ardupilot/libraries/AP_Declination/AP_Declination.cpp
Andrew Tridgell e4e052ff91 AP_Declination: save some more memory by putting the declination keys in progmem
there was a comment saying this was too slow, but it actually costs
about 30 usec extra, which is trivial given the full auto declination
call costs 680 usec and its only called once per boot
2012-03-30 14:25:27 +11:00

212 lines
16 KiB
C++

/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
/*
* Adam M Rivera
* With direction from: Andrew Tridgell, Jason Short, Justin Beech
*
* Adapted from: http://www.societyofrobots.com/robotforum/index.php?topic=11855.0
* Scott Ferguson
* scottfromscott@gmail.com
*
*
* This library 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.
*/
#include <FastSerial.h>
#include <AP_Common.h>
#include <AP_Declination.h>
#include <avr/pgmspace.h>
#include <math.h>
// 1 byte - 4 bits for value + 1 bit for sign + 3 bits for repeats => 8 bits
struct row_value{
// Offset has a max value of 15
uint8_t abs_offset:4;
// Sign of the offset, 0 = negative, 1 = positive
uint8_t offset_sign:1;
// The highest repeat is 7
uint8_t repeats:3;
};
// 730 bytes
static const uint8_t exceptions[10][73] PROGMEM = \
{ \
{150,145,140,135,130,125,120,115,110,105,100,95,90,85,80,75,70,65,60,55,50,45,40,35,30,25,20,15,10,5,0,4,9,14,19,24,29,34,39,44,49,54,59,64,69,74,79,84,89,94,99,104,109,114,119,124,129,134,139,144,149,154,159,164,169,174,179,175,170,165,160,155,150}, \
{143,137,131,126,120,115,110,105,100,95,90,85,80,75,71,66,62,57,53,48,44,39,35,31,27,22,18,14,9,5,1,3,7,11,16,20,25,29,34,38,43,47,52,57,61,66,71,76,81,86,91,96,101,107,112,117,123,128,134,140,146,151,157,163,169,175,178,172,166,160,154,148,143}, \
{130,124,118,112,107,101,96,92,87,82,78,74,70,65,61,57,54,50,46,42,38,34,31,27,23,19,16,12,8,4,1,2,6,10,14,18,22,26,30,34,38,43,47,51,56,61,65,70,75,79,84,89,94,100,105,111,116,122,128,135,141,148,155,162,170,177,174,166,159,151,144,137,130}, \
{111,104,99,94,89,85,81,77,73,70,66,63,60,56,53,50,46,43,40,36,33,30,26,23,20,16,13,10,6,3,0,3,6,9,13,16,20,24,28,32,36,40,44,48,52,57,61,65,70,74,79,84,88,93,98,103,109,115,121,128,135,143,152,162,172,176,165,154,144,134,125,118,111}, \
{85,81,77,74,71,68,65,63,60,58,56,53,51,49,46,43,41,38,35,32,29,26,23,19,16,13,10,7,4,1,1,3,6,9,13,16,19,23,26,30,34,38,42,46,50,54,58,62,66,70,74,78,83,87,91,95,100,105,110,117,124,133,144,159,178,160,141,125,112,103,96,90,85}, \
{62,60,58,57,55,54,52,51,50,48,47,46,44,42,41,39,36,34,31,28,25,22,19,16,13,10,7,4,2,0,3,5,8,10,13,16,19,22,26,29,33,37,41,45,49,53,56,60,64,67,70,74,77,80,83,86,89,91,94,97,101,105,111,130,109,84,77,74,71,68,66,64,62}, \
{46,46,45,44,44,43,42,42,41,41,40,39,38,37,36,35,33,31,28,26,23,20,16,13,10,7,4,1,1,3,5,7,9,12,14,16,19,22,26,29,33,36,40,44,48,51,55,58,61,64,66,68,71,72,74,74,75,74,72,68,61,48,25,2,22,33,40,43,45,46,47,46,46}, \
{6,9,12,15,18,21,23,25,27,28,27,24,17,4,14,34,49,56,60,60,60,58,56,53,50,47,43,40,36,32,28,25,21,17,13,9,5,1,2,6,10,14,17,21,24,28,31,34,37,39,41,42,43,43,41,38,33,25,17,8,0,4,8,10,10,10,8,7,4,2,0,3,6}, \
{22,24,26,28,30,32,33,31,23,18,81,96,99,98,95,93,89,86,82,78,74,70,66,62,57,53,49,44,40,36,32,27,23,19,14,10,6,1,2,6,10,15,19,23,27,31,35,38,42,45,49,52,55,57,60,61,63,63,62,61,57,53,47,40,33,28,23,21,19,19,19,20,22}, \
{168,173,178,176,171,166,161,156,151,146,141,136,131,126,121,116,111,106,101,96,91,86,81,76,71,66,61,56,51,46,41,36,31,26,21,16,11,6,1,3,8,13,18,23,28,33,38,43,48,53,58,63,68,73,78,83,88,93,98,103,108,113,118,123,128,133,138,143,148,153,158,163,168} \
};
// 100 bytes
static const uint8_t exception_signs[10][10] PROGMEM = \
{ \
{0,0,0,1,255,255,224,0,0,0}, \
{0,0,0,1,255,255,240,0,0,0}, \
{0,0,0,1,255,255,248,0,0,0}, \
{0,0,0,1,255,255,254,0,0,0}, \
{0,0,0,3,255,255,255,0,0,0}, \
{0,0,0,3,255,255,255,240,0,0}, \
{0,0,0,15,255,255,255,254,0,0}, \
{0,3,255,255,252,0,0,7,252,0}, \
{0,127,255,255,252,0,0,0,0,0}, \
{0,0,31,255,254,0,0,0,0,0} \
};
// 76 bytes
static const uint8_t declination_keys[2][37] PROGMEM = \
{ \
// Row start values
{36,30,25,21,18,16,14,12,11,10,9,9,9,8,8,8,7,6,6,5,4,4,4,3,4,4,4}, \
// Row length values
{39,38,33,35,37,35,37,36,39,34,41,42,42,28,39,40,43,51,50,39,37,34,44,51,49,48,55} \
};
// 1056 total values @ 1 byte each = 1056 bytes
static const row_value declination_values[] PROGMEM = \
{ \
{0,0,4},{1,1,0},{0,0,2},{1,1,0},{0,0,2},{1,1,3},{2,1,1},{3,1,3},{4,1,1},{3,1,1},{2,1,1},{3,1,0},{2,1,0},{1,1,0},{2,1,1},{1,1,0},{2,1,0},{3,1,4},{4,1,1},{3,1,0},{4,1,0},{3,1,2},{2,1,2},{1,1,1},{0,0,0},{1,0,1},{3,0,0},{4,0,0},{6,0,0},{8,0,0},{11,0,0},{13,0,1},{10,0,0},{9,0,0},{7,0,0},{5,0,0},{4,0,0},{2,0,0},{1,0,2}, \
{0,0,6},{1,1,0},{0,0,6},{1,1,2},{2,1,0},{3,1,2},{4,1,2},{3,1,3},{2,1,0},{1,1,0},{2,1,0},{1,1,2},{2,1,2},{3,1,3},{4,1,0},{3,1,3},{2,1,1},{1,1,1},{0,0,0},{1,0,1},{2,0,0},{4,0,0},{5,0,0},{6,0,0},{7,0,0},{8,0,0},{9,0,0},{8,0,0},{6,0,0},{7,0,0},{6,0,0},{4,0,1},{3,0,0},{2,0,0},{1,0,0},{2,0,0},{0,0,0},{1,0,0}, \
{0,0,1},{1,0,0},{0,0,1},{1,1,0},{0,0,6},{1,0,0},{1,1,0},{0,0,0},{1,1,1},{2,1,1},{3,1,0},{4,1,3},{3,1,0},{4,1,0},{3,1,1},{2,1,0},{1,1,7},{2,1,0},{3,1,6},{2,1,0},{1,1,2},{0,0,0},{1,0,0},{2,0,0},{3,0,1},{5,0,1},{6,0,0},{7,0,0},{6,0,2},{4,0,2},{3,0,1},{2,0,2},{1,0,1}, \
{0,0,0},{1,0,0},{0,0,7},{0,0,5},{1,1,1},{2,1,1},{3,1,0},{4,1,5},{3,1,1},{1,1,0},{2,1,0},{1,1,0},{0,0,0},{1,1,0},{0,0,1},{1,1,0},{0,0,0},{2,1,2},{3,1,1},{2,1,0},{3,1,0},{2,1,1},{1,1,0},{0,0,1},{1,0,0},{2,0,1},{4,0,1},{5,0,4},{4,0,0},{3,0,1},{4,0,0},{2,0,0},{3,0,0},{2,0,2},{1,0,2}, \
{0,0,0},{1,0,0},{0,0,7},{0,0,5},{1,1,2},{2,1,0},{4,1,0},{3,1,0},{5,1,0},{3,1,0},{5,1,0},{4,1,1},{3,1,0},{2,1,1},{1,1,2},{0,0,2},{1,0,0},{0,0,1},{1,1,0},{2,1,2},{3,1,0},{2,1,1},{1,1,1},{0,0,0},{1,0,0},{2,0,1},{3,0,1},{4,0,0},{5,0,0},{4,0,0},{5,0,0},{4,0,0},{3,0,1},{1,0,0},{3,0,0},{2,0,4},{1,0,3}, \
{0,0,1},{1,0,0},{0,0,7},{1,1,0},{0,0,4},{1,1,0},{2,1,1},{3,1,0},{4,1,2},{5,1,0},{4,1,0},{3,1,1},{2,1,1},{1,1,1},{0,0,2},{1,0,1},{2,0,0},{1,0,0},{0,0,0},{1,1,1},{2,1,3},{1,1,1},{1,0,2},{2,0,0},{3,0,1},{4,0,2},{3,0,1},{2,0,0},{1,0,0},{2,0,1},{1,0,0},{2,0,1},{1,0,0},{2,0,0},{1,0,3}, \
{0,0,2},{1,0,0},{0,0,5},{1,1,0},{0,0,4},{1,1,2},{2,1,0},{4,1,0},{3,1,0},{4,1,1},{5,1,0},{4,1,0},{3,1,1},{2,1,0},{1,1,1},{0,0,2},{1,0,0},{2,0,0},{1,0,0},{3,0,0},{2,0,0},{1,0,0},{0,0,1},{2,1,2},{1,1,0},{2,1,0},{0,0,1},{1,0,1},{2,0,1},{3,0,2},{4,0,0},{2,0,1},{1,0,2},{2,0,0},{1,0,1},{2,0,0},{1,0,5}, \
{0,0,0},{1,0,0},{0,0,7},{0,0,1},{1,1,0},{0,0,2},{1,1,2},{3,1,2},{4,1,3},{3,1,0},{2,1,1},{1,1,0},{0,0,2},{1,0,1},{2,0,0},{3,0,0},{2,0,0},{3,0,0},{2,0,0},{1,0,0},{0,0,0},{1,1,0},{2,1,0},{1,1,0},{2,1,1},{0,0,0},{1,1,0},{1,0,2},{2,0,1},{3,0,1},{2,0,1},{1,0,1},{0,0,0},{1,0,2},{2,0,0},{1,0,5}, \
{0,0,4},{1,0,0},{0,0,3},{1,1,0},{0,0,3},{1,1,0},{0,0,0},{1,1,0},{2,1,1},{3,1,1},{4,1,3},{3,1,0},{2,1,0},{1,1,0},{0,0,2},{1,0,0},{2,0,3},{3,0,0},{2,0,0},{3,0,0},{1,0,1},{1,1,1},{2,1,0},{1,1,0},{2,1,0},{1,1,0},{0,0,2},{1,0,0},{2,0,0},{1,0,0},{2,0,0},{3,0,0},{2,0,0},{1,0,0},{0,0,0},{1,0,0},{0,0,0},{1,0,7},{1,0,1}, \
