kenney for most of the game assets - https://www.kenney.nl/
• Hanabi for the slingshot sprites

Thanks

• Crystal Bit community for the continuos support
• Gameloop.it community for the Harvard CS50 gamedev course
• YouAreUto game & team
• Godot Engine Italia

angry-aliens's Issues

Create slingshot sprites

The slingshot is made with 3 brown rectangles.
It's ugly.

It would be nice to make some sprite similar to the 2 references from Angry Birds (the 2nd and 3rd image).

Random error on startup in Develop branch

Sometimes, with low probability, this error is generated when starting from editor:

Running: D:\Work\Virtual Reality\Godot\Godot_v3.2.2-stable_win64\Godot_v3.2.2-stable_win64.exe --path D:/GoogleDrive/_GODOT/Projects/3.2/angry-aliens-develop --remote-debug 127.0.0.1:6007 --allow_focus_steal_pid 3224 --position 485,270
Godot Engine v3.2.2.stable.official - https://godotengine.org
OpenGL ES 2.0 Renderer: AMD Radeon HD 5700 Series
OpenGL ES 2.0 Batching: ON

ERROR: Node not found: Label.
   At: scene/main/node.cpp:1381
ERROR: Node not found: Label.
   At: scene/main/node.cpp:1381
SCRIPT ERROR: _set_btn_text: Invalid set index 'text' (on base: 'null instance') with value of type 'String'.
          At: res://Objects/GUI/Button1/Button.gd:33

Probably due to not fast enough initialization. Sorry, I don't have enough knowledge of Godot to investigate ...

Create level selection menu

Add sounds to the game

Blocked by #11

Generalize the Level scene and Create a new level

Add score counter GUI

Camera: set limits from AreaOfInterest

Make camera follow projectile

Graphic glitch with default settings "Framebuffer Allocation 3D"

With the settings rendering/quality/intended_usage/framebuffer_allocation set to 3D (default value) I have some graphic glitch on the sprites used for the background.
Setting framebuffer_allocation to 2D seems to solve the problem (however I still have to commit this change to the repo).

• Video

It would be interesting to know if this happens on other devices as well.

Image used for background: blue_desert.png, 1024x1024px

System:    Kernel: 5.5.2-1-MANJARO x86_64 bits: 64 Desktop: KDE Plasma 5.17.5 Distro: Manjaro Linux 
Machine:   Type: Laptop System: Dell product: XPS 15 7590 v: N/A serial: <root required> 
           Mobo: Dell model: 0VYV0G v: A00 serial: <root required> UEFI: Dell v: 1.2.3 date: 07/23/2019 
CPU:       Topology: 6-Core model: Intel Core i7-9750H bits: 64 type: MT MCP L2 cache: 12.0 MiB 
           Speed: 4096 MHz min/max: 800/4500 MHz Core speeds (MHz): 1: 4068 2: 4099 3: 4091 4: 4095 5: 4093 6: 4099 7: 4101 
           8: 4098 9: 4086 10: 4100 11: 4097 12: 4091 
Graphics:  Device-1: Intel UHD Graphics 630 driver: i915 v: kernel 
           Device-2: NVIDIA driver: N/A 
           Display: x11 server: X.Org 1.20.7 driver: intel unloaded: modesetting resolution: 1920x1080~60Hz, 1920x1080~60Hz 
           OpenGL: renderer: Mesa DRI Intel UHD Graphics 630 (Coffeelake 3x8 GT2) v: 4.6 Mesa 19.3.3 

Use PoolableNode2D for every pooled object

VFX objects managed by ParticlesManager.gd should use PoolableNode2D and Node2DPool.

• Consider making a global pool
• Free pooled objects on scene change
• Manage orphan nodes

Level end screen: Create 3-stars score GUI

Use pools for particles/debris

assets

Implement camera pan on player touch input

Godot 4 support?

Create main menu and level selection screen

Complete game flow

• Player should be able to throw 3 aliens.
• Player should see a level end screen after clearing the level or after throwing 3 aliens.
  

Scores: add data persistence

English written tutorials?

I'm thinking about doing tutorials also in English. I don't know if I'll have enough time, but still I want to consider this option.

If someone is interested, please let me know here by leaving a thumbs up 👍 or by leaving a comment.

If there is enough interest, I'll create markdown files in a tutorial folder in this repository.

Create/search for sounds

Add persistent trail for previous launched projectiles

Add persistent smoke trail as a reference for the player of the previous launched projectile .

Disable also the trajectory drawer node.

Implement camera pinch to zoom?

Projectile trail effect

• Add projectile sprite trail to improve aesthetic