Class-A surfacing 3/3: blend curves, curved-edge fillets, the G2 corner and continuity analysis (#1642)

Thanks @midasdf.

crates/render/src/curve_display.rs

@@ -115,7 +115,9 @@ fn controls(segment: &Seg2, plane: &Plane) -> Option<(Vec<Vec<H>>, H)> {
         Seg2::Line { a, b } => vec![vec![h(a, 1.0), h(b, 1.0)]],
         Seg2::Cubic { p0, p1, p2, p3 } => vec![vec![h(p0, 1.0), h(p1, 1.0), h(p2, 1.0), h(p3, 1.0)]],
         Seg2::Conic { a, apex, b, w } if w > 0.0 => vec![vec![h(a, 1.0), h(apex, w), h(b, 1.0)]],
-        Seg2::Bezier { n, p } if (1..=7).contains(&n) => vec![p[..=n as usize].iter().map(|p| h(*p, 1.0)).collect()],
+        Seg2::Bezier { n, p } if (1..=solidcraft_geom::MAX_BEZIER_DEGREE as u8).contains(&n) => {
+            vec![p[..=n as usize].iter().map(|p| h(*p, 1.0)).collect()]
+        }
         Seg2::Arc { center, radius, start, sweep }
             if radius > 0.0 && start.is_finite() && sweep.is_finite() && sweep.abs() <= std::f64::consts::TAU + 1e-9 =>
         {