Inline header files

Makefile

 PRG            = crowbx
-OBJ            = crowbx.o midi.o list.o clamp_add.o pitch_env.o vibrato_rate.o voice.o
+OBJ            = crowbx.o midi.o list.o pitch_env.o vibrato_rate.o voice.o
 MCU_TARGET = atmega328p
 
 OPTIMIZE       = -O3

clamp_add.c

-#include "clamp_add.h"
-
-uint16_t clamp_add(uint16_t x, int16_t delta) {
-	if (delta < 0) {
-		uint16_t sub = -delta;
-		if (x < sub) {
-			return 0;
-		}
-		return x - sub;
-	}
-
-	uint16_t add = delta;
-	if (UINT16_MAX - x < add) {
-		return UINT16_MAX;
-	}
-	return x + add;
-}

clamp_add.h

-#ifndef CLAMP_ADD_H
-#define CLAMP_ADD_H
-
-#include <stdint.h>
-
-uint16_t clamp_add(uint16_t x, int16_t delta);
-
-#endif

crowbx.c

@@ -5,19 +5,43 @@
 #include <util/delay.h>
 
 #include "array_size.h"
-#include "clamp_add.h"
-#include "dac.h"
-#include "gate.h"
 #include "list.h"
 #include "midi.h"
-#include "notes.h"
-#include "pitch.h"
 #include "pitch_env.h"
 #include "uart.h"
-#include "vibrato.h"
 #include "vibrato_rate.h"
 #include "voice.h"
 
+uint16_t clamp_add(uint16_t x, int16_t delta);
+
+void dac_init(void);
+uint16_t dac_pitch_delta(uint8_t semitones);
+void dac_send(uint8_t command, uint16_t data);
+uint16_t dac_note_pitch(uint8_t voice, uint8_t note);
+uint8_t dac_command_set(uint8_t voice);
+
+void gate_init(void);
+void gate_on(uint8_t voice);
+void gate_on_legato(uint8_t voice);
+void gate_off(uint8_t voice);
+void gate_update(uint8_t delta);
+
+enum { NUM_NOTES = 128 };
+
+int16_t vibrato_detune(void);
+void vibrato_update(uint8_t delta);
+void vibrato_set_rate(uint8_t val);
+void vibrato_set_depth(uint8_t val);
+
+void pitch_set_note(uint8_t voice, uint8_t note, int16_t detune);
+void pitch_set_bend(uint16_t bend);
+uint16_t pitch_delta(uint8_t semitones);
+void pitch_update_clock(uint8_t delta);
+void pitch_env_set_decay(uint8_t decay);
+void pitch_env_set_amount(uint8_t amount);
+void pitch_env_trigger(uint8_t voice);
+
+
 static struct {
 	uint8_t data[16];
 	uint8_t head;
@@ -645,3 +669,19 @@ uint16_t dac_note_pitch(uint8_t v, uint8_t note) {
 	    d->offset + octave * d->scale,
 	    dac_semitone_offset((note - MIDI_LOWEST) % NUM_SEMITONES));
 }
+
+uint16_t clamp_add(uint16_t x, int16_t delta) {
+	if (delta < 0) {
+		uint16_t sub = -delta;
+		if (x < sub) {
+			return 0;
+		}
+		return x - sub;
+	}
+
+	uint16_t add = delta;
+	if (UINT16_MAX - x < add) {
+		return UINT16_MAX;
+	}
+	return x + add;
+}

