Struct tetra::graphics::mesh::GeometryBuilder

pub struct GeometryBuilder { /* private fields */ }

A builder for creating primitive shape geometry, and associated buffers/meshes.

Performance

GeometryBuilder stores the generated vertex and index data in a pair of Vecs. This means that creating a new builder (as well as cloning an existing one) will allocate memory. Consider reusing a GeometryBuilder if you need to reuse the generated data, or if you need to create new data every frame.

Creating buffers/meshes from the generated geometry is a fairly expensive operation. Try to avoid creating lots of seperate buffers/meshes, and pack multiple shapes into the same buffers/mesh if they don’t move relative to each other.

Examples

The shapes example demonstrates how to draw primitive shapes, both through the simplified API on Mesh, and the more powerful GeometryBuilder API.

Implementations

impl GeometryBuilder

pub fn new() -> GeometryBuilder

Creates a new empty geometry builder.

pub fn rectangle( &mut self, style: ShapeStyle, rectangle: Rectangle ) -> Result<&mut GeometryBuilder>

Adds a rectangle.

Errors

• TetraError::TessellationError will be returned if the shape could not be turned into vertex data.

pub fn rounded_rectangle( &mut self, style: ShapeStyle, rectangle: Rectangle, radii: BorderRadii ) -> Result<&mut GeometryBuilder>

Adds a rounded rectangle.

Errors

• TetraError::TessellationError will be returned if the shape could not be turned into vertex data.

pub fn circle( &mut self, style: ShapeStyle, center: Vec2<f32>, radius: f32 ) -> Result<&mut GeometryBuilder>

Adds a circle.

Errors

• TetraError::TessellationError will be returned if the shape could not be turned into vertex data.

pub fn ellipse( &mut self, style: ShapeStyle, center: Vec2<f32>, radii: Vec2<f32> ) -> Result<&mut GeometryBuilder>

Adds an ellipse.

Errors

• TetraError::TessellationError will be returned if the shape could not be turned into vertex data.

pub fn polygon( &mut self, style: ShapeStyle, points: &[Vec2<f32>] ) -> Result<&mut GeometryBuilder>

Adds a polygon.

Errors

• TetraError::TessellationError will be returned if the shape could not be turned into vertex data.

pub fn polyline( &mut self, stroke_width: f32, points: &[Vec2<f32>] ) -> Result<&mut GeometryBuilder>

Adds a polyline.

Errors

• TetraError::TessellationError will be returned if the shape could not be turned into vertex data.

pub fn set_color(&mut self, color: Color) -> &mut GeometryBuilder

Sets the color that will be used for subsequent shapes.

You can also use DrawParams::color to tint an entire mesh - this method only needs to be used if you want to display multiple colors in a single piece of geometry.

pub fn clear(&mut self) -> &mut GeometryBuilder

Clears the geometry builder’s data.

pub fn vertices(&self) -> &[Vertex]

Returns a view of the generated vertex data.

pub fn indices(&self) -> &[u32]

Returns a view of the generated index data.

pub fn into_data(self) -> (Vec<Vertex>, Vec<u32>)

Consumes the builder, returning the generated geometry.

pub fn build_buffers( &self, ctx: &mut Context ) -> Result<(VertexBuffer, IndexBuffer)>

Builds a vertex and index buffer from the generated geometry.

This involves uploading the geometry to the GPU, and is a fairly expensive operation.

Errors

• TetraError::PlatformError will be returned if the underlying graphics API encounters an error.

pub fn build_mesh(&self, ctx: &mut Context) -> Result<Mesh>

Builds a mesh from the generated geometry.

This involves uploading the geometry to the GPU, and is a fairly expensive operation.

Errors

• TetraError::PlatformError will be returned if the underlying graphics API encounters an error.

Trait Implementations

impl Clone for GeometryBuilder

fn clone(&self) -> GeometryBuilder

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for GeometryBuilder

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for GeometryBuilder

fn default() -> Self

Returns the “default value” for a type.