Rantz Spatial2D

A 2d transform system for the Bevy game engine that supports Transform propogation controls.

Core Types

Position2D

The Position2D struct represents a 2D point in space. It has two fields: x and y, representing the Cartesian coordinates of the point.

Rotation2D

The Rotation2D struct represents a 2D rotation. It can be used with either radians or degrees.

Scale2D

The Scale2D struct represents a 2D scale. It has two fields: x and y, representing the scale factors for the x and y axes respectively.

SpatialBundle2D

The SpatialBundle2D struct represents the spatial state of a transform in 2D. It contains a Position2D, Rotation2D, and Scale2D. It provides a convenient way to store and manipulate the spatial state of your game objects.

When you add a SpatialBundle2D to an entity, it will also automatically add a SpatialBundle, making it easy to use the spatial 2D system with Bevy's built-in transform system.

DrawOrder

The DrawOrder struct is used to specify the draw layering of entities in your game. It is a wrapper over an f32, with higher values drawing above lower values.

Propogation Types

The following enums are used to control how the spatial components of an entity are propogated to its children.

PositionPropogation

The PositionPropogation enum has two variants:

Relative: **[Default]**The position of a child entity is relative to its parent's position.

Absolute: The position of a child entity is absolute and does not take into account its parent's position.

RotationPropogation

The RotationPropogation enum has two variants:

Relative: **[Default]**The rotation of a child entity is relative to its parent's rotation.

Absolute: The rotation of a child entity is absolute and does not take into account its parent's rotation. By default, both PositionPropogation and RotationPropogation are set to Relative.

ScalePropogation

The ScalePropogation enum has two variants:

Relative: **[Default]**The rotation of a child entity is relative to its parent's rotation.

Absolute: The rotation of a child entity is absolute and does not take into account its parent's rotation.

Compasses

In addition to the above, and not included in the SpatialBundle2D are Compass, CompassRose, and CompassHalfwinds. It is very common in 2D games to need to know the compass direction a given entity is facing in order to choose which sprite to draw. These enums can be included as a component on anything with a Rotation2D, and as part of transform propogation, there values will be updated to match the objects rotation.

Feature Flags

• bevy - Adds systems to update Bevys internal transform based on the contents of SpatialBundle2D, and a plugin to manage said systems, register types, etc.
• serde - Adds impls for serde:Serialize and serde:Deserialize

Default: bevy

Usage

Add the crate to your Cargo.toml

If using bevy, add SpatialPlugin2D to your app.