svg_path/measure
Arc length, distance-addressed evaluation, and subdivision. Distances are in path-coordinate units; segment parameters are not length fractions.
Values
pub fn default_length_options() -> svg_path.LengthOptionsReturn the default options for segment and subpath length approximation.
pub fn path_derivative_at_length(
path: svg_path.Path,
distance distance: Float,
) -> Result(svg_path.Point, svg_path.Error)Return the path derivative at a traveled distance from the path start.
pub fn path_derivative_at_length_with(
path: svg_path.Path,
distance distance: Float,
options options: svg_path.LengthOptions,
) -> Result(svg_path.Point, svg_path.Error)Return the path derivative at a traveled distance using explicit options.
pub fn path_length(
path: svg_path.Path,
) -> Result(Float, svg_path.Error)Return the approximate length of a path.
Empty paths have length 0.0. Move-only subpaths contribute 0.0.
pub fn path_length_upper_bound(
path: svg_path.Path,
) -> Result(Float, svg_path.Error)Sum the cheap segment-length upper bounds across a path’s subpaths.
Empty paths and move-only subpaths contribute 0.0; gaps between subpaths
contribute nothing. See segment_length_upper_bound for numerical limits.
pub fn path_length_with(
path: svg_path.Path,
options options: svg_path.LengthOptions,
) -> Result(Float, svg_path.Error)Return the approximate length of a path using explicit options.
pub fn path_parameter_at_length(
path: svg_path.Path,
distance distance: Float,
) -> Result(svg_path.PathParameter, svg_path.Error)Return the path parameter at a traveled distance from the path start.
The distance is measured across subpaths in path order. Move-only subpaths
contribute no length and are skipped for lookup. The returned value is an
ordinary public PathParameter.
pub fn path_parameter_at_length_with(
path: svg_path.Path,
distance distance: Float,
options options: svg_path.LengthOptions,
) -> Result(svg_path.PathParameter, svg_path.Error)Return the path parameter at a traveled distance using explicit options.
pub fn path_point_at_length(
path: svg_path.Path,
distance distance: Float,
) -> Result(svg_path.Point, svg_path.Error)Return the path point at a traveled distance from the path start.
pub fn path_point_at_length_with(
path: svg_path.Path,
distance distance: Float,
options options: svg_path.LengthOptions,
) -> Result(svg_path.Point, svg_path.Error)Return the path point at a traveled distance using explicit options.
pub fn path_subdivide_to_max_length(
path: svg_path.Path,
max_length max_length: Float,
) -> Result(svg_path.Path, svg_path.Error)Subdivide every segment in a path into pieces of at most max_length.
Existing subpath boundaries and closed states are preserved.
pub fn path_subdivide_to_max_length_with(
path: svg_path.Path,
max_length max_length: Float,
options options: svg_path.LengthOptions,
) -> Result(svg_path.Path, svg_path.Error)Subdivide every segment in a path into pieces of at most max_length using
explicit length options.
pub fn segment_between_lengths(
segment: svg_path.Segment,
from from: Float,
to to: Float,
) -> Result(svg_path.Segment, svg_path.Error)Return the portion of a segment between two traveled distances.
Distances are measured in path coordinate units from the segment start and
must be inside 0.0..length, inclusive. If from is greater than to, the
returned segment traverses the interval in reverse.
pub fn segment_between_lengths_many(
segment: svg_path.Segment,
between distances: List(Float),
) -> Result(List(svg_path.Segment), svg_path.Error)Return segment portions between adjacent traveled distances.
Distances are measured in path coordinate units from the segment start and
must be inside 0.0..length, inclusive. Empty and singleton lists return an
empty list.
pub fn segment_between_lengths_many_with(
segment: svg_path.Segment,
between distances: List(Float),
options options: svg_path.LengthOptions,
) -> Result(List(svg_path.Segment), svg_path.Error)Return segment portions between adjacent traveled distances using explicit length options.
pub fn segment_between_lengths_with(
segment: svg_path.Segment,
from from: Float,
to to: Float,
options options: svg_path.LengthOptions,
) -> Result(svg_path.Segment, svg_path.Error)Return the portion of a segment between two traveled distances using explicit length options.
pub fn segment_chord_length(segment: svg_path.Segment) -> FloatReturn the distance between a segment’s start and end points.
