svg_path
Core SVG path data structures and constructors.
This module models paths as a list of subpaths, and subpaths as continuous
segment lists. Use svg_path/parse and svg_path/serialize when working
directly with SVG path data strings.
Types
Options for detecting scalar zero crossings along a segment.
pub type CrossingOptions {
CrossingOptions(
samples: Int,
tolerance: Float,
max_iterations: Int,
)
}
Constructors
-
CrossingOptions( samples: Int, tolerance: Float, max_iterations: Int, )
Options for finding the distance from a point to a segment.
pub type DistanceOptions {
DistanceOptions(
samples: Int,
tolerance: Float,
max_iterations: Int,
)
}
Constructors
-
DistanceOptions( samples: Int, tolerance: Float, max_iterations: Int, )
How construction and editing helpers reconcile segment endpoints.
pub type EndpointPolicy {
Strict
Wiggle
Bridge
WiggleThenBridge
Custom(fn(Segment, Segment) -> #(Segment, Segment))
}
Constructors
-
StrictEndpoints must already match exactly.
-
WiggleMove nearby endpoints together within the default wiggle tolerance.
-
BridgeKeep endpoints unchanged and insert a straight line if needed.
-
WiggleThenBridgeTry
Wiggle; if that fails, useBridge. -
Reconcile non-matching adjacent segments with a caller-provided function.
Errors returned by path construction and editing helpers.
pub type Error {
AlreadyClosed
Discontinuous(
previous_index: Int,
next_index: Int,
expected: vec2.Vec2(Float),
got: vec2.Vec2(Float),
distance: Float,
)
EmptySubpath
NotClosed
EmptyPath
EmptySubpaths
DegenerateArc
CannotMapArcNonlinearly
IncompatibleHorizontalWiggle(
previous_end: vec2.Vec2(Float),
next_start: vec2.Vec2(Float),
)
IncompatibleVerticalWiggle(
previous_end: vec2.Vec2(Float),
next_start: vec2.Vec2(Float),
)
InvalidSplice(start: Int, delete: Int, length: Int)
InvalidOpenIndex(index: Int, length: Int)
InvalidCrossingSamples(samples: Int)
InvalidCrossingTolerance(tolerance: Float)
InvalidCrossingMaxIterations(max_iterations: Int)
CrossingMaxIterationsReached(estimate: Float, value: Float)
InvalidMinimizeSamples(samples: Int)
InvalidMinimizeTolerance(tolerance: Float)
InvalidMinimizeMaxIterations(max_iterations: Int)
MinimizeMaxIterationsReached(estimate: Float, value: Float)
InvalidDistanceSamples(samples: Int)
InvalidDistanceTolerance(tolerance: Float)
InvalidDistanceMaxIterations(max_iterations: Int)
DistanceMaxIterationsReached(estimate: Float, value: Float)
InvalidIntersectionTolerance(tolerance: Float)
InvalidIntersectionMaxDepth(max_depth: Int)
OverlappingSegments
MultipleNonemptySubpaths
NotCloseEnough(
expected: vec2.Vec2(Float),
got: vec2.Vec2(Float),
tolerance: Float,
)
SplitOutsideSegment
}
Constructors
-
AlreadyClosedThe subpath is already closed and cannot accept more segments.
-
Discontinuous( previous_index: Int, next_index: Int, expected: vec2.Vec2(Float), got: vec2.Vec2(Float), distance: Float, )A segment starts somewhere other than the previous segment’s end point.
previous_indexis the segment whose end point was expected.next_indexis the segment whose start point did not match.distanceis the distance betweenexpectedandgot. -
EmptySubpathThe operation requires a non-empty subpath.
-
NotClosedThe operation requires a closed subpath.
-
EmptyPathThe operation requires a path with at least one subpath.
-
EmptySubpathsThe operation requires a path with at least one non-empty subpath.
-
DegenerateArcThe arc cannot be converted to center-parameter form.
-
CannotMapArcNonlinearlyNonlinear point mapping cannot preserve an SVG arc segment.
-
A wiggle operation could not reconcile two horizontal line segments.
