Struct Contour 

struct Contour<'a, C, D>
where
    C: PointCoord,
    D: PointCoord + From<C>,
{
    points: &'a [Point<C>],
    flags: &'a [PointFlags],
    out_points: &'a mut [Point<D>],
}

One contour’s worth of points, as input coordinates and the moved coordinates being derived from them.

All three slices have the same length, so indices are interchangeable between them and are always in bounds.

Fields

points: &'a [Point<C>]

flags: &'a [PointFlags]

out_points: &'a mut [Point<D>]

Implementations

impl<C, D> Contour<'_, C, D>

where C: PointCoord, D: PointCoord + From<C>,

fn interpolate_untouched(&mut self)

Infers the deltas of every point in this contour that the current tuple did not reference.

fn shift(&mut self, reference: usize)

Shifts the whole contour by the delta of its one referenced point.

Modeled after the FreeType implementation: https://github.com/freetype/freetype/blob/bbfcd79eacb4985d4b68783565f4b494aa64516b/src/truetype/ttgxvar.c#L3776

fn interpolate(&mut self, range: Range<usize>, ref1: usize, ref2: usize)

Interpolates the unreferenced points in range between the referenced points at ref1 and ref2.

Modeled after the FreeType implementation: https://github.com/freetype/freetype/blob/bbfcd79eacb4985d4b68783565f4b494aa64516b/src/truetype/ttgxvar.c#L3813

For details on the algorithm, see: https://learn.microsoft.com/en-us/typography/opentype/spec/gvar#inferred-deltas-for-un-referenced-point-numbers