aboutsummaryrefslogtreecommitdiff
path: root/svg-flatten/src/svg_pattern.cpp
blob: fc74d734e270f9a68aecb3358c9c074627615c3a (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
/*
 * 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/>.
 */

#include <assert.h>
#include "svg_import_util.h"
#include "svg_pattern.h"
#include "svg_import_defs.h"
#include "svg_geom.h"
#include <gerbolyze.hpp>

using namespace std;

gerbolyze::Pattern::Pattern(const pugi::xml_node &node, SVGDocument &doc) : _node(node), doc(&doc) {
    /* Read pattern attributes from SVG node */
    x = usvg_double_attr(node, "x");
    y = usvg_double_attr(node, "y");
    w = usvg_double_attr(node, "width");
    h = usvg_double_attr(node, "height");

    patternTransform = xform2d(node.attribute("patternTransform").value());

    bool invert_success = false;
    patternTransform_inv = xform2d(patternTransform).invert(&invert_success);
    if (!invert_success) {
        cerr << "Warning: Cannot invert patternTransform matrix on pattern \"" << node.attribute("id").value() << "\"." << endl;
    }

    string vb_s(node.attribute("viewBox").value());
    has_vb = !vb_s.empty();
    if (has_vb) {
        istringstream vb_stream(vb_s);
        vb_stream >> vb_x >> vb_y >> vb_w >> vb_h;
    }

    patternUnits = map_str_to_units(node.attribute("patternUnits").value(), SVG_ObjectBoundingBox);
    patternContentUnits = map_str_to_units(node.attribute("patternContentUnits").value(), SVG_UserSpaceOnUse);
}

/* Tile pattern into gerber. Note that this function may be called several times in case the pattern is
 * referenced from multiple places, so we must not clobber any of the object's state. */
void gerbolyze::Pattern::tile (gerbolyze::RenderContext &ctx) {
    assert(doc);

    /* Transform x, y, w, h from pattern coordinate space into parent coordinates by applying the inverse
     * patternTransform. This is necessary so we iterate over the correct bounds when tiling below */
    d2p pos_xf = ctx.mat().doc2phys(d2p{x, y});
    double inst_x = pos_xf[0], inst_y = pos_xf[1];
    double inst_w = ctx.mat().doc2phys_dist(w);
    double inst_h = ctx.mat().doc2phys_dist(h);

    ClipperLib::IntRect clip_bounds = get_paths_bounds(ctx.clip());
    double bx = clip_bounds.left / clipper_scale;
    double by = clip_bounds.top / clipper_scale;
    double bw = (clip_bounds.right - clip_bounds.left) / clipper_scale;
    double bh = (clip_bounds.bottom - clip_bounds.top) / clipper_scale;

    d2p clip_p0 = patternTransform_inv.doc2phys(d2p{bx, by});
    d2p clip_p1 = patternTransform_inv.doc2phys(d2p{bx+bw, by+bh});

    bx = fmin(clip_p0[0], clip_p1[0]);
    by = fmin(clip_p0[1], clip_p1[1]);
    bw = fmax(clip_p0[0], clip_p1[0]) - bx;
    bh = fmax(clip_p0[1], clip_p1[1]) - by;

    if (patternUnits == SVG_ObjectBoundingBox) {
        inst_x *= bw;
        inst_y *= bh;
        inst_w *= bw;
        inst_h *= bh;
    }

    /* Switch to pattern coordinates */
    RenderContext pat_ctx(ctx, patternTransform);

    /* Iterate over all pattern tiles in pattern coordinates */
    for (double inst_off_x = fmod(inst_x, inst_w) - 2*inst_w;
            inst_off_x < bx + bw + 2*inst_w;
            inst_off_x += inst_w) {

        for (double inst_off_y = fmod(inst_y, inst_h) - 2*inst_h;
                inst_off_y < by + bh + 2*inst_h;
                inst_off_y += inst_h) {

            xform2d elem_xf;
            /* Change into this individual tile's coordinate system */
            elem_xf.translate(inst_off_x, inst_off_y);
            if (has_vb) {
                elem_xf.translate(vb_x, vb_y);
                elem_xf.scale(inst_w / vb_w, inst_h / vb_h);
            } else if (patternContentUnits == SVG_ObjectBoundingBox) {
                elem_xf.scale(bw, bh);
            }

            /* Export the pattern tile's content like a group */
            RenderContext elem_ctx(pat_ctx, elem_xf);

            if (ctx.settings().pattern_complete_tiles_only) {
                ClipperLib::Clipper c;

                double eps = 1e-6;
                Polygon poly = {{eps, eps}, {inst_w-eps, eps}, {inst_w-eps, inst_h-eps}, {eps, inst_h-eps}};
                elem_ctx.mat().transform_polygon(poly);
                ClipperLib::Path path(poly.size());
                for (size_t i=0; i<poly.size(); i++) {
                    long long int x = poly[i][0] * clipper_scale, y = poly[i][1] * clipper_scale;
                    path[i] = {x, y};
                }

                ClipperLib::Paths out;
                c.StrictlySimple(true);
                c.AddPath(path, ClipperLib::ptSubject, /* closed */ true);
                c.AddPaths(elem_ctx.clip(), ClipperLib::ptClip, /* closed */ true);
                c.Execute(ClipperLib::ctDifference, out, ClipperLib::pftNonZero);
                if (out.size() > 0) {
                    continue;
                }
            }

            doc->export_svg_group(elem_ctx, _node);
        }
    }
}