SLGLVertexArray encapsulates the core OpenGL drawing. More...

#include <SLGLVertexArray.h>

Inheritance diagram for SLGLVertexArray:

Public Member Functions
	SLGLVertexArray ()

	~SLGLVertexArray ()

void	deleteGL ()
	Deletes all vertex array & vertex buffer objects. More...

void	clearAttribs ()
	Clears the attribute definition. More...

SLint	vaoID () const
	Returns either the VAO id or the VBO id. More...

SLint	tfoID () const
	Returns the TFO id. More...

void	setAttrib (SLGLAttributeType type, SLint elementSize, SLint location, void *dataPointer, SLGLBufferType dataType=BT_float)
	Adds a vertex attribute with data pointer and an element size. More...

void	setAttrib (SLGLAttributeType type, SLint location, SLVuint *data)
	Adds a vertex attribute with vector of SLuint. More...

void	setAttrib (SLGLAttributeType type, SLint location, SLVfloat *data)
	Adds a vertex attribute with vector of SLfloat. More...

void	setAttrib (SLGLAttributeType type, SLint location, SLVVec2f *data)
	Adds a vertex attribute with vector of SLVec2f. More...

void	setAttrib (SLGLAttributeType type, SLint location, SLVVec3f *data)
	Adds a vertex attribute with vector of SLVec3f. More...

void	setAttrib (SLGLAttributeType type, SLint location, SLVVec4f *data)
	Adds a vertex attribute with vector of SLVec4f. More...

void	setIndices (SLuint numIndicesElements, SLGLBufferType indexDataType, void indexDataElements, SLuint numIndicesEdges=0, void indexDataEdges=nullptr)
	Adds the index array for indexed element drawing. More...

void	setIndices (SLVubyte indicesElements, SLVubyte indicesEdges=nullptr)
	Adds the index array for indexed element drawing with a vector of ubyte. More...

void	setIndices (SLVushort indicesElements, SLVushort indicesEdges=nullptr)
	Adds the index array for indexed element drawing with a vector of ushort. More...

void	setIndices (SLVuint indicesElements, SLVuint indicesEdges=nullptr)
	Adds the index array for indexed element drawing with a vector of uint. More...

void	updateAttrib (SLGLAttributeType type, SLint elementSize, void *dataPointer)
	Updates a specific vertex attribute in the VBO. More...

void	updateAttrib (SLGLAttributeType type, SLVuint *data)
	Updates a specific vertex attribute in the VBO. More...

void	updateAttrib (SLGLAttributeType type, SLVfloat *data)
	Updates a specific vertex attribute in the VBO. More...

void	updateAttrib (SLGLAttributeType type, SLVVec2f *data)
	Updates a specific vertex attribute in the VBO. More...

void	updateAttrib (SLGLAttributeType type, SLVVec3f *data)
	Updates a specific vertex attribute in the VBO. More...

void	updateAttrib (SLGLAttributeType type, SLVVec4f *data)
	Updates a specific vertex attribute in the VBO. More...

void	generate (SLuint numVertices, SLGLBufferUsage usage=BU_static, SLbool outputInterleaved=true)
	Generates the VA & VB objects for a NO. of vertices. More...

void	generateTF (SLuint numVertices, SLGLBufferUsage usage=BU_static, SLbool outputInterleaved=true)
	Generates the VA & VB & TF objects. More...

void	beginTF (SLuint tfoID)
	Begin transform feedback. More...

void	endTF ()
	End transform feedback. More...

void	drawElementsAs (SLGLPrimitiveType primitiveType, SLuint numIndexes=0, SLuint indexOffsetBytes=0)
	Draws the VAO by element indices with a primitive type. More...

void	drawArrayAs (SLGLPrimitiveType primitiveType, SLint firstVertex=0, SLsizei countVertices=0)
	Draws the VAO as an array with a primitive type. More...

void	drawEdges (SLCol4f color, SLfloat lineWidth=1.0f)
	Draws the hard edges of the VAO with the edge indices. More...

SLuint	numVertices () const

SLuint	numIndicesElements () const

SLuint	numIndicesEdges () const

Static Public Attributes
static SLuint	totalDrawCalls = 0

static SLuint	totalPrimitivesRendered = 0
	static total no. of draw calls More...

Protected Attributes
SLuint	_vaoID
	static total no. of primitives rendered More...

SLuint	_tfoID
	OpenGL id of vertex array object. More...

SLuint	_numVertices
	OpenGL id of transform feedback object. More...

SLGLVertexBuffer	_VBOf
	NO. of vertices in array. More...

SLuint	_idVBOIndices
	Vertex buffer object for float attributes. More...

SLuint	_numIndicesElements
	OpenGL id of index vbo. More...

void *	_indexDataElements
	NO. of vertex indices in array for triangles, lines or points. More...

