1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144

//! Paths through 2D and 3D space
//!
//! See [`SurfacePath`] and [`GlobalPath`].
//!
//! # Implementation Note
//!
//! This is a bit of an in-between module. It is closely associated with curves
//! ([`Curve`]/[`GlobalCurve`]) and [`Surface`]s, but paths are not really
//! objects themselves, as logically speaking, they are owned and not referenced
//! (practically speaking, all objects are owned and not referenced, but that is
//! an implementation detail; see [#1021] for context on where things are
//! going).
//!
//! On the other hand, the types in this module don't follow the general style
//! of types in `fj-math`.
//!
//! We'll see how it shakes out. Maybe it will stay its own thing, maybe it will
//! move to `fj-math`, maybe something else entirely will happen.
//!
//! [`Curve`]: crate::objects::Curve
//! [`GlobalCurve`]: crate::objects::GlobalCurve
//! [`Surface`]: crate::objects::Surface
//! [#1021]: https://github.com/hannobraun/Fornjot/issues/1021

use fj_math::{Circle, Line, Point, Scalar, Vector};

/// A path through surface (2D) space
#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
pub enum SurfacePath {
    /// A circle
    Circle(Circle<2>),

    /// A line
    Line(Line<2>),
}

impl SurfacePath {
    /// Build a circle from the given radius
    pub fn circle_from_radius(radius: impl Into<Scalar>) -> Self {
        let radius = radius.into();

        SurfacePath::Circle(Circle::from_center_and_radius(
            Point::origin(),
            radius,
        ))
    }

    /// Construct a line from two points
    pub fn line_from_points(points: [impl Into<Point<2>>; 2]) -> Self {
        Self::Line(Line::from_points(points))
    }

    /// Convert a point on the path into global coordinates
    pub fn point_from_path_coords(
        &self,
        point: impl Into<Point<1>>,
    ) -> Point<2> {
        match self {
            Self::Circle(circle) => circle.point_from_circle_coords(point),
            Self::Line(line) => line.point_from_line_coords(point),
        }
    }
}

/// A path through global (3D) space
#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
pub enum GlobalPath {
    /// A circle
    Circle(Circle<3>),

    /// A line
    Line(Line<3>),
}

impl GlobalPath {
    /// Construct a `GlobalPath` that represents the x-axis
    pub fn x_axis() -> Self {
        Self::Line(Line::from_origin_and_direction(
            Point::origin(),
            Vector::unit_x(),
        ))
    }

    /// Construct a `GlobalPath` that represents the y-axis
    pub fn y_axis() -> Self {
        Self::Line(Line::from_origin_and_direction(
            Point::origin(),
            Vector::unit_y(),
        ))
    }

    /// Construct a `GlobalPath` that represents the z-axis
    pub fn z_axis() -> Self {
        Self::Line(Line::from_origin_and_direction(
            Point::origin(),
            Vector::unit_z(),
        ))
    }

    /// Build a circle from the given radius
    pub fn circle_from_radius(radius: impl Into<Scalar>) -> Self {
        let radius = radius.into();

        GlobalPath::Circle(Circle::from_center_and_radius(
            Point::origin(),
            radius,
        ))
    }

    /// Construct a line from two points
    pub fn line_from_points(points: [impl Into<Point<3>>; 2]) -> Self {
        Self::Line(Line::from_points(points))
    }

    /// Access the origin of the path's coordinate system
    pub fn origin(&self) -> Point<3> {
        match self {
            Self::Circle(circle) => circle.center() + circle.a(),
            Self::Line(line) => line.origin(),
        }
    }

    /// Convert a point on the path into global coordinates
    pub fn point_from_path_coords(
        &self,
        point: impl Into<Point<1>>,
    ) -> Point<3> {
        match self {
            Self::Circle(circle) => circle.point_from_circle_coords(point),
            Self::Line(line) => line.point_from_line_coords(point),
        }
    }

    /// Convert a vector on the path into global coordinates
    pub fn vector_from_path_coords(
        &self,
        vector: impl Into<Vector<1>>,
    ) -> Vector<3> {
        match self {
            Self::Circle(circle) => circle.vector_from_circle_coords(vector),
            Self::Line(line) => line.vector_from_line_coords(vector),
        }
    }
}