aw/pentabug
1
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

noise

Browse Source
This commit is contained in:
twobit 2012-08-06 04:05:19 +02:00
parent aeeafffc6b
commit aa94ac20e3
1 changed files with 8 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
firmware/synth.c
View File

@ -2,7 +2,7 @@
// sample rate is 8M / (3 * 64)
enum { WAVE_PULSE, WAVE_SAW, };
enum { WAVE_PULSE, WAVE_SAW, WAVE_NOISE };
typedef struct {
uint8_t wave;
@ -43,14 +43,14 @@ static synth_t synth;
void synth_init(void)
{
// some test values
synth.channels[0].wave = WAVE_PULSE;
synth.channels[0].wave = WAVE_PULSE + 10;
synth.channels[0].speed = 1153;
synth.channels[0].pulse_sweep = 0;
synth.channels[0].pulse_width = 1 << 31;
synth.channels[1].wave = WAVE_SAW;
synth.channels[1].wave = WAVE_NOISE;
synth.channels[1].speed = 1728;
}
uint16_t synth_mix(void)
@ -93,6 +93,11 @@ uint16_t synth_mix(void)
amp = (chan->phase >> 8);
break;
case WAVE_NOISE: // shitty noise
chan->phase = (chan->phase >> 1) ^ (-(chan->phase & 1) & 0xb400);
amp = (chan->phase >> 8);
break;
default:
amp = 0;
break;