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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
commit | cca66b9ec4e494c1d919bff0f71a820d8afab1fa (patch) | |
tree | 146f39ded1c938019e1ed42d30923c2ac9e86789 /src/line-geometry.h | |
parent | Initial commit. (diff) | |
download | inkscape-upstream.tar.xz inkscape-upstream.zip |
Adding upstream version 1.2.2.upstream/1.2.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/line-geometry.h | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/src/line-geometry.h b/src/line-geometry.h new file mode 100644 index 0000000..9837b37 --- /dev/null +++ b/src/line-geometry.h @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Routines for dealing with lines (intersections, etc.) + * + * Authors: + * Maximilian Albert <Anhalter42@gmx.de> + * + * Copyright (C) 2007 authors + * + * Released under GNU GPL v2+, read the file 'COPYING' for more information. + */ + +#ifndef SEEN_LINE_GEOMETRY_H +#define SEEN_LINE_GEOMETRY_H + +#include <2geom/point.h> +#include <optional> + +#include "axis-manip.h" // FIXME: This is only for Box3D::epsilon; move that to a better location +#include "object/persp3d.h" + +class SPDesktop; +typedef unsigned int guint32; + +namespace Box3D { + +class Line { +public: + Line(Geom::Point const &start, Geom::Point const &vec, bool is_endpoint = true); + Line(Line const &line); + virtual ~Line() = default; + Line &operator=(Line const &line); + virtual std::optional<Geom::Point> intersect(Line const &line); + inline Geom::Point direction () { return v_dir; } + + Geom::Point closest_to(Geom::Point const &pt); // returns the point on the line closest to pt + + friend inline std::ostream &operator<< (std::ostream &out_file, const Line &in_line); + std::optional<Geom::Point> intersection_with_viewbox (SPDesktop *desktop); + inline bool lie_on_same_side (Geom::Point const &A, Geom::Point const &B) { + /* If A is a point in the plane and n is the normal vector of the line then + the sign of dot(A, n) specifies the half-plane in which A lies. + Thus A and B lie on the same side if the dot products have equal sign. */ + return ((Geom::dot(A, normal) - d0) * (Geom::dot(B, normal) - d0)) > 0; + } + + double lambda (Geom::Point const pt); + inline Geom::Point point_from_lambda (double const lambda) { + return (pt + lambda * Geom::unit_vector (v_dir)); } + +protected: + void set_direction(Geom::Point const &dir); + inline static bool pts_coincide (Geom::Point const pt1, Geom::Point const pt2) + { + return (Geom::L2 (pt2 - pt1) < epsilon); + } + + Geom::Point pt; + Geom::Point v_dir; + Geom::Point normal; + Geom::Coord d0; +}; + +inline double determinant (Geom::Point const &a, Geom::Point const &b) +{ + return (a[Geom::X] * b[Geom::Y] - a[Geom::Y] * b[Geom::X]); +} +std::pair<double, double> coordinates (Geom::Point const &v1, Geom::Point const &v2, Geom::Point const &w); +bool lies_in_sector (Geom::Point const &v1, Geom::Point const &v2, Geom::Point const &w); +bool lies_in_quadrangle (Geom::Point const &A, Geom::Point const &B, Geom::Point const &C, Geom::Point const &D, Geom::Point const &pt); +std::pair<Geom::Point, Geom::Point> side_of_intersection (Geom::Point const &A, Geom::Point const &B, + Geom::Point const &C, Geom::Point const &D, + Geom::Point const &pt, Geom::Point const &dir); + +/** A function to print out the Line. It just prints out the coordinates of start point and + direction on the given output stream */ +inline std::ostream &operator<< (std::ostream &out_file, const Line &in_line) { + out_file << "Start: " << in_line.pt << " Direction: " << in_line.v_dir; + return out_file; +} + +} // namespace Box3D + + +#endif /* !SEEN_LINE_GEOMETRY_H */ + +/* + Local Variables: + mode:c++ + c-file-style:"stroustrup" + c-file-offsets:((innamespace . 0)(inline-open . 0)) + indent-tabs-mode:nil + fill-column:99 + End: +*/ +// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 : |