1 #define INKSCAPE_LPE_PATTERN_ALONG_PATH_CPP
3 /*
4 * Copyright (C) Johan Engelen 2007 <j.b.c.engelen@utwente.nl>
5 *
6 * Released under GNU GPL, read the file 'COPYING' for more information
7 */
9 #include "live_effects/lpe-patternalongpath.h"
10 #include "live_effects/lpeobject.h"
11 #include "sp-shape.h"
12 #include "display/curve.h"
13 #include "svg/svg.h"
14 #include "ui/widget/scalar.h"
16 #include <2geom/sbasis.h>
17 #include <2geom/sbasis-geometric.h>
18 #include <2geom/bezier-to-sbasis.h>
19 #include <2geom/sbasis-to-bezier.h>
20 #include <2geom/d2.h>
21 #include <2geom/piecewise.h>
23 #include <algorithm>
24 using std::vector;
27 /* Theory in e-mail from J.F. Barraud
28 Let B be the skeleton path, and P the pattern (the path to be deformed).
30 P is a map t --> P(t) = ( x(t), y(t) ).
31 B is a map t --> B(t) = ( a(t), b(t) ).
33 The first step is to re-parametrize B by its arc length: this is the parametrization in which a point p on B is located by its distance s from start. One obtains a new map s --> U(s) = (a'(s),b'(s)), that still describes the same path B, but where the distance along B from start to
34 U(s) is s itself.
36 We also need a unit normal to the path. This can be obtained by computing a unit tangent vector, and rotate it by 90°. Call this normal vector N(s).
38 The basic deformation associated to B is then given by:
40 (x,y) --> U(x)+y*N(x)
42 (i.e. we go for distance x along the path, and then for distance y along the normal)
44 Of course this formula needs some minor adaptations (as is it depends on the absolute position of P for instance, so a little translation is needed
45 first) but I think we can first forget about them.
46 */
48 namespace Inkscape {
49 namespace LivePathEffect {
51 static const Util::EnumData<PAPCopyType> PAPCopyTypeData[PAPCT_END] = {
52 {PAPCT_SINGLE, N_("Single"), "single"},
53 {PAPCT_SINGLE_STRETCHED, N_("Single, stretched"), "single_stretched"},
54 {PAPCT_REPEATED, N_("Repeated"), "repeated"},
55 {PAPCT_REPEATED_STRETCHED, N_("Repeated, stretched"), "repeated_stretched"}
56 };
57 static const Util::EnumDataConverter<PAPCopyType> PAPCopyTypeConverter(PAPCopyTypeData, PAPCT_END);
59 LPEPatternAlongPath::LPEPatternAlongPath(LivePathEffectObject *lpeobject) :
60 Effect(lpeobject),
61 pattern(_("Pattern source"), _("Path to put along the skeleton path"), "pattern", &wr, this, "M0,0 L1,0"),
62 copytype(_("Pattern copies"), _("How many pattern copies to place along the skeleton path"), "copytype", PAPCopyTypeConverter, &wr, this, PAPCT_SINGLE_STRETCHED),
63 prop_scale(_("Width"), _("Width of the pattern"), "prop_scale", &wr, this, 1),
64 scale_y_rel(_("Width in units of length"), _("Scale the width of the pattern in units of its length"), "scale_y_rel", &wr, this, false),
65 spacing(_("Spacing"), _("Space between copies of the pattern. Negative values allowed, but are limited to -90% of pattern width."), "spacing", &wr, this, 0),
66 normal_offset(_("Normal offset"), "", "normal_offset", &wr, this, 0),
67 tang_offset(_("Tangential offset"), "", "tang_offset", &wr, this, 0),
68 prop_units(_("Offsets in unit of pattern size"), _("Spacing, tangential and normal offset are expressed as a ratio of width/height"), "prop_units", &wr, this, false),
69 vertical_pattern(_("Pattern is vertical"), _("Rotate pattern 90 deg before applying"), "vertical_pattern", &wr, this, false),
70 fuse_tolerance(_("Fuse nearby ends"), "Fuse ends closer than this number. 0 means don't fuse.", "fuse_tolerance", &wr, this, 0)
71 {
72 registerParameter( dynamic_cast<Parameter *>(&pattern) );
73 registerParameter( dynamic_cast<Parameter *>(©type) );
74 registerParameter( dynamic_cast<Parameter *>(&prop_scale) );
75 registerParameter( dynamic_cast<Parameter *>(&scale_y_rel) );
76 registerParameter( dynamic_cast<Parameter *>(&spacing) );
77 registerParameter( dynamic_cast<Parameter *>(&normal_offset) );
78 registerParameter( dynamic_cast<Parameter *>(&tang_offset) );
79 registerParameter( dynamic_cast<Parameter *>(&prop_units) );
80 registerParameter( dynamic_cast<Parameter *>(&vertical_pattern) );
81 registerParameter( dynamic_cast<Parameter *>(&fuse_tolerance) );
83 prop_scale.param_set_digits(3);
84 prop_scale.param_set_increments(0.01, 0.10);
85 }
87 LPEPatternAlongPath::~LPEPatternAlongPath()
88 {
90 }
92 Geom::Piecewise<Geom::D2<Geom::SBasis> >
93 LPEPatternAlongPath::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in)
94 {
95 using namespace Geom;
97 /* Much credit should go to jfb and mgsloan of lib2geom development for the code below! */
98 Piecewise<D2<SBasis> > output;
99 std::vector<Geom::Piecewise<Geom::D2<Geom::SBasis> > > pre_output;
101 PAPCopyType type = copytype.get_value();
103 D2<Piecewise<SBasis> > patternd2 = make_cuts_independent(pattern.get_pwd2());
104 Piecewise<SBasis> x0 = vertical_pattern.get_value() ? Piecewise<SBasis>(patternd2[1]) : Piecewise<SBasis>(patternd2[0]);
105 Piecewise<SBasis> y0 = vertical_pattern.get_value() ? Piecewise<SBasis>(patternd2[0]) : Piecewise<SBasis>(patternd2[1]);
106 OptInterval pattBndsX = bounds_exact(x0);
107 OptInterval pattBndsY = bounds_exact(y0);
108 if (pattBndsX && pattBndsY) {
109 x0 -= pattBndsX->min();
110 y0 -= pattBndsY->middle();
112 double xspace = spacing;
113 double noffset = normal_offset;
114 double toffset = tang_offset;
115 if (prop_units.get_value() && pattBndsY){
116 xspace *= pattBndsX->extent();
117 noffset *= pattBndsY->extent();
118 toffset *= pattBndsX->extent();
119 }
121 //Prevent more than 90% overlap...
122 if (xspace < -pattBndsX->extent()*.9) {
123 xspace = -pattBndsX->extent()*.9;
124 }
125 //TODO: dynamical update of parameter ranges?
126 //if (prop_units.get_value()){
127 // spacing.param_set_range(-.9, NR_HUGE);
128 // }else{
129 // spacing.param_set_range(-pattBndsX.extent()*.9, NR_HUGE);
130 // }
132 y0+=noffset;
134 std::vector<Geom::Piecewise<Geom::D2<Geom::SBasis> > > paths_in;
135 paths_in = split_at_discontinuities(pwd2_in);
137 for (unsigned idx = 0; idx < paths_in.size(); idx++){
138 Geom::Piecewise<Geom::D2<Geom::SBasis> > path_i = paths_in[idx];
139 Piecewise<SBasis> x = x0;
140 Piecewise<SBasis> y = y0;
141 Piecewise<D2<SBasis> > uskeleton = arc_length_parametrization(path_i,2,.1);
142 uskeleton = remove_short_cuts(uskeleton,.01);
143 Piecewise<D2<SBasis> > n = rot90(derivative(uskeleton));
144 n = force_continuity(remove_short_cuts(n,.1));
146 int nbCopies = 0;
147 double scaling = 1;
148 switch(type) {
149 case PAPCT_REPEATED:
150 nbCopies = static_cast<int>(floor((uskeleton.domain().extent() - toffset + xspace)/(pattBndsX->extent()+xspace)));
151 pattBndsX = Interval(pattBndsX->min(),pattBndsX->max()+xspace);
152 break;
154 case PAPCT_SINGLE:
155 nbCopies = (toffset + pattBndsX->extent() < uskeleton.domain().extent()) ? 1 : 0;
156 break;
158 case PAPCT_SINGLE_STRETCHED:
159 nbCopies = 1;
160 scaling = (uskeleton.domain().extent() - toffset)/pattBndsX->extent();
161 break;
163 case PAPCT_REPEATED_STRETCHED:
164 // if uskeleton is closed:
165 if(path_i.segs.front().at0() == path_i.segs.back().at1()){
166 nbCopies = static_cast<int>(std::floor((uskeleton.domain().extent() - toffset)/(pattBndsX->extent()+xspace)));
167 pattBndsX = Interval(pattBndsX->min(),pattBndsX->max()+xspace);
168 scaling = (uskeleton.domain().extent() - toffset)/(((double)nbCopies)*pattBndsX->extent());
169 // if not closed: no space at the end
170 }else{
171 nbCopies = static_cast<int>(std::floor((uskeleton.domain().extent() - toffset + xspace)/(pattBndsX->extent()+xspace)));
172 pattBndsX = Interval(pattBndsX->min(),pattBndsX->max()+xspace);
173 scaling = (uskeleton.domain().extent() - toffset)/(((double)nbCopies)*pattBndsX->extent() - xspace);
174 }
175 break;
177 default:
178 return pwd2_in;
179 };
181 double pattWidth = pattBndsX->extent() * scaling;
183 if (scaling != 1.0) {
184 x*=scaling;
185 }
186 if ( scale_y_rel.get_value() ) {
187 y*=(scaling*prop_scale);
188 } else {
189 if (prop_scale != 1.0) y *= prop_scale;
190 }
191 x += toffset;
193 double offs = 0;
194 for (int i=0; i<nbCopies; i++){
195 if (fuse_tolerance > 0){
196 Geom::Piecewise<Geom::D2<Geom::SBasis> > output_piece = compose(uskeleton,x+offs)+y*compose(n,x+offs);
197 std::vector<Geom::Piecewise<Geom::D2<Geom::SBasis> > > splited_output_piece = split_at_discontinuities(output_piece);
198 pre_output.insert(pre_output.end(), splited_output_piece.begin(), splited_output_piece.end() );
199 }else{
200 output.concat(compose(uskeleton,x+offs)+y*compose(n,x+offs));
201 }
202 offs+=pattWidth;
203 }
204 }
205 if (fuse_tolerance > 0){
206 pre_output = fuse_nearby_ends(pre_output, fuse_tolerance);
207 for (unsigned i=0; i<pre_output.size(); i++){
208 output.concat(pre_output[i]);
209 }
210 }
211 return output;
212 } else {
213 return pwd2_in;
214 }
215 }
217 LPEFreehandShape::LPEFreehandShape(LivePathEffectObject *lpeobject) : LPEPatternAlongPath(lpeobject)
218 {
219 }
221 } // namespace LivePathEffect
222 } /* namespace Inkscape */
224 /*
225 Local Variables:
226 mode:c++
227 c-file-style:"stroustrup"
228 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
229 indent-tabs-mode:nil
230 fill-column:99
231 End:
232 */
233 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :