#define INKSCAPE_LPE_POWERSTROKE_CPP

#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>

namespace Geom {

namespace Interpolate {

class Interpolator {

public:

Interpolator() {};

virtual ~Interpolator() {};

virtual 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&);

};

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&);

};

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&);

};

} //namespace Interpolate

} //namespace Geom

namespace Inkscape {

namespace LivePathEffect {

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)

{

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) );

}

LPEPowerStroke::~LPEPowerStroke()

{

}

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::CubicBezierJohan interpolator;

Path strokepath = interpolator.interpolateToPath(ts);

Path mirroredpath = strokepath.reverse() * Geom::Scale(1,-1);

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::CubicBezierJohan interpolator;

Path strokepath = interpolator.interpolateToPath(ts);

// 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 */