crystal-bit / hacktoberfest-2020

Create a videogame collaboratively during Hacktoberfest 2020 by implementing a 2D tower defense game.

Tower Defense game - Hacktoberfest 2020

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UPDATE

⚠ This repository is now freezed.

If you want to contribute to this Tower Defense game go to the defending-todot fork

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ORIGINAL README:

Defending Todot it's an open source tower defense game inspired by Kingdom Rush.

It has been created for people who want to practice game development collaboratively while partecipating to the Hacktoberfest 2020.

Made with the open source Godot Engine v3.2.3.

🎮 Play it now

• Browser HTML5
• Linux / Windows / Mac builds

Discuss with the community

Join the Discord server

How to appear in the game credits

Before making a pull request, consider adding yourself to the credits.gd script so that you will appear in the game credits!

Project conventions

Lower case letters only for filenames

To avoid issues when multiple contributors are working on the same project across various file systems and operating systems. See more details here.

Node names

Use CamelCase style for node names.
This is the default style used in Godot and, moreover, it's easier to reference node names which don't have dash symbol or whitespaces in their name (see this comment)

Code style

There are no strict requirements on code style, but try to be consistent with the code that you'll find.

Ideally the code should follow the official GDScript style guide.

For the order of variables, signals, functions, please follow this order (simplified from GDQuest's guidelines):

1.  Extends and class_name
2.  """docstring"""

3.  Signals
4.  Node dependencies
5.  Constants
6.  Variables (properties)

7.  Built-in virtual callbacks (eg: \_ready, \_input, \_process, ...)
8.  Signal callbacks (eg: on_button_pressed, on_area_entered, on_body_entered, ...)
9.  Methods

Reference Kingdom Rush gameplay

• https://www.youtube.com/watch?v=kHcO2NFInuY
• https://www.youtube.com/watch?v=dZ56Y2FYYU0

License

• Code: GPLv3
• Assets CC-BY
• Kenney assets are released under CC0
  • https://www.kenney.nl/assets/topdown-tanks-redux
  • https://www.kenney.nl/assets/tower-defense-top-down

hacktoberfest-2020's Issues

Find a new font

Find a font that fits well with the current assets.

Implement Tower.fire() method

Implement Tower.fire() method: https://github.com/crystal-bit/hacktoberfest-2020/blob/master/scenes/tower/tower.gd#L112

Towers already detect enemies in range. We need the towers to fire missiles/bullets to enemies.
Dealing HP damage will be implemented in another issue.

Implement enemy path navigation from the spawn point to the HitArea

Enemies need a logic to move from the start point (the spawn point) to the hit area.

Fix z-order of enemy HP bars

Create Tower scene

After #11, create a Turret scene.

The Turret will be created on StrategicPointMenu tower_selected signal defined in #7.

Requirements:

• A Sprite node. Ideally the Tower will set the Sprite texture depending on its type (probably sent via the tower_selected signal)

Things to keep in mind (we still need to clearly define the design of the towers):

• Some tower types may use a Rally point to deploy troops
• Some tower types may have a range attack

Implementation is open to discuss.

Fix turret and missile rotation

Turret and missiles should be rotated to face the target enemy.

Should we rename Ammo to Projectile?

https://github.com/crystal-bit/hacktoberfest-2020/tree/master/scenes/ammo

Create a license warning for users making pull requests

Investigate Github Pull Request templates

Create enemy scene

Create an enemy scene that will be expanded in the future to support the various types defined in the game design document: https://github.com/crystal-bit/hacktoberfest-2020/blob/master/docs/gdd.md#enemies

Note that we still have to define enemy behavior. Feel free to discuss it here.

If you don't find any good sprite to use, feel free to use placeholder sprites (eg: a colored rectangle).

If you want further details, feel free to ask.

Tower and Enemy resources lose the Texture property on import

Steps to reproduce:

1. Clone the repo git clone https://github.com/crystal-bit/hacktoberfest-2020.git
2. Open with Godot (it will import all the assets)
3. Open a Tower or Enemy resource in the inspector

Expected result:
Tower and Enemy resources load the correct textures as specified in the import files.

