Files
sdrtrunk/src/util/ArcTangent.java
denny f4d8ea281d Initial commit of redesigned internal processing and audio management.
Note: Several of the decoders are currently non-functioning in this
commit.  If you want the latest functioning codebase, please checkout
the commit prior to this one.  All decoders will eventually be updated
with this new architecture.

Currently broken:
- Logging and recording
- Aux decoders (Fleetsync/MDC/LoJack/Tait)
- LTR/Passport decoders

Changes in this commit:
- Module architecture for decoders and components with central
provisioning by the DecoderFactory
- Transition from Complex sample stream processing to float buffer
processing for improved memory management
- Redesigned filter structures - to support buffers and streams
- Resolved several memory leak issues
- Universal sharing of the thread pool manager
- Added centralized audio management with call/user prioritization and
new gui with mute/volume controls
- Embedded audio metadata for eventual streaming support
- Redesigned ProcessingChain to support independent re-use
- Added new TrafficChannelManager to handle traffic channel allocations
- Traffic Channel pool size and Call timeout available in P25 and
MPT1327 configs
- Redesigned channel and decoder gui components
2015-09-01 07:10:26 -04:00

263 lines
9.0 KiB
Java

/*******************************************************************************
* SDR Trunk
* Copyright (C) 2014 Dennis Sheirer
*
* 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 3 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, see <http://www.gnu.org/licenses/>
*
* ----------------------------------------------
* Adapted from GNU Radio's gr_fast_atan2f() method, retrieved Jan 2013 from
* https://raw.github.com/gnuradio/gnuradio/master/gnuradio-core/src/lib/general/gr_fast_atan2f.cc
*
* Copyright 2005 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio 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 3, or (at your option)
* any later version.
*
* GNU Radio 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 GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
package util;
import sample.complex.Complex;
public class ArcTangent
{
public static final double sTANGENT_MAP_RESOLUTION = 0.003921549;
public static final double sRADIANS_PER_DEGREE = 0.017453293;
public static final int sTANGENT_MAP_SIZE = 256;
public static final double sHALF_PI = Math.PI / 2;
//ArcTangents from 0 to pi/4 radians
private static double[] sLOOKUP_TABLE = new double[] {
0.000000e+00, 3.921549e-03, 7.842976e-03, 1.176416e-02,
1.568499e-02, 1.960533e-02, 2.352507e-02, 2.744409e-02,
3.136226e-02, 3.527947e-02, 3.919560e-02, 4.311053e-02,
4.702413e-02, 5.093629e-02, 5.484690e-02, 5.875582e-02,
6.266295e-02, 6.656816e-02, 7.047134e-02, 7.437238e-02,
7.827114e-02, 8.216752e-02, 8.606141e-02, 8.995267e-02,
9.384121e-02, 9.772691e-02, 1.016096e-01, 1.054893e-01,
1.093658e-01, 1.132390e-01, 1.171087e-01, 1.209750e-01,
1.248376e-01, 1.286965e-01, 1.325515e-01, 1.364026e-01,
1.402496e-01, 1.440924e-01, 1.479310e-01, 1.517652e-01,
1.555948e-01, 1.594199e-01, 1.632403e-01, 1.670559e-01,
1.708665e-01, 1.746722e-01, 1.784728e-01, 1.822681e-01,
1.860582e-01, 1.898428e-01, 1.936220e-01, 1.973956e-01,
2.011634e-01, 2.049255e-01, 2.086818e-01, 2.124320e-01,
2.161762e-01, 2.199143e-01, 2.236461e-01, 2.273716e-01,
2.310907e-01, 2.348033e-01, 2.385093e-01, 2.422086e-01,
2.459012e-01, 2.495869e-01, 2.532658e-01, 2.569376e-01,
2.606024e-01, 2.642600e-01, 2.679104e-01, 2.715535e-01,
2.751892e-01, 2.788175e-01, 2.824383e-01, 2.860514e-01,
2.896569e-01, 2.932547e-01, 2.968447e-01, 3.004268e-01,
3.040009e-01, 3.075671e-01, 3.111252e-01, 3.146752e-01,
3.182170e-01, 3.217506e-01, 3.252758e-01, 3.287927e-01,
3.323012e-01, 3.358012e-01, 3.392926e-01, 3.427755e-01,
3.462497e-01, 3.497153e-01, 3.531721e-01, 3.566201e-01,
3.600593e-01, 3.634896e-01, 3.669110e-01, 3.703234e-01,
3.737268e-01, 3.771211e-01, 3.805064e-01, 3.838825e-01,
3.872494e-01, 3.906070e-01, 3.939555e-01, 3.972946e-01,
4.006244e-01, 4.039448e-01, 4.072558e-01, 4.105574e-01,
4.138496e-01, 4.171322e-01, 4.204054e-01, 4.236689e-01,
4.269229e-01, 4.301673e-01, 4.334021e-01, 4.366272e-01,
4.398426e-01, 4.430483e-01, 4.462443e-01, 4.494306e-01,
4.526070e-01, 4.557738e-01, 4.589307e-01, 4.620778e-01,
4.652150e-01, 4.683424e-01, 4.714600e-01, 4.745676e-01,
