// K-3D
// Copyright (c) 1995-2006, Timothy M. Shead
//
// Contact: tshead@k-3d.com
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

/** \file
	\author Tim Shead (tshead@k-3d.com)
*/

#include <k3dsdk/basic_math.h>
#include <k3dsdk/bezier.h>

namespace k3d
{

double BernsteinBasis(const unsigned long Order, const unsigned long ControlPoint, const double Parameter)
{
	// Sanity checks ...
	assert(Order > 1);
	assert(ControlPoint <= Order);

	const int n = Order - 1;
	const int i = ControlPoint;
	const double t = Parameter;

	const double ni = factorial(n) / (factorial(i) * factorial(n - i));

	return ni * pow(t, i) * pow((1 - t), (n - i));
}

} // namespace k3d