{0,0,7},{0,0,5},{1,1,0},{0,0,1},{2,1,0},{1,1,0},{3,1,3},{4,1,1},{3,1,1},{1,1,1},{0,0,1},{1,0,0},{2,0,3},{3,0,0},{2,0,3},{0,0,2},{2,1,0},{1,1,0},{2,1,0},{1,1,0},{0,0,0},{1,1,0},{1,0,0},{0,0,0},{1,0,0},{2,0,0},{1,0,0},{2,0,1},{0,0,0},{1,0,0},{0,0,1},{1,0,0},{0,0,0},{1,0,7}, \
{0,0,6},{1,0,0},{0,0,0},{1,1,0},{0,0,4},{1,1,0},{0,0,0},{2,1,0},{1,1,0},{3,1,0},{2,1,0},{4,1,0},{3,1,0},{4,1,1},{2,1,2},{0,0,1},{1,0,0},{2,0,7},{2,0,0},{1,0,1},{0,0,1},{1,1,1},{2,1,0},{1,1,0},{0,0,0},{1,1,0},{0,0,0},{1,0,0},{0,0,0},{1,0,1},{2,0,0},{1,0,0},{0,0,0},{1,0,0},{0,0,2},{1,0,1},{0,0,0},{2,0,0},{1,0,2},{0,0,0},{1,0,0}, \
{0,0,7},{0,0,3},{1,1,0},{0,0,2},{1,1,0},{2,1,0},{1,1,0},{3,1,0},{2,1,0},{4,1,0},{3,1,0},{4,1,0},{3,1,0},{2,1,1},{1,1,0},{0,0,0},{1,0,1},{2,0,1},{3,0,0},{2,0,2},{1,0,0},{2,0,0},{1,0,1},{0,0,0},{1,0,0},{0,0,0},{1,1,0},{0,0,0},{2,1,0},{1,1,0},{0,0,0},{1,1,0},{0,0,1},{1,0,0},{0,0,0},{1,0,2},{0,0,3},{1,0,0},{0,0,0},{1,0,6},{0,0,0},{1,0,0}, \
{0,0,2},{1,1,0},{0,0,1},{1,0,0},{0,0,3},{1,1,0},{0,0,2},{1,1,2},{2,1,0},{3,1,0},{2,1,0},{3,1,0},{4,1,0},{3,1,1},{2,1,0},{1,1,1},{0,0,0},{1,0,0},{2,0,2},{3,0,0},{2,0,1},{1,0,0},{2,0,0},{1,0,1},{0,0,0},{1,0,0},{0,0,2},{1,1,0},{0,0,0},{1,1,1},{0,0,0},{1,1,0},{0,0,0},{1,0,0},{0,0,0},{1,0,0},{0,0,0},{1,0,0},{0,0,5},{1,0,7},{0,0,0},{1,0,0}, \
{0,0,5},{1,0,0},{0,0,4},{1,1,0},{0,0,1},{1,1,1},{2,1,2},{3,1,4},{2,1,0},{1,1,0},{0,0,0},{1,0,1},{2,0,6},{1,0,1},{0,0,0},{1,0,1},{0,0,2},{1,1,1},{0,0,0},{1,1,0},{0,0,1},{1,1,0},{0,0,0},{1,0,0},{0,0,0},{1,0,0},{0,0,7},{1,0,7}, \
{0,0,3},{1,0,0},{0,0,7},{1,1,0},{0,0,0},{1,1,0},{2,1,3},{3,1,3},{2,1,0},{1,1,1},{0,0,0},{1,0,1},{2,0,2},{3,0,0},{1,0,0},{2,0,0},{1,0,0},{2,0,0},{0,0,1},{1,0,1},{0,0,2},{1,1,0},{0,0,0},{1,1,0},{0,0,1},{1,1,0},{0,0,3},{1,0,0},{0,0,2},{1,1,0},{0,0,3},{1,0,0},{0,0,0},{1,0,0},{2,0,0},{1,0,1},{2,0,0},{0,0,0},{1,0,0}, \
{0,0,1},{1,0,0},{0,0,2},{1,0,0},{0,0,5},{1,1,2},{2,1,1},{3,1,0},{2,1,0},{3,1,2},{2,1,1},{1,1,0},{0,0,1},{1,0,0},{2,0,0},{1,0,0},{2,0,4},{1,0,1},{0,0,0},{1,0,1},{0,0,0},{1,0,0},{0,0,0},{1,1,0},{0,0,0},{1,1,1},{0,0,7},{0,0,0},{1,1,0},{0,0,0},{1,1,0},{0,0,3},{1,0,1},{0,0,0},{1,0,0},{2,0,0},{1,0,0},{2,0,0},{1,0,0},{1,0,0}, \
{0,0,0},{1,0,1},{0,0,1},{1,0,0},{0,0,0},{1,0,0},{0,0,3},{1,1,0},{0,0,0},{1,1,0},{2,1,2},{3,1,0},{2,1,0},{4,1,0},{3,1,0},{2,1,2},{1,1,0},{0,0,0},{1,0,2},{2,0,4},{1,0,0},{2,0,0},{0,0,0},{1,0,0},{0,0,0},{1,0,1},{0,0,2},{1,1,0},{0,0,0},{1,1,0},{0,0,0},{1,1,0},{0,0,5},{1,1,0},{0,0,0},{1,1,1},{0,0,0},{1,1,0},{0,0,1},{1,0,4},{2,0,1},{1,0,0},{1,0,0}, \
{0,0,0},{2,0,0},{1,0,0},{0,0,0},{1,0,1},{0,0,0},{1,0,0},{0,0,3},{1,1,0},{0,0,0},{2,1,2},{3,1,0},{2,1,0},{3,1,0},{4,1,0},{3,1,0},{2,1,1},{1,1,1},{1,0,0},{0,0,0},{2,0,0},{1,0,0},{2,0,1},{1,0,0},{2,0,2},{1,0,0},{0,0,0},{1,0,1},{0,0,0},{1,0,0},{0,0,0},{1,0,0},{1,1,0},{0,0,1},{1,1,0},{0,0,0},{1,1,0},{0,0,1},{1,1,0},{0,0,2},{1,1,3},{0,0,0},{1,1,0},{0,0,2},{1,0,0},{2,0,0},{1,0,1},{2,0,0},{1,0,0},{2,0,0},{1,0,0}, \
{0,0,0},{1,0,1},{2,0,0},{1,0,1},{0,0,0},{1,0,0},{0,0,0},{1,0,0},{0,0,0},{1,1,0},{0,0,0},{2,1,0},{1,1,0},{2,1,0},{3,1,1},{2,1,0},{4,1,1},{3,1,0},{2,1,1},{1,1,0},{0,0,1},{1,0,0},{2,0,0},{1,0,0},{2,0,2},{1,0,0},{2,0,1},{1,0,0},{0,0,0},{1,0,2},{0,0,0},{1,0,0},{0,0,3},{1,1,0},{0,0,1},{1,1,0},{0,0,0},{1,1,0},{0,0,0},{1,1,0},{0,0,0},{1,1,2},{2,1,0},{1,1,1},{0,0,1},{1,0,3},{2,0,0},{1,0,0},{2,0,1},{2,0,0}, \
{0,0,0},{2,0,0},{1,0,0},{2,0,0},{1,0,4},{0,0,1},{1,1,0},{0,0,0},{2,1,0},{1,1,0},{3,1,3},{4,1,1},{3,1,0},{2,1,1},{1,1,0},{0,0,0},{1,0,2},{2,0,0},{1,0,0},{2,0,4},{1,0,0},{0,0,0},{1,0,3},{0,0,0},{1,0,0},{0,0,4},{1,1,0},{0,0,0},{1,1,0},{0,0,0},{1,1,4},{2,1,1},{1,1,1},{0,0,2},{1,0,1},{2,0,2},{1,0,0},{2,0,0},{2,0,0}, \
{0,0,0},{2,0,3},{1,0,3},{0,0,2},{1,1,0},{2,1,2},{4,1,0},{3,1,0},{4,1,2},{3,1,1},{1,1,1},{0,0,0},{1,0,2},{2,0,4},{1,0,0},{2,0,1},{0,0,0},{1,0,0},{2,0,0},{0,0,0},{1,0,2},{0,0,0},{1,0,0},{0,0,3},{1,1,4},{2,1,0},{1,1,0},{2,1,2},{1,1,2},{0,0,1},{1,0,0},{2,0,1},{1,0,0},{3,0,0},{1,0,0},{2,0,0},{2,0,0}, \
{0,0,0},{2,0,4},{1,0,3},{0,0,0},{1,1,2},{3,1,1},{4,1,2},{5,1,0},{4,1,0},{3,1,1},{1,1,1},{0,0,0},{1,0,1},{2,0,0},{1,0,0},{2,0,1},{3,0,0},{2,0,2},{1,0,2},{2,0,0},{1,0,5},{0,0,4},{1,1,1},{2,1,4},{3,1,0},{2,1,1},{1,1,1},{0,0,0},{1,0,2},{2,0,1},{3,0,0},{2,0,0},{1,0,0},{3,0,0}, \
{0,0,0},{2,0,1},{3,0,0},{2,0,1},{1,0,0},{2,0,0},{1,0,0},{0,0,2},{1,1,0},{2,1,0},{3,1,1},{5,1,4},{3,1,1},{1,1,1},{1,0,0},{0,0,0},{2,0,1},{1,0,0},{3,0,0},{2,0,2},{3,0,0},{2,0,1},{1,0,1},{2,0,1},{1,0,0},{2,0,0},{1,0,3},{0,0,0},{1,0,0},{1,1,0},{0,0,0},{1,1,0},{2,1,2},{3,1,0},{2,1,0},{3,1,2},{2,1,0},{1,1,1},{0,0,0},{1,0,2},{2,0,1},{3,0,0},{2,0,1},{3,0,0}, \
