Files
lmms/plugins/LadspaEffect/caps/HRTF.cc

149 lines
2.7 KiB
C++

/*
HRTF.cc
Copyright 2002-7 Tim Goetze <tim@quitte.de>
http://quitte.de/dsp/
high-order IIR filtering modeled after HRTF impulse responses
*/
/*
This program 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 program 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 program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA or point your web browser to http://www.gnu.org.
*/
#include "basics.h"
#include "HRTF.h"
#include "Descriptor.h"
#include "elev0.h"
/* //////////////////////////////////////////////////////////////////////// */
void
HRTF::init()
{
h = 0;
}
void
HRTF::set_pan (int p)
{
n = 31;
pan = p;
if (p >= 0)
{
left.a = elev0[p].left.a;
left.b = elev0[p].left.b;
right.a = elev0[p].right.a;
right.b = elev0[p].right.b;
}
else
{
p = -p;
left.a = elev0[p].right.a;
left.b = elev0[p].right.b;
right.a = elev0[p].left.a;
right.b = elev0[p].left.b;
}
memset (left.y, 0, sizeof (left.y));
memset (right.y, 0, sizeof (right.y));
}
template <sample_func_t F>
void
HRTF::one_cycle (int frames)
{
sample_t * s = ports[0];
int p = (int) getport(1);
if (p != pan) set_pan (p);
sample_t * dl = ports[2];
sample_t * dr = ports[3];
double l, r;
for (int i = 0; i < frames; ++i)
{
x[h] = l = r = s[i] + normal;
l *= left.a[0];
r *= right.a[0];
for (int j = 1, z = h - 1; j < n; --z, ++j)
{
z &= 31;
l += left.a[j] * x[z];
l += left.b[j] * left.y[z];
r += right.a[j] * x[z];
r += right.b[j] * right.y[z];
}
left.y[h] = l;
right.y[h] = r;
h = (h + 1) & 31;
F (dl, i, l, adding_gain);
F (dr, i, r, adding_gain);
}
}
/* //////////////////////////////////////////////////////////////////////// */
PortInfo
HRTF::port_info [] =
{
{
"in",
INPUT | AUDIO,
{BOUNDED, -1, 1}
}, {
"pan",
INPUT | CONTROL,
{BOUNDED | INTEGER | DEFAULT_0, -36, 36}
}, {
"out:l",
OUTPUT | AUDIO,
{0}
}, {
"out:r",
OUTPUT | AUDIO,
{0}
}
};
template <> void
Descriptor<HRTF>::setup()
{
UniqueID = 1787;
Label = "HRTF";
Properties = HARD_RT;
Name = CAPS "HRTF - Head-related transfer function at elevation 0";
Maker = "Tim Goetze <tim@quitte.de>";
Copyright = "GPL, 2004-7";
/* fill port info and vtable */
autogen();
}