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/*
** ClanLib SDK
** Copyright (c) 1997-2005 The ClanLib Team
**
** This software is provided 'as-is', without any express or implied
** warranty. In no event will the authors be held liable for any damages
** arising from the use of this software.
**
** Permission is granted to anyone to use this software for any purpose,
** including commercial applications, and to alter it and redistribute it
** freely, subject to the following restrictions:
**
** 1. The origin of this software must not be misrepresented; you must not
** claim that you wrote the original software. If you use this software
** in a product, an acknowledgment in the product documentation would be
** appreciated but is not required.
** 2. Altered source versions must be plainly marked as such, and must not be
** misrepresented as being the original software.
** 3. This notice may not be removed or altered from any source distribution.
**
** Note: Some of the libraries ClanLib may link to may have additional
** requirements or restrictions.
**
** File Author(s):
**
** Magnus Norddahl
** (if your name is missing here, please add it)
*/
#include "Sound/precomp.h"
#ifdef _MSC_VER
#pragma warning (disable:4786)
#endif
#include "fadefilter_generic.h"
CL_FadeFilter::CL_FadeFilter(float initial_volume)
{
if(initial_volume < 0.0f)
initial_volume = 0.0f;
if(initial_volume > 1.0f)
initial_volume = 1.0f;
impl = new CL_FadeFilter_Generic;
impl->cur_volume = initial_volume;
impl->new_volume = initial_volume;
impl->speed = 0;
}
CL_FadeFilter::~CL_FadeFilter()
{
delete impl;
}
float CL_FadeFilter::get_volume() const
{
return impl->cur_volume;
}
void CL_FadeFilter::set_volume(float new_volume)
{
if(new_volume < 0.0f)
new_volume = 0.0f;
if(new_volume > 1.0f)
new_volume = 1.0f;
impl->cur_volume = new_volume;
impl->speed = 0.0f;
}
void CL_FadeFilter::fade_to_volume(float new_volume, int duration)
{
if(new_volume < 0.0f)
new_volume = 0.0f;
if(new_volume > 1.0f)
new_volume = 1.0f;
impl->new_volume = new_volume;
float delta_volume = impl->new_volume - impl->cur_volume;
impl->speed = delta_volume / 22.05f / duration;
}
void CL_FadeFilter::filter(int **sample_data, int num_samples, int channels)
{
if (impl->speed == 0 && impl->cur_volume == 1)
{
return; //no reason to waste processor power here, we've already faded to our target
}
float &cur_volume = impl->cur_volume;
float &new_volume = impl->new_volume;
float &speed = impl->speed;
for (int i=0; i<num_samples; i++)
{
for (int j=0; j<channels; j++)
{
sample_data[j][i] = (int) (sample_data[j][i] * cur_volume);
}
// change volume for every second sample (because data is in stereo).
cur_volume += speed;
if (
(speed > 0 && cur_volume > new_volume) ||
(speed < 0 && cur_volume < new_volume))
{
cur_volume = new_volume;
speed = 0;
}
}
}
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