// Copyright (C) 2015 Rémi Bèges
// This file is part of the "Nazara Engine".
// For conditions of distribution and use, see copyright notice in Config.hpp

#include <Nazara/Core/Error.hpp>
#include <Nazara/Noise/Config.hpp>
#include <Nazara/Noise/HybridMultiFractal3D.hpp>
#include <Nazara/Noise/Perlin3D.hpp>
#include <Nazara/Noise/Simplex3D.hpp>
#include <Nazara/Noise/Debug.hpp>

namespace Nz
{
	HybridMultiFractal3D::HybridMultiFractal3D(NoiseType source, unsigned int seed)
	{
		switch(source)
		{
			case PERLIN:
				m_source = new Perlin3D();
			break;

			default:
				m_source = new Simplex3D();
			break;
		}
		m_source->SetNewSeed(seed);
		m_source->ShufflePermutationTable();
		m_noiseType = source;
	}

	float HybridMultiFractal3D::GetValue(float x, float y, float z, float resolution)
	{
		this->RecomputeExponentArray();

		m_offset = 1.0f;

		m_value = (m_source->GetValue(x,y,z,resolution) + m_offset) * m_exponent_array[0];
		m_weight = m_value;
		m_signal = 0.f;

		resolution *= m_lacunarity;

		for(int i(1) ; i < m_octaves; ++i)
		{
			if (m_weight > 1.f)
				m_weight = 1.f;

			m_signal = (m_source->GetValue(x,y,z,resolution) + m_offset) * m_exponent_array[i];
			m_value += m_weight * m_signal;

			m_weight *= m_signal;

			resolution *= m_lacunarity;
		}

		m_remainder = m_octaves - static_cast<int>(m_octaves);
		if (m_remainder > 0.f)
			m_value += m_remainder * m_source->GetValue(x,y,z,resolution) * m_exponent_array[static_cast<int>(m_octaves-1)];

		return m_value/this->m_sum - m_offset;
	}

	HybridMultiFractal3D::~HybridMultiFractal3D()
	{
		delete m_source;
	}
}