This is the endpoint chord length. It can be zero even when a curve has nonzero interior geometry.
pub fn segment_chord_length_squared(
segment: svg_path.Segment,
) -> FloatReturn the squared distance between a segment’s start and end points.
This is the square of the endpoint chord length. It can be zero even when a curve has nonzero interior geometry.
pub fn segment_derivative_at_length(
segment: svg_path.Segment,
distance distance: Float,
) -> Result(svg_path.Point, svg_path.Error)Return the segment derivative at a traveled distance from the segment start.
pub fn segment_derivative_at_length_with(
segment: svg_path.Segment,
distance distance: Float,
options options: svg_path.LengthOptions,
) -> Result(svg_path.Point, svg_path.Error)Return the segment derivative at a traveled distance using explicit options.
pub fn segment_is_zero_length(
segment: svg_path.Segment,
tolerance tolerance: Float,
) -> Result(Bool, svg_path.Error)Return whether a segment has length at most tolerance.
tolerance is measured in path coordinate units and may be exactly 0.0
for an exact zero-length check. Lines are measured exactly. Quadratic
Beziers, cubic Beziers, and arcs are measured with default length options.
pub fn segment_length(
segment: svg_path.Segment,
) -> Result(Float, svg_path.Error)Return the approximate length of a segment.
Lines are measured exactly. Quadratic Beziers, cubic Beziers, and arcs are approximated by adaptive Simpson integration of segment speed.
pub fn segment_length_upper_bound(
segment: svg_path.Segment,
) -> Result(Float, svg_path.Error)Return a cheap upper bound on a segment’s length.
Lines use their chord length. Beziers use the sum of their control-polygon
edge lengths. Arcs use absolute angular travel in radians times the larger
corrected ellipse radius. No numerical integration or subdivision is used.
These mathematical upper bounds are evaluated with ordinary floating-point
arithmetic, not outward-rounded interval arithmetic, and can substantially
overestimate length. Arcs rejected by arc_center_data return
DegenerateArc; see that function for endpoint and radius restrictions.
pub fn segment_length_with(
segment: svg_path.Segment,
options options: svg_path.LengthOptions,
) -> Result(Float, svg_path.Error)Return the approximate length of a segment using explicit options.
pub fn segment_parameter_at_length(
segment: svg_path.Segment,
distance distance: Float,
) -> Result(Float, svg_path.Error)Return the segment parameter at a traveled distance from the segment start.
The distance is measured in path coordinate units, not normalized. Lines are
inverted exactly. Quadratic Beziers, cubic Beziers, and arcs are inverted
numerically using the same length options as segment_length_with.
pub fn segment_parameter_at_length_with(
segment: svg_path.Segment,
distance distance: Float,
options options: svg_path.LengthOptions,
) -> Result(Float, svg_path.Error)Return the segment parameter at a traveled distance using explicit options.
pub fn segment_point_at_length(
segment: svg_path.Segment,
distance distance: Float,
) -> Result(svg_path.Point, svg_path.Error)Return the segment point at a traveled distance from the segment start.
pub fn segment_point_at_length_with(
segment: svg_path.Segment,
distance distance: Float,
options options: svg_path.LengthOptions,
) -> Result(svg_path.Point, svg_path.Error)Return the segment point at a traveled distance using explicit options.
pub fn segment_subdivide_to_max_length(
segment: svg_path.Segment,
max_length max_length: Float,
) -> Result(List(svg_path.Segment), svg_path.Error)Subdivide a segment into pieces of at most max_length.
Splits are chosen by traveled arc length, not by equal Bezier or arc parameter spacing. Zero-length segments are returned unchanged.
pub fn segment_subdivide_to_max_length_with(
segment: svg_path.Segment,
max_length max_length: Float,
options options: svg_path.LengthOptions,
) -> Result(List(svg_path.Segment), svg_path.Error)Subdivide a segment into pieces of at most max_length using explicit
length options.
pub fn subpath_between_lengths(
subpath: svg_path.Subpath,
from from: Float,
to to: Float,
) -> Result(svg_path.Subpath, svg_path.Error)Return the open subpath between two traveled distances.
