teensy-audio/waveforms.c

#include <stdint.h>

// These audio waveforms have a period of 256 points, plus a 257th
// point that is a duplicate of the first point.  This duplicate
// is needed because the waveform generator uses linear interpolation
// between each point and the next point in the waveform.

const int16_t AudioWaveformSine[257] = {
     0,   804,  1608,  2410,  3212,  4011,  4808,  5602,  6393,  7179,
  7962,  8739,  9512, 10278, 11039, 11793, 12539, 13279, 14010, 14732,
 15446, 16151, 16846, 17530, 18204, 18868, 19519, 20159, 20787, 21403,
 22005, 22594, 23170, 23731, 24279, 24811, 25329, 25832, 26319, 26790,
 27245, 27683, 28105, 28510, 28898, 29268, 29621, 29956, 30273, 30571,
 30852, 31113, 31356, 31580, 31785, 31971, 32137, 32285, 32412, 32521,
 32609, 32678, 32728, 32757, 32767, 32757, 32728, 32678, 32609, 32521,
 32412, 32285, 32137, 31971, 31785, 31580, 31356, 31113, 30852, 30571,
 30273, 29956, 29621, 29268, 28898, 28510, 28105, 27683, 27245, 26790,
 26319, 25832, 25329, 24811, 24279, 23731, 23170, 22594, 22005, 21403,
 20787, 20159, 19519, 18868, 18204, 17530, 16846, 16151, 15446, 14732,
 14010, 13279, 12539, 11793, 11039, 10278,  9512,  8739,  7962,  7179,
  6393,  5602,  4808,  4011,  3212,  2410,  1608,   804,     0,  -804,
 -1608, -2410, -3212, -4011, -4808, -5602, -6393, -7179, -7962, -8739,
 -9512,-10278,-11039,-11793,-12539,-13279,-14010,-14732,-15446,-16151,
-16846,-17530,-18204,-18868,-19519,-20159,-20787,-21403,-22005,-22594,
-23170,-23731,-24279,-24811,-25329,-25832,-26319,-26790,-27245,-27683,
-28105,-28510,-28898,-29268,-29621,-29956,-30273,-30571,-30852,-31113,
-31356,-31580,-31785,-31971,-32137,-32285,-32412,-32521,-32609,-32678,
-32728,-32757,-32767,-32757,-32728,-32678,-32609,-32521,-32412,-32285,
-32137,-31971,-31785,-31580,-31356,-31113,-30852,-30571,-30273,-29956,
-29621,-29268,-28898,-28510,-28105,-27683,-27245,-26790,-26319,-25832,
-25329,-24811,-24279,-23731,-23170,-22594,-22005,-21403,-20787,-20159,
-19519,-18868,-18204,-17530,-16846,-16151,-15446,-14732,-14010,-13279,
-12539,-11793,-11039,-10278, -9512, -8739, -7962, -7179, -6393, -5602,
 -4808, -4011, -3212, -2410, -1608,  -804,     0
};

#if 0
#! /usr/bin/perl
use Math::Trig ':pi';
$len = 256;
print "const int16_t AudioWaveformSine[257] = {\n";
for ($i=0; $i <= $len; $i++) {
        $f = sin($i / $len * 2 * pi);
        $d = sprintf "%.0f", $f * 32767.0;
        #print $d;
        printf "%6d", $d + 0;
        print "," if ($i < $len);
        print "\n" if ($i % 10) == 9;
}
print "\n" unless ($len % 10) == 9;
print "};\n";
#endif

