summaryrefslogtreecommitdiffstats
path: root/src/live_effects/lpe-spiro.cpp
blob: e0464a2a04ed36a50924ec3d841510dbd6e4b275 (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
// SPDX-License-Identifier: GPL-2.0-or-later
#define INKSCAPE_LPE_SPIRO_C

/*
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */

#include "live_effects/lpe-spiro.h"

#include "display/curve.h"
#include <2geom/curves.h>
#include "helper/geom-nodetype.h"
#include "helper/geom-curves.h"

#include "live_effects/spiro.h"

// For handling un-continuous paths:
#include "message-stack.h"
#include "inkscape.h"

namespace Inkscape {
namespace LivePathEffect {

LPESpiro::LPESpiro(LivePathEffectObject *lpeobject) :
    Effect(lpeobject)
{
}

LPESpiro::~LPESpiro()
= default;

void
LPESpiro::doEffect(SPCurve * curve)
{
    sp_spiro_do_effect(curve);
}

void sp_spiro_do_effect(SPCurve *curve){
    using Geom::X;
    using Geom::Y;

    // Make copy of old path as it is changed during processing
    Geom::PathVector const original_pathv = curve->get_pathvector();
    guint len = curve->get_segment_count() + 2;

    curve->reset();
    Spiro::spiro_cp *path = g_new (Spiro::spiro_cp, len);
    int ip = 0;

    for(const auto & path_it : original_pathv) {
        if (path_it.empty())
            continue;

        // start of path
        {
            Geom::Point p = path_it.initialPoint();
            path[ip].x = p[X];
            path[ip].y = p[Y];
            path[ip].ty = '{' ;  // for closed paths, this is overwritten
            ip++;
        }

        // midpoints
        Geom::Path::const_iterator curve_it1 = path_it.begin();      // incoming curve
        Geom::Path::const_iterator curve_it2 = ++(path_it.begin());         // outgoing curve
        Geom::Path::const_iterator curve_endit = path_it.end_default(); // this determines when the loop has to stop

        while ( curve_it2 != curve_endit )
        {
            /* This deals with the node between curve_it1 and curve_it2.
             * Loop to end_default (so without last segment), loop ends when curve_it2 hits the end
             * and then curve_it1 points to end or closing segment */
            Geom::Point p = curve_it1->finalPoint();
            path[ip].x = p[X];
            path[ip].y = p[Y];

            // Determine type of spiro node this is, determined by the tangents (angles) of the curves
            // TODO: see if this can be simplified by using /helpers/geom-nodetype.cpp:get_nodetype
            bool this_is_line = is_straight_curve(*curve_it1);
            bool next_is_line = is_straight_curve(*curve_it2);

            Geom::NodeType nodetype = Geom::get_nodetype(*curve_it1, *curve_it2);

            if ( nodetype == Geom::NODE_SMOOTH || nodetype == Geom::NODE_SYMM )
            {
                if (this_is_line && !next_is_line) {
                    path[ip].ty = ']';
                } else if (next_is_line && !this_is_line) {
                    path[ip].ty = '[';
                } else {
                    path[ip].ty = 'c';
                }
            } else {
                path[ip].ty = 'v';
            }

            ++curve_it1;
            ++curve_it2;
            ip++;
        }

        // add last point to the spiropath
        Geom::Point p = curve_it1->finalPoint();
        path[ip].x = p[X];
        path[ip].y = p[Y];
        if (path_it.closed()) {
            // curve_it1 points to the (visually) closing segment. determine the match between first and this last segment (the closing node)
            Geom::NodeType nodetype = Geom::get_nodetype(*curve_it1, path_it.front());
            switch (nodetype) {
                case Geom::NODE_NONE: // can't happen! but if it does, it means the path isn't closed :-)
                    path[ip].ty = '}';
                    ip++;
                    break;
                case Geom::NODE_CUSP:
                    path[0].ty = path[ip].ty = 'v';
                    break;
                case Geom::NODE_SMOOTH:
                case Geom::NODE_SYMM:
                    path[0].ty = path[ip].ty = 'c';
                    break;
            }
        } else {
            // set type to path closer
            path[ip].ty = '}';
            ip++;
        }

        // run subpath through spiro
        int sp_len = ip;
        Spiro::spiro_run(path, sp_len, *curve);
        ip = 0;
    }

    g_free (path);
}

}; //namespace LivePathEffect
}; /* namespace Inkscape */

/*
  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 :