/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * Copyright 2009-2011 Jörg Hermann Müller
 *
 * This file is part of AudaSpace.
 *
 * Audaspace 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.
 *
 * AudaSpace 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 Audaspace; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file audaspace/intern/AUD_AnimateableProperty.cpp
 *  \ingroup audaspaceintern
 */


#include "AUD_AnimateableProperty.h"
#include "AUD_MutexLock.h"

#include <cstring>
#include <cmath>

AUD_AnimateableProperty::AUD_AnimateableProperty(int count) :
	AUD_Buffer(count * sizeof(float)), m_count(count), m_isAnimated(false)
{
	memset(getBuffer(), 0, count * sizeof(float));

	pthread_mutexattr_t attr;
	pthread_mutexattr_init(&attr);
	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);

	pthread_mutex_init(&m_mutex, &attr);

	pthread_mutexattr_destroy(&attr);
}

AUD_AnimateableProperty::AUD_AnimateableProperty(int count, float value) :
	AUD_Buffer(count * sizeof(float)), m_count(count), m_isAnimated(false)
{
	sample_t* buf = getBuffer();

	for(int i = 0; i < count; i++)
		buf[i] = value;

	pthread_mutexattr_t attr;
	pthread_mutexattr_init(&attr);
	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);

	pthread_mutex_init(&m_mutex, &attr);

	pthread_mutexattr_destroy(&attr);
}

void AUD_AnimateableProperty::updateUnknownCache(int start, int end)
{
	float* buf = getBuffer();

	for(int i = start; i <= end; i++)
		// TODO: maybe first instead of zero order interpolation?
		memcpy(buf + i * m_count, buf + (start - 1) * m_count, m_count * sizeof(float));
}

AUD_AnimateableProperty::~AUD_AnimateableProperty()
{
	pthread_mutex_destroy(&m_mutex);
}

void AUD_AnimateableProperty::lock()
{
	pthread_mutex_lock(&m_mutex);
}

void AUD_AnimateableProperty::unlock()
{
	pthread_mutex_unlock(&m_mutex);
}

void AUD_AnimateableProperty::write(const float* data)
{
	AUD_MutexLock lock(*this);

	m_isAnimated = false;
	m_unknown.clear();
	memcpy(getBuffer(), data, m_count * sizeof(float));
}

void AUD_AnimateableProperty::write(const float* data, int position, int count)
{
	AUD_MutexLock lock(*this);

	int pos = getSize() / (sizeof(float) * m_count);

	if(!m_isAnimated)
		pos = 0;

	m_isAnimated = true;

	assureSize((count + position) * m_count * sizeof(float), true);

	float* buf = getBuffer();

	memcpy(buf + position * m_count, data, count * m_count * sizeof(float));

	// have to fill up space between?
	if(pos < position)
	{
		m_unknown.push_back(Unknown(pos, position - 1));

		if(pos == 0)
		{
			for(int i = 0; i < position; i++)
				memcpy(buf + i * m_count, data, m_count * sizeof(float));
		}
		else
			updateUnknownCache(pos, position - 1);
	}
	// otherwise it's not at the end, let's check if some unknown part got filled
	else
	{
		bool erased = false;

		for(std::list<Unknown>::iterator it = m_unknown.begin(); it != m_unknown.end(); erased ? it : it++)
		{
			erased = false;

			// unknown area before position
			if(it->end < position)
				continue;

			// we're after the new area, let's stop
			if(it->start >= position + count)
				break;

			// we have an intersection, now 4 cases:
			// the start is included
			if(position <= it->start)
			{
				// the end is included
				if(position + count > it->end)
				{
					// simply delete
					it = m_unknown.erase(it);
					erased = true;
				}
				// the end is excluded, a second part remains
				else
				{
					// update second part
					it->start = position + count;
					updateUnknownCache(it->start, it->end);
					break;
				}
			}
			// start is excluded, a first part remains
			else
			{
				// the end is included
				if(position + count > it->end)
				{
					// update first part
					it->end = position - 1;
				}
				// the end is excluded, a second part remains
				else
				{
					// add another item and update both parts
					m_unknown.insert(it, Unknown(it->start, position - 1));
					it->start = position + count;
					updateUnknownCache(it->start, it->end);
				}
			}
		}
	}
}

void AUD_AnimateableProperty::read(float position, float* out)
{
	AUD_MutexLock lock(*this);

	if(!m_isAnimated)
	{
		memcpy(out, getBuffer(), m_count * sizeof(float));
		return;
	}

	int last = getSize() / (sizeof(float) * m_count) - 1;
	float t = position - floor(position);

	if(position >= last)
	{
		position = last;
		t = 0;
	}

	if(t == 0)
	{
		memcpy(out, getBuffer() + int(floor(position)) * m_count, m_count * sizeof(float));
	}
	else
	{
		int pos = int(floor(position)) * m_count;
		float t2 = t * t;
		float t3 = t2 * t;
		float m0, m1;
		float* p0;
		float* p1 = getBuffer() + pos;
		float* p2;
		float* p3;
		last *= m_count;

		if(pos == 0)
			p0 = p1;
		else
			p0 = p1 - m_count;

		p2 = p1 + m_count;
		if(pos + m_count == last)
			p3 = p2;
		else
			p3 = p2 + m_count;

		for(int i = 0; i < m_count; i++)
		{
			m0 = (p2[i] - p0[i]) / 2.0f;
			m1 = (p3[i] - p1[i]) / 2.0f;

			out[i] = (2 * t3 - 3 * t2 + 1) * p0[i] + (-2 * t3 + 3 * t2) * p1[i] +
					 (t3 - 2 * t2 + t) * m0 + (t3 - t2) * m1;
		}
	}
}

bool AUD_AnimateableProperty::isAnimated() const
{
	return m_isAnimated;
}