Eg: scenes/tower/tower_types/sniper_1.tres should load "res://assets/sprites/tower-defense-top-down/png/tower-defense_tile249.png"

Current behaviour:
Tower and Enemy resources lose the texture references.

This is confirmed as well looking at the git status:

Note
If, after importing all the assets, you close Godot and reset the repository using git reset --hard and you open again the project, the issue is fixed and the resources are in place.

Define turret and troop types

1. How many Turrets we want to support?
2. What kind of Troops will they spawn?
3. What are the advantages/disadvantages in combat between each Troop vs Enemy? (see #12)
4. Which stats will the Troops have (hp, attack, range, speed, cost)?

Requirements:

• Update the game design document with the new information

In Kingdom Rush it seems there are 4 types of Turrets that allow to spawn 4 troops.

Handle the enemy deletion (queue_free) when enemies reach player base

Add a graphical feedback for the press state in the credits scene

I would add a circular texture progress as @davcri asked in #38.

Create battle music theme

We need at least one music battle theme to be played during the gameplay scene.

The game's theme will be military, read the game design document for more info.

Add a "bodies in range" array in the tower script

I would add an array to preserve all the bodies in the tower's range. It can be useful for adding a tower that can shoot multiple enemies and for resolving many bugs, for example if an enemy is faster than another. Since it is easy to implement, I can do this issue with another one.

Balance enemies, waves, turrets stats (speed, hp, attack rate,...)

Only after #32 is done and we have a currency system in place, tweak the values of the game entities to have a balanced level1.

It should be simple to let the player understand the game flow. Then we can have a more challenging level 2, 3 and so on.

Create TowerDescription popup element

A TowerDescription is a popup menu that appears when a slot of StrategicPointMenu is pressed (see #5).

Requirements:

• Create a TowerDescription scene
• It should show Tower data (Name, Description, Speed, Attack Power)

Future work

We will need to check the spawn position of the TowerDescription popup to make sure that there is enough space to show all of its content. Should we set a max width and height for this element?

Decide game title

This project needs a title!
I would say to wait till we have some gameplay in-place or a game pitch to assign any title (we will change this repository name, probably). However if you have any idea, feel free to propose it.

Localization

For the usability of a game / program the language localization is very important to me

Update gameplay.tscn to support multiple levels

After Level1 is created (#10), we need to update gameplay.tscn to allow for loading multiple levels.

Requirements:

• create a placeholder node (eg: LevelPlacholder) that will be used to instantiate the correct level based on passed parameters from a LevelSelection scene (we still need to create this, for now you can assume that we are always loading the first level)
• by default, the placeholder node should show the content of Level1

Hint: you can take a look at how the LevelBase scene is implemented in angry-aliens in the develop branch: https://github.com/crystal-bit/angry-aliens/tree/develop

Add logic to StrategicPointMenu slots

After #5 is done, we need to add slot logic:

• when a slot is pressed:
  • it should open a TowerDescription popup menu
  • it should change the state of the pressed slot. Graphically it should highlight or change the slot texture.
• when a slot is pressed and it's highlighted and the user has enough money to buy the tower:
  • it should dispatch a signal (eg: tower_selected).

Connect sound effects to UI events

We have some sfx from issue #36 that we need to connect to UI events.

Also we need to add the music battle theme to the gamplay scene.

We still lack some sfx so I would say: let's wait for all the sounds to be ready before adding them.

Wrong tower name in TowerDescriptionPopup

The tower name that appears in TowerDescriptionPopup doesn't seem in sync with what appears in the Slot.
See attached picture.

Improve Level 1 aesthetic

Currently level1 layout is fine, but it can be improved by placing some graphic element in the scene (maybe also slightly animated to simulate a wind effect).

• Add grass, trees, improve tiles

If you want to create new level tiles, feel free to open a new issue.

The current state of Level1 (at the time of writing) is:

Add descriptions to Tower_Resource

Tower_Resource does not have a description property.

• Add the property and update the existing resources with some description
• Update strategic-point.gd : _on_slot_activated to use the new description property, so that the popup will be initialized correctly

Remember to take inspiration from what we currently have in the GDD.

@vittorio-del-bianco if you have some ideas for the descriptions feel free to write them here!

Add enemy detection to Tower

Add enemy detection logic to the Tower:

1. the tower should detect objects (enemies) that are inside the Attack Range
2. once an enemy enters the Attack Range, the tower should change state to something like ATTACKING and it should save the target enemy in a variable
3. once the ATTACKING state is started, a timer should be started as well to call a fire method periodically according to the tower's rate of fire

The fire method is optional, we can do it in another issue.

note: Enemies are going to extend the Enemy class which is a KinematicBody2d. I'm working on Enemies in #28. However this can be tested even without the enemy scene itself.

Update Game Design Document with main game flow mechanics

We need to specify in the gdd some main game mechanics such as:

• What happens when an Enemy reaches the BaseArea/HitArea (HitArea is the name currently used in the Level1 scene)
• How the player gains money?
• Where the strategic points can be placed?
• Which input peripherals should the game support?
• Should the towers be destroyable by the player? (eg: remove a tower to place another tower type)
• probably other stuff too...

Create banner image for the README

Create credits scene

I would like to have a credits scene with all the contributors of the project.

Ideally every contributor will add their name to the credits scene when making a Pull Request.

Feel free to propose a layout.

Create sound effects for UI events

We need some audio effects for the UI events.
You can create them or search for assets compatible with the project licensing.

Some suggestions: Kenney has a CC0 UI asset pack here https://www.kenney.nl/assets/ui-audio
Nice online tool to generate chiptune sfx https://jfxr.frozenfractal.com/

On menu.tscn:

• Button pressed

On map.tscn:

• Level locked
• Level selected

On gameplay.tscn:

• StrategicPoint pressed
• Slot pressed
• Tower selected, positive sound (to play when the player has enough money to buy it)
• Tower selected, negative sound (to play when the player doesn't have enough money to buy it)

Implement enemy waves logic

This depends on #28.

Each level needs data about enemy waves.
See gdd for reference: https://github.com/crystal-bit/hacktoberfest-2020/blob/master/docs/gdd.md#enemy-waves

For now it's okay to just work on level1, but keep in mind that the code will need to be extended for the other levels.

Create level 1 scene

Since this will be the first level, use a simple layout. We will create more complex levels afterward.

Requirements:

• create Level1 scene
• create the level graphic (road, grass, trees,...)
  • we already have some assets. If you want to create new level tiles, open a new issue.
• add a spawn point*
• create a navigation path for the enemies*
• create one hitarea* (the area that the player needs to defend)

*Logic for the spawn point, navigation path and the hit area will be implemented in the future.

Future Work

• add various StrategicPoints
• at at least a spawn point for enemies
• add level data for enemy waves
• add logic for enemy waves

Create StrategicPoint scene

A StrategicPoint is a point where the the player can build a tower. It is detailed in this screenshot taken from Kingdom Rush:

Video gameplay here: https://youtu.be/kHcO2NFInuY

Requirements:

• Create a StrategicPoint scene
• It should open the StrategicPointMenu on pressing an activation area
• It should hide the StrategicPointMenu on pressing outside an activation area

Create HP bar for enemies

Create an HP bar for the enemy scene.

Something like:

This will be used to show enemy's hp after #71 is implemented.

Add "call enemy wave" button

This depends on #56.

Add an interactive widget to call the next wave.

Add missing properties to Enemy resource

Add missing stats to the enemy resource.

• add properties like hp, armor, regen, speed, damage, money dropped.
  See the game design document for more info.
• add update the specific enemies' resources (see enemy/enemy-types/)
• [optional] update missing enemy textures. Feel free to open a new issue if you need new assets

Update StrategicPoint and complete tower buying flow

Once #32 is done, we need to complete the buy_tower method in strategic-point-menu.gd.

