Container for mesh index data defining vertex connectivity and topology. More...

#include <IndexBuffer.hpp>

Inheritance diagram for Infinity::Types::Rendering::IndexBuffer:

Collaboration diagram for Infinity::Types::Rendering::IndexBuffer:

Public Types
enum class	IndexType { UInt16 , UInt32 }
	Index data format determining maximum vertex count. More...

enum class	Topology { Triangles , Lines , TriangleStrip , Quads }
	Primitive topology defining how indices form geometry. More...

Public Member Functions
	IndexBuffer ()
	Default constructor.

	IndexBuffer (const size_t size, IndexType type=IndexType::UInt16, Topology topology=Topology::Triangles)
	Constructs an index buffer with pre-allocated capacity.

	IndexBuffer (const Containers::Array< uint16_t > &indices, Topology topology=Topology::Triangles)
	Constructs an index buffer from a 16-bit index array.

	IndexBuffer (const Containers::Array< uint32_t > &indices, Topology topology=Topology::Triangles)
	Constructs an index buffer from a 32-bit index array.

virtual	~IndexBuffer ()
	Destructor.

std::unique_ptr< Core::Base >	clone () const override

void	reserve (size_t capacity)
	Pre-allocates storage for a specified number of indices.

void	clear ()
	Removes all indices from the buffer.

uint32_t	operator[] (size_t index) const
	Accesses an index value (unchecked).

uint32_t	at (size_t index) const
	Accesses an index value (checked).

void	setIndex (size_t index, uint32_t value)
	Sets the value of an existing index.

void	pushIndex (uint16_t index)
	Appends a single 16-bit index.

void	pushIndex (uint32_t index)
	Appends a single 32-bit index.

void	pushTriangle (uint16_t v0, uint16_t v1, uint16_t v2)
	Appends three 16-bit indices forming a triangle.

void	pushTriangle (uint32_t v0, uint32_t v1, uint32_t v2)
	Appends three 32-bit indices forming a triangle.

void	pushQuad (uint16_t v0, uint16_t v1, uint16_t v2, uint16_t v3)
	Appends indices for a quad (as two triangles).

void	pushQuad (uint32_t v0, uint32_t v1, uint32_t v2, uint32_t v3)
	Appends indices for a quad (as two triangles).

void	pushLine (uint16_t v0, uint16_t v1)
	Appends two 16-bit indices forming a line segment.

void	pushLine (uint32_t v0, uint32_t v1)
	Appends two 32-bit indices forming a line segment.

void	pushIndices (const Containers::Array< uint16_t > &indices)
	Appends multiple 16-bit indices from an array.

void	pushIndices (const Containers::Array< uint32_t > &indices)
	Appends multiple 32-bit indices from an array.

Core::span< const uint16_t >	asUInt16Buffer () const
	Gets a const span view of the data as 16-bit indices.

Core::span< uint16_t >	asUInt16Buffer ()
	Gets a mutable span view of the data as 16-bit indices.

Core::span< const uint32_t >	asUInt32Buffer () const
	Gets a const span view of the data as 32-bit indices.

Core::span< uint32_t >	asUInt32Buffer ()
	Gets a mutable span view of the data as 32-bit indices.

size_t	count () const
	Gets the number of indices in the buffer.

const Infinity::Types::TypeID &	typeId () const override
	Gets the TypeID for IndexBuffer.

Public Member Functions inherited from Infinity::Types::Core::Data
	Data ()

	Data (const Data &other)

	Data (Data &&other)

Data &	operator= (const Data &other)

Data &	operator= (Data &&other)

virtual	~Data ()
	Virtual destructor.

bool	hasProperty (const std::string &key) const

template<typename T >
void	setProperty (const std::string &key, T &&value)
	Sets a typed property value.

template<typename T >
void	setProperty (const std::string &key, const T &value)
	Sets a typed property value.

void	setProperty (const std::string &key, PropertyValue &&value)
	Sets a typed property value.

const PropertyValue &	getProperty (const std::string &key) const
	Gets a property value without type checking.

template<typename T >
const T &	getProperty (const std::string &key) const
	Gets a typed property value.

void	removeProperty (const std::string &key)

Public Member Functions inherited from Infinity::Types::Core::Base
virtual	~Base ()
	Virtual destructor.

virtual std::istream &	legibleDataRead (std::istream &in) override
	Deserializes the object from a single-line text representation.

virtual std::ostream &	legibleDataWrite (std::ostream &out) const override
	Serializes the object to a single-line text representation.

Public Attributes
IndexType	type = IndexType::UInt16
	Index data format.

Topology	topology = Topology::Triangles
	Primitive topology.

Containers::Array< uint8_t >	data
	Raw index data storage.

