pub const OPAQUE_BLEND: f32 = 0.5;Expand description
The stroke_blend level at or above which a line scene draws through the
opacity-preserving seam (ADR-0138). Below it the batch is additive light.
A midpoint threshold on a continuous param, for the reason every other
quantized param in this engine carries one: [smoothing] eases a value
through everything between its endpoints, so a binding that steps 0 -> 1
is 0.37 for a frame or two on the way. The seam has no state to interpolate
— a draw call has one blend mode — so the decision is taken CPU-side, once
per frame, at the midpoint.