1
#define INKSCAPE_LPE_PATTERN_ALONG_PATH_CPP
4
* Copyright (C) Johan Engelen 2007 <j.b.c.engelen@utwente.nl>
6
* Released under GNU GPL, read the file 'COPYING' for more information
9
#include "live_effects/lpe-patternalongpath.h"
10
#include "live_effects/lpeobject.h"
12
#include "display/curve.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>
21
#include <2geom/piecewise.h>
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
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:
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.
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"}
57
static const Util::EnumDataConverter<PAPCopyType> PAPCopyTypeConverter(PAPCopyTypeData, PAPCT_END);
59
LPEPatternAlongPath::LPEPatternAlongPath(LivePathEffectObject *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"),
63
"copytype", PAPCopyTypeConverter, &wr, this, PAPCT_SINGLE_STRETCHED),
64
prop_scale(_("Width"), _("Width of the pattern"), "prop_scale", &wr, this, 1),
65
scale_y_rel(_("Width in units of length"),
66
_("Scale the width of the pattern in units of its length"),
67
"scale_y_rel", &wr, this, false),
69
// xgettext:no-c-format
70
_("Space between copies of the pattern. Negative values allowed, but are limited to -90% of pattern width."),
71
"spacing", &wr, this, 0),
72
normal_offset(_("Normal offset"), "", "normal_offset", &wr, this, 0),
73
tang_offset(_("Tangential offset"), "", "tang_offset", &wr, this, 0),
74
prop_units(_("Offsets in unit of pattern size"),
75
_("Spacing, tangential and normal offset are expressed as a ratio of width/height"),
76
"prop_units", &wr, this, false),
77
vertical_pattern(_("Pattern is vertical"), _("Rotate pattern 90 deg before applying"),
78
"vertical_pattern", &wr, this, false),
79
fuse_tolerance(_("Fuse nearby ends"), _("Fuse ends closer than this number. 0 means don't fuse."),
80
"fuse_tolerance", &wr, this, 0)
82
registerParameter( dynamic_cast<Parameter *>(&pattern) );
83
registerParameter( dynamic_cast<Parameter *>(©type) );
84
registerParameter( dynamic_cast<Parameter *>(&prop_scale) );
85
registerParameter( dynamic_cast<Parameter *>(&scale_y_rel) );
86
registerParameter( dynamic_cast<Parameter *>(&spacing) );
87
registerParameter( dynamic_cast<Parameter *>(&normal_offset) );
88
registerParameter( dynamic_cast<Parameter *>(&tang_offset) );
89
registerParameter( dynamic_cast<Parameter *>(&prop_units) );
90
registerParameter( dynamic_cast<Parameter *>(&vertical_pattern) );
91
registerParameter( dynamic_cast<Parameter *>(&fuse_tolerance) );
93
prop_scale.param_set_digits(3);
94
prop_scale.param_set_increments(0.01, 0.10);
97
LPEPatternAlongPath::~LPEPatternAlongPath()
102
Geom::Piecewise<Geom::D2<Geom::SBasis> >
103
LPEPatternAlongPath::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in)
105
using namespace Geom;
107
/* Much credit should go to jfb and mgsloan of lib2geom development for the code below! */
108
Piecewise<D2<SBasis> > output;
109
std::vector<Geom::Piecewise<Geom::D2<Geom::SBasis> > > pre_output;
111
PAPCopyType type = copytype.get_value();
113
D2<Piecewise<SBasis> > patternd2 = make_cuts_independent(pattern.get_pwd2());
114
Piecewise<SBasis> x0 = vertical_pattern.get_value() ? Piecewise<SBasis>(patternd2[1]) : Piecewise<SBasis>(patternd2[0]);
115
Piecewise<SBasis> y0 = vertical_pattern.get_value() ? Piecewise<SBasis>(patternd2[0]) : Piecewise<SBasis>(patternd2[1]);
116
OptInterval pattBndsX = bounds_exact(x0);
117
OptInterval pattBndsY = bounds_exact(y0);
118
if (pattBndsX && pattBndsY) {
119
x0 -= pattBndsX->min();
120
y0 -= pattBndsY->middle();
122
double xspace = spacing;
123
double noffset = normal_offset;
124
double toffset = tang_offset;
125
if (prop_units.get_value() && pattBndsY){
126
xspace *= pattBndsX->extent();
127
noffset *= pattBndsY->extent();
128
toffset *= pattBndsX->extent();
131
//Prevent more than 90% overlap...
132
if (xspace < -pattBndsX->extent()*.9) {
133
xspace = -pattBndsX->extent()*.9;
135
//TODO: dynamical update of parameter ranges?
136
//if (prop_units.get_value()){
137
// spacing.param_set_range(-.9, NR_HUGE);
139
// spacing.param_set_range(-pattBndsX.extent()*.9, NR_HUGE);
144
std::vector<Geom::Piecewise<Geom::D2<Geom::SBasis> > > paths_in;
145
paths_in = split_at_discontinuities(pwd2_in);
147
for (unsigned idx = 0; idx < paths_in.size(); idx++){
148
Geom::Piecewise<Geom::D2<Geom::SBasis> > path_i = paths_in[idx];
149
Piecewise<SBasis> x = x0;
150
Piecewise<SBasis> y = y0;
151
Piecewise<D2<SBasis> > uskeleton = arc_length_parametrization(path_i,2,.1);
152
uskeleton = remove_short_cuts(uskeleton,.01);
153
Piecewise<D2<SBasis> > n = rot90(derivative(uskeleton));
154
n = force_continuity(remove_short_cuts(n,.1));
160
nbCopies = static_cast<int>(floor((uskeleton.domain().extent() - toffset + xspace)/(pattBndsX->extent()+xspace)));
161
pattBndsX = Interval(pattBndsX->min(),pattBndsX->max()+xspace);
165
nbCopies = (toffset + pattBndsX->extent() < uskeleton.domain().extent()) ? 1 : 0;
168
case PAPCT_SINGLE_STRETCHED:
170
scaling = (uskeleton.domain().extent() - toffset)/pattBndsX->extent();
173
case PAPCT_REPEATED_STRETCHED:
174
// if uskeleton is closed:
175
if(path_i.segs.front().at0() == path_i.segs.back().at1()){
176
nbCopies = static_cast<int>(std::floor((uskeleton.domain().extent() - toffset)/(pattBndsX->extent()+xspace)));
177
pattBndsX = Interval(pattBndsX->min(),pattBndsX->max()+xspace);
178
scaling = (uskeleton.domain().extent() - toffset)/(((double)nbCopies)*pattBndsX->extent());
179
// if not closed: no space at the end
181
nbCopies = static_cast<int>(std::floor((uskeleton.domain().extent() - toffset + xspace)/(pattBndsX->extent()+xspace)));
182
pattBndsX = Interval(pattBndsX->min(),pattBndsX->max()+xspace);
183
scaling = (uskeleton.domain().extent() - toffset)/(((double)nbCopies)*pattBndsX->extent() - xspace);
191
double pattWidth = pattBndsX->extent() * scaling;
193
if (scaling != 1.0) {
196
if ( scale_y_rel.get_value() ) {
197
y*=(scaling*prop_scale);
199
if (prop_scale != 1.0) y *= prop_scale;
204
for (int i=0; i<nbCopies; i++){
205
if (fuse_tolerance > 0){
206
Geom::Piecewise<Geom::D2<Geom::SBasis> > output_piece = compose(uskeleton,x+offs)+y*compose(n,x+offs);
207
std::vector<Geom::Piecewise<Geom::D2<Geom::SBasis> > > splited_output_piece = split_at_discontinuities(output_piece);
208
pre_output.insert(pre_output.end(), splited_output_piece.begin(), splited_output_piece.end() );
210
output.concat(compose(uskeleton,x+offs)+y*compose(n,x+offs));
215
if (fuse_tolerance > 0){
216
pre_output = fuse_nearby_ends(pre_output, fuse_tolerance);
217
for (unsigned i=0; i<pre_output.size(); i++){
218
output.concat(pre_output[i]);
228
LPEPatternAlongPath::transform_multiply(Geom::Matrix const& postmul, bool set)
230
// overriding the Effect class default method, disabling transform forwarding to the parameters.
232
// only take translations into account
233
if (postmul.isTranslation()) {
234
pattern.param_transform_multiply(postmul, set);
238
} // namespace LivePathEffect
239
} /* namespace Inkscape */
244
c-file-style:"stroustrup"
245
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
250
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :