Ashley ECS libGDX 2D Extensions

A set of Ashley ECS components and systems that are generic, and useful for 2D games built with libGDX.

Features

• Provides the basic Components needed for all included Systems
• Included Components are going to be useful for many of your game-specific Systems as well
• Supports GWT, just include the -sources jar in your html project and add the node below to your GdxDefinition.gwt.xml and GdxDefinitionSuperdev.gwt.xml files

<inherits name='AshleyExtensions' />

Included Systems

Animation System

• Uses libGDX Animation class

• Supports different states using the StateComponent

• Supports switching from Looping to not Looping through the StateComponent

• Example usage:

  //TODO: Provide Example Usage

Gravity System

• Takes in a Vector2 for world gravity

• Applies gravity to Entities with the VelocityComponent

• Ignores Entities with the KinematicComponent -Example Usage:

  //TODO: Provide Example Usage

Movement System

• Updates the TransformComponent.position vector based on the Entities VelocityComponent

• Example Usage:

  //TODO: Provide Example Usage

Rendering System

• Renders the Entity's TextureComponent's TextureRegion

• Rendering properties are based on the TransformComponent

• Uses the TextureRegion's size to determine origin

• Based off of the Ashley Super Jumper example project

• TODO: Allow for "constrain to Bounds" or "Render Size" component

• Example Usage:

  //TODO: Provide Example Usage

Bounds System

• Updates an Entity's BoundComponent position based on TransformComponent

• Example Usage:

  //TODO: Provide Example Usage

Debug System

• Renders Center point of Entity based on Bounds

• Renders the BoundComponent bound for an Entity

• Should be added AFTER the RenderingSystem

• Defaults to Toggling on/off via TAB key

• Key(s) for toggling can be overridden in constructor

• Example Usage:

  //TODO: Provide example usage

Health Rendering System

• Renders Health Bars for Entitys with HealthComponent

• Requires a BoundsComponent at the moment

• TODO: Add support for a WidthComponet or something else to control size

• Currently changes from GREEN, YELLOW, RED, with shifts at 75%, and 50% health

• TODO: Add support for custom color and shift percentage points

• Example Usage:

  //TODO: Provide Example Usage

Rotation System

• Rotates entities at their given speed

• Supports a targetRotation so you can rotate to a specific rotation amount

  • Supports values larger than 360 degrees in targetRotation to allow for scenarios like "rotate 3 times" via the RotationComponent
  • Removes the RotationComponent from the entity once reaching the target Rotation

• Example Usage:

  //TODO: Provide Example Usage

Example Application

An example application is included under the /example folder. You can run this example with the gradle command:

./gradlew example:run

Included in the example are 4 Screens:

Screen 1

Access by hitting 1.

This screen shows basic rotation, color tweening, text rendering with colors, and a particle emitter.

Hit space to toggle the particle emissions.

Screen 2

Access by hitting 2

This screen shows several position and transform based tweening operations simultaneously.

Screen 3

Access by hitting 3

This screen shows the bounds system. You can hit Tab to render the bounds of various items, and the paths between their rotation origins.

Screen 4

Access by hitting 4

This shows an example of the physics system, and a "player" you can control with WASD.