Struct Mesh2DFile 

pub struct Mesh2DFile {
    pub pos_attr: Pos2DATTR,
    pub layer: u8,
    pub aspect: f32,
    pub col_attr: ColATTR,
    pub uvm_attr: UVMATTR,
    pub ind_attr: IndATTR,
    pub cus_attrs: Vec<CustomATTR>,
}

CPU-side 2D mesh geometry — positions, UVs, colours, indices, layer, and centre.

Mesh2DFile is the 2D counterpart of Mesh3DFile. It adds:

• A layer field for draw-order sorting.
• An aspect ratio and Center enumeration for positioning.

Generated primitives

Function	Description
quad	Textured quad sized to a canvas pixel area
fullscreen_quad	NDC-space quad (-1..1)
rect	Rectangle centred at origin
circle	Approximated by a regular polygon
polygon	Regular polygon (same as circle)
ring	Annulus (donut) shape

Fields

pos_attr: Pos2DATTR

layer: u8

aspect: f32

col_attr: ColATTR

uvm_attr: UVMATTR

ind_attr: IndATTR

cus_attrs: Vec<CustomATTR>

Implementations

impl Mesh2DFile

pub fn empty() -> Self

Creates an empty 2D mesh.

pub fn set_pos_attr(&mut self, attr: Pos2DATTR)

Replaces the position attribute.

pub fn set_layer(&mut self, layer: u8)

Sets the draw layer (higher values render on top).

pub fn set_center(&mut self, center: Center)

Offsets all vertex positions by the centre vector.

pub fn set_col_attr(&mut self, attr: ColATTR)

Replaces the colour attribute.

pub fn set_uvm_attr(&mut self, attr: UVMATTR)

Replaces the UV attribute.

pub fn set_ind_attr(&mut self, attr: IndATTR)

Replaces the index attribute.

pub fn quad(size: &Size2D) -> Self

Creates a textured quad sized to fill the given canvas area.

The quad’s aspect ratio matches the canvas, and it is centred by default. Used for rendering sprites or UI elements where the quad should preserve the canvas’s proportions in NDC space.

Conventions

• Position — 2D in NDC-like space (aspect-ratio aware).
• UVs — full [0,1]² coverage.
• Topology — 2 triangles, 4 vertices.

pub fn fullscreen_quad() -> Self

Creates a quad covering the entire NDC space (-1 to +1 on both axes).

Useful for full-screen post-processing effects.

pub fn attach_custom_attr(&mut self, attr: CustomATTR)

Attaches a custom per-vertex attribute.

pub fn circle(radius: f32, segments: u32) -> Self

Creates a circle approximated by a regular polygon.

The first vertex is at the centre, creating a fan topology.

pub fn polygon(radius: f32, sides: u32) -> Self

Creates a regular polygon (alias for circle).

pub fn ring(inner_radius: f32, outer_radius: f32, segments: u32) -> Self

Creates an annular (ring) shape with inner and outer radii.

pub fn rect(width: f32, height: f32) -> Self

Creates a rectangle centred at the origin with the given dimensions.

This is a 2D quad in world-space units (not NDC). Use for billboards, 2D physics bodies, or UI elements that need precise world-space sizing.

Conventions

• Position — 2D world-space, centred.
• UVs — full [0,1]² coverage.
• Topology — 2 triangles, 4 vertices.

pub fn starts_with_custom(&self) -> bool

Returns true if no built-in vertex attributes are populated.

pub fn ship(&self) -> MeshHandle

Interleaves vertex attributes and uploads to the GPU.