test2/source/blender/freestyle/intern/geometry/Bezier.cpp

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/** \file blender/freestyle/intern/geometry/Bezier.cpp
 *  \ingroup freestyle
 *  \brief Class to define a Bezier curve of order 4.
 *  \author Stephane Grabli
 *  \date 04/06/2003
 */

#include "Bezier.h"
#include "FitCurve.h"

using namespace std;

namespace Freestyle {

BezierCurveSegment::BezierCurveSegment()
{
}

BezierCurveSegment::~BezierCurveSegment()
{
}

void BezierCurveSegment::AddControlPoint(const Vec2d& iPoint)
{
	_ControlPolygon.push_back(iPoint);
	if (_ControlPolygon.size() == 4)
		Build();
}

void BezierCurveSegment::Build()
{
	if (_ControlPolygon.size() != 4)
		return;

	// Compute the rightmost part of the matrix:
	vector<Vec2d>::const_iterator p0, p1, p2, p3;
	p0 = _ControlPolygon.begin();
	p1 = p0;
	++p1;
	p2 = p1;
	++p2;
	p3 = p2;
	++p3;
	float x[4], y[4];

	x[0] = -p0->x() + 3 * p1->x() - 3 * p2->x() + p3->x();
	x[1] = 3 * p0->x() - 6 * p1->x() + 3 * p2->x();
	x[2] = -3 * p0->x() + 3 * p1->x();
	x[3] = p0->x();

	y[0] = -p0->y() + 3 * p1->y() - 3 * p2->y() + p3->y();
	y[1] = 3 * p0->y() - 6 * p1->y() + 3 * p2->y();
	y[2] = -3 * p0->y() + 3 * p1->y();
	y[3] = p0->y();

	int nvertices = 12;
	float increment = 1.0 / (float)nvertices;
	float t = 0.0f;
	for (int i = 0; i <= nvertices; ++i) {
		_Vertices.push_back(Vec2d((x[3] + t * (x[2] + t * (x[1] + t * x[0]))),
		                          (y[3] + t * (y[2] + t * (y[1] + t * y[0])))));
		t += increment;
	}
}

BezierCurve::BezierCurve()
{
	_currentSegment = new BezierCurveSegment;
}

BezierCurve::BezierCurve(vector<Vec2d>& iPoints, double error)
{
	FitCurveWrapper fitcurve;
	_currentSegment = new BezierCurveSegment;
	vector<Vec2d> curve;

	fitcurve.FitCurve(iPoints, curve, error);
	int i = 0;
	vector<Vec2d>::iterator v, vend;
	for (v = curve.begin(), vend = curve.end(); v != vend; ++v) {
		if ((i == 0) || (i % 4 != 0))
			AddControlPoint(*v);
		++i;
	}
}

BezierCurve::~BezierCurve()
{
	if (!_Segments.empty()) {
		vector<BezierCurveSegment*>::iterator v, vend;
		for (v = _Segments.begin(), vend = _Segments.end(); v != vend; ++v)
			delete *v;
	}
	if (_currentSegment)
		delete _currentSegment;
}

void BezierCurve::AddControlPoint(const Vec2d& iPoint)
{
	_ControlPolygon.push_back(iPoint);
	_currentSegment->AddControlPoint(iPoint);
	if (_currentSegment->size() == 4) {
		_Segments.push_back(_currentSegment);
		_currentSegment = new BezierCurveSegment;
		_currentSegment->AddControlPoint(iPoint);
	}
}

} /* namespace Freestyle */