lpe-powerstroke.cpp revision 7ef929c9f7a586c21eacd035f6c0ebf7af3cf36d
#define INKSCAPE_LPE_POWERSTROKE_CPP
/** \file
* @brief PowerStroke LPE implementation. Creates curves with modifiable stroke width.
*/
/* Authors:
* Johan Engelen <j.b.c.engelen@utwente.nl>
*
* Copyright (C) 2010 Authors
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#include "live_effects/lpe-powerstroke.h"
#include "sp-shape.h"
#include "display/curve.h"
#include <2geom/path.h>
#include <2geom/piecewise.h>
#include <2geom/sbasis-geometric.h>
#include <2geom/transforms.h>
#include <2geom/bezier-utils.h>
#include "live_effects/bezctx.h"
#include "live_effects/bezctx_intf.h"
#include "live_effects/spiro.h"
/// @TODO Move this to 2geom
namespace Geom {
namespace Interpolate {
enum InterpolatorType {
INTERP_LINEAR,
INTERP_CUBICBEZIER,
INTERP_CUBICBEZIER_JOHAN,
INTERP_SPIRO
};
class Interpolator {
public:
Interpolator() {};
virtual ~Interpolator() {};
static Interpolator* create(InterpolatorType type);
// virtual Piecewise<D2<SBasis> > interpolateToPwD2Sb(std::vector<Point> points) = 0;
virtual Geom::Path interpolateToPath(std::vector<Point> points) = 0;
private:
Interpolator(const Interpolator&);
Interpolator& operator=(const Interpolator&);
};
class Linear : public Interpolator {
public:
Linear() {};
virtual ~Linear() {};
virtual Path interpolateToPath(std::vector<Point> points) {
Path path;
path.start( points.at(0) );
for (unsigned int i = 1 ; i < points.size(); ++i) {
path.appendNew<Geom::LineSegment>(points.at(i));
}
return path;
};
private:
Linear(const Linear&);
Linear& operator=(const Linear&);
};
// this class is terrible
class CubicBezierFit : public Interpolator {
public:
CubicBezierFit() {};
virtual ~CubicBezierFit() {};
virtual Path interpolateToPath(std::vector<Point> points) {
unsigned int n_points = points.size();
// worst case gives us 2 segment per point
int max_segs = 8*n_points;
Geom::Point * b = g_new(Geom::Point, max_segs);
Geom::Point * points_array = g_new(Geom::Point, 4*n_points);
for (unsigned i = 0; i < n_points; ++i) {
points_array[i] = points.at(i);
}
double tolerance_sq = 0; // this value is just a random guess
int const n_segs = Geom::bezier_fit_cubic_r(b, points_array, n_points,
tolerance_sq, max_segs);
Geom::Path fit;
if ( n_segs > 0)
{
fit.start(b[0]);
for (int c = 0; c < n_segs; c++) {
fit.appendNew<Geom::CubicBezier>(b[4*c+1], b[4*c+2], b[4*c+3]);
}
}
g_free(b);
g_free(points_array);
return fit;
};
private:
CubicBezierFit(const CubicBezierFit&);
CubicBezierFit& operator=(const CubicBezierFit&);
};
/// @todo invent name for this class
class CubicBezierJohan : public Interpolator {
public:
CubicBezierJohan() {};
virtual ~CubicBezierJohan() {};
virtual Path interpolateToPath(std::vector<Point> points) {
Path fit;
fit.start(points.at(0));
for (unsigned int i = 1; i < points.size(); ++i) {
Point p0 = points.at(i-1);
Point p1 = points.at(i);
Point dx = Point(p1[X] - p0[X], 0);
fit.appendNew<CubicBezier>(p0+0.2*dx, p1-0.2*dx, p1);
}
return fit;
};
private:
CubicBezierJohan(const CubicBezierJohan&);
CubicBezierJohan& operator=(const CubicBezierJohan&);
};
#define SPIRO_SHOW_INFINITE_COORDINATE_CALLS
class SpiroInterpolator : public Interpolator {
public:
SpiroInterpolator() {};
virtual ~SpiroInterpolator() {};
virtual Path interpolateToPath(std::vector<Point> points) {
Path fit;
Coord scale_y = 100.;
guint len = points.size();
bezctx *bc = new_bezctx_ink(&fit);
spiro_cp *controlpoints = g_new (spiro_cp, len);
for (unsigned int i = 0; i < len; ++i) {
controlpoints[i].x = points[i][X];
controlpoints[i].y = points[i][Y] / scale_y;
controlpoints[i].ty = 'c';
}
controlpoints[0].ty = '{';
controlpoints[1].ty = 'v';
controlpoints[len-2].ty = 'v';
