summaryrefslogtreecommitdiffstats
path: root/src/object/sp-polygon.cpp
blob: b92dfcbe7640fedb116d93c28b0a9e01cf8cd961 (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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * SVG <polygon> implementation
 *
 * Authors:
 *   Lauris Kaplinski <lauris@kaplinski.com>
 *   Abhishek Sharma
 *
 * Copyright (C) 1999-2002 Lauris Kaplinski
 * Copyright (C) 2000-2001 Ximian, Inc.
 *
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */

#include "attributes.h"
#include "sp-polygon.h"
#include "display/curve.h"
#include <glibmm/i18n.h>
#include <2geom/curves.h>
#include "helper/geom-curves.h"
#include "svg/stringstream.h"
#include "xml/repr.h"
#include "document.h"

SPPolygon::SPPolygon() : SPShape() {
}

SPPolygon::~SPPolygon() = default;

void SPPolygon::build(SPDocument *document, Inkscape::XML::Node *repr) {
	SPPolygon* object = this;

    SPShape::build(document, repr);

    object->readAttr(SPAttr::POINTS);
}

/*
 * sp_svg_write_polygon: Write points attribute for polygon tag.
 * pathv may only contain paths with only straight line segments
 * Return value: points attribute string.
 */
static gchar *sp_svg_write_polygon(Geom::PathVector const & pathv)
{
    Inkscape::SVGOStringStream os;

    for (const auto & pit : pathv) {
        for (Geom::Path::const_iterator cit = pit.begin(); cit != pit.end_default(); ++cit) {
            if ( is_straight_curve(*cit) )
            {
                os << cit->finalPoint()[0] << "," << cit->finalPoint()[1] << " ";
            } else {
                g_error("sp_svg_write_polygon: polygon path contains non-straight line segments");
            }
        }
    }

    return g_strdup(os.str().c_str());
}

Inkscape::XML::Node* SPPolygon::write(Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, guint flags) {
    // Tolerable workaround: we need to update the object's curve before we set points=
    // because it's out of sync when e.g. some extension attrs of the polygon or star are changed in XML editor
	this->set_shape();

    if ((flags & SP_OBJECT_WRITE_BUILD) && !repr) {
        repr = xml_doc->createElement("svg:polygon");
    }

    /* We can safely write points here, because all subclasses require it too (Lauris) */
    /* While saving polygon element without points attribute _curve is NULL (see bug 1202753) */
    if (this->_curve != nullptr) {
        gchar *str = sp_svg_write_polygon(this->_curve->get_pathvector());
        repr->setAttribute("points", str);
        g_free(str);
    }

    SPShape::write(xml_doc, repr, flags);

    return repr;
}


static gboolean polygon_get_value(gchar const **p, gdouble *v)
{
    while (**p != '\0' && (**p == ',' || **p == '\x20' || **p == '\x9' || **p == '\xD' || **p == '\xA')) {
        (*p)++;
    }

    if (**p == '\0') {
        return false;
    }

    gchar *e = nullptr;
    *v = g_ascii_strtod(*p, &e);

    if (e == *p) {
        return false;
    }

    *p = e;

    return true;
}

void SPPolygon::set(SPAttr key, const gchar* value) {
    switch (key) {
        case SPAttr::POINTS: {
            if (!value) {
                /* fixme: The points attribute is required.  We should handle its absence as per
                 * http://www.w3.org/TR/SVG11/implnote.html#ErrorProcessing. */
                break;
            }

            auto curve = std::make_unique<SPCurve>();
            gboolean hascpt = FALSE;

            gchar const *cptr = value;
            bool has_error = false;

            while (TRUE) {
                gdouble x;

                if (!polygon_get_value(&cptr, &x)) {
                    break;
                }

                gdouble y;

                if (!polygon_get_value(&cptr, &y)) {
                    /* fixme: It is an error for an odd number of points to be specified.  We
                     * should display the points up to now (as we currently do, though perhaps
                     * without the closepath: the spec isn't quite clear on whether to do a
                     * closepath or not, though I'd guess it's best not to do a closepath), but
                     * then flag the document as in error, as per
                     * http://www.w3.org/TR/SVG11/implnote.html#ErrorProcessing.
                     *
                     * (Ref: http://www.w3.org/TR/SVG11/shapes.html#PolygonElement.) */
                    has_error = true;
                    break;
                }

                if (hascpt) {
                    curve->lineto(x, y);
                } else {
                    curve->moveto(x, y);
                    hascpt = TRUE;
                }
            }

            if (has_error || *cptr != '\0') {
                /* TODO: Flag the document as in error, as per
                 * http://www.w3.org/TR/SVG11/implnote.html#ErrorProcessing. */
            } else if (hascpt) {
                /* We might have done a moveto but no lineto.  I'm not sure how we're supposed to represent
                 * a single-point polygon in SPCurve. TODO: add a testcase with only one coordinate pair */
                curve->closepath();
            }

            setCurve(std::move(curve));
            break;
        }
        default:
            SPShape::set(key, value);
            break;
    }
}

const char* SPPolygon::typeName() const {
    return "path";
}

gchar* SPPolygon::description() const {
    return g_strdup(_("<b>Polygon</b>"));
}

/*
  Local Variables:
  mode:c++
  c-file-style:"stroustrup"
  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  indent-tabs-mode:nil
  fill-column:99
  End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :