1 files changed, 167 insertions, 0 deletions
diff --git a/src/svg/path-string.cpp b/src/svg/path-string.cpp
new file mode 100644
index 0000000..516fe35
--- /dev/null
+++ b/src/svg/path-string.cpp
@@ -0,0 +1,167 @@
+// 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 :