Struct lyon::tessellation::geometry_builder::BuffersBuilder

pub struct BuffersBuilder<'l, VertexType, Input, Ctor> where Ctor: VertexConstructor<Input, VertexType>, VertexType: 'l { /* fields omitted */ }

A temporary view on a VertexBuffers object which facilitate the population of vertex and index data.

BuffersBuilders record the vertex offset from when they are created so that algorithms using them don't need to worry about offsetting indices if some geometry was added beforehand. This means that from the point of view of a BuffersBuilder user, the first added vertex is at always offset at the offset 0 and VertexBuilfer takes care of translating indices adequately.

Often, algorithms are built to generate vertex positions without knowledge of eventual other vertex attributes. The VertexConstructor does the translation from generic Input to VertexType. If your logic generates the actual vertex type directly, you can use the SimpleBuffersBuilder convenience typedef.

Methods

impl<'l, VertexType, Input, Ctor> BuffersBuilder<'l, VertexType, Input, Ctor> where Ctor: VertexConstructor<Input, VertexType>, VertexType: 'l

fn new(buffers: &'l mut VertexBuffers<VertexType>,
       ctor: Ctor)
       -> BuffersBuilder<'l, VertexType, Input, Ctor>

Trait Implementations

impl<'l, VertexType, Input, Ctor> BezierGeometryBuilder<Input> for BuffersBuilder<'l, VertexType, Input, Ctor> where Ctor: VertexConstructor<Input, VertexType>, VertexType: 'l + Clone

fn add_quadratic_bezier(&mut self, _from: VertexId, _to: VertexId, _ctrl: Input)

Insert a quadratic bezier curve. The interrior is on the right side of the curve.

impl<'l, VertexType, Input, Ctor> GeometryBuilder<Input> for BuffersBuilder<'l, VertexType, Input, Ctor> where Ctor: VertexConstructor<Input, VertexType>, VertexType: 'l + Clone

fn begin_geometry(&mut self)

Called at the beginning of a generation.

fn end_geometry(&mut self) -> Count

Called at the end of a generation. Returns the number of vertices and indices added since the last time begin_geometry was called.

fn add_vertex(&mut self, v: Input) -> VertexId

Inserts a vertex, providing its position, and optionally a normal. Retuns a vertex id that is only valid between begin_geometry and end_geometry.

fn add_triangle(&mut self, a: VertexId, b: VertexId, c: VertexId)

Insert a triangle made of vertices that were added after the last call to begin_geometry.

fn abort_geometry(&mut self)

abort_geometry is called instead of end_geometry if an error occured while producing the geometry and we won't be able to finish.