summaryrefslogtreecommitdiffstats
path: root/src/svg/path-string.cpp
blob: 516fe3583e7c4036d8fb09c416a1b8f6c1855538 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/** @file
 * Inkscape::SVG::PathString - builder for SVG path strings
 *//*
 * Authors: see git history
 * 
 * Copyright 2008 Jasper van de Gronde <th.v.d.gronde@hccnet.nl>
 * Copyright 2013 Tavmjong Bah <tavmjong@free.fr>
 * Copyright (C) 2018 Authors
 * 
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */

#include "svg/path-string.h"
#include "svg/stringstream.h"
#include "svg/svg.h"
#include "preferences.h"

// 1<=numericprecision<=16, doubles are only accurate upto (slightly less than) 16 digits (and less than one digit doesn't make sense)
// Please note that these constants are used to allocate sufficient space to hold serialized numbers
static int const minprec = 1;
static int const maxprec = 16;

int Inkscape::SVG::PathString::numericprecision;
int Inkscape::SVG::PathString::minimumexponent;
Inkscape::SVG::PATHSTRING_FORMAT Inkscape::SVG::PathString::format;

Inkscape::SVG::PathString::PathString() :
    force_repeat_commands(!Inkscape::Preferences::get()->getBool("/options/svgoutput/disable_optimizations" ) && Inkscape::Preferences::get()->getBool("/options/svgoutput/forcerepeatcommands"))
{
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
    format = (PATHSTRING_FORMAT)prefs->getIntLimited("/options/svgoutput/pathstring_format", 1, 0, PATHSTRING_FORMAT_SIZE - 1 );
    numericprecision = std::max<int>(minprec,std::min<int>(maxprec, prefs->getInt("/options/svgoutput/numericprecision", 8)));
    minimumexponent = prefs->getInt("/options/svgoutput/minimumexponent", -8);
}

// For absolute and relative paths... the entire path is kept in the "tail".
// For optimized path, at a switch between absolute and relative, add tail to commonbase.
void Inkscape::SVG::PathString::_appendOp(char abs_op, char rel_op) {
    bool abs_op_repeated = _abs_state.prevop == abs_op && !force_repeat_commands;
    bool rel_op_repeated = _rel_state.prevop == rel_op && !force_repeat_commands;

    // For absolute and relative paths... do nothing.
    switch (format) {
        case PATHSTRING_ABSOLUTE:
            if ( !abs_op_repeated ) _abs_state.appendOp(abs_op);
            break;
        case PATHSTRING_RELATIVE:
            if ( !rel_op_repeated ) _rel_state.appendOp(rel_op);
            break;
        case PATHSTRING_OPTIMIZE:
            {
            unsigned int const abs_added_size = abs_op_repeated ? 0 : 2;
            unsigned int const rel_added_size = rel_op_repeated ? 0 : 2;
            if ( _rel_state.str.size()+2 < _abs_state.str.size()+abs_added_size ) {

                // Store common prefix
                commonbase += _rel_state.str;
                _rel_state.str.clear();
                // Copy rel to abs
                _abs_state = _rel_state;
                _abs_state.switches++;
                abs_op_repeated = false;
                // We do not have to copy abs to rel:
                //   _rel_state.str.size()+2 < _abs_state.str.size()+abs_added_size
                //   _rel_state.str.size()+rel_added_size < _abs_state.str.size()+2
                //   _abs_state.str.size()+2 > _rel_state.str.size()+rel_added_size
            } else if ( _abs_state.str.size()+2 < _rel_state.str.size()+rel_added_size ) {

                // Store common prefix
                commonbase += _abs_state.str;
                _abs_state.str.clear();
                // Copy abs to rel
                _rel_state = _abs_state;
                _abs_state.switches++;
                rel_op_repeated = false;
            }
            if ( !abs_op_repeated ) _abs_state.appendOp(abs_op);
            if ( !rel_op_repeated ) _rel_state.appendOp(rel_op);
            }
            break;
        default:
            std::cout << "Better not be here!" << std::endl;
    }
}

void Inkscape::SVG::PathString::State::append(Geom::Coord v) {
    str += ' ';
    appendNumber(v);
}

void Inkscape::SVG::PathString::State::append(Geom::Point p) {
    str += ' ';
    appendNumber(p[Geom::X]);
    str += ',';
    appendNumber(p[Geom::Y]);
}

void Inkscape::SVG::PathString::State::append(Geom::Coord v, Geom::Coord& rv) {
    str += ' ';
    appendNumber(v, rv);
}

void Inkscape::SVG::PathString::State::append(Geom::Point p, Geom::Point &rp) {
    str += ' ';
    appendNumber(p[Geom::X], rp[Geom::X]);
    str += ',';
    appendNumber(p[Geom::Y], rp[Geom::Y]);
}

// NOTE: The following appendRelativeCoord function will not be exact if the total number of digits needed
// to represent the difference exceeds the precision of a double. This is not very likely though, and if
// it does happen the imprecise value is not likely to be chosen (because it will probably be a lot longer
// than the absolute value).

// NOTE: This assumes v and r are already rounded (this includes flushing to zero if they are < 10^minexp)
void Inkscape::SVG::PathString::State::appendRelativeCoord(Geom::Coord v, Geom::Coord r) {
    int const minexp = minimumexponent-numericprecision+1;
    int const digitsEnd = (int)floor(log10(std::min(fabs(v),fabs(r)))) - numericprecision; // Position just beyond the last significant digit of the smallest (in absolute sense) number
    double const roundeddiff = floor((v-r)*pow(10.,-digitsEnd-1)+.5);
    int const numDigits = (int)floor(log10(fabs(roundeddiff)))+1; // Number of digits in roundeddiff
    if (r == 0) {
        appendNumber(v, numericprecision, minexp);
    } else if (v == 0) {
        appendNumber(-r, numericprecision, minexp);
    } else if (numDigits>0) {
        appendNumber(v-r, numDigits, minexp);
    } else {
        // This assumes the input numbers are already rounded to 'precision' digits
        str += '0';
    }
}

void Inkscape::SVG::PathString::State::appendRelative(Geom::Point p, Geom::Point r) {
    str += ' ';
    appendRelativeCoord(p[Geom::X], r[Geom::X]);
    str += ',';
    appendRelativeCoord(p[Geom::Y], r[Geom::Y]);
}

void Inkscape::SVG::PathString::State::appendRelative(Geom::Coord v, Geom::Coord r) {
    str += ' ';
    appendRelativeCoord(v, r);
}

void Inkscape::SVG::PathString::State::appendNumber(double v, int precision, int minexp) {

    str.append(sp_svg_number_write_de(v, precision, minexp));
}

void Inkscape::SVG::PathString::State::appendNumber(double v, double &rv, int precision, int minexp) {
    size_t const oldsize = str.size();
    appendNumber(v, precision, minexp);
    char* begin_of_num = const_cast<char*>(str.data()+oldsize); // Slightly evil, I know (but std::string should be storing its data in one big block of memory, so...)
    sp_svg_number_read_d(begin_of_num, &rv);
}

/*
  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:fileencoding=utf-8:textwidth=99 :