{0,0,0},{3,0,1},{2,0,0},{3,0,0},{2,0,0},{1,0,0},{2,0,0},{1,0,1},{0,0,1},{2,1,1},{3,1,0},{4,1,0},{6,1,0},{5,1,0},{7,1,0},{6,1,0},{5,1,0},{3,1,1},{1,1,0},{0,0,1},{1,0,0},{2,0,3},{3,0,0},{2,0,0},{3,0,0},{2,0,0},{3,0,0},{2,0,1},{1,0,0},{2,0,5},{1,0,2},{0,0,2},{1,1,0},{2,1,0},{3,1,2},{4,1,0},{3,1,0},{4,1,0},{3,1,0},{2,1,1},{1,1,0},{1,0,0},{0,0,0},{2,0,0},{1,0,0},{2,0,0},{3,0,0},{2,0,0},{3,0,0},{2,0,0},{2,0,0}, \
{0,0,0},{2,0,0},{3,0,1},{2,0,0},{3,0,0},{2,0,1},{1,0,1},{0,0,1},{2,1,1},{4,1,0},{6,1,0},{7,1,1},{8,1,0},{7,1,0},{5,1,0},{3,1,0},{2,1,0},{1,1,0},{0,0,0},{1,0,1},{2,0,1},{3,0,0},{2,0,0},{3,0,2},{2,0,0},{3,0,2},{1,0,0},{3,0,0},{2,0,0},{3,0,0},{2,0,4},{1,0,1},{0,0,1},{1,1,0},{2,1,0},{3,1,0},{4,1,0},{5,1,0},{4,1,1},{5,1,0},{4,1,0},{2,1,1},{1,1,0},{0,0,0},{1,0,0},{2,0,3},{3,0,1},{2,0,0},{3,0,0}, \
{0,0,0},{3,0,2},{2,0,0},{3,0,0},{2,0,2},{1,0,0},{0,0,1},{2,1,0},{3,1,0},{5,1,0},{8,1,0},{9,1,0},{10,1,1},{7,1,0},{5,1,0},{3,1,0},{1,1,0},{0,0,0},{1,0,1},{2,0,0},{3,0,0},{2,0,0},{3,0,3},{4,0,0},{3,0,7},{2,0,0},{3,0,0},{2,0,0},{3,0,0},{2,0,0},{1,0,0},{2,0,0},{0,0,2},{2,1,0},{3,1,0},{4,1,0},{5,1,0},{7,1,0},{5,1,0},{6,1,0},{4,1,1},{2,1,0},{0,0,1},{1,0,1},{2,0,1},{3,0,2},{2,0,0},{3,0,0}, \
{0,0,0},{3,0,5},{2,0,1},{1,0,0},{0,0,0},{1,1,0},{2,1,0},{5,1,0},{8,1,0},{12,1,0},{14,1,0},{13,1,0},{9,1,0},{6,1,0},{3,1,0},{1,1,0},{0,0,0},{2,0,0},{1,0,0},{3,0,0},{2,0,0},{3,0,0},{4,0,0},{3,0,1},{4,0,0},{3,0,0},{4,0,1},{3,0,0},{4,0,0},{3,0,2},{4,0,0},{3,0,1},{4,0,0},{3,0,0},{2,0,0},{3,0,0},{2,0,2},{0,0,1},{1,1,0},{2,1,0},{4,1,0},{5,1,0},{7,1,0},{8,1,0},{6,1,1},{5,1,0},{3,1,0},{1,1,1},{1,0,1},{2,0,0},{3,0,0},{2,0,0},{3,0,1},{2,0,0},{3,0,0}, \
};
#define PGM_UINT8(p) (uint8_t)pgm_read_byte_far(p)
float
AP_Declination::get_declination(float lat, float lon)
{
int16_t decSW, decSE, decNW, decNE, lonmin, latmin;
uint8_t latmin_index,lonmin_index;
float decmin, decmax;
// Constrain to valid inputs
lat = constrain(lat, -90, 90);
lon = constrain(lon, -180, 180);
latmin = floor(lat/5)*5;
lonmin = floor(lon/5)*5;
latmin_index= (90+latmin)/5;
lonmin_index= (180+lonmin)/5;
decSW = get_lookup_value(latmin_index, lonmin_index);
decSE = get_lookup_value(latmin_index, lonmin_index+1);
decNE = get_lookup_value(latmin_index+1, lonmin_index+1);
decNW = get_lookup_value(latmin_index+1, lonmin_index);