-
A wiggle operation could not reconcile two vertical line segments.
-
InvalidSplice(start: Int, delete: Int, length: Int)A splice was requested with invalid bounds.
This is returned when
startis negative,deleteis negative, orstartis greater than the subpath length. -
InvalidOpenIndex(index: Int, length: Int)An open index was outside the valid range for a closed subpath.
indexmust be between-lengthandlength, inclusive. -
InvalidCrossingSamples(samples: Int)The number of crossing scan samples must be greater than zero.
-
InvalidCrossingTolerance(tolerance: Float)The crossing tolerance must be greater than zero.
-
InvalidCrossingMaxIterations(max_iterations: Int)The crossing bisection iteration limit must be greater than zero.
-
CrossingMaxIterationsReached(estimate: Float, value: Float)A bracketed crossing could not be refined within the iteration limit.
-
InvalidMinimizeSamples(samples: Int)The number of minimization scan samples must be greater than zero.
-
InvalidMinimizeTolerance(tolerance: Float)The minimization tolerance must be greater than zero.
-
InvalidMinimizeMaxIterations(max_iterations: Int)The minimization iteration limit must be greater than zero.
-
MinimizeMaxIterationsReached(estimate: Float, value: Float)A minimization window could not be refined within the iteration limit.
-
InvalidDistanceSamples(samples: Int)The number of distance scan samples must be greater than zero.
-
InvalidDistanceTolerance(tolerance: Float)The distance tolerance must be greater than zero.
-
InvalidDistanceMaxIterations(max_iterations: Int)The distance bisection iteration limit must be greater than zero.
-
DistanceMaxIterationsReached(estimate: Float, value: Float)A bracketed distance candidate could not be refined within the iteration limit.
-
InvalidIntersectionTolerance(tolerance: Float)The intersection tolerance must be greater than zero.
-
InvalidIntersectionMaxDepth(max_depth: Int)The intersection subdivision depth must be greater than zero.
-
OverlappingSegmentsThe two segments overlap in more than a single point.
-
MultipleNonemptySubpathsThe path contains more than one non-empty subpath.
-
Two points were too far apart for a wiggle operation to merge them.
-
SplitOutsideSegmentThe requested split point is outside the segment’s
0.0..1.0parameter range.
Options for finding segment intersections.
pub type IntersectionOptions {
IntersectionOptions(tolerance: Float, max_depth: Int)
}
Constructors
-
IntersectionOptions(tolerance: Float, max_depth: Int)
Options for minimizing a scalar function along a segment.
pub type MinimizeOptions {
MinimizeOptions(
samples: Int,
tolerance: Float,
max_iterations: Int,
)
}
Constructors
-
MinimizeOptions( samples: Int, tolerance: Float, max_iterations: Int, )
A 2D point.
This is a vec.Vec2(Float), so its coordinates are available as .x and
.y.
pub type Point =
vec2.Vec2(Float)
A single SVG path segment.
pub type Segment {
Line(start: vec2.Vec2(Float), end: vec2.Vec2(Float))
QuadraticBezier(
start: vec2.Vec2(Float),
control: vec2.Vec2(Float),
end: vec2.Vec2(Float),
)
CubicBezier(
start: vec2.Vec2(Float),
control1: vec2.Vec2(Float),
control2: vec2.Vec2(Float),
end: vec2.Vec2(Float),
)
Arc(
start: vec2.Vec2(Float),
radius: vec2.Vec2(Float),
x_axis_rotation: Float,
large_arc: Bool,
sweep: Bool,
end: vec2.Vec2(Float),
)
}
Constructors
-
A straight line segment.
-
A quadratic Bezier curve segment.
-
CubicBezier( start: vec2.Vec2(Float), control1: vec2.Vec2(Float), control2: vec2.Vec2(Float), end: vec2.Vec2(Float), )A cubic Bezier curve segment.
-
Arc( start: vec2.Vec2(Float), radius: vec2.Vec2(Float), x_axis_rotation: Float, large_arc: Bool, sweep: Bool, end: vec2.Vec2(Float), )An elliptical arc segment.
A positioned sequence of path segments, optionally closed.