SLuint	_numIndicesEdges
	Pointer to index data for elements. More...

void *	_indexDataEdges
	NO. of vertex indices in array for hard edges. More...

SLGLBufferType	_indexDataType
	Pointer to index data for hard edges. More...

Detailed Description

SLGLVertexArray encapsulates the core OpenGL drawing.

An SLGLVertexArray instance handles all OpenGL drawing with an OpenGL Vertex Array Object (VAO), a vertex buffer objects (VBO) for the attributes and an index buffer for element drawing. Attributes can be stored in a float VBO of type SLGLVertexBuffer.
VAOs where introduces OpenGL 3.0 and reduce the overhead per draw call. All vertex attributes (e.g. position, normals, texture coords, etc.) must be float at the input. All float attributes will be in one VBO (_VBOf). Vertices can be drawn either directly as in the array (SLGLVertexArray::drawArrayAs) or by element (SLGLVertexArray::drawElementsAs) with a separate indices buffer.
The setup of a VAO has multiple steps:

Define one ore more attributes with SLGLVertexArray::setAttrib.
Define the index array for element drawing with SLGLVertexArray::setIndices.
Generate the OpenGL VAO and VBO with SLGLVertexArray::generate.
It is important that the data structures passed in SLGLVertexArray::setAttrib and SLGLVertexArray::setIndices are still present when generate is called. The VAO has no or one active index buffer. For drawArrayAs no indices are needed. For drawElementsAs the index buffer is used. For triangle meshes also hard edges are generated. Their indices are stored behind the indices of the triangles. See SLMesh::computeHardEdgesIndices for more infos on hard edges.

Constructor & Destructor Documentation

◆ SLGLVertexArray()

SLGLVertexArray::SLGLVertexArray ( )

Constructor initializing with default values

◆ ~SLGLVertexArray()

SLGLVertexArray::~SLGLVertexArray ( )

inline

Member Function Documentation

◆ beginTF()

void SLGLVertexArray::beginTF ( SLuint tfoID )

Begin transform feedback.

Discard the rendering because we just compute next position with the transform feedback. We need to bind a transform feedback object but not the same from this vao, because we want to read from one vao and write on another.

◆ clearAttribs()

void SLGLVertexArray::clearAttribs ( )

inline

Clears the attribute definition.

◆ deleteGL()

void SLGLVertexArray::deleteGL ( )

Deletes all vertex array & vertex buffer objects.

Deletes the OpenGL objects for the vertex array and the vertex buffer. The vector _attribs with the attribute information is not cleared.

◆ drawArrayAs()

void SLGLVertexArray::drawArrayAs	(	SLGLPrimitiveType	primitiveType,
		SLint	firstVertex = `0`,
		SLsizei	countVertices = `0`
	)

Draws the VAO as an array with a primitive type.

Draws the vertex attributes as a specified primitive type as the vertices are defined in the attribute arrays.

◆ drawEdges()

void SLGLVertexArray::drawEdges	(	SLCol4f	color,
		SLfloat	lineWidth = `1.0f`
	)

Draws the hard edges of the VAO with the edge indices.

Draws the hard edges with the specified color. The VAO has no or one active index buffer. For drawArrayAs no indices are needed. For drawElementsAs the index buffer is used. For triangle meshes also hard edges are generated. Their indices are stored behind the indices of the triangles.

◆ drawElementsAs()

void SLGLVertexArray::drawElementsAs	(	SLGLPrimitiveType	primitiveType,
		SLuint	numIndexes = `0`,
		SLuint	indexOffset = `0`
	)

Draws the VAO by element indices with a primitive type.

Draws the vertex attributes as a specified primitive type by elements with the indices from the index buffer defined in setIndices.

◆ endTF()

void SLGLVertexArray::endTF ( )

End transform feedback.

We activate back the rendering and stop the transform feedback.

◆ generate()

void SLGLVertexArray::generate	(	SLuint	numVertices,
		SLGLBufferUsage	usage = `BU_static`,
		SLbool	outputInterleaved = `true`
	)

Generates the VA & VB objects for a NO. of vertices.

Generates the OpenGL objects for the vertex array and the vertex buffer object. If the input data is an interleaved array (all attribute data pointer where identical) also the output buffer will be generated as an interleaved array. Vertex arrays with attributes that are updated can not be interleaved. Vertex attributes with separate arrays can generate an interleaved or a sequential vertex buffer.



