src/live_effects/lpe-recursiveskeleton.cpp

   1 #define INKSCAPE_LPE_RECURSIVESKELETON_CPP
   2 /** \file
   3  * @brief
   4  *
   5  * Inspired by Hofstadter's 'Goedel Escher Bach', chapter V.
   6  */
   7 /* Authors:
   8  *   Johan Engelen <j.b.c.engelen@utwente.nl>
   9  *
  10  * Copyright (C) 2007-2009 Authors
  11  *
  12  * Released under GNU GPL, read the file 'COPYING' for more information
  13  */
  14
  15 #include "live_effects/lpe-recursiveskeleton.h"
  16
  17 #include <2geom/path.h>
  18 #include <2geom/sbasis.h>
  19 #include <2geom/sbasis-geometric.h>
  20 #include <2geom/bezier-to-sbasis.h>
  21 #include <2geom/sbasis-to-bezier.h>
  22 #include <2geom/d2.h>
  23 #include <2geom/piecewise.h>
  24
  25 namespace Inkscape {
  26 namespace LivePathEffect {
  27
  28 LPERecursiveSkeleton::LPERecursiveSkeleton(LivePathEffectObject *lpeobject) :
  29     Effect(lpeobject),
  30     iterations(_("Iterations"), _("recursivity"), "iterations", &wr, this, 2)
  31 {
  32     show_orig_path = true;
  33     concatenate_before_pwd2 = true;
  34     iterations.param_make_integer(true);
  35     iterations.param_set_range(1, 15);
  36     registerParameter( dynamic_cast<Parameter *>(&iterations) );
  37
  38 }
  39
  40 LPERecursiveSkeleton::~LPERecursiveSkeleton()
  41 {
  42
  43 }
  44
  45
  46 Geom::Piecewise<Geom::D2<Geom::SBasis> >
  47 LPERecursiveSkeleton::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in)
  48 {
  49     using namespace Geom;
  50
  51     Piecewise<D2<SBasis> > output;
  52     std::vector<Piecewise<D2<SBasis> > > pre_output;
  53
  54     double prop_scale = 1.0;
  55
  56     D2<Piecewise<SBasis> > patternd2 = make_cuts_independent(pwd2_in);
  57     Piecewise<SBasis> x0 = false /*vertical_pattern.get_value()*/ ? Piecewise<SBasis>(patternd2[1]) : Piecewise<SBasis>(patternd2[0]);
  58     Piecewise<SBasis> y0 = false /*vertical_pattern.get_value()*/ ? Piecewise<SBasis>(patternd2[0]) : Piecewise<SBasis>(patternd2[1]);
  59     OptInterval pattBndsX = bounds_exact(x0);
  60     OptInterval pattBndsY = bounds_exact(y0);
  61
  62     if ( !pattBndsX || !pattBndsY) {
  63         return pwd2_in;
  64     }
  65
  66     x0 -= pattBndsX->min();
  67     y0 -= pattBndsY->middle();
  68
  69     double xspace  = 0;//spacing;
  70     double noffset = 0;//normal_offset;
  71     double toffset = 0;//tang_offset;
  72     if (false /*prop_units.get_value()*/){
  73         xspace  *= pattBndsX->extent();
  74         noffset *= pattBndsY->extent();
  75         toffset *= pattBndsX->extent();
  76     }
  77
  78     y0+=noffset;
  79
  80     output = pwd2_in;
  81
  82     for (int i = 0; i < iterations; ++i) {
  83         std::vector<Piecewise<D2<SBasis> > > skeleton = split_at_discontinuities(output);
  84
  85         output.clear();
  86         for (unsigned idx = 0; idx < skeleton.size(); idx++){
  87             Piecewise<D2<SBasis> > path_i = skeleton[idx];
  88             Piecewise<SBasis> x = x0;
  89             Piecewise<SBasis> y = y0;
  90             Piecewise<D2<SBasis> > uskeleton = arc_length_parametrization(path_i,2,.1);
  91             uskeleton = remove_short_cuts(uskeleton,.01);
  92             Piecewise<D2<SBasis> > n = rot90(derivative(uskeleton));
  93             n = force_continuity(remove_short_cuts(n,.1));
  94
  95             double scaling = 1;
  96             scaling = (uskeleton.domain().extent() - toffset)/pattBndsX->extent();
  97
  98             // TODO investigate why pattWidth is not being used:
  99             double pattWidth = pattBndsX->extent() * scaling;
 100
 101             if (scaling != 1.0) {
 102                 x*=scaling;
 103             }
 104
 105             if ( true /*scale_y_rel.get_value()*/ ) {
 106                 y*=(scaling*prop_scale);
 107             } else {
 108                 if (prop_scale != 1.0) y *= prop_scale;
 109             }
 110             x += toffset;
 111
 112             output.concat(compose(uskeleton,x)+y*compose(n,x));
 113         }
 114     }
 115
 116     return output;
 117 }
 118
 119
 120 } //namespace LivePathEffect
 121 } /* namespace Inkscape */
 122
 123 /*
 124   Local Variables:
 125   mode:c++
 126   c-file-style:"stroustrup"
 127   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 128   indent-tabs-mode:nil
 129   fill-column:99
 130   End:
 131 */
 132 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :