Struct CurveData 

pub struct CurveData {
    pub cx: Box<[f64]>,
    pub cy: Box<[f64]>,
    pub c_next: Box<[i32]>,
}

Stack storage for the De Casteljau subdivision loop.

Lazy-allocated (via Option<Box<CurveData>>) because it is ~25 KB — only needed for paths containing Bezier curves.

Array sizing

MAX_CURVE_SPLITS = 1024, so the slot count is n = 1025.

• cx / cy: length n * 3 = 3075. The maximum slot index used is max_u = 1024, giving a maximum array index of 1024 * 3 + 2 = 3074, which is within bounds (no off-by-one).
• c_next: length n = 1025. The maximum index used is max_u = 1024, which is also within bounds.

Fields

cx: Box<[f64]>

X coordinates: 3 control points per slot, indexed by slot * 3 + {0,1,2}.

cy: Box<[f64]>

Y coordinates: same layout as cx.

c_next: Box<[i32]>

cNext[p1] = index of the next segment’s first slot after p1.

Implementations

impl CurveData

pub fn new() -> Box<Self>

Allocate a new CurveData.

Panics

Panics if MAX_CURVE_SPLITS is negative. It is defined as the positive constant 1024 (matching splashMaxCurveSplits in SplashTypes.h), so this branch is unreachable in practice.