It should:

• close the StrategicPointMenu
• remove money from the player
• disable input (in the future we should implement a logic to show an tower upgrade menu)

Also we need to improve the behaviour of the StrategicPoint:

• close the StrategicPointMenu by clicking outside of it
• when the user closes the StrategicPointMenu and they didn't buy the tower, make sure that the tower is removed
  • eg: click on the StrategicPointMenu, click on a Slot to preview the tower, click again on the StrategicPointMenu to hide the menu. Now the tower should not be visible

Stop the credits scene with ESC

Once the game is complete, the credit list will be very long.
I would like to add the functionality to stop it and return to the main menu by pressing ESC.

Guidelines

In general, feel free to discuss anything.
You can comment on already existing issues or open new ones.

Assets

Many issues will require assets that are not available in the repository. In these cases you have 2 options:

1. ask other contributor to find/create the asset by creating a new issue
   • while you wait for the assets, you can use placeholders and work on the issue (eg: default Godot control nodes, squares, etc)
   • you can ask for help on the Discord server
2. find/create the assets yourself

Creating new assets

For audio files: use wav or ogg.
Also read these guidelines on the official Godot documentation.

Assigning issues

Leave a comment in the issue that you want to work on, and I'll assign the issue to you.

Wait for dependent issues

To minimize merge conflicts, avoid working on an issue that depends on another one. It's better to wait for the blocking issue to be implemented first.

Define Enemy types

1. How many Enemies we want to support?
2. Define stats for each Enemy (hp, speed, range, type)

Requirements:

• Update the game design document with the new information

Some enemy in Kingdom Rush:

Create a layer for the UI with a money & hp counter, pause button

Note that in game.gd we already have a variable to keep track of player's money.

Reference image from Kingdom Rush (feel free to experiment with different layouts if you want):

Future work:

• wave gui indicator

Add background music to main menu

We have some new audio files created specifically for the main menu that we need to integrate: #73

Update SlotBottomRight to be inactive and set a "locked" image

We now have 3 tower types but we have 4 slots in the strategic point menu scene. I simple solution would be to block the 4th slot (SlotBottomRight) and show an image to tell the player that the slot could be unlocked in the future.

Make sure that input is disabled on the button.

Update SlotButton to show a "Buy" image

We need a more explicit way to show how to buy a tower.
We currently have a white decoration that is not really intuitive. We could use a texture with an icon and/or a "Buy" text.

In Kigndom Rush is handled in this way:

Add credits button to the main menu

I implemented the credits scene in #2, now we need to add a button the main menu in order to load the credits scene.

Requirements:

• Create a new "Credits" button in the main menu
• Load the credits scene
• Remember to add yourself to the contributors list in the credits.gd script!
• Once the credits are finished, make the game return to the main menu

Replace the current call enemies button with "EnemyCallButton" scene

Create StrategicPointMenu scene

A StrategicPointMenu is the menu opened by pressing on a StrategicPoint (see #4).

Video gameplay here: https://youtu.be/kHcO2NFInuY

Requirements:

• Create a StrategicPointMenu scene
• It should have multiple interactive slots (it's okay to have 4 slots like Kingdom Rush. Currently we still have to decide how many tower types we will support)
  • each slot should show an icon and tower cost

Slot logic will be handled in another issue.

Create level selection scene

You have freedom to experiment different layouts. The basic requirement is to have the possibility to load levels defined in scenes/gameplay/levels/.

The "Start" button on main menu should load this level selection scene.

Future work

• implement level completed persistence
• load save file and mark completed levels as done

Reference from Kingdom Rush

Video reference: https://youtu.be/kHcO2NFInuY?t=14

Refactoring enemy queue_free()

Write a pitch and story for the game

Create a short pitch and story setting for the game.

Please keep in mind that probably we are going to use these free assets: https://github.com/crystal-bit/hacktoberfest-2020/tree/master/assets/sprites

Radical changes in the game aesthetic should be discussed with other developers in a separate issue or on the Discord server.

Requirements:

• Update the game design document