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Do not use double/float calculations but predefined tables in mod codec. Reduces codesize by several kilobytes.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30107 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Andree Buschmann 2011-06-30 21:53:02 +00:00
parent 143d451403
commit f27028dbb6
1 changed files with 66 additions and 6 deletions
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72
apps/codecs/mod.c
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@ -178,12 +178,11 @@ struct s_modplayer {
/* Information about the channels */
struct s_modchannel modchannel[8];
/* The Amiga Period Table
(+1 because we use index 0 for period 0 = no new note) */
unsigned short periodtable[37*8+1];
/* The Amiga Period Table */
unsigned short *periodtable;
/* The sinus table [-255,255] */
signed short sintable[0x40];
signed short *sintable;
/* Is the glissando effect enabled? */
bool glissandoenabled;
@ -239,6 +238,58 @@ struct s_song modsong IDATA_ATTR; /* The Song */
struct s_modplayer modplayer IDATA_ATTR; /* The Module Player */
struct s_mixer mixer IDATA_ATTR;
/* The Amiga Period Table (+1 because we use index 0 for period 0 = no new note) */
static unsigned short s_periodtable[37*8+1] IDATA_ATTR =
{ 0, 907, 900, 893, 887, 881, 874, 868,
862, 856, 849, 843, 837, 831, 825, 819,
813, 808, 802, 796, 790, 785, 779, 773,
768, 762, 757, 751, 746, 740, 735, 730,
725, 719, 714, 709, 704, 699, 694, 689,
684, 679, 674, 669, 664, 660, 655, 650,
645, 641, 636, 632, 627, 623, 618, 614,
609, 605, 600, 596, 592, 588, 583, 579,
575, 571, 567, 563, 559, 555, 551, 547,
543, 539, 535, 531, 527, 523, 520, 516,
512, 509, 505, 501, 498, 494, 490, 487,
483, 480, 477, 473, 470, 466, 463, 460,
456, 453, 450, 446, 443, 440, 437, 434,
431, 428, 424, 421, 418, 415, 412, 409,
406, 404, 401, 398, 395, 392, 389, 386,
384, 381, 378, 375, 373, 370, 367, 365,
362, 359, 357, 354, 352, 349, 347, 344,
342, 339, 337, 334, 332, 330, 327, 325,
322, 320, 318, 316, 313, 311, 309, 307,
304, 302, 300, 298, 296, 294, 291, 289,
287, 285, 283, 281, 279, 277, 275, 273,
271, 269, 267, 265, 263, 261, 260, 258,
256, 254, 252, 250, 249, 247, 245, 243,
241, 240, 238, 236, 235, 233, 231, 230,
228, 226, 225, 223, 221, 220, 218, 217,
215, 214, 212, 210, 209, 207, 206, 204,
203, 202, 200, 199, 197, 196, 194, 193,
192, 190, 189, 187, 186, 185, 183, 182,
181, 179, 178, 177, 176, 174, 173, 172,
171, 169, 168, 167, 166, 165, 163, 162,
161, 160, 159, 158, 156, 155, 154, 153,
152, 151, 150, 149, 148, 147, 145, 144,
143, 142, 141, 140, 139, 138, 137, 136,
135, 134, 133, 132, 131, 130, 130, 129,
128, 127, 126, 125, 124, 123, 122, 121,
120, 120, 119, 118, 117, 116, 115, 115,
114, 113, 112, 111, 110, 110, 109, 108,
107};
/* The sin table */
static signed short s_sintable[0x40] IDATA_ATTR =
{ 0, 25, 49, 74, 97, 120, 141, 162,
180, 197, 212, 225, 235, 244, 250, 254,
255, 254, 250, 244, 235, 225, 212, 197,
180, 161, 141, 120, 97, 73, 49, 24,
0, -25, -50, -74, -98, -120, -142, -162,
-180, -197, -212, -225, -236, -244, -250, -254,
-255, -254, -250, -244, -235, -224, -211, -197,
-180, -161, -141, -119, -97, -73, -49, -24};
const unsigned short mixingrate = 44100;
STATICIRAM void mixer_playsample(int channel, int instrument) ICODE_ATTR;
@ -299,8 +350,13 @@ static inline void mixer_setamigaperiod(int channel, int amigaperiod)
STATICIRAM void initmodplayer(void) ICODE_ATTR;
void initmodplayer(void)
{
unsigned int i,c;
unsigned int c;
#if 0
/* As the calculation of periodtable and sintable uses float and double
* rockbox uses two predefined tables. This reduces the codesize by
* several KB. */
unsigned int i;
/* Calculate Amiga Period Values
* Start with Period 907 (= C-1 with Finetune -8) and work upwards */
double f = 907.0f;
@ -347,7 +403,11 @@ void initmodplayer(void)
a = a+b;
b = b-dd*a;
}
#else
/* Point to the predefined tables */
modplayer.periodtable = s_periodtable;
modplayer.sintable = s_sintable;
#endif
/* Set Default Player Values */
modplayer.currentline = 0;
modplayer.currenttick = 0;