WhoiUtil.cpp

// Copyright 2012-2023:
//   GobySoft, LLC (2013-)
//   Massachusetts Institute of Technology (2007-2014)
//   Community contributors (see AUTHORS file)
// File authors:
//   Toby Schneider <toby@gobysoft.org>
//
//
// This file is part of the Dynamic Compact Control Language Library
// ("DCCL").
//
// DCCL is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 2.1 of the License, or
// (at your option) any later version.
//
// DCCL 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with DCCL.  If not, see <http://www.gnu.org/licenses/>.
#include <ctime> // P.Brodsky
 
#include "WhoiUtil.h"
 
LATLON_COMPRESSED Encode_latlon(double latlon_in)
{
    /* Latitude and longitude are compressed into 3 byte values each. */
    LONG_AND_COMP out;
    double encoded;
    encoded = latlon_in * ((double)(0x007FFFFFL) / 180.0);
    encoded += (encoded > 0.0) ? 0.5 : -0.5;
    // deal with truncation
    //  std::cout << std::setprecision(16) << encoded << std::endl;
    out.as_long = (long int)encoded;
    // std::cout << std::hex << out.as_long << std::endl;
    return (out.as_compressed);
}
 
double Decode_latlon(LATLON_COMPRESSED latlon_in)
{
    LONG_AND_COMP in;
    in.as_long = 0; //Clear the MSB
    in.as_compressed = latlon_in;
 
    if (in.as_long & 0x00800000L) // if is negative,
        in.as_long |= ~0xFFFFFFL; // sign extend
 
    return (double)in.as_long * (180.0 / (double)(0x007FFFFFL));
}
 
unsigned char Encode_heading(float heading)
{
    return ((unsigned char)(heading * 255.0 / 360.0 + 0.5));
}
 
double Decode_heading(unsigned char heading) { return ((double)heading * 360.0 / 255.0); }
 
/* Encodes velocity in meters per second into a single byte with a 
 * resolution of 2.5 cm/sec. Input range is 0- ~6 meters/second 
 * (12 knots). 
 */
char Encode_est_velocity(float est_velocity)
{
    return ((char)(est_velocity * 25.0 + 0.5)); // added 0.5 to perform basic positive rounding
}
 
float Decode_est_velocity(char est_velocity) { return (est_velocity / 25.0); }
 
/* Code-decode salinity in range of 20-45 parts per thousand at a 
 * resolution of 0.1 part per thousand. */
unsigned char Encode_salinity(float salinity)
{
    float output;
    if (salinity < 20.0)
        return (0);
    else
    {
        output = (salinity - 20.0) * 10;
        if (output > 255)
            output = 255;
        return ((unsigned char)output);
    }
}
 
float Decode_salinity(unsigned char sal)
{
    if (sal == 0)
        return (sal);
    return (((float)sal / 10.0) + 20.0);
}
 
unsigned short Encode_depth(float depth)
/* 0 -100 meters: 0-1000 (10 cm resolution) 
      * 100 -200 meters: 1001-1500 (20 cm resolution) 
      * 200 -1000 meters: 1501-3100 (50 cm resolution) 
      * 1000-6000 meters: 3101-8100 (1 meter resolution) */
{
    if (depth < 0)
        return (0);
    if (depth < 100)
        return ((short unsigned int)((depth + .05) * 1.0 / 0.1));
    if (depth < 200)
        return ((short unsigned int)(((depth - 100) + 0.1) * 1.0 / 0.2 + 1000));
    if (depth < 1000)
        return ((short unsigned int)(((depth - 200) + 0.25) * 1.0 / 0.5 + 1500));
    if (depth < 6000)
        return ((short unsigned int)(((depth - 1000) + 0.5) * 1.0 / 1.0 + 3100));
    return (8100);
}
 
float Decode_depth(unsigned short depth)
{
    /* 0 -100 meters: 0-1000 (10 cm resolution) 
   * 100 -200 meters: 1001-1500 (20 cm resolution) 
   * 200 -1000 meters: 1501-3100 (50 cm resolution) 
   * 1000-6000 meters: 3101-8100 (1 meter resolution) 
   */
    unsigned short DEPTH_MODE_MASK = 0x1FFF; // P.Brodsky
    depth &= DEPTH_MODE_MASK;                // Only using bottom 13 bits.
    if (depth <= 1000)
        return (depth * 0.1 / 1.0);
    else if (depth <= 1500)
        return (100 + (depth - 1000) * 0.2 / 1.0);
    else if (depth <= 3100)
        return (200 + (depth - 1500) * 0.5 / 1.0);
    else if (depth <= 8100)
        return (1000 + (depth - 3100) * 1.0 / 1.0);
    else
        return (6000);
}
 
unsigned char Encode_temperature(float temperature)
{
    if (temperature < -4)
        temperature = -4;
    temperature += 4;
    temperature = temperature * 256.0 / 40.0 + 0.5;
    if (temperature > 255)
        temperature = 255;
    return ((unsigned char)temperature);
}
 
float Decode_temperature(unsigned char temperature) { return (temperature * 40.0 / 256.0 - 4.0); }
 
unsigned char Encode_sound_speed(float sound_speed)
{
    return ((unsigned char)((sound_speed - 1425.0) * 2));
}
 
float Decode_sound_speed(unsigned char sound_speed) { return ((float)sound_speed / 2.0 + 1425.0); }
 
unsigned short Encode_hires_altitude(float alt) /* 10 cm resolution to 655 meters. */
{
    alt *= 100;
    if (alt > 65535.0)
        return (65535U);
    else if (alt < 0)
        return (0);
    else
        return ((unsigned short)alt);
}
 
float Decode_hires_altitude(unsigned short alt) { return ((float)alt / 100.0); }
 
unsigned short Encode_gfi_pitch_oil(float gfi, float pitch, float oil)
{
    /* We are encoding 3 parameters that are somewhat specific to 
   * the REMUS 6000 into 2 bytes. * GFI= 5 bits: 0-100 (3.3 resolution) 
   * OIL= 5 bits: this gives us resolution of 3.3 percent 
   * Pitch=6 bits;
   180 into 64, resolution of 3 degrees. */
    unsigned short result;
    unsigned short temp;
    if (gfi < 0) // 5 bits of gfi
        gfi = 0;
    else if (gfi > 100)
        gfi = 100;
    result = (unsigned short)(gfi * 31.0 / 100.0);
    if (oil < 0) // 5 bits of oil
        oil = 0;
    else if (oil > 100)
        oil = 100;
    oil *= 31.0 / 100.0;
    result |= ((unsigned short)oil << 5);
    if (pitch > 90) // 6 bits of pitch
        pitch = 90;
    else if (pitch < -90)
        pitch = -90;
    pitch *= 63.0 / 180.0;
    // Scale to 6 bits;
    if (pitch > 0.0)
        pitch += 0.5;
    else if (pitch < 0)
        pitch -= 0.5;
    // shift as unsigned: left-shifting a negative value is undefined, and
    // pitch is negative for any downward angle
    temp = (unsigned short)((unsigned int)(unsigned short)(short)pitch << 10);
    result |= temp & 0xFC00;
    return (result);
}
 
void Decode_gfi_pitch_oil(unsigned short gfi_pitch_oil, float* gfi, float* pitch, float* oil)
{
    unsigned short temp;
    short temp_pitch;
 
    temp = (unsigned int)((gfi_pitch_oil & 0x001F) * 100.0 / 31.0);
    *gfi = temp;
    temp = (gfi_pitch_oil & 0x03E0) >> 5;
    *oil = temp * 100.0 / 31.0;
    temp_pitch = ((short)(gfi_pitch_oil & 0xFC00)) >> 10;
    *pitch = temp_pitch * 180.0 / 63.0;
}
 
TIME_DATE Encode_time_date(long secs_since_1970)
{
    /* The time is encoded as follows: 
   * Month 4 bits * Day 5 bits 
   * hour 5 bits 
   * Min 6 bits 
   * Secs 4 bits 
   // 4 secs per bit 
   * The year is not encoded. 
*/
    struct tm tm;
    TIME_DATE_LONG comp;
    /* Note: substitute localtime() for local timezone 
   * instead of GMT. */
    time_t secs_since_1970_time_t(secs_since_1970);
    tm = *gmtime(&secs_since_1970_time_t);
    comp.as_long = (unsigned long)tm.tm_sec >> 2;
    comp.as_long += (unsigned long)tm.tm_min << 4;
    comp.as_long += (unsigned long)tm.tm_hour << (4 + 6);
    comp.as_long += (unsigned long)tm.tm_mday << (4 + 6 + 5);
    comp.as_long += (unsigned long)(tm.tm_mon + 1) << (4 + 6 + 5 + 5);
    return (comp.as_time_date);
}
 
long Decode_time_date(TIME_DATE input, short* mon, short* day, short* hour, short* min, short* sec)
{
    TIME_DATE_LONG comp;
    comp.as_long = 0;
    comp.as_time_date = input;
 