controlpoints[len-1].ty = '}';
spiro_seg *s = run_spiro(controlpoints, len);
spiro_to_bpath(s, len, bc);
free(s);
free(bc);
fit *= Scale(1,scale_y);
return fit;
};
private:
typedef struct {
bezctx base;
Path *path;
int is_open;
} bezctx_ink;
static void bezctx_ink_moveto(bezctx *bc, double x, double y, int /*is_open*/)
{
bezctx_ink *bi = (bezctx_ink *) bc;
if ( IS_FINITE(x) && IS_FINITE(y) ) {
bi->path->start(Point(x, y));
}
#ifdef SPIRO_SHOW_INFINITE_COORDINATE_CALLS
else {
g_message("spiro moveto not finite");
}
#endif
}
static void bezctx_ink_lineto(bezctx *bc, double x, double y)
{
bezctx_ink *bi = (bezctx_ink *) bc;
if ( IS_FINITE(x) && IS_FINITE(y) ) {
bi->path->appendNew<LineSegment>( Point(x, y) );
}
#ifdef SPIRO_SHOW_INFINITE_COORDINATE_CALLS
else {
g_message("spiro lineto not finite");
}
#endif
}
static void bezctx_ink_quadto(bezctx *bc, double xm, double ym, double x3, double y3)
{
bezctx_ink *bi = (bezctx_ink *) bc;
if ( IS_FINITE(xm) && IS_FINITE(ym) && IS_FINITE(x3) && IS_FINITE(y3) ) {
bi->path->appendNew<QuadraticBezier>(Point(xm, ym), Point(x3, y3));
}
#ifdef SPIRO_SHOW_INFINITE_COORDINATE_CALLS
else {
g_message("spiro quadto not finite");
}
#endif
}
static void bezctx_ink_curveto(bezctx *bc, double x1, double y1, double x2, double y2,
double x3, double y3)
{
bezctx_ink *bi = (bezctx_ink *) bc;
if ( IS_FINITE(x1) && IS_FINITE(y1) && IS_FINITE(x2) && IS_FINITE(y2) ) {
bi->path->appendNew<CubicBezier>(Point(x1, y1), Point(x2, y2), Point(x3, y3));
}
#ifdef SPIRO_SHOW_INFINITE_COORDINATE_CALLS
else {
g_message("spiro curveto not finite");
}
#endif
}
bezctx *
new_bezctx_ink(Geom::Path *path) {
bezctx_ink *result = g_new(bezctx_ink, 1);
result->base.moveto = bezctx_ink_moveto;
result->base.lineto = bezctx_ink_lineto;
result->base.quadto = bezctx_ink_quadto;
result->base.curveto = bezctx_ink_curveto;
result->base.mark_knot = NULL;
result->path = path;
return &result->base;
}
SpiroInterpolator(const SpiroInterpolator&);
SpiroInterpolator& operator=(const SpiroInterpolator&);
};
Interpolator*
Interpolator::create(InterpolatorType type) {
switch (type) {
case INTERP_LINEAR:
return new Geom::Interpolate::Linear();
case INTERP_CUBICBEZIER:
return new Geom::Interpolate::CubicBezierFit();
case INTERP_CUBICBEZIER_JOHAN:
return new Geom::Interpolate::CubicBezierJohan();
case INTERP_SPIRO:
return new Geom::Interpolate::SpiroInterpolator();
default:
return new Geom::Interpolate::Linear();
}
}
} //namespace Interpolate
} //namespace Geom
namespace Inkscape {
namespace LivePathEffect {
static const Util::EnumData<unsigned> InterpolatorTypeData[] = {
{Geom::Interpolate::INTERP_LINEAR , N_("Linear"), "Linear"},
{Geom::Interpolate::INTERP_CUBICBEZIER , N_("CubicBezierFit"), "CubicBezierFit"},
{Geom::Interpolate::INTERP_CUBICBEZIER_JOHAN , N_("CubicBezierJohan"), "CubicBezierJohan"},
{Geom::Interpolate::INTERP_SPIRO , N_("SpiroInterpolator"), "SpiroInterpolator"}
};
static const Util::EnumDataConverter<unsigned> InterpolatorTypeConverter(InterpolatorTypeData, sizeof(InterpolatorTypeData)/sizeof(*InterpolatorTypeData));
LPEPowerStroke::LPEPowerStroke(LivePathEffectObject *lpeobject) :
Effect(lpeobject),
offset_points(_("Offset points"), _("Offset points"), "offset_points", &wr, this),
sort_points(_("Sort points"), _("Sort offset points according to their time value along the curve."), "sort_points", &wr, this, true),
interpolator_type(_("Interpolator type"), _("Determines which kind of interpolator will be used to interpolate between stroke width along the path."), "interpolator_type", InterpolatorTypeConverter, &wr, this, Geom::Interpolate::INTERP_CUBICBEZIER_JOHAN)
{
show_orig_path = true;
/// @todo offset_points are initialized with empty path, is that bug-save?
registerParameter( dynamic_cast<Parameter *>(&offset_points) );
registerParameter( dynamic_cast<Parameter *>(&sort_points) );
registerParameter( dynamic_cast<Parameter *>(&interpolator_type) );
}
LPEPowerStroke::~LPEPowerStroke()
{
}
void
LPEPowerStroke::doOnApply(SPLPEItem *lpeitem)
{
std::vector<Geom::Point> points;
Geom::Path::size_type size = SP_SHAPE(lpeitem)->curve->get_pathvector().front().size_open();
points.push_back( Geom::Point(0,0) );
points.push_back( Geom::Point(0.5*size,0) );
points.push_back( Geom::Point(size,0) );
offset_points.param_set_and_write_new_value(points);
}
static bool compare_offsets (Geom::Point first, Geom::Point second)
{
return first[Geom::X] < second[Geom::X];
}
Geom::Piecewise<Geom::D2<Geom::SBasis> >
LPEPowerStroke::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in)
{
using namespace Geom;
offset_points.set_pwd2(pwd2_in);
Piecewise<D2<SBasis> > der = unitVector(derivative(pwd2_in));
Piecewise<D2<SBasis> > n = rot90(der);
offset_points.set_pwd2_normal(n);
// see if we should treat the path as being closed.
bool closed_path = false;
if ( are_near(pwd2_in.firstValue(), pwd2_in.lastValue()) ) {
closed_path = true;
}
Piecewise<D2<SBasis> > output;
if (!closed_path) {
// perhaps use std::list instead of std::vector?
std::vector<Geom::Point> ts(offset_points.data().size() + 2);
// first and last point coincide with input path (for now at least)
ts.front() = Point(pwd2_in.domain().min(),0);
ts.back() = Point(pwd2_in.domain().max(),0);
for (unsigned int i = 0; i < offset_points.data().size(); ++i) {
ts.at(i+1) = offset_points.data().at(i);
}
if (sort_points) {
sort(ts.begin(), ts.end(), compare_offsets);
}
// create stroke path where points (x,y) := (t, offset)
Geom::Interpolate::Interpolator *interpolator = Geom::Interpolate::Interpolator::create(static_cast<Geom::Interpolate::InterpolatorType>(interpolator_type.get_value()));
Geom::Path strokepath = interpolator->interpolateToPath(ts);
Geom::Path mirroredpath = strokepath.reverse() * Geom::Scale(1,-1);
delete interpolator;
strokepath.append(mirroredpath, Geom::Path::STITCH_DISCONTINUOUS);
strokepath.close();
D2<Piecewise<SBasis> > patternd2 = make_cuts_independent(strokepath.toPwSb());
Piecewise<SBasis> x = Piecewise<SBasis>(patternd2[0]);
Piecewise<SBasis> y = Piecewise<SBasis>(patternd2[1]);
output = compose(pwd2_in,x) + y*compose(n,x);
} else {
// path is closed
// perhaps use std::list instead of std::vector?
std::vector<Geom::Point> ts = offset_points.data();
if (sort_points) {
sort(ts.begin(), ts.end(), compare_offsets);
}
// add extra points for interpolation between first and last point
Point first_point = ts.front();
Point last_point = ts.back();
ts.insert(ts.begin(), last_point - Point(pwd2_in.domain().extent() ,0));
ts.push_back( first_point + Point(pwd2_in.domain().extent() ,0) );
// create stroke path where points (x,y) := (t, offset)
Geom::Interpolate::Interpolator *interpolator = Geom::Interpolate::Interpolator::create(static_cast<Geom::Interpolate::InterpolatorType>(interpolator_type.get_value()));
Geom::Path strokepath = interpolator->interpolateToPath(ts);
delete interpolator;
// output 2 separate paths
D2<Piecewise<SBasis> > patternd2 = make_cuts_independent(strokepath.toPwSb());
Piecewise<SBasis> x = Piecewise<SBasis>(patternd2[0]);
Piecewise<SBasis> y = Piecewise<SBasis>(patternd2[1]);
// find time values for which x lies outside path domain
// and only take portion of x and y that lies within those time values
std::vector< double > rtsmin = roots (x - pwd2_in.domain().min());
std::vector< double > rtsmax = roots (x - pwd2_in.domain().max());
if ( !rtsmin.empty() && !rtsmax.empty() ) {
x = portion(x, rtsmin.at(0), rtsmax.at(0));
y = portion(y, rtsmin.at(0), rtsmax.at(0));
}
output = compose(pwd2_in,x) + y*compose(n,x);
x = reverse(x);
y = reverse(y);
output.concat(compose(pwd2_in,x) - y*compose(n,x));
}
return output;
}
/* ######################## */
} //namespace LivePathEffect
} /* namespace Inkscape */
/*
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 :