Add option to write out path data using only relative coordinates

(in addition to using only absolute coordinates or using a mixture
of absolute and relative coordinates optimized for length).

(bzr r12480)

5 files changed, 73 insertions, 35 deletions

diff --git a/src/preferences-skeleton.h b/src/preferences-skeleton.h
index c5d972966..17b912d33 100644
--- a/src/preferences-skeleton.h
+++ b/src/preferences-skeleton.h
@@ -326,7 +326,7 @@ static char const preferences_skeleton[] =
 "           minimumexponent=\"-8\" "
 "           inlineattrs=\"0\" "
 "           indent=\"2\" "
-"           allowrelativecoordinates=\"1\" "
+"           pathstring_format=\"2\" "
 "           forcerepeatcommands=\"0\" "
 "           incorrect_attributes_warn=\"1\" "
 "           incorrect_attributes_remove=\"0\" "
diff --git a/src/svg/path-string.cpp b/src/svg/path-string.cpp
index 61e9c90a2..6dddeadff 100644
--- a/src/svg/path-string.cpp
+++ b/src/svg/path-string.cpp
@@ -2,6 +2,7 @@
  * Inkscape::SVG::PathString - builder for SVG path strings
  *
  * Copyright 2008 Jasper van de Gronde <th.v.d.gronde@hccnet.nl>
+ * Copyright 2013 Tavmjong Bah <tavmjong@free.fr>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -25,44 +26,65 @@ 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() :
-    allow_relative_coordinates(Inkscape::Preferences::get()->getBool("/options/svgoutput/allowrelativecoordinates", true)),
     force_repeat_commands(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;
-    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 && allow_relative_coordinates ) {
-        // 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;
+
+    // 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;
     }
-    if ( !abs_op_repeated ) _abs_state.appendOp(abs_op);
-    if ( !rel_op_repeated ) _rel_state.appendOp(rel_op);
 }
 
 void Inkscape::SVG::PathString::State::append(Geom::Coord v) {
diff --git a/src/svg/path-string.h b/src/svg/path-string.h
index 11018e65c..3a891873d 100644
--- a/src/svg/path-string.h
+++ b/src/svg/path-string.h
@@ -1,6 +1,7 @@
 /*
  * Copyright 2007 MenTaLguY <mental@rydia.net>
  * Copyright 2008 Jasper van de Gronde <th.v.d.gronde@hccnet.nl>
+ * Copyright 2013 Tavmjong Bah <tavmjong@free.fr>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -23,6 +24,14 @@ namespace Inkscape {
 
 namespace SVG {
 
+// Relative vs. absolute coordinates
+enum PATHSTRING_FORMAT {
+    PATHSTRING_ABSOLUTE,  // Use only absolute coordinates
+    PATHSTRING_RELATIVE,  // Use only relative coordinates
+    PATHSTRING_OPTIMIZE,  // Optimize for path string length
+    PATHSTRING_FORMAT_SIZE
+};
+
 /**
  * Builder for SVG path strings.
  */
@@ -38,6 +47,7 @@ public:
         final.reserve(commonbase.size()+t.size());
         final = commonbase;
         final += tail();
+        // std::cout << " final: " << final << std::endl;
         return final;
     }
 
@@ -130,12 +140,10 @@ public:
     }
 
     PathString &closePath() {
-        commonbase += _abs_state.str;
-        _abs_state.str.clear();
-        _rel_state = _abs_state;
+
         _abs_state.appendOp('Z');
         _rel_state.appendOp('z');
-        _rel_state.switches++;
+
         _current_point = _initial_point;
         return *this;
     }
@@ -229,9 +237,13 @@ private:
     // to cause a quadratic time complexity (in the number of characters/operators)
     std::string commonbase;
     std::string final;
-    std::string const &tail() const { return ((_abs_state <= _rel_state || !allow_relative_coordinates) ? _abs_state.str : _rel_state.str); }
+    std::string const &tail() const {
+        return ( (format == PATHSTRING_ABSOLUTE) ||
+                 (format == PATHSTRING_OPTIMIZE && _abs_state <= _rel_state ) ?
+                 _abs_state.str : _rel_state.str );
+    }
 
-    bool const allow_relative_coordinates;
+    static PATHSTRING_FORMAT format;
     bool const force_repeat_commands;
     static int numericprecision;
     static int minimumexponent;
diff --git a/src/ui/dialog/inkscape-preferences.cpp b/src/ui/dialog/inkscape-preferences.cpp
index 7890b0b4c..b06c1fd1f 100644
--- a/src/ui/dialog/inkscape-preferences.cpp
+++ b/src/ui/dialog/inkscape-preferences.cpp
@@ -879,8 +879,12 @@ void InkscapePreferences::initPageIO()
 
     _page_svgoutput.add_group_header( _("Path data"));
 
-    _svgoutput_allowrelativecoordinates.init( _("Allow relative coordinates"), "/options/svgoutput/allowrelativecoordinates", true);
-    _page_svgoutput.add_line( true, "", _svgoutput_allowrelativecoordinates, "", _("If set, relative coordinates may be used in path data"), false);
+    int const numPathstringFormat = 3;
+    Glib::ustring pathstringFormatLabels[numPathstringFormat] = {_("Absolute"), _("Relative"), _("Optimized")};
+    int pathstringFormatValues[numPathstringFormat] = {0, 1, 2};
+
+    _svgoutput_pathformat.init("/options/svgoutput/pathstring_format", pathstringFormatLabels, pathstringFormatValues, numPathstringFormat, 2);
+    _page_svgoutput.add_line( true, _("Path string format"), _svgoutput_pathformat, "", _("Path data should be written: only with absolute coordinates, only with relative coordinates, or optimized for string length (mixed absolute and relative coordinates)"), false);
 
     _svgoutput_forcerepeatcommands.init( _("Force repeat commands"), "/options/svgoutput/forcerepeatcommands", false);
     _page_svgoutput.add_line( true, "", _svgoutput_forcerepeatcommands, "", _("Force repeating of the same path command (for example, 'L 1,2 L 3,4' instead of 'L 1,2 3,4')"), false);
diff --git a/src/ui/dialog/inkscape-preferences.h b/src/ui/dialog/inkscape-preferences.h
index 37c05df05..56222fb22 100644
--- a/src/ui/dialog/inkscape-preferences.h
+++ b/src/ui/dialog/inkscape-preferences.h
@@ -426,7 +426,7 @@ protected:
     UI::Widget::PrefSpinButton    _svgoutput_minimumexponent;
     UI::Widget::PrefCheckButton   _svgoutput_inlineattrs;
     UI::Widget::PrefSpinButton    _svgoutput_indent;
-    UI::Widget::PrefCheckButton   _svgoutput_allowrelativecoordinates;
+    UI::Widget::PrefCombo         _svgoutput_pathformat;
     UI::Widget::PrefCheckButton   _svgoutput_forcerepeatcommands;
 
     // Attribute Checking controls for SVG Output page: