Struct glium::vertex::VertexBufferSlice

pub struct VertexBufferSlice<'b, T: 'b> where T: Copy {
    // some fields omitted
}

Represents a slice of a VertexBuffer.

Methods

impl<'b, T: 'b> VertexBufferSlice<'b, T> where T: Copy + Content

fn per_instance(&'b self) -> Result<PerInstance, InstancingNotSupported>

Creates a marker that instructs glium to use multiple instances.

Instead of calling surface.draw(&vertex_buffer.slice(...).unwrap(), ...) you can call surface.draw(vertex_buffer.slice(...).unwrap().per_instance(), ...). This will draw one instance of the geometry for each element in this buffer slice. The attributes are still passed to the vertex shader, but each entry is passed for each different instance.

Methods from Deref<Target=BufferSlice<'a, [T]>>

fn get_size(&self) -> usize

Returns the size in bytes of this slice.

fn get_context(&self) -> &Rc<Context>

Returns the context corresponding to this buffer.

fn write(&self, data: &T)

Uploads some data in this buffer.

Implementation

• For persistent-mapped buffers, waits untils the data is no longer used by the GPU then memcpies the data to the mapping.
• For immutable buffers, creates a temporary buffer that contains the data then calls glCopyBufferSubData to copy from the temporary buffer to the real one.
• For other types, calls glBufferSubData.

Panic

Panics if the length of data is different from the length of this buffer.

fn invalidate(&self)

Invalidates the content of the slice. The data becomes undefined.

This operation is a no-op if the backend doesn't support it and for persistent-mapped buffers.

Implementation

Calls glInvalidateBufferSubData if supported.

fn read(&self) -> Result<T::Owned, ReadError>

Reads the content of the buffer.

fn copy_to<S>(&self, target: S) -> Result<(), CopyError> where S: Into<BufferSlice<'a, T>>

Copies the content of this slice to another slice.

Panic

Panics if T is unsized and the other buffer is too small.

unsafe fn slice_custom<F, R: ?Sized>(&self, f: F) -> BufferSlice<'a, R> where F: for<'r> FnOnce(&'r T) -> &'r R, R: Content

Builds a slice that contains an element from inside the buffer.

This method builds an object that represents a slice of the buffer. No actual operation OpenGL is performed.

Example

#[derive(Copy, Clone)]
struct BufferContent {
    value1: u16,
    value2: u16,
}
let slice = unsafe { buffer.slice_custom(|content| &content.value2) };

Safety

The object whose reference is passed to the closure is uninitialized. Therefore you must not access the content of the object.

You must return a reference to an element from the parameter. The closure must not panic.

fn as_slice_any(&self) -> BufferAnySlice<'a>

Builds a slice-any containing the whole subbuffer.

This method builds an object that represents a slice of the buffer. No actual operation OpenGL is performed.

fn len(&self) -> usize

Returns the number of elements in this slice.

fn slice<R: RangeArgument<usize>>(&self, range: R) -> Option<BufferSlice<'a, [T]>>

Builds a subslice of this slice. Returns None if out of range.

This method builds an object that represents a slice of the buffer. No actual operation OpenGL is performed.

fn read_as_texture_1d<S>(&self) -> Result<S, ReadError> where S: Texture1dDataSink<T>

Reads the content of the buffer.

Trait Implementations

impl<'a, T> Deref for VertexBufferSlice<'a, T> where T: Copy

type Target = BufferSlice<'a, [T]>

The resulting type after dereferencing

fn deref(&self) -> &BufferSlice<'a, [T]>

The method called to dereference a value

impl<'a, T> DerefMut for VertexBufferSlice<'a, T> where T: Copy

fn deref_mut(&mut self) -> &mut BufferSlice<'a, [T]>

The method called to mutably dereference a value

impl<'a, T> IntoVerticesSource<'a> for VertexBufferSlice<'a, T> where T: Copy

fn into_vertices_source(self) -> VerticesSource<'a>

Builds the VerticesSource.