pub fn segment_to_thick_quad(
ax: f64,
ay: f64,
color_a: [f32; 4],
bx: f64,
by: f64,
color_b: [f32; 4],
thickness_clip: f32,
) -> [CustomWaveVertex; 6]Expand description
Expand two consecutive per-point outputs into a thick-line segment
quad — six clip-space vertices forming a screen-space rectangle of
thickness_clip perpendicular to the segment direction. Mirrors
the line_vertex shape used by waveform_advanced.wgsl for
b_wave_thick, so MD2’s “thick custom-wave trail” looks identical
to the thick-static-wave path.
color_a / color_b come from the two source points so the segment
gracefully interpolates colour along a fading per-point trail.
Caller supplies (x, y) in MD2 preset space; we convert internally.