Module buffer 

Vertex / uniform data layouts for the headless solid-fill + gradient pipelines.

All structs are #[repr(C)] and implement bytemuck::Pod / bytemuck::Zeroable so they can be uploaded to the GPU as raw bytes with a guaranteed, stable memory layout.

Vertex layout (56 bytes = 14 × f32)

The struct was extended from the original 48-byte form to add an extra field ([f32; 2]) that carries per-kind auxiliary parameters:

kind	local	shape_xy	shape_r	extra
0 rect	pixel pos	–	–	–
1 circle	pixel pos	centre (cx,cy)	radius	–
2 rrect-uniform	pixel pos	centre (cx,cy)	radius	half-size (hw,hh)
3 rrect-per-corner	pixel pos	centre (cx,cy)	pack16(tl,tr)	pack16(br,bl), pack16(hw,hh)
4 ellipse	pixel pos	centre (cx,cy)	–	(rx, ry)
5 line-seg	pixel pos	from (ax,ay)	half_width (+0.5=aa)	to (bx,by)

For kind=3 the four corner radii and the half-extents are packed as u16 pairs into f32 bit patterns (see pack_u16_pair).

Structs

Globals

Per-frame uniform block matching the WGSL Globals struct.

GradientUniforms

Per-gradient uniform block sent to gradient.wgsl.

GradientVertex

A single vertex fed to gradient.wgsl.

LineQuadParams

Parameters for a line-segment SDF quad.

Vertex

A single vertex fed to solid.wgsl.

Constants

KIND_CIRCLE

Primitive discriminator value for an SDF circle.

KIND_ELLIPSE

Primitive discriminator value for an SDF ellipse.

KIND_LINE_SEG

Primitive discriminator value for a line-segment SDF.

KIND_RECT

Primitive discriminator value for a solid rectangle.

KIND_ROUNDED_RECT

Primitive discriminator value for a uniformly-rounded rectangle (SDF).

KIND_ROUNDED_RECT_PC

Primitive discriminator value for a per-corner rounded rectangle (SDF).

MAX_GRADIENT_STOPS

Maximum number of gradient colour stops supported in a single gradient draw.

Functions

pack_u16_pair

Pack two u16 values into the bit pattern of a f32.

push_circle_quad

Append six vertices covering the bounding quad of the circle centred at (cx, cy) with radius, tagged as an SDF circle.

push_ellipse_quad

Append six vertices for an SDF ellipse centred at (cx, cy) with horizontal radius rx and vertical radius ry.

push_gradient_quad

Append six gradient vertices covering (x, y, w, h).

push_line_quad

Append six vertices for a line-segment SDF quad.

push_rect_quad

Append six vertices (two triangles) covering the axis-aligned rectangle (x, y, w, h) with a uniform color, tagged as a solid rectangle.

push_rounded_rect_per_corner_quad

Append six vertices for a per-corner rounded rectangle (SDF).

push_rounded_rect_quad

Append six vertices for a uniformly-rounded rectangle (SDF).

push_triangle

Append three vertices (one triangle) for a path fill triangle.