    *mon = (short)((comp.as_long >> (4 + 6 + 5 + 5)) & 0x000F);
    *day = (short)((comp.as_long >> (4 + 6 + 5)) & 0x001F);
    *hour = (short)((comp.as_long >> (4 + 6)) & 0x001F);
    *min = (short)((comp.as_long >> (4)) & 0x003F);
    *sec = (short)(((comp.as_long) & 0x000F) * 4);
 
    /* It is possible to force this routine to return the 
   * seconds since 1970. Left as an exercise for the reader� 
   */
    return (0);
}
 
unsigned char Encode_watts(float volts, float amps)
{
    /* Resolution is 4 watts, max is unsaturated is 1018 watts. */
    float watts = (volts * amps) / 4;
    if (watts > 255)
        watts = 255;
    else if (watts < 0)
        watts = 0;
    // ok, not possible...
    return ((unsigned char)watts);
}
 
float Decode_watts(unsigned char watts_encoded) { return ((float)watts_encoded * 4.0); }
 
char Encode_speed(SPEED_MODE mode, float speed)
{
    /* Max RPM: 2540 * Max Speed: 4.2 meters/sec (8.1 knots) */
    switch (mode)
    {
        case SPEED_MODE_RPM: // Clamp to avoid errors. speed /= 20.0;
            if (speed > 127)
                speed = 127;
            else if (speed < -127)
                speed = -127;
            break;
        case SPEED_MODE_KNOTS: // Convert to m/sec speed *= 0.5144444;
                               // Fall thru...
        case SPEED_MODE_MSEC:
            speed *= 30;
            if (speed > 127)
                speed = 127;
            else if (speed < -127)
                speed = -127;
            break;
    }
 
    speed += (speed > 0.0) ? 0.5 : -0.5;
 
    return ((char)speed);
}
 
float Decode_speed(SPEED_MODE mode, char speed)
{
    switch (mode)
    {
        case SPEED_MODE_RPM: return (speed * 20.0);
        case SPEED_MODE_MSEC: return ((float)speed / 30.0);
        case SPEED_MODE_KNOTS: // "Knots mode not supported by modem codec"
            return (0);
    }
    return (0);
}
 
double DecodeRangerLL(unsigned char c1, unsigned char c2, unsigned char c3, unsigned char c4,
                      unsigned char c5)
{
    int deg100, deg10, deg1, min10, min1, minp1000, minp100, minp10, minp1, sign;
    double fMin, fDeg, fSign, fRet;
 
    // deg
    deg100 = ((c1 & 0xf0) >> 4);
    deg10 = c1 & 0x0f;
    deg1 = ((c2 & 0xf0) >> 4);
    fDeg = deg100 * 100.0 + deg10 * 10.0 + deg1 * 1.0;
 
    // sign
    sign = c2 & 0x0f;
    if ((sign == 0x0c) || (sign == 0x0d))
        fSign = -1.0;
    else
        fSign = 1.0;
 
    // min
    min10 = ((c3 & 0xf0) >> 4);
    min1 = c3 & 0x0f;
    minp1000 = ((c4 & 0xf0) >> 4);
    minp100 = c4 & 0x0f;
    minp10 = ((c5 & 0xf0) >> 4);
    minp1 = c5 & 0x0f;
    fMin = min10 * 10.0 + min1 * 1.0 + minp1000 * 0.1 + minp100 * 0.01 + minp10 * 0.001 +
           minp1 * 0.0001;
 
    fRet = (fDeg + (fMin / 60.0)) * fSign;
 
    return fRet;
}
 
double DecodeRangerBCD2(unsigned char c1, unsigned char c2)
{
    int i1000, i100, i10, i1;
 
    i1000 = ((c1 & 0xf0) >> 4);
    i100 = c1 & 0x0f;
    i10 = ((c2 & 0xf0) >> 4);
    i1 = c2 & 0x0f;
 
    return i1000 * 1000.0 + i100 * 100.0 + i10 * 10.0 + i1 * 1.0;
}
 
double DecodeRangerBCD(unsigned char c1)
{
    int i10, i1;
 
    i10 = ((c1 & 0xf0) >> 4);
    i1 = c1 & 0x0f;
 
    return i10 * 10.0 + i1 * 1.0;
}