4.776654e-01, 4.807532e-01, 4.838312e-01, 4.868992e-01,
4.899573e-01, 4.930055e-01, 4.960437e-01, 4.990719e-01,
5.020902e-01, 5.050985e-01, 5.080968e-01, 5.110852e-01,
5.140636e-01, 5.170320e-01, 5.199904e-01, 5.229388e-01,
5.258772e-01, 5.288056e-01, 5.317241e-01, 5.346325e-01,
5.375310e-01, 5.404195e-01, 5.432980e-01, 5.461666e-01,
5.490251e-01, 5.518738e-01, 5.547124e-01, 5.575411e-01,
5.603599e-01, 5.631687e-01, 5.659676e-01, 5.687566e-01,
5.715357e-01, 5.743048e-01, 5.770641e-01, 5.798135e-01,
5.825531e-01, 5.852828e-01, 5.880026e-01, 5.907126e-01,
5.934128e-01, 5.961032e-01, 5.987839e-01, 6.014547e-01,
6.041158e-01, 6.067672e-01, 6.094088e-01, 6.120407e-01,
6.146630e-01, 6.172755e-01, 6.198784e-01, 6.224717e-01,
6.250554e-01, 6.276294e-01, 6.301939e-01, 6.327488e-01,
6.352942e-01, 6.378301e-01, 6.403565e-01, 6.428734e-01,
6.453808e-01, 6.478788e-01, 6.503674e-01, 6.528466e-01,
6.553165e-01, 6.577770e-01, 6.602282e-01, 6.626701e-01,
6.651027e-01, 6.675261e-01, 6.699402e-01, 6.723452e-01,
6.747409e-01, 6.771276e-01, 6.795051e-01, 6.818735e-01,
6.842328e-01, 6.865831e-01, 6.889244e-01, 6.912567e-01,
6.935800e-01, 6.958943e-01, 6.981998e-01, 7.004964e-01,
7.027841e-01, 7.050630e-01, 7.073330e-01, 7.095943e-01,
7.118469e-01, 7.140907e-01, 7.163258e-01, 7.185523e-01,
7.207701e-01, 7.229794e-01, 7.251800e-01, 7.273721e-01,
7.295557e-01, 7.317307e-01, 7.338974e-01, 7.360555e-01,
7.382053e-01, 7.403467e-01, 7.424797e-01, 7.446045e-01,
7.467209e-01, 7.488291e-01, 7.509291e-01, 7.530208e-01,
7.551044e-01, 7.571798e-01, 7.592472e-01, 7.613064e-01,
7.633576e-01, 7.654008e-01, 7.674360e-01, 7.694633e-01,
7.714826e-01, 7.734940e-01, 7.754975e-01, 7.774932e-01,
7.794811e-01, 7.814612e-01, 7.834335e-01, 7.853983e-01,
7.853983e-01 };
/**
* Lookup radian angle from polar coordinates represented by the
* ComplexSample
*
* @param sample representing polar coordinates
* @return - angle in radians
*/
public static double getAngle( Complex sample )
{
return getAngle( ( (double) sample.inphase() ),
( (double) sample.quadrature() ) );
}
/**
* Lookup radian angle from polar coordinates x and y
* @param x - x polar coordinate
* @param y - y polar coordinate
* @return - angle in radians
*/
public static double getAngle( double x, double y )
{
/**
* Calculates the angle of the vector (x,y) based on a table lookup and
* linear interpolation. The table uses a 256 point table covering
* -45 to +45 degrees and uses symmetry to determine the final angle
* value in the range of -180 to 180 degrees. Note that this function
* uses the small angle approximation for values close to zero. This
* routine calculates the arc tangent with an average error of
* +/- 0.045 degrees.
*/
double alpha;
double angle;
double base_angle;
int index;
//Check for divide by zero
if( x == 0.0 && y == 0.0 )
{
return 0.0;
}
//Normalize to +/- 45 degree range
double x_abs = Math.abs( x );
double y_abs = Math.abs( y );
//Calculate the ratio ( opposite/adjacent )
double z;
if( x_abs < y_abs )
{
z = x_abs / y_abs;
}
else
{
z = y_abs / x_abs;
}
//When the ratio approaches table resolution, the angle is best
//approximated with the argument itself
if( z < sTANGENT_MAP_RESOLUTION )
{
base_angle = z;
}
else
{
alpha = z * (double)( sTANGENT_MAP_SIZE - .5 );
index = (int)alpha;
alpha -= (double)index;
//Determine base angle based on quadrant and add or subtract table
//value from base angle, based on quadrant
base_angle = sLOOKUP_TABLE[ index ];
base_angle += ( sLOOKUP_TABLE[ index + 1 ] -
sLOOKUP_TABLE[ index ] ) * alpha;
}
//Map the angle to the correct quadrant
if( x_abs > y_abs ) // -45 to 45, or 135 to -135
{
if( x >= 0.0 ) // -45 to 45
{
if( y >= 0.0 )
{
angle = base_angle; // 0 to 45
}
else
{
angle = -base_angle; // -45 to 0
}
}
else // 135 to 180 or -180 to -135
{
angle = Math.PI;
if( y >= 0.0 )
{
angle -= base_angle; // 135 to 180
}
else
{
angle = base_angle - angle; // 180 to -135
}
}
}
else // 45 to 135, or -135 to -45
{
if( y >= 0.0 ) //45 to 135
{
angle = sHALF_PI;
if( x >= 0.0 )
{
angle -= base_angle; // 45 to 90
}
else
{
angle += base_angle; // 90 to 135
}
}
else
{
angle = -sHALF_PI;
if( x >= 0.0 )
{
angle += base_angle; //-90 to -45
}
else
{
angle -= base_angle; //-135 to -90
}
}
}
// //Check for negative radian angle value
//
// if( angle < 0 )
// {
// angle += 2 * Math.PI;
// }
return angle;
}
}