 Sequential attribute layout:


           |          Positions          |           Normals           |     TexCoords     |


 Attribs:  |   Position0  |   Position1  |    Normal0   |    Normal1   |  UV1_0  |  UV1_1  |


 Elements: | PX | PY | PZ | PX | PY | PZ | NX | NY | NZ | NX | NY | NZ | TX | TY | TX | TY |


 Bytes:    |#### #### ####|#### #### ####|#### #### ####|#### #### ####|#### ####|#### ####|


           |                             |                             |


           |<------ offset Normals ----->|                             |


           |<----------------------- offset UVs ---------------------->|




 Interleaved attribute layout:


           |               Vertex 0                |               Vertex 1                |


 Attribs:  |   Position0  |    Normal0   |  UV1_0  |   Position1  |    Normal1   |  UV1_1  |


 Elements: | PX | PY | PZ | NX | NY | NZ | TX | TY | PX | PY | PZ | NX | NY | NZ | TX | TY |


 Bytes:    |#### #### ####|#### #### ####|#### ####|#### #### ####|#### #### ####|#### ####|


           |              |              |         |


           |<-offsetN=32->|              |         |


           |<------- offsetUV=32 ------->|         |


           |                                       |


           |<---------- strideBytes=32 ----------->|

The VAO has no or one active index buffer. For drawArrayAs no indices are needed. For drawElementsAs the index buffer is used. For triangle meshes also hard edges are generated. Their indices are stored behind the indices of the triangles.

◆ generateTF()

void SLGLVertexArray::generateTF	(	SLuint	numVertices,
		SLGLBufferUsage	usage = `BU_static`,
		SLbool	outputInterleaved = `true`
	)

Generates the VA & VB & TF objects.

Same as generate but with transform feedback

◆ numIndicesEdges()

SLuint SLGLVertexArray::numIndicesEdges ( ) const

inline

◆ numIndicesElements()

SLuint SLGLVertexArray::numIndicesElements ( ) const

inline

◆ numVertices()

SLuint SLGLVertexArray::numVertices ( ) const

inline

◆ setAttrib() [1/6]

void SLGLVertexArray::setAttrib	(	SLGLAttributeType	type,
		SLint	elementSize,
		SLint	location,
		void *	dataPointer,
		SLGLBufferType	dataType = `BT_float`
	)

Adds a vertex attribute with data pointer and an element size.

Defines a vertex attribute for the later generation. It must be of a specific SLVertexAttribType. Each attribute can appear only once in an vertex array. If all attributes of a vertex array have the same data pointer the data input will be interpreted as an interleaved array. See example in SLGLOculus::init. Be aware that the VBO for the attribute will not be generated until generate is called. The data pointer must still be valid when SLGLVertexArray::generate is called.

◆ setAttrib() [2/6]

void SLGLVertexArray::setAttrib	(	SLGLAttributeType	type,
		SLint	location,
		SLVfloat *	data
	)

inline

Adds a vertex attribute with vector of SLfloat.

◆ setAttrib() [3/6]

void SLGLVertexArray::setAttrib	(	SLGLAttributeType	type,
		SLint	location,
		SLVuint *	data
	)

inline

Adds a vertex attribute with vector of SLuint.

◆ setAttrib() [4/6]

void SLGLVertexArray::setAttrib	(	SLGLAttributeType	type,
		SLint	location,
		SLVVec2f *	data
	)

inline

Adds a vertex attribute with vector of SLVec2f.

◆ setAttrib() [5/6]

void SLGLVertexArray::setAttrib	(	SLGLAttributeType	type,
		SLint	location,
		SLVVec3f *	data
	)

inline

Adds a vertex attribute with vector of SLVec3f.

◆ setAttrib() [6/6]

void SLGLVertexArray::setAttrib	(	SLGLAttributeType	type,
		SLint	location,
		SLVVec4f *	data
	)

inline

Adds a vertex attribute with vector of SLVec4f.

◆ setIndices() [1/4]

void SLGLVertexArray::setIndices	(	SLuint	numIndicesElements,
		SLGLBufferType	indexDataType,
		void *	indexDataElements,
		SLuint	numIndicesEdges = `0`,
		void *	indexDataEdges = `nullptr`
	)

Adds the index array for indexed element drawing.

Defines the vertex indices for the element drawing. Without indices vertex array can only be drawn with SLGLVertexArray::drawArrayAs. Be aware that the VBO for the indices will not be generated until generate is called. The data pointer must still be valid when generate is called.

◆ setIndices() [2/4]

void SLGLVertexArray::setIndices	(	SLVubyte *	indicesElements,
		SLVubyte *	indicesEdges = `nullptr`
	)

inline

Adds the index array for indexed element drawing with a vector of ubyte.

◆ setIndices() [3/4]

void SLGLVertexArray::setIndices	(	SLVuint *	indicesElements,
		SLVuint *	indicesEdges = `nullptr`
	)

inline

Adds the index array for indexed element drawing with a vector of uint.

◆ setIndices() [4/4]

void SLGLVertexArray::setIndices	(	SLVushort *	indicesElements,
		SLVushort *	indicesEdges = `nullptr`
	)

inline

Adds the index array for indexed element drawing with a vector of ushort.

◆ tfoID()

SLint SLGLVertexArray::tfoID ( ) const

inline

Returns the TFO id.