dac.c

-#include "dac.h"
-#include "clamp_add.h"
-#include "voice.h"
-#include <avr/io.h>
-#include <util/delay.h>
-
-uint16_t dac_pitch_delta(uint8_t semitones) {
-	if (semitones >= NUM_SEMITONES) {
-		semitones = NUM_SEMITONES - 1;
-	}
-
-	return dac_semitone_offset(semitones);
-}
-
-uint8_t spi_io(uint8_t data) {
-	SPDR = data;
-	loop_until_bit_is_set(SPSR, SPIF);
-	return SPDR;
-}
-
-#define DAC_SYNC PORTB1
-#define MOSI PORTB3
-#define MISO PORTB4
-#define SCK PORTB5
-#define SS PORTB2
-
-uint8_t dac_command_set(uint8_t v) {
-	struct dac *d = dac(v);
-	if (!d) {
-		return 0;
-	};
-
-	return 0b00110000 | d->channel;
-}
-
-void dac_send(uint8_t command, uint16_t data) {
-	PORTB &= ~_BV(DAC_SYNC);
-	spi_io(command);
-	spi_io(data >> 8);
-	spi_io(data & 0xff);
-	PORTB |= _BV(DAC_SYNC);
-}
-
-void spi_init(void) {
-	// slave select, sck, mosi all as output
-	DDRB |= _BV(SS) | _BV(MOSI) | _BV(SCK);
-
-	PORTB |= _BV(MISO); // MISO pull-up to save power
-
-	// spi enable
-	SPCR |= _BV(SPE) | _BV(MSTR) | _BV(CPOL);
-	SPSR |= _BV(SPI2X);
-}
-
-void dac_init(void) {
-	DDRB |= _BV(DAC_SYNC);
-
-	spi_init();
-
-	// dac sync high for power saving
-	PORTB |= _BV(DAC_SYNC);
-
-	_delay_ms(1); // let dac boot up
-}
-
-#define MIDI_LOWEST 24
-
-uint16_t dac_note_pitch(uint8_t v, uint8_t note) {
-	struct dac *d = dac(v);
-	if (!d) {
-		return 0;
-	};
-
-	// Don't go lower than "C0"
-	if (note < MIDI_LOWEST) {
-		note = MIDI_LOWEST;
-	}
-	if (note > 127) {
-		note = 127;
-	}
-
-	uint8_t octave = (note - MIDI_LOWEST) / NUM_SEMITONES;
-	if (octave > 7) {
-		return 0;
-	}
-
-	return clamp_add(
-	    d->offset + octave * d->scale,
-	    dac_semitone_offset((note - MIDI_LOWEST) % NUM_SEMITONES));
-}

dac.h

-#ifndef DAC_H
-#define DAC_H
-
-#include <stdint.h>
-
-void dac_init(void);
-uint16_t dac_pitch_delta(uint8_t semitones);
-void dac_send(uint8_t command, uint16_t data);
-uint16_t dac_note_pitch(uint8_t voice, uint8_t note);
-uint8_t dac_command_set(uint8_t voice);
-
-#endif

gate.h

-#ifndef GATE_H
-#define GATE_H
-
-#include <stdint.h>
-
-void gate_init(void);
-void gate_on(uint8_t voice);
-void gate_on_legato(uint8_t voice);
-void gate_off(uint8_t voice);
-void gate_update(uint8_t delta);
-
-#endif

notes.h

-#ifndef NOTES_H
-#define NOTES_H
-
-enum { NUM_NOTES = 128,
-};
-
-#endif

pitch.h

-#ifndef PITCH_H
-#define PITCH_H
-
-#include <stdint.h>
-
-void pitch_set_note(uint8_t voice, uint8_t note, int16_t detune);
-void pitch_set_bend(uint16_t bend);
-uint16_t pitch_delta(uint8_t semitones);
-void pitch_update_clock(uint8_t delta);
-void pitch_env_set_decay(uint8_t decay);
-void pitch_env_set_amount(uint8_t amount);
-void pitch_env_trigger(uint8_t voice);
-
-#endif

vibrato.h

-#ifndef VIBRATO_H
-#define VIBRATO_H
-
-#include <stdint.h>
-
-int16_t vibrato_detune(void);
-void vibrato_update(uint8_t delta);
-void vibrato_set_rate(uint8_t val);
-void vibrato_set_depth(uint8_t val);
-
-#endif