Public Attributes inherited from Infinity::Types::Core::Data
std::unordered_map< std::string, PropertyValue >	properties
	Property storage for arbitrary metadata.

Detailed Description

Container for mesh index data defining vertex connectivity and topology.

IndexBuffer stores indices that define how vertices from a VertexBuffer are connected to form geometric primitives (triangles, lines, etc.). It provides efficient mesh representation by allowing vertices to be reused across multiple primitives, reducing memory usage and improving rendering performance.

The index buffer supports:

Two index formats: 16-bit (up to 65,535 vertices) or 32-bit (billions of vertices)
Multiple topologies: Triangles, Lines, TriangleStrip, Quads
Convenient primitive methods: pushTriangle(), pushQuad(), pushLine()
Dynamic construction: Build indices incrementally during mesh generation
Type-safe access: Automatic handling of 16-bit vs 32-bit indices

Index ordering determines face winding and visibility. Counter-clockwise (CCW) winding is the default front-facing convention in most rendering systems.

Common use cases:

Procedural mesh generation (terrain, shapes, buildings)
Mesh optimization and vertex sharing
LOD (Level of Detail) mesh construction
Dynamic mesh modification
Wireframe and debug visualization

Note: Use UInt16 for meshes with < 65,536 vertices (more memory efficient).; Use UInt32 for large meshes exceeding 65,535 vertices.; Triangle topology is most common for solid geometry rendering.; All index values must be valid vertex indices in the associated VertexBuffer.

Example usage:

// Create index buffer for a quad (2 triangles)
IndexBuffer indices;
indices.pushTriangle(0, 1, 2);  // First triangle (CCW)
indices.pushTriangle(0, 2, 3);  // Second triangle (CCW)
 
// Or use quad helper
IndexBuffer quadIndices;
quadIndices.pushQuad(0, 1, 2, 3);  // Automatically creates 2 triangles
 
// Terrain mesh with grid topology
IndexBuffer terrainIndices(IndexBuffer::IndexType::UInt32);
for (uint32_t z = 0; z < height - 1; ++z) {
    for (uint32_t x = 0; x < width - 1; ++x) {
        uint32_t topLeft = z * width + x;
        uint32_t topRight = topLeft + 1;
        uint32_t bottomLeft = (z + 1) * width + x;
        uint32_t bottomRight = bottomLeft + 1;
        
        // Two triangles per quad
        terrainIndices.pushTriangle(topLeft, bottomLeft, topRight);
        terrainIndices.pushTriangle(topRight, bottomLeft, bottomRight);
    }
}
 
// Wireframe rendering (lines topology)
IndexBuffer wireframe(64, IndexBuffer::IndexType::UInt16, 
                      IndexBuffer::Topology::Lines);
for (size_t i = 0; i < triangleCount; ++i) {
    uint16_t v0 = triangles[i * 3 + 0];
    uint16_t v1 = triangles[i * 3 + 1];
    uint16_t v2 = triangles[i * 3 + 2];
    wireframe.pushLine(v0, v1);
    wireframe.pushLine(v1, v2);
    wireframe.pushLine(v2, v0);
}
 
// Pre-allocate for known size
size_t triangleCount = 1000;
IndexBuffer optimized;
optimized.reserve(triangleCount * 3);  // 3 indices per triangle
 
// Use with ProceduralSystem
system->setIn("mesh_indices", std::move(indices));

Member Enumeration Documentation

◆ IndexType

enum class Infinity::Types::Rendering::IndexBuffer::IndexType

strong

Index data format determining maximum vertex count.

Enumerator
UInt16	16-bit indices (0-65,535 vertices, more memory efficient)
UInt32	32-bit indices (0-4,294,967,295 vertices, for large meshes)

◆ Topology

enum class Infinity::Types::Rendering::IndexBuffer::Topology

strong

Primitive topology defining how indices form geometry.

Enumerator
Triangles	Each 3 indices form an independent triangle (most common)
Lines	Each 2 indices form an independent line segment.
TriangleStrip	Connected triangles sharing edges (memory efficient)
Quads	Each 4 indices form a quadrilateral (converted to 2 triangles)

Constructor & Destructor Documentation

◆ IndexBuffer() [1/4]

Infinity::Types::Rendering::IndexBuffer::IndexBuffer ( )

Default constructor.

Creates an empty index buffer with 16-bit indices and triangle topology.

◆ IndexBuffer() [2/4]

Infinity::Types::Rendering::IndexBuffer::IndexBuffer	(	const size_t	size,
		IndexType	type = `IndexType::UInt16`,
		Topology	topology = `Topology::Triangles`
	)

Constructs an index buffer with pre-allocated capacity.

Parameters

size	Number of indices to pre-allocate space for.
type	Index format (UInt16 or UInt32).
topology	Primitive topology.