Distances are measured in path coordinate units from the subpath start and
must be inside 0.0..length, inclusive. The resulting parameters follow
the same interval rules as subpath_between.
pub fn subpath_between_lengths_with(
subpath: svg_path.Subpath,
from from: Float,
to to: Float,
options options: svg_path.LengthOptions,
) -> Result(svg_path.Subpath, svg_path.Error)Return the open subpath between two traveled distances using explicit length options.
pub fn subpath_derivative_at_length(
subpath: svg_path.Subpath,
distance distance: Float,
) -> Result(svg_path.Point, svg_path.Error)Return the subpath derivative at a traveled distance from the subpath start.
pub fn subpath_derivative_at_length_with(
subpath: svg_path.Subpath,
distance distance: Float,
options options: svg_path.LengthOptions,
) -> Result(svg_path.Point, svg_path.Error)Return the subpath derivative at a traveled distance using explicit options.
pub fn subpath_is_zero_length(
subpath: svg_path.Subpath,
tolerance tolerance: Float,
) -> Result(Bool, svg_path.Error)Return whether a subpath is a zero-length drawing subpath.
Empty subpaths are not considered zero-length drawing subpaths. A non-empty
subpath is zero-length when every segment has length at most tolerance.
pub fn subpath_length(
subpath: svg_path.Subpath,
) -> Result(Float, svg_path.Error)Return the approximate length of a subpath.
Empty subpaths have length 0.0.
pub fn subpath_length_upper_bound(
subpath: svg_path.Subpath,
) -> Result(Float, svg_path.Error)Sum the cheap segment-length upper bounds of a subpath.
Empty subpaths return 0.0. The closed flag adds no implicit segment.
See segment_length_upper_bound for the bounds and numerical limitations.
pub fn subpath_length_with(
subpath: svg_path.Subpath,
options options: svg_path.LengthOptions,
) -> Result(Float, svg_path.Error)Return the approximate length of a subpath using explicit options.
pub fn subpath_parameter_at_length(
subpath: svg_path.Subpath,
distance distance: Float,
) -> Result(svg_path.SubpathParameter, svg_path.Error)Return the subpath parameter at a traveled distance from the subpath start.
The distance is measured in path coordinate units, not normalized. The
returned value is an ordinary public SubpathParameter.
pub fn subpath_parameter_at_length_with(
subpath: svg_path.Subpath,
distance distance: Float,
options options: svg_path.LengthOptions,
) -> Result(svg_path.SubpathParameter, svg_path.Error)Return the subpath parameter at a traveled distance using explicit options.
pub fn subpath_point_at_length(
subpath: svg_path.Subpath,
distance distance: Float,
) -> Result(svg_path.Point, svg_path.Error)Return the subpath point at a traveled distance from the subpath start.
pub fn subpath_point_at_length_with(
subpath: svg_path.Subpath,
distance distance: Float,
options options: svg_path.LengthOptions,
) -> Result(svg_path.Point, svg_path.Error)Return the subpath point at a traveled distance using explicit options.
pub fn subpath_split_at_lengths(
subpath: svg_path.Subpath,
at distances: List(Float),
) -> Result(List(svg_path.Subpath), svg_path.Error)Split a subpath at multiple traveled distances.
Distances are measured in path coordinate units from the subpath start and
must be inside 0.0..length, inclusive. The resulting parameters follow
the same split-point rules as subpath_split_many.
pub fn subpath_split_at_lengths_with(
subpath: svg_path.Subpath,
at distances: List(Float),
options options: svg_path.LengthOptions,
) -> Result(List(svg_path.Subpath), svg_path.Error)Split a subpath at multiple traveled distances using explicit length options.
pub fn subpath_subdivide_to_max_length(
subpath: svg_path.Subpath,
max_length max_length: Float,
) -> Result(svg_path.Subpath, svg_path.Error)Subdivide every segment in a subpath into pieces of at most max_length.
Existing segment boundaries are preserved. The subpath’s closed state is preserved.
pub fn subpath_subdivide_to_max_length_with(
subpath: svg_path.Subpath,
max_length max_length: Float,
options options: svg_path.LengthOptions,
) -> Result(svg_path.Subpath, svg_path.Error)Subdivide every segment in a subpath into pieces of at most max_length
using explicit length options.