Module flo_curves::bezier::path

source ·
Expand description

Manipulates multiple Bezier curves joined into a path

let rectangle = BezierPathBuilder::<SimpleBezierPath>::start(Coord2(1.0, 1.0))
    .line_to(Coord2(5.0, 1.0))
    .line_to(Coord2(5.0, 5.0))
    .line_to(Coord2(1.0, 5.0))
    .line_to(Coord2(1.0, 1.0))
    .build();
let circle = Circle::new(Coord2(3.0, 3.0), 1.0).to_path::<SimpleBezierPath>();

let rectangle_with_hole = path_sub::<SimpleBezierPath>(&vec![rectangle], &vec![circle], 0.01);

Anything that implements the BezierPath trait can be treated as a path. The SimpleBezierPath type is provided as a convenient default implementation of this trait. These paths represent a single perimeter of a region.

The arithmetic operations such as path_sub(), path_add(), path_intersect() all work with collections of these perimeters, stored in a Vec. A path with a hole in the middle will have two perimeters, for example.

These perimeters must not be self-intersecting: flo_curves doesn’t use a winding rule as such but instead considers all edges to be exterior edges (which is very similar to an even-odd winding rule). A couple of methods are provided for fixing paths with self-intersections: path_remove_interior_points() will find the outermost perimeter of a shape - which is useful for tidying up the subpaths. path_remove_overlapped_points() will combine subpaths so that there are no overlapping edges. These two functions provide much finer control than is possible through the traditional idea of the winding rule.

There are a few more advanced algorithms: for example, the flood_fill_concave() function provides a vector implementation of the flood fill algorithm, returning a path that fills a space defined by a ray-casting function.

Modules

Structs

  • BezierPathBuilder
    Used to build a bezier path
  • GraphEdge
    Represents an edge in a graph path
  • GraphEdgeRef
    Reference to a graph edge
  • GraphPath
    A graph path is a path where each point can have more than one connected edge. Edges are categorized into interior and exterior edges depending on if they are on the outside or the inside of the combined shape.
  • PathCut
    The result of a path cut operation
  • PathIntersection
    The result of a path cut operation
  • PathLabel
    Label attached to a path used for arithmetic

Enums

Traits

  • BezierPath
    Trait representing a path made out of bezier sections
  • BezierPathFactory
    Trait implemented by types that can construct new bezier paths
  • PathWithIsClockwise
    Trait implemented by paths that can determine if their points are in a clockwise ordering or not

Functions

  • path_add
    Generates the path formed by adding two sets of paths
  • path_add_chain
    Adds multiple paths in a single operation
  • path_bounding_box
    Finds the bounds of a path
  • path_combine
    Performs a series of path combining operations to generate an output path
  • path_contains_point
    Returns true if a particular point is within a bezier path
  • path_cut
    Cuts a path (path1) into two along another path (path2), returning the part of path1 that was interior to path2 and the part that was exterior in one operation
  • path_fast_bounding_box
    Finds the bounds of a path using the looser ‘fast’ algorithm
  • path_full_intersect
    Intersects two paths, returning both the path that is the intersection and the paths that are outside
  • path_intersect
    Generates the path formed by intersecting two sets of paths
  • path_intersects_line
    Determines the intersections of a path and a line
  • path_intersects_path
    Finds the points where a path intersects another path
  • path_intersects_ray
    Determines the intersections of a path and a ray.
  • path_remove_interior_points
    Generates the path formed by removing any interior points from an existing path. This considers only the outermost edges of the path to be the true edges, so if there are sub-paths inside an outer path, they will be removed.
  • path_remove_overlapped_points
    Generates the path formed by removing any interior points from an existing path. This considers all edges to be exterior edges and will remove those that are obscured by another part of the path.
  • path_sub
    Generates the path formed by subtracting two sets of paths
  • path_to_curves
    Converts a path to a series of bezier curves
  • points_are_clockwise
    Determines if a set of points are in a clockwise ordering (assuming that a positive y value indicates an upwards direction)

Type Definitions