Struct RectPackAtlas

Implementation of the rectangles packing atlas into 2D atlas with padding. Uses simple space division via Binary Tree but stored in a linear memory allocation.

Implementation based on https://github.com/TeamHypersomnia/rectpack2D?tab=readme-ov-file#algorithm and https://blackpawn.com/texts/lightmaps/default.html.

RectPackAtlas
Assembly: FlaxEngine.dll
File: Engine/Utilities/RectPack.h
Syntax
public struct RectPackAtlas<NodeType, NodesMemoryChunkSize>
Type Parameters
NodeType

NodesMemoryChunkSize

Fields

BordersPadding

Declaration
public Size BordersPadding = 0
Field Value
Size

Height

Declaration
public Size Height = 0
Field Value
Size

Nodes

Declaration
public ChunkedArray<NodeType, NodesMemoryChunkSize> Nodes
Field Value
ChunkedArray<NodeType, NodesMemoryChunkSize>

Width

Declaration
public Size Width = 0
Field Value
Size

Methods

Clear()

Clears the atlas. This won't invoke OnFree for atlas tiles.

Declaration
public void Clear()

Free(NodeType* node, Args&& ... args)

Frees the node.

Declaration
public void Free(NodeType* node, Args&& ... args)
Parameters
NodeType node

The node to remove from atlas.
Args... args

Type Parameters
Args

Init(Size atlasWidth, Size atlasHeight, Size bordersPadding = 0)

Initializes the atlas of a given size. Clears any previously added nodes. This won't invoke OnFree for atlas tiles.

Declaration
public void Init(Size atlasWidth, Size atlasHeight, Size bordersPadding = 0)
Parameters
Size atlasWidth

The atlas width (in pixels).
Size atlasHeight

The atlas height (in pixels).
Size bordersPadding

The nodes padding (in pixels). Distance from node contents to atlas borders or other nodes.

Insert(Size width, Size height, Args&& ... args)

Tries to insert a node into the atlas using rectangle pack algorithm.

Declaration
public NodeType* Insert(Size width, Size height, Args&& ... args)
Parameters
Size width

The node width (in pixels).
Size height

The node height (in pixels).
Args... args

The additional arguments.
Returns
NodeType

The node that contains inserted an item or null if failed to find a free space.
Type Parameters
Args

IsInitialized()

Declaration
public bool IsInitialized()
Returns
bool

Reset()

Clears and resets atlas back to the initial state.

Declaration
public void Reset()