◆ IndexBuffer() [3/4]

Infinity::Types::Rendering::IndexBuffer::IndexBuffer	(	const Containers::Array< uint16_t > &	indices,
		Topology	topology = `Topology::Triangles`
	)

Constructs an index buffer from a 16-bit index array.

Parameters

indices	Array of 16-bit indices to copy.
topology	Primitive topology.

◆ IndexBuffer() [4/4]

Infinity::Types::Rendering::IndexBuffer::IndexBuffer	(	const Containers::Array< uint32_t > &	indices,
		Topology	topology = `Topology::Triangles`
	)

Constructs an index buffer from a 32-bit index array.

Parameters

indices	Array of 32-bit indices to copy.
topology	Primitive topology.

◆ ~IndexBuffer()

virtual Infinity::Types::Rendering::IndexBuffer::~IndexBuffer ( )

virtual

Destructor.

Member Function Documentation

◆ asUInt16Buffer() [1/2]

Core::span< uint16_t > Infinity::Types::Rendering::IndexBuffer::asUInt16Buffer ( )

Gets a mutable span view of the data as 16-bit indices.

Returns: Mutable span of uint16_t indices.

Warning: Only valid when type is UInt16.

◆ asUInt16Buffer() [2/2]

Core::span< const uint16_t > Infinity::Types::Rendering::IndexBuffer::asUInt16Buffer ( ) const

Gets a const span view of the data as 16-bit indices.

Returns: Const span of uint16_t indices.

Warning: Only valid when type is UInt16.

◆ asUInt32Buffer() [1/2]

Core::span< uint32_t > Infinity::Types::Rendering::IndexBuffer::asUInt32Buffer ( )

Gets a mutable span view of the data as 32-bit indices.

Returns: Mutable span of uint32_t indices.

Warning: Only valid when type is UInt32.

◆ asUInt32Buffer() [2/2]

Core::span< const uint32_t > Infinity::Types::Rendering::IndexBuffer::asUInt32Buffer ( ) const

Gets a const span view of the data as 32-bit indices.

Returns: Const span of uint32_t indices.

Warning: Only valid when type is UInt32.

◆ at()

uint32_t Infinity::Types::Rendering::IndexBuffer::at ( size_t index ) const

Accesses an index value (checked).

Parameters

index Position of the index to retrieve.

Returns: Index value as uint32_t (automatically converted from storage format).

Note: Currently doesn't perform bounds checking despite the name.

◆ clear()

void Infinity::Types::Rendering::IndexBuffer::clear ( )

Removes all indices from the buffer.

Resets the buffer to empty state while preserving type and topology.

◆ clone()

std::unique_ptr< Core::Base > Infinity::Types::Rendering::IndexBuffer::clone ( ) const

overridevirtual

Reimplemented from Infinity::Types::Core::Data.

◆ count()

size_t Infinity::Types::Rendering::IndexBuffer::count ( ) const

Gets the number of indices in the buffer.

Returns: Total count of indices.

Note: For Triangles topology: count / 3 = triangle count.; For Lines topology: count / 2 = line segment count.

◆ operator[]()

uint32_t Infinity::Types::Rendering::IndexBuffer::operator[] ( size_t index ) const

Accesses an index value (unchecked).

Parameters

index Position of the index to retrieve.

Returns: Index value as uint32_t (automatically converted from storage format).

Warning: No bounds checking. Use at() for checked access.

◆ pushIndex() [1/2]

void Infinity::Types::Rendering::IndexBuffer::pushIndex ( uint16_t index )

Appends a single 16-bit index.

Parameters

index Index value to append.

Note: Only valid when type is UInt16.

◆ pushIndex() [2/2]

void Infinity::Types::Rendering::IndexBuffer::pushIndex ( uint32_t index )

Appends a single 32-bit index.

Parameters

index Index value to append.

Note: Only valid when type is UInt32.

◆ pushIndices() [1/2]

void Infinity::Types::Rendering::IndexBuffer::pushIndices ( const Containers::Array< uint16_t > & indices )

Appends multiple 16-bit indices from an array.

Parameters

indices Array of indices to append.

◆ pushIndices() [2/2]

void Infinity::Types::Rendering::IndexBuffer::pushIndices ( const Containers::Array< uint32_t > & indices )

Appends multiple 32-bit indices from an array.

Parameters

indices Array of indices to append.

◆ pushLine() [1/2]

void Infinity::Types::Rendering::IndexBuffer::pushLine	(	uint16_t	v0,
		uint16_t	v1
	)

Appends two 16-bit indices forming a line segment.

Parameters

v0	Start vertex index.
v1	End vertex index.

Note: Typically used with Lines topology.

