Struct QuadVertex 

#[repr(C)]
pub struct QuadVertex {
    pub position: [f32; 2],
    pub tex_coord: [f32; 2],
    pub color: [f32; 4],
    pub flags: u32,
    pub _pad: u32,
}

Vertex for the textured quad pipeline (glyphs, images).

Fields

position: [f32; 2]

tex_coord: [f32; 2]

color: [f32; 4]

flags: u32

Per-vertex bitfield. Bit 0 (QUAD_FLAG_COLOR_GLYPH) selects the color emoji path in the fragment shader.

_pad: u32

Padding so the struct stride stays a multiple of 8 bytes, matching wgpu’s vertex buffer layout expectations.

Implementations

impl QuadVertex

pub fn from_glyph_quad_transformed( quad: &GlyphQuad, scale_factor: f32, atlas_width: u32, atlas_height: u32, transform: &Transform2D, ) -> [QuadVertex; 4]

Convert a glyph quad to 4 vertices (two triangles via index buffer), applying scale_factor (logical → physical pixels) and the current affine transform (linear part unitless, translation already in physical pixels). Atlas coordinates are in texels and normalized to 0..1 using the atlas dimensions. Returned positions are in physical pixels — the caller converts to NDC; it must NOT transform again.

Pixel-snap invariant. The glyph atlas is sampled with bilinear filtering so the residual GPU scaling between raster-scale buckets (≤ ~12%, see quantize_raster_scale) stays smooth. Bilinear is only loss-free when each texel maps exactly onto one framebuffer pixel, and glyph origins are inherently fractional: shaping pen advances, widget offsets, and scroll positions are all fractional floats. An unsnapped origin makes the 2×2 kernel mix neighboring texels at every edge (uniform blur) and bleed the glyph’s last row into the transparent atlas gutter (visibly cropping the bottom of letters like “c”/“e”). So whenever the transformed quad maps 1:1 onto its atlas bitmap — axis-aligned transform and transformed size equal to the bitmap size within GLYPH_SNAP_SIZE_EPS — the origin is rounded to the integer pixel grid and the opposite corner pinned at exactly origin + bitmap size, making linear sampling an identity. This covers identity, fractional DPI, pure translations, and exact-bucket zoom (e.g. a 1.25× transform over a 1.25-bucket raster). Rotated or residually scaled quads (mid-bucket zoom) skip the snap and ride bilinear filtering as intended.

Trait Implementations

impl Clone for QuadVertex

fn clone(&self) -> QuadVertex

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for QuadVertex

impl Debug for QuadVertex

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

Formats the value using the given formatter.

impl Pod for QuadVertex

impl Zeroable for QuadVertex

fn zeroed() -> Self

Calls zeroed.