const int16_t AudioWaveformTriangle[257] = {
     0,   512,  1024,  1536,  2048,  2560,  3072,  3584,  4096,  4608,
  5120,  5632,  6144,  6656,  7168,  7680,  8192,  8704,  9216,  9728,
 10240, 10752, 11264, 11776, 12288, 12800, 13312, 13824, 14336, 14848,
 15360, 15872, 16384, 16895, 17407, 17919, 18431, 18943, 19455, 19967,
 20479, 20991, 21503, 22015, 22527, 23039, 23551, 24063, 24575, 25087,
 25599, 26111, 26623, 27135, 27647, 28159, 28671, 29183, 29695, 30207,
 30719, 31231, 31743, 32255, 32767, 32255, 31743, 31231, 30719, 30207,
 29695, 29183, 28671, 28159, 27647, 27135, 26623, 26111, 25599, 25087,
 24575, 24063, 23551, 23039, 22527, 22015, 21503, 20991, 20479, 19967,
 19455, 18943, 18431, 17919, 17407, 16895, 16384, 15872, 15360, 14848,
 14336, 13824, 13312, 12800, 12288, 11776, 11264, 10752, 10240,  9728,
  9216,  8704,  8192,  7680,  7168,  6656,  6144,  5632,  5120,  4608,
  4096,  3584,  3072,  2560,  2048,  1536,  1024,   512,     0,  -512,
 -1024, -1536, -2048, -2560, -3072, -3584, -4096, -4608, -5120, -5632,
 -6144, -6656, -7168, -7680, -8192, -8704, -9216, -9728,-10240,-10752,
-11264,-11776,-12288,-12800,-13312,-13824,-14336,-14848,-15360,-15872,
-16384,-16895,-17407,-17919,-18431,-18943,-19455,-19967,-20479,-20991,
-21503,-22015,-22527,-23039,-23551,-24063,-24575,-25087,-25599,-26111,
-26623,-27135,-27647,-28159,-28671,-29183,-29695,-30207,-30719,-31231,
-31743,-32255,-32767,-32255,-31743,-31231,-30719,-30207,-29695,-29183,
-28671,-28159,-27647,-27135,-26623,-26111,-25599,-25087,-24575,-24063,
-23551,-23039,-22527,-22015,-21503,-20991,-20479,-19967,-19455,-18943,
-18431,-17919,-17407,-16895,-16384,-15872,-15360,-14848,-14336,-13824,
-13312,-12800,-12288,-11776,-11264,-10752,-10240, -9728, -9216, -8704,
 -8192, -7680, -7168, -6656, -6144, -5632, -5120, -4608, -4096, -3584,
 -3072, -2560, -2048, -1536, -1024,  -512,     0
};

#if 0
#! /usr/bin/perl
$len = 256;
print "const int16_t AudioWaveformTriangle[257] = {\n";
for ($i=0; $i <= $len; $i++) {

        $f = 0;
        if ($i < $len / 4) {
                $f = $i / ($len / 4);
        } elsif ($i < $len * 3 / 4) {
                $f = 2 - $i / ($len / 4);
        } else {
                $f = $i / ($len / 4) - 4;
                #print "$i  $f\n";
        }
        $d = sprintf "%.0f", $f * 32767.0;
        printf "%6d", $d + 0;
        print "," if ($i < $len);
        print "\n" if ($i % 10) == 9;
}
print "\n" unless ($len % 10) == 9;
print "};\n";
#endif

const int16_t AudioWaveformSquare[257] = {
 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,
 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,
 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,
 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,
 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,
 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,
 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,
 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,
 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,
 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,
 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,
 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,
 32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,-32767,-32767,
-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,
-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,
-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,
-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,
-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,
-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,
-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,
-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,
-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,
-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,
-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,
-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,-32767,
-32767,-32767,-32767,-32767,-32767,-32767, 32767
};

#if 0
#! /usr/bin/perl
$len = 256;
print "const int16_t AudioWaveformSquare[257] = {\n";
for ($i=0; $i <= $len; $i++) {
        $f = 1.0;
        if ($i < $len / 2) {
                $f = 1.0;
        } elsif ($i < $len) {
                $f = -1.0;
        } 
        $d = sprintf "%.0f", $f * 32767.0;
        printf "%6d", $d + 0;
        print "," if ($i < $len);
        print "\n" if ($i % 10) == 9;
}
print "\n" unless ($len % 10) == 9;
print "};\n";
#endif

const int16_t AudioWaveformSawtooth[257] = {
     0,   256,   512,   768,  1024,  1280,  1536,  1792,  2048,  2304,
  2560,  2816,  3072,  3328,  3584,  3840,  4096,  4352,  4608,  4864,
  5120,  5376,  5632,  5888,  6144,  6400,  6656,  6912,  7168,  7424,
  7680,  7936,  8192,  8448,  8704,  8960,  9216,  9472,  9728,  9984,
 10240, 10496, 10752, 11008, 11264, 11520, 11776, 12032, 12288, 12544,
 12800, 13056, 13312, 13568, 13824, 14080, 14336, 14592, 14848, 15104,
 15360, 15616, 15872, 16128, 16384, 16639, 16895, 17151, 17407, 17663,
 17919, 18175, 18431, 18687, 18943, 19199, 19455, 19711, 19967, 20223,
 20479, 20735, 20991, 21247, 21503, 21759, 22015, 22271, 22527, 22783,
 23039, 23295, 23551, 23807, 24063, 24319, 24575, 24831, 25087, 25343,
 25599, 25855, 26111, 26367, 26623, 26879, 27135, 27391, 27647, 27903,
 28159, 28415, 28671, 28927, 29183, 29439, 29695, 29951, 30207, 30463,
 30719, 30975, 31231, 31487, 31743, 31999, 32255, 32511,-32767,-32511,
-32255,-31999,-31743,-31487,-31231,-30975,-30719,-30463,-30207,-29951,
-29695,-29439,-29183,-28927,-28671,-28415,-28159,-27903,-27647,-27391,
-27135,-26879,-26623,-26367,-26111,-25855,-25599,-25343,-25087,-24831,
-24575,-24319,-24063,-23807,-23551,-23295,-23039,-22783,-22527,-22271,
-22015,-21759,-21503,-21247,-20991,-20735,-20479,-20223,-19967,-19711,
-19455,-19199,-18943,-18687,-18431,-18175,-17919,-17663,-17407,-17151,
-16895,-16639,-16384,-16128,-15872,-15616,-15360,-15104,-14848,-14592,
-14336,-14080,-13824,-13568,-13312,-13056,-12800,-12544,-12288,-12032,
-11776,-11520,-11264,-11008,-10752,-10496,-10240, -9984, -9728, -9472,
 -9216, -8960, -8704, -8448, -8192, -7936, -7680, -7424, -7168, -6912,
 -6656, -6400, -6144, -5888, -5632, -5376, -5120, -4864, -4608, -4352,
 -4096, -3840, -3584, -3328, -3072, -2816, -2560, -2304, -2048, -1792,
 -1536, -1280, -1024,  -768,  -512,  -256,     0
};

#if 0
#! /usr/bin/perl
$len = 256;
print "const int16_t AudioWaveformSawtooth[257] = {\n";
for ($i=0; $i <= $len; $i++) {
        $f = 0;
        if ($i < $len / 2) {
                $f = $i / $len * 2;
        } else {
                $f = -2 + $i / $len * 2;
                #print "$i  $f\n";
        }
        $d = sprintf "%.0f", $f * 32767.0;
        printf "%6d", $d + 0;
        print "," if ($i < $len);
        print "\n" if ($i % 10) == 9;
}
print "\n" unless ($len % 10) == 9;
print "};\n";
#endif



const int16_t fader_table[257] = {
    0,    1,    4,   11,   19,   30,   44,   60,   78,   99,
  123,  149,  177,  208,  241,  276,  314,  355,  398,  443,
  490,  541,  593,  648,  705,  764,  826,  891,  957, 1026,
 1097, 1171, 1247, 1325, 1405, 1488, 1572, 1660, 1749, 1840,
 1934, 2030, 2128, 2228, 2330, 2435, 2541, 2650, 2761, 2873,
 2988, 3105, 3224, 3344, 3467, 3592, 3718, 3847, 3977, 4109,
 4243, 4379, 4517, 4657, 4798, 4941, 5086, 5232, 5380, 5530,
 5682, 5835, 5989, 6145, 6303, 6462, 6623, 6785, 6949, 7114,
 7281, 7448, 7618, 7788, 7960, 8133, 8307, 8483, 8660, 8838,
 9017, 9197, 9378, 9560, 9743, 9928,10113,10299,10486,10674,
10863,11053,11244,11435,11627,11820,12013,12207,12402,12597,
12793,12989,13186,13384,13582,13780,13979,14178,14377,14577,
14777,14977,15177,15378,15579,15780,15981,16182,16383,16584,
16785,16986,17187,17387,17588,17788,17989,18188,18388,18588,
18787,18985,19184,19382,19579,19776,19972,20168,20364,20558,
20752,20946,21139,21331,21522,21712,21902,22091,22279,22466,
22652,22838,23022,23205,23388,23569,23749,23928,24106,24283,
24458,24633,24806,24977,25148,25317,25485,25651,25817,25980,
26142,26303,26463,26620,26776,26931,27084,27236,27385,27534,
27680,27825,27968,28109,28249,28386,28522,28656,28789,28919,
29048,29174,29299,29422,29542,29661,29778,29893,30006,30116,
30225,30331,30436,30538,30638,30736,30832,30926,31017,31107,
31194,31279,31361,31442,31520,31596,31669,31740,31809,31876,
31940,32002,32062,32119,32174,32226,32276,32324,32369,32412,
32452,32490,32526,32559,32590,32618,32644,32667,32688,32707,
32723,32737,32748,32756,32763,32766,32767
};
#if 0
#! /usr/bin/perl
print "const int16_t fader_table[257] = {\n";
$len = 256;
for ($i=0; $i < $len+1; $i++) {
        $a = cos(3.14149 * $i / $len);
        $in = (1 - $a) / 2;
        $d = $in * 32768;
        $d = 32767 if $d >= 32767.5;
        printf "%5d", $d;
        print "," if ($i < $len);
        print "\n" if ($i % 10) == 9;
}
print "\n};\n";
#endif