git ssb

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#include <math.h>
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#include <malloc.h>
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#include <unistd.h>
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#include "tune.h"
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#include "foobuf.h"
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#include <err.h>
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static float notes[256] = {0};
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static float dampen[256] = {0};
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static float freqs[256] = {0};
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static int got_freqs = 0;
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// static float buf[48000] = {0};
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float get_freq(int i)
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{
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	if (!got_freqs) {
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		for (int i = 0; i < 256; i++) {
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			freqs[i] = 440. * exp2((i-69) / 12.);
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		}
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		got_freqs = 1;
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	}
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	return freqs[i];
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}
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float saw(float x, float t)
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{
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	return fmodf(t, 1./x) * x*2. - 1.;
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}
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float play(void **obj, double time, float in, unsigned char midi_cmd[3])
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{
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	// return in * 10;
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	// return sin(2. * M_PI * time * 440.) * 0.1 + in * 0.9;
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	struct {
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		struct foobuf *buf;
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		// float *keymap;
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	} **statep = (void *)obj, *state;
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	if (struct_init(statep)) {
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		warn("foobuf_init");
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		return 0;
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	}
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	state = *statep;
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	if (foobuf_init(&state->buf, 48000)) {
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		warn("foobuf_init");
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		return 0;
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	}
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	// array_init(&state->keymap, 256);
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	/*
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	static float keymap[256];
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	if (!state->keymap) {
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		state->keymap = keymap;
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		for (size_t i = 0; i < 256; i++) keymap[i] = 0;
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	}
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	*/
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	float out = 0;
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	if (midi_cmd) {
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		// float val = sin(2. * M_PI * (float)i/buf_size * freq);
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		if (midi_cmd[0] == 0x90) {
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			// printf("key %u\n", midi_cmd[1]);
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			notes[midi_cmd[1]] += (float)midi_cmd[2]/255.;
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			dampen[midi_cmd[1]] = 0;
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		} else if (midi_cmd[0] == 0x80) {
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			dampen[midi_cmd[1]] += (float)midi_cmd[2]/255.;
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		} else {
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			// printf("midi %x %x %x\n", buf[0], buf[1], buf[2]);
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		}
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	}
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	float total = 0;
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	for (int i = 0; i < 256; i++) {
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		if (notes[i] > 0.01) {
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			float freq = get_freq(i);
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			total += notes[i];
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			out += notes[i] * saw(freq, time);
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			// out += notes[i] * sin(2. * M_PI * time * freq);
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			notes[i] *= 0.99999 * (1 - dampen[i] * 0.001);
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		}
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		if (dampen[i] > 0.001) dampen[i] *= 0.9999;
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	}
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	// return sin(2. * M_PI * time * 440.) * 0.25 + in * 0.75;
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	// out += foobuf_read(state->buf, 500)*0.9;
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	out += in*180;
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	// out = in*0.1 + foobuf_read(state->buf, 48000)*0.9;
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	foobuf_write(state->buf, out);
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	// return out;
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	return out * 0.25;
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	// return out / total;
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	// return 1/(1. + exp(-out * 4)) * 0.99;
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}
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