◆ pushLine() [2/2]

void Infinity::Types::Rendering::IndexBuffer::pushLine	(	uint32_t	v0,
		uint32_t	v1
	)

Appends two 32-bit indices forming a line segment.

Parameters

v0	Start vertex index.
v1	End vertex index.

◆ pushQuad() [1/2]

void Infinity::Types::Rendering::IndexBuffer::pushQuad	(	uint16_t	v0,
		uint16_t	v1,
		uint16_t	v2,
		uint16_t	v3
	)

Appends indices for a quad (as two triangles).

Automatically generates two triangles with proper winding:

Triangle 1: v0, v1, v2
Triangle 2: v0, v2, v3

Parameters

v0	First corner (e.g., bottom-left).
v1	Second corner (e.g., bottom-right).
v2	Third corner (e.g., top-right).
v3	Fourth corner (e.g., top-left).

◆ pushQuad() [2/2]

void Infinity::Types::Rendering::IndexBuffer::pushQuad	(	uint32_t	v0,
		uint32_t	v1,
		uint32_t	v2,
		uint32_t	v3
	)

Appends indices for a quad (as two triangles).

Parameters

v0	First corner.
v1	Second corner.
v2	Third corner.
v3	Fourth corner.

◆ pushTriangle() [1/2]

void Infinity::Types::Rendering::IndexBuffer::pushTriangle	(	uint16_t	v0,
		uint16_t	v1,
		uint16_t	v2
	)

Appends three 16-bit indices forming a triangle.

Parameters

v0	First vertex index.
v1	Second vertex index.
v2	Third vertex index.

Note: Order determines face winding (CCW = front-facing).

◆ pushTriangle() [2/2]

void Infinity::Types::Rendering::IndexBuffer::pushTriangle	(	uint32_t	v0,
		uint32_t	v1,
		uint32_t	v2
	)

Appends three 32-bit indices forming a triangle.

Parameters

v0	First vertex index.
v1	Second vertex index.
v2	Third vertex index.

Note: Order determines face winding (CCW = front-facing).

◆ reserve()

void Infinity::Types::Rendering::IndexBuffer::reserve ( size_t capacity )

Pre-allocates storage for a specified number of indices.

Reserves memory without changing the index count, avoiding reallocations during subsequent pushes.

Parameters

capacity Number of indices to reserve space for.

◆ setIndex()

void Infinity::Types::Rendering::IndexBuffer::setIndex	(	size_t	index,
		uint32_t	value
	)

Sets the value of an existing index.

Parameters

index	Position of the index to modify.
value	New index value to set.

◆ typeId()

const Infinity::Types::TypeID & Infinity::Types::Rendering::IndexBuffer::typeId ( ) const

overridevirtual

Gets the TypeID for IndexBuffer.

Returns: TypeID identifying this IndexBuffer type.

Reimplemented from Infinity::Types::Core::Data.

Member Data Documentation

◆ data

Containers::Array<uint8_t> Infinity::Types::Rendering::IndexBuffer::data

Raw index data storage.

Internal byte array storing index values in the format specified by type. Use the convenience methods (pushTriangle, pushIndex, etc.) rather than manipulating this directly.

◆ topology

Topology Infinity::Types::Rendering::IndexBuffer::topology = Topology::Triangles

Primitive topology.

Defines how indices are interpreted to form geometric primitives. Default: Triangles

◆ type

IndexType Infinity::Types::Rendering::IndexBuffer::type = IndexType::UInt16

Index data format.

Determines whether indices are stored as 16-bit or 32-bit values. Default: UInt16

Public Types

Public Member Functions

Public Attributes

Detailed Description

Member Enumeration Documentation

◆ IndexType

◆ Topology

Constructor & Destructor Documentation

◆ IndexBuffer() [1/4]

◆ IndexBuffer() [2/4]

◆ IndexBuffer() [3/4]

◆ IndexBuffer() [4/4]

◆ ~IndexBuffer()

Member Function Documentation

◆ asUInt16Buffer() [1/2]

◆ asUInt16Buffer() [2/2]

◆ asUInt32Buffer() [1/2]

◆ asUInt32Buffer() [2/2]

◆ at()

◆ clear()

◆ clone()

◆ count()

◆ operator[]()

◆ pushIndex() [1/2]

◆ pushIndex() [2/2]

◆ pushIndices() [1/2]

◆ pushIndices() [2/2]

◆ pushLine() [1/2]

◆ pushLine() [2/2]

◆ pushQuad() [1/2]

◆ pushQuad() [2/2]

◆ pushTriangle() [1/2]

◆ pushTriangle() [2/2]

◆ reserve()

◆ setIndex()

◆ typeId()

Member Data Documentation

◆ data

◆ topology

◆ type