The first segment, when present, starts at the subpath start point. The last segment of a closed subpath, when present, also ends at the subpath start point. Empty subpaths may be open or closed.
The constructor is opaque so that these invariants are maintained. Use
subpath, empty_subpath, append_segment, or their _with variants to
build values.
pub opaque type Subpath
Values
pub fn append_segment(
subpath: Subpath,
segment: Segment,
) -> Result(Subpath, Error)
Append a segment to an open subpath.
The new segment must start exactly at the current end point.
pub fn append_segment_with(
subpath: Subpath,
segment: Segment,
policy endpoint_policy: EndpointPolicy,
) -> Result(Subpath, Error)
Append a segment to an open subpath using the given endpoint policy.
pub fn arc_from_center_data(
data: ellipse.CenterArcData,
) -> Segment
Create an elliptical arc segment from center-parameter arc data.
pub fn arc_from_endpoint_data(
data: ellipse.EndpointArcData,
) -> Segment
Create an elliptical arc segment from endpoint-parameter arc data.
pub fn as_subpath(path: Path) -> Result(Subpath, Error)
Convert a path with zero or one non-empty subpaths into a subpath.
Empty subpaths are ignored. If more than one non-empty subpath is present,
this returns MultipleNonemptySubpaths. If a path has only empty subpaths,
the first empty subpath is returned.
pub fn assert_append_segment(
subpath: Subpath,
segment: Segment,
) -> Subpath
Append a segment to an open subpath, panicking if invalid.
pub fn assert_append_segment_with(
subpath: Subpath,
segment: Segment,
policy endpoint_policy: EndpointPolicy,
) -> Subpath
Append a segment with an endpoint policy, panicking if invalid.
pub fn assert_join_with(
subpaths: List(Subpath),
policy endpoint_policy: EndpointPolicy,
) -> Subpath
Join open subpaths with an endpoint policy, panicking if invalid.
pub fn assert_set_closed(
subpath: Subpath,
closed closed: Bool,
) -> Subpath
Set a subpath’s semantic closed state, panicking if invalid.
pub fn assert_set_closed_with(
subpath: Subpath,
closed closed: Bool,
policy endpoint_policy: EndpointPolicy,
) -> Subpath
Set a subpath’s semantic closed state with an endpoint policy, panicking if invalid.
pub fn assert_splice(
subpath: Subpath,
start start: Int,
delete delete: Int,
insert insert: List(Segment),
) -> Subpath
Replace a range of segments, panicking if the splice is invalid.
pub fn assert_splice_with(
subpath: Subpath,
start start: Int,
delete delete: Int,
insert insert: List(Segment),
policy endpoint_policy: EndpointPolicy,
) -> Subpath
Replace a range of segments with an endpoint policy, panicking if invalid.
pub fn assert_subpath(segments: List(Segment)) -> Subpath
Create an open subpath from a non-empty continuous list of segments, panicking if the segments are invalid.
This is useful for hand-authored paths where invalid continuity would be a
programmer error. Use subpath when you want to handle construction errors.
pub fn assert_subpath_with(
segments: List(Segment),
policy endpoint_policy: EndpointPolicy,
) -> Subpath
Create an open subpath with an endpoint policy, panicking if construction fails.
pub fn bounding_box_center(box: BoundingBox) -> vec2.Vec2(Float)
Return the center point of a bounding box.
pub fn bounding_box_diameter(box: BoundingBox) -> Float
Return the taxicab diameter of a bounding box.
This is the box width plus the box height.
pub fn bounding_box_height(box: BoundingBox) -> Float
Return the height of a bounding box.
pub fn bounding_box_width(box: BoundingBox) -> Float
Return the width of a bounding box.
pub fn clean_subpath(subpath: Subpath) -> Subpath
Remove zero-length line segments from a subpath.
