Magnum::GL::MeshView class
#include <Magnum/GL/MeshView.h>

Mesh view.

Allows different interpretation of given Mesh data via different vertex or index count and offset. It is then possible to reuse one mesh buffer configuration for different views. Mesh primitive, index type, attribute bindings and attached buffers are reused from original mesh.

The same rules as in Mesh apply, i.e. if the view has non-zero index count, it is treated as indexed mesh, otherwise it is treated as non-indexed mesh. If both index and vertex count is zero, the view is treated as empty and no draw commands are issued when calling AbstractShaderProgram::draw().

You must ensure that the original mesh remains available for whole view lifetime.

Public static functions

static void draw(AbstractShaderProgram& shader, Containers::ArrayView<const Containers::Reference<MeshView>> meshes) deprecated in 2020.06
Draw multiple meshes at once.
static void draw(AbstractShaderProgram&& shader, Containers::ArrayView<const Containers::Reference<MeshView>> meshes) deprecated in 2020.06
static void draw(AbstractShaderProgram& shader, std::initializer_list<Containers::Reference<MeshView>> meshes) deprecated in 2020.06
static void draw(AbstractShaderProgram&& shader, std::initializer_list<Containers::Reference<MeshView>> meshes) deprecated in 2020.06

Constructors, destructors, conversion operators

MeshView(Mesh& original) explicit
Constructor.

Public functions

auto mesh() -> Mesh&
Original mesh.
auto mesh() const -> const Mesh&
auto count() const -> Int
Vertex/index count.
auto setCount(Int count) -> MeshView&
Set vertex/index count.
auto baseVertex() const -> Int
Base vertex.
auto setBaseVertex(Int baseVertex) -> MeshView&
Set base vertex.
auto indexOffset() const -> Int new in Git master
Index offset.
auto setIndexOffset(Int offset, UnsignedInt start, UnsignedInt end) -> MeshView& new in Git master
Set index offset.
auto setIndexRange(Int offset, UnsignedInt start, UnsignedInt end) -> MeshView& deprecated in Git master
Set index offset.
auto setIndexOffset(Int offset) -> MeshView& new in Git master
Set index offset.
auto setIndexRange(Int offset) -> MeshView& deprecated in Git master
Set index offset.
auto instanceCount() const -> Int
Instance count.
auto setInstanceCount(Int count) -> MeshView&
Set instance count.
auto baseInstance() const -> UnsignedInt
Base instance.
auto setBaseInstance(UnsignedInt baseInstance) -> MeshView&
Set base instance.
auto draw(AbstractShaderProgram& shader) -> MeshView& deprecated in 2020.06
Draw the mesh.
auto draw(AbstractShaderProgram&& shader) -> MeshView& deprecated in 2020.06
auto draw(AbstractShaderProgram& shader, TransformFeedback& xfb, UnsignedInt stream = 0) -> MeshView& deprecated in 2020.06
Draw the mesh with vertices coming out of transform feedback.
auto draw(AbstractShaderProgram&& shader, TransformFeedback& xfb, UnsignedInt stream = 0) -> MeshView& deprecated in 2020.06

Function documentation

static void Magnum::GL::MeshView::draw(AbstractShaderProgram&& shader, Containers::ArrayView<const Containers::Reference<MeshView>> meshes)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

static void Magnum::GL::MeshView::draw(AbstractShaderProgram& shader, std::initializer_list<Containers::Reference<MeshView>> meshes)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

static void Magnum::GL::MeshView::draw(AbstractShaderProgram&& shader, std::initializer_list<Containers::Reference<MeshView>> meshes)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Magnum::GL::MeshView::MeshView(Mesh& original) explicit

Constructor.

Parameters
original Original, already configured mesh

const Mesh& Magnum::GL::MeshView::mesh() const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

MeshView& Magnum::GL::MeshView::setCount(Int count)

Set vertex/index count.

Returns Reference to self (for method chaining)

Ignored when calling AbstractShaderProgram::drawTransformFeedback().

MeshView& Magnum::GL::MeshView::setBaseVertex(Int baseVertex)

Set base vertex.

Returns Reference to self (for method chaining)

Sets number of vertices of which the vertex buffer will be offset when drawing. Ignored when calling AbstractShaderProgram::drawTransformFeedback(). Default is 0.

MeshView& Magnum::GL::MeshView::setIndexOffset(Int offset, UnsignedInt start, UnsignedInt end) new in Git master

Set index offset.

Parameters
offset First index
start Minimum array index contained in the buffer
end Maximum array index contained in the buffer
Returns Reference to self (for method chaining)

The offset gets multiplied by index type size and added to the base offset that was specified in Mesh::setIndexBuffer(). The start and end parameters may help to improve memory access performance, as only a portion of vertex buffer needs to be acccessed. On OpenGL ES 2.0 this function behaves the same as setIndexOffset(Int), as index range functionality is not available there. Ignored when calling AbstractShaderProgram::drawTransformFeedback().

Expects that the original mesh is indexed.

MeshView& Magnum::GL::MeshView::setIndexRange(Int offset, UnsignedInt start, UnsignedInt end)

Set index offset.

MeshView& Magnum::GL::MeshView::setIndexOffset(Int offset) new in Git master

Set index offset.

Returns Reference to self (for method chaining)

The offset gets multiplied by index type size and added to the base offset that was specified in Mesh::setIndexBuffer(). Prefer to use setIndexOffset(Int, UnsignedInt, UnsignedInt) for potential better performance in certain drivers. Ignored when calling AbstractShaderProgram::drawTransformFeedback().

Expects that the original mesh is indexed.

MeshView& Magnum::GL::MeshView::setIndexRange(Int offset)

Set index offset.

MeshView& Magnum::GL::MeshView::setBaseInstance(UnsignedInt baseInstance)

Set base instance.

Returns Reference to self (for method chaining)

Ignored when calling AbstractShaderProgram::drawTransformFeedback(). Default is 0.

MeshView& Magnum::GL::MeshView::draw(AbstractShaderProgram& shader)

Draw the mesh.

MeshView& Magnum::GL::MeshView::draw(AbstractShaderProgram&& shader)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

MeshView& Magnum::GL::MeshView::draw(AbstractShaderProgram& shader, TransformFeedback& xfb, UnsignedInt stream = 0)

Draw the mesh with vertices coming out of transform feedback.

MeshView& Magnum::GL::MeshView::draw(AbstractShaderProgram&& shader, TransformFeedback& xfb, UnsignedInt stream = 0)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.