/* approximate declination within the grid using bilinear interpolation */
decmin = (lon - lonmin) / 5 * (decSE - decSW) + decSW;
decmax = (lon - lonmin) / 5 * (decNE - decNW) + decNW;
return (lat - latmin) / 5 * (decmax - decmin) + decmin;
}
int16_t
AP_Declination::get_lookup_value(uint8_t x, uint8_t y)
{
// return value
int16_t val = 0;
// These are exception indicies
if(x <= 6 || x >= 34)
{
// If the x index is in the upper range we need to translate it
// to match the 10 indicies in the exceptions lookup table
if(x >= 34) x -= 27;
// Read the unsigned value from the array
val = PGM_UINT8(&exceptions[x][y]);
// Read the 8 bit compressed sign values
uint8_t sign = PGM_UINT8(&exception_signs[x][y/8]);
// Check the sign bit for this index
if(sign & (0x80 >> y%8))
val = -val;
return val;
}
// Because the values were removed from the start of the
// original array (0-6) to the exception array, all the indicies
// in this main lookup need to be shifted left 7
// EX: User enters 7 -> 7 is the first row in this array so it needs to be zero
if(x >= 7) x -= 7;
// If we are looking for the first value we can just use the
// row start value from declination_keys
if(y == 0) return PGM_UINT8(&declination_keys[0][x]);
// Init vars
row_value stval;
int16_t offset = 0;
// These will never exceed the second dimension length of 73
uint8_t current_virtual_index = 0, r;
// This could be the length of the array or less (1075 or less)
uint16_t start_index = 0, i;
// Init value to row start
val = PGM_UINT8(&declination_keys[0][x]);
// Find the first element in the 1D array
// that corresponds with the target row
for(i = 0; i < x; i++){
start_index += PGM_UINT8(&declination_keys[1][i]);
}
// Traverse the row until we find our value
for(i = start_index; i < (start_index + PGM_UINT8(&declination_keys[1][x])) && current_virtual_index <= y; i++){
// Pull out the row_value struct
memcpy_P((void*) &stval, (const prog_char *)&declination_values[i], sizeof(struct row_value));
// Pull the first offset and determine sign
offset = stval.abs_offset;
offset = (stval.offset_sign == 1) ? -offset : offset;
// Add offset for each repeat
// This will at least run once for zero repeat
for(r = 0; r <= stval.repeats && current_virtual_index <= y; r++){
val += offset;
current_virtual_index++;
}
}
return val;
}