If cleanup would remove every segment, one zero-length line is preserved so a zero-length drawing subpath does not become a move-only subpath.
pub fn default_crossing_options() -> CrossingOptions
Return the default options for segment crossing detection.
pub fn default_distance_options() -> DistanceOptions
Return the default options for point-to-segment distance measurement.
pub fn default_intersection_options() -> IntersectionOptions
Return the default options for segment intersection detection.
pub fn default_minimize_options() -> MinimizeOptions
Return the default options for segment minimization.
pub fn empty_subpath(at start: vec2.Vec2(Float)) -> Subpath
Create an empty open subpath at a start point.
This represents a move-only subpath such as M 0 0.
pub fn join(subpaths: List(Subpath)) -> Result(Subpath, Error)
Join open subpaths into one open subpath.
Each subpath’s end point must exactly match the next subpath’s start point. Empty open subpaths can act as identity values when their start points line up with their neighbors.
pub fn join_with(
subpaths: List(Subpath),
policy endpoint_policy: EndpointPolicy,
) -> Result(Subpath, Error)
Join open subpaths using the given endpoint policy.
pub fn map_path_points(
path: Path,
with f: fn(vec2.Vec2(Float)) -> vec2.Vec2(Float),
) -> Result(Path, Error)
Map the defining points of every segment in a path.
Each subpath’s closed state is preserved. For nonlinear functions, this maps
endpoints and control points, not the exact image of every point on each
rendered curve. If any segment is an arc, this returns
CannotMapArcNonlinearly.
pub fn map_segment_points(
segment: Segment,
with f: fn(vec2.Vec2(Float)) -> vec2.Vec2(Float),
) -> Result(Segment, Error)
Map the defining points of a segment.
Lines, quadratic Beziers, and cubic Beziers are mapped by applying f to
their endpoints and control points. For nonlinear functions, this is not the
exact image of every point on the rendered curve. Arc segments return
CannotMapArcNonlinearly because an arbitrary nonlinear mapping does not
generally preserve SVG arc parameters.
pub fn map_subpath_points(
subpath: Subpath,
with f: fn(vec2.Vec2(Float)) -> vec2.Vec2(Float),
) -> Result(Subpath, Error)
Map the defining points of every segment in a subpath.
The subpath’s closed state is preserved. For nonlinear functions, this maps
endpoints and control points, not the exact image of every point on each
rendered curve. If any segment is an arc, this returns
CannotMapArcNonlinearly.
pub fn open_at(
subpath: Subpath,
index index: Int,
) -> Result(Subpath, Error)
Break open a closed subpath at the given segment index.
The index denotes the segment that will become the first segment of the
returned open subpath. Negative indices count from the end. index must be
between -length and length, inclusive, where length is the number of
segments in the subpath. After validation, the index is taken modulo the
length, so length, 0, and -length all open at the first segment.
Opening a closed empty subpath at index 0 returns an open empty subpath
with the same start point.
pub fn path_arcs_to_cubic_beziers(path: Path) -> Path
Convert every arc in a path to cubic Bezier curves.
This applies subpath_arcs_to_cubic_beziers to each subpath.
pub fn path_bounding_box(
path: Path,
) -> Result(BoundingBox, Error)
Return the exact axis-aligned bounding box of all non-empty subpaths.
pub fn path_end(path: Path) -> Result(vec2.Vec2(Float), Error)
Return the end point of the last subpath in a path.
pub fn path_filter_subpaths(
path: Path,
keeping predicate: fn(Subpath) -> Bool,
) -> Path
Keep only the subpaths that satisfy a predicate.
pub fn path_map_subpaths(
path: Path,
with f: fn(Subpath) -> Subpath,
) -> Path
Map over the subpaths in a path.
pub fn path_start(path: Path) -> Result(vec2.Vec2(Float), Error)
Return the start point of the first subpath in a path.
pub fn path_to_cubic_beziers(path: Path) -> Path
Convert every segment in a path to cubic Bezier curves.
This applies subpath_to_cubic_beziers to each subpath.
pub fn point(x: Float, y: Float) -> vec2.Vec2(Float)
Create a point from x and y coordinates.
pub fn reverse_path(path: Path) -> Path
Reverse the traversal direction of a path.
This reverses each subpath and reverses the path’s subpath order.
pub fn reverse_subpath(subpath: Subpath) -> Subpath
Reverse the traversal direction of every segment in a subpath.
