aboutsummaryrefslogtreecommitdiff
path: root/svg-flatten/include/geom2d.hpp
blob: ac5662834cc1b149606414913a11408b5f750983 (plain)
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
145
146
147
148
149
150
151
152
153
154
155
156
157
/*
 * This file is part of gerbolyze, a vector image preprocessing toolchain 
 * Copyright (C) 2021 Jan Sebastian Götte <gerbolyze@jaseg.de>
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#pragma once

#include <array>
#include <string>
#include <sstream>
#include <cmath>
#include <algorithm>

#include <clipper.hpp>

#include "svg_import_defs.h"

using namespace std;

namespace gerbolyze {

    typedef std::array<double, 2> d2p;
    typedef std::vector<d2p> Polygon;

    class xform2d {
        public:
            xform2d(double xx, double yx, double xy, double yy, double x0=0.0, double y0=0.0) :
                xx(xx), yx(yx), xy(xy), yy(yy), x0(x0), y0(y0) {}
            
            xform2d() : xform2d(1.0, 0.0, 0.0, 1.0) {}

            xform2d(const string &svg_transform) : xform2d() {
                if (svg_transform.empty())
                    return;

                string start("matrix(");
                if (svg_transform.substr(0, start.length()) != start)
                    return;
                if (svg_transform.back() != ')')
                    return;

                const string &foo = svg_transform.substr(start.length(), svg_transform.length());
                const string &bar = foo.substr(0, foo.length() - 1);

                istringstream xform(bar);

                double a, c, e,
                       b, d, f;
                xform >> a >> b >> c >> d >> e >> f;
                if (xform.fail())
                    return;

                xx=a, yx=b, xy=c, yy=d, x0=e, y0=f;
            }

            xform2d &translate(double x, double y) {
                x0 += x;
                y0 += y;
                return *this;
            }

            xform2d &scale(double x, double y) {
                xx *= x; yx *= y; xy *= x;
                yy *= y; x0 *= x; y0 *= y;
                return *this;
            }

            xform2d &transform(const xform2d &other) {
                double n_xx = xx * other.xx + yx * other.xy;
                double n_yx = xx * other.yx + yx * other.yy;

                double n_xy = xy * other.xx + yy * other.xy;
                double n_yy = xy * other.yx + yy * other.yy;

                double n_x0 = x0 * other.xx + y0 * other.xy + other.x0;
                double n_y0 = x0 * other.yx + y0 * other.yy + other.y0;

                xx = n_xx;
                yx = n_yx;
                xy = n_xy;
                yy = n_yy;
                x0 = n_x0;
                y0 = n_y0;

                return *this;
            };

            double doc2phys_dist(double dist_doc) {
                return xx * dist_doc;
            }

            double phys2doc_dist(double dist_doc) {
                return xx * dist_doc;
            }

            d2p doc2phys(const d2p p) {
                return d2p {
                    xx * p[0] + xy * p[1] + x0,
                    xy * p[1] + yy * p[1] + y0
                };
            }

            xform2d &invert(bool *success_out=nullptr) {
                /* From Cairo source */

                /* inv (A) = 1/det (A) * adj (A) */
                double det = xx*yy - yx*xy;

                if (det == 0 || !isfinite(det)) {
                    if (success_out)
                        *success_out = false;
                    *this = xform2d(); /* unity matrix */
                    return *this;
                }

                *this = xform2d(yy/det, -yx/det,
                        -xy/det, xx/det,
                        (xy*y0 - yy*x0)/det, (yx*x0 - xx*y0)/det);

                if (success_out)
                    *success_out = true;
                return *this;
            }

            /* Transform given clipper paths */
            void transform_paths(ClipperLib::Paths &paths) {
                for (auto &p : paths) {
                    std::transform(p.begin(), p.end(), p.begin(),
                            [this](ClipperLib::IntPoint p) -> ClipperLib::IntPoint {
                                d2p out(this->doc2phys(d2p{p.X / clipper_scale, p.Y / clipper_scale}));
                                return {
                                    (ClipperLib::cInt)round(out[0] * clipper_scale),
                                    (ClipperLib::cInt)round(out[1] * clipper_scale)
                                };
                            });
                }
            }

        private:
            double xx, yx,
                   xy, yy,
                   x0, y0;
    };
}