template<UnsignedInt location, class T>
Magnum::GL::Attribute class

Base class for attribute location and type.

Contents

For use in AbstractShaderProgram subclasses. Template parameter location is vertex attribute location, number between 0 and AbstractShaderProgram::maxVertexAttributes(). To ensure compatibility, you should always have vertex attribute with location 0.

Template parameter T is the type which is used for shader attribute, e.g. Vector4i for ivec4. DataType is type of passed data when adding vertex buffers to mesh. By default it is the same as type used in shader (e.g. DataType::Int for Vector4i). It's also possible to pass integer data to floating-point shader inputs. In this case you may want to normalize the values (e.g. color components from 0 – 255 to 0.0f – 1.0f) — see DataOption::Normalized.

Only some types are allowed as attribute types, see Mapping between GLSL and Magnum types for more information.

See Subclassing workflow for example usage in shaders and Mesh configuration for example usage when adding vertex buffers to mesh.

Public types

enum (anonymous): UnsignedInt { Location = location, VectorCount = Implementation::Attribute<T>::VectorCount }
enum class Components: GLint { One = 1, Two = 2, Three = 3, Four = 4, BGRA = GL_BGRA }
Component count.
enum class DataType: GLenum { UnsignedByte = GL_UNSIGNED_BYTE, Byte = GL_BYTE, UnsignedShort = GL_UNSIGNED_SHORT, Short = GL_SHORT, UnsignedInt = GL_UNSIGNED_INT, Int = GL_INT, HalfFloat = GL_HALF_FLOAT, Float = GL_FLOAT, Double = GL_DOUBLE, UnsignedInt10f11f11fRev = GL_UNSIGNED_INT_10F_11F_11F_REV, UnsignedInt2101010Rev = GL_UNSIGNED_INT_2_10_10_10_REV, Int2101010Rev = GL_INT_2_10_10_10_REV }
Data type.
enum class DataOption: UnsignedByte { Normalized = 1 << 0 }
Data option.
using Type = T
Type.
using ScalarType = Implementation::Attribute<T>::ScalarType
Scalar type.
using DataOptions = Containers::EnumSet<DataOption>
Data options.

Constructors, destructors, conversion operators

Attribute(Components components, DataType dataType = Implementation::Attribute<T>::DefaultDataType, DataOptions dataOptions = DataOptions()) constexpr
Constructor.
Attribute(DataType dataType = Implementation::Attribute<T>::DefaultDataType, DataOptions dataOptions = DataOptions()) constexpr
Constructor.

Public functions

auto components() const -> Components constexpr
Component count of passed data.
auto dataType() const -> DataType constexpr
Type of passed data.
auto vectorSize() const -> UnsignedInt
Size of each vector in passed data.
auto dataOptions() const -> DataOptions constexpr
Data options.

Enum documentation

template<UnsignedInt location, class T>
enum Magnum::GL::Attribute<location, T>::(anonymous): UnsignedInt

Enumerators
Location

Location to which the attribute is bound
VectorCount

Count of vectors in this type

template<UnsignedInt location, class T>
enum class Magnum::GL::Attribute<location, T>::Components: GLint

Component count.

Count of components passed to the shader. If passing smaller count of components than corresponding type has, unspecified components are set to default values (second and third to 0, fourth to 1).

Enumerators
One

Only first component is specified. Second, third and fourth component are set to 0, 0, 1, respectively. Only for scalar and vector types, not matrices.
Two

First two components are specified. Third and fourth component are set to 0, 1, respectively. Only for two, three and four-component vector types and 2x2, 3x2 and 4x2 matrix types.
Three

First three components are specified. Fourth component is set to 1. Only for three and four-component vector types, 2x3, 3x3 and 4x3 matrix types.
Four

All four components are specified. Only for four-component vector types and 2x4, 3x4 and 4x4 matrix types.
BGRA

Four components with BGRA ordering. Only for four-component float vector type. Must be used along with DataType::UnsignedByte and DataOption::Normalized.

template<UnsignedInt location, class T>
enum class Magnum::GL::Attribute<location, T>::DataType: GLenum

Data type.

Type of data passed to shader.

Enumerators
UnsignedByte

Unsigned byte
Byte

Byte
UnsignedShort

Unsigned short
Short

Short
UnsignedInt

Unsigned int
Int

Int
HalfFloat

Half float. Only for float attribute types.
Float

Float. Only for float attribute types.
Double

Double. Only for float and double attribute types.
UnsignedInt10f11f11fRev

Unsigned 10.11.11 packed float. Only for three-component float vector attribute type.
UnsignedInt2101010Rev

Unsigned 2.10.10.10 packed integer. Only for four-component float vector attribute type.
Int2101010Rev

Signed 2.10.10.10 packed integer. Only for four-component float vector attribute type.

template<UnsignedInt location, class T>
enum class Magnum::GL::Attribute<location, T>::DataOption: UnsignedByte

Data option.

Enumerators
Normalized

Normalize integer components. Only for float attribute types. Default is to not normalize.

Typedef documentation

template<UnsignedInt location, class T>
typedef T Magnum::GL::Attribute<location, T>::Type

Type.

Type used in shader code.

template<UnsignedInt location, class T>
typedef Implementation::Attribute<T>::ScalarType Magnum::GL::Attribute<location, T>::ScalarType

Scalar type.

The underlying scalar type of the attribute.

template<UnsignedInt location, class T>
typedef Containers::EnumSet<DataOption> Magnum::GL::Attribute<location, T>::DataOptions

Data options.

Function documentation

template<UnsignedInt location, class T>
Magnum::GL::Attribute<location, T>::Attribute(Components components, DataType dataType = Implementation::Attribute<T>::DefaultDataType, DataOptions dataOptions = DataOptions()) constexpr

Constructor.

Parameters
components Component count
dataType Type of passed data. Default is the same as type used in shader (e.g. DataType::Int for Vector4i).
dataOptions Data options. Default is no options.

template<UnsignedInt location, class T>
Magnum::GL::Attribute<location, T>::Attribute(DataType dataType = Implementation::Attribute<T>::DefaultDataType, DataOptions dataOptions = DataOptions()) constexpr

Constructor.

Parameters
dataType Type of passed data. Default is the same as type used in shader (e.g. DataType::Int for Vector4i).
dataOptions Data options. Default is no options.

Component count is set to the same value as in type used in shader (e.g. Components::Three for Vector3).

template<UnsignedInt location, class T>
UnsignedInt Magnum::GL::Attribute<location, T>::vectorSize() const

Size of each vector in passed data.

template<UnsignedInt location, class T> template<class T>
Debug& operator<<(Debug& debug, Attribute<T>::Components)

Debug output operator.

template<UnsignedInt location, class T> template<class T>
Debug& operator<<(Debug& debug, Attribute<T>::DataType)

Debug output operator.