The subpath’s closed state is preserved.
pub fn segment_arcs_to_cubic_beziers(
segment: Segment,
) -> List(Segment)
Convert an arc segment to cubic Bezier curves, preserving other segments.
Non-arc segments are returned unchanged as a single-item list. An arc may become several cubic Bezier segments.
pub fn segment_bounding_box(
segment: Segment,
) -> Result(BoundingBox, Error)
Return a segment’s exact axis-aligned bounding box.
pub fn segment_crossings(
segment: Segment,
where f: fn(vec2.Vec2(Float)) -> Float,
) -> Result(List(Float), Error)
Find scalar sign-change crossings along a segment using default options.
This samples t in 0.0..1.0, detects sign changes of f(segment_point(t)),
and refines each bracket with bisection. It finds crossings visible at the
configured sampling resolution; tangent roots and pairs of crossings inside
one sample window may be missed.
pub fn segment_crossings_with(
segment: Segment,
where f: fn(vec2.Vec2(Float)) -> Float,
options options: CrossingOptions,
) -> Result(List(Float), Error)
Find scalar sign-change crossings along a segment using explicit options.
pub fn segment_derivative(
segment: Segment,
at t: Float,
) -> Result(vec2.Vec2(Float), Error)
Return a segment’s derivative with respect to parameter t.
t is not clamped.
pub fn segment_distance(
point: vec2.Vec2(Float),
to segment: Segment,
) -> Result(Float, Error)
Return the shortest distance from a point to a segment.
Lines are measured exactly. Quadratic Beziers, cubic Beziers, and arcs are
measured by finding stationary points of squared distance in 0.0..1.0.
pub fn segment_distance_with(
point: vec2.Vec2(Float),
to segment: Segment,
options options: DistanceOptions,
) -> Result(Float, Error)
Return the shortest distance from a point to a segment using explicit options.
pub fn segment_intersections(
left: Segment,
right: Segment,
) -> Result(List(SegmentIntersection), Error)
Return point intersections between two segments.
Overlapping segments return OverlappingSegments, since they have more than
a finite list of point intersections.
pub fn segment_intersections_with(
left: Segment,
right: Segment,
options options: IntersectionOptions,
) -> Result(List(SegmentIntersection), Error)
Return point intersections between two segments using explicit options.
pub fn segment_minimize(
segment: Segment,
measure f: fn(vec2.Vec2(Float)) -> Float,
) -> Result(Float, Error)
Return the segment parameter where a scalar function is minimized.
This numerically minimizes f(segment_point(t)) for t in 0.0..1.0.
pub fn segment_minimize_with(
segment: Segment,
measure f: fn(vec2.Vec2(Float)) -> Float,
options options: MinimizeOptions,
) -> Result(Float, Error)
Return the segment parameter where a scalar function is minimized using explicit options.
pub fn segment_point(
segment: Segment,
at t: Float,
) -> Result(vec2.Vec2(Float), Error)
Evaluate a segment at parameter t.
t is not clamped. Values outside 0.0..1.0 extrapolate along the same
segment.
pub fn segment_to_cubic_beziers(
segment: Segment,
) -> List(Segment)
Convert a segment to one or more cubic Bezier curves.
Lines and quadratic Beziers are converted exactly. Cubic Beziers are returned unchanged. Arcs may become several cubic Bezier segments.
pub fn set_closed(
subpath: Subpath,
closed closed: Bool,
) -> Result(Subpath, Error)
Set a subpath’s semantic closed state.
Setting closed to False always succeeds. Setting it to True requires a
non-empty subpath’s end point to exactly match its start point. Empty
subpaths may be closed.
pub fn set_closed_with(
subpath: Subpath,
closed closed: Bool,
policy endpoint_policy: EndpointPolicy,
) -> Result(Subpath, Error)
Set a subpath’s semantic closed state with an endpoint policy.
Setting closed to False always succeeds. Setting it to True uses the
given endpoint policy to reconcile a non-empty subpath’s end point with its
start point. Empty subpaths may be closed.
pub fn splice(
subpath: Subpath,
start start: Int,
delete delete: Int,
insert insert: List(Segment),
) -> Result(Subpath, Error)
Replace a range of segments in a subpath.
start is a zero-based segment index and delete is the number of
segments to remove. If start + delete extends past the end of the subpath,
everything from start onward is deleted. Negative start, negative
delete, and start greater than the subpath length return
InvalidSplice.
The edited subpath must remain continuous. Closed subpaths preserve their closed state. If the splice result is nonempty, the subpath start is updated to the first resulting segment’s start point. If the splice result is empty, the previous start point is preserved.
pub fn splice_with(
subpath: Subpath,
start start: Int,
delete delete: Int,
insert insert: List(Segment),
policy endpoint_policy: EndpointPolicy,
) -> Result(Subpath, Error)
Replace a range of segments in a subpath using the given endpoint policy.
pub fn split_segment(
segment: Segment,
at t: Float,
) -> Result(#(Segment, Segment), Error)
Split a segment at parameter t.
t is not clamped. Values outside 0.0..1.0 extrapolate along the same
segment.
pub fn split_segment_inside(
segment: Segment,
at t: Float,
) -> Result(#(Segment, Segment), Error)
Split a segment at parameter t, returning an error outside 0.0..1.0.
Values exactly at 0.0 or 1.0 are accepted and produce one zero-length
segment.
pub fn start(subpath: Subpath) -> Result(vec2.Vec2(Float), Error)
Return the start point of a subpath.
pub fn sub_segment(
segment: Segment,
from from: Float,
to to: Float,
) -> Result(Segment, Error)
Return the portion of a segment between two parameters.
from and to are not clamped. Values outside 0.0..1.0 extrapolate
along the same segment. If from is greater than to, the returned segment
traverses the interval in reverse.
pub fn sub_segment_inside(
segment: Segment,
from from: Float,
to to: Float,
) -> Result(Segment, Error)
Return the portion of a segment between two parameters.
from and to must be inside 0.0..1.0, inclusive. If from is greater
than to, the returned segment traverses the interval in reverse.
pub fn sub_segments(
segment: Segment,
between points: List(Float),
) -> Result(List(Segment), Error)
Return segment portions between adjacent parameters.
Parameters are not clamped. Values outside 0.0..1.0 extrapolate along the
same segment. Empty and singleton lists return an empty list.
pub fn sub_segments_inside(
segment: Segment,
between points: List(Float),
) -> Result(List(Segment), Error)
Return segment portions between adjacent parameters.
All parameters must be inside 0.0..1.0, inclusive. Empty and singleton
lists return an empty list.
pub fn subpath(segments: List(Segment)) -> Result(Subpath, Error)
Create an open subpath from a non-empty continuous list of segments.
Returns EmptySubpath if the segment list is empty. Use empty_subpath
when you need to represent a move-only subpath.
Returns Discontinuous if any segment starts somewhere other than the
previous segment’s end point. The error includes the two segment indices
that failed to meet.
pub fn subpath_arcs_to_cubic_beziers(subpath: Subpath) -> Subpath
Convert every arc in a subpath to cubic Bezier curves.
Lines, quadratic Beziers, and cubic Beziers are preserved. Elliptical arcs are approximated with one or more cubic Beziers, split into chunks of at most a quarter turn. Degenerate arcs fall back to a straight-line cubic Bezier between their endpoints.
pub fn subpath_bounding_box(
subpath: Subpath,
) -> Result(BoundingBox, Error)
Return a non-empty subpath’s exact axis-aligned bounding box.
pub fn subpath_to_cubic_beziers(subpath: Subpath) -> Subpath
Convert every segment in a subpath to cubic Bezier curves.
Lines and quadratic Beziers are converted exactly. Cubic Beziers are preserved. Elliptical arcs are approximated with one or more cubic Beziers, split into chunks of at most a quarter turn.
pub fn subpath_with(
segments: List(Segment),
policy endpoint_policy: EndpointPolicy,
) -> Result(Subpath, Error)
Create an open subpath using the given endpoint reconciliation policy.
Empty segment lists still return EmptySubpath.