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Diffstat (limited to 'src/sounds.c')
-rw-r--r--src/sounds.c150
1 files changed, 109 insertions, 41 deletions
diff --git a/src/sounds.c b/src/sounds.c
index 904b76b..89da2b0 100644
--- a/src/sounds.c
+++ b/src/sounds.c
@@ -1,8 +1,60 @@
#define MIDI_FREQS_LIST
#include "sounds.h"
+typedef enum {
+ ENV_OFF,
+ ENV_ATTACK,
+ ENV_DECAY,
+ ENV_SUSTAIN,
+ ENV_RELEASE,
+} EnvelopeState;
+
+typedef struct {
+ int attack_time;
+ int decay_time;
+ float sustain_level;
+ int release_time;
+} EnvelopeParams;
+
+typedef struct {
+ EnvelopeState state;
+ int counter;
+ float current_inc;
+ float current_value;
+ EnvelopeParams params;
+} Envelope;
+
+typedef struct {
+ bool active;
+ float freq;
+ float phase;
+ float phase_inc;
+ Envelope envelope;
+} SynthVoice;
+
+typedef struct {
+ SynthVoice *buffer;
+ size_t size;
+} SynthVoices;
+
+typedef struct {
+ OscilatorType oscilator_type;
+ float master_volume;
+ EnvelopeParams envelope_params;
+} SynthParams;
+
+typedef struct {
+ SynthParams params;
+ SynthVoice *last_voice;
+
+ MessageQueue *queue;
+ WaveData *wave_data;
+ SynthVoices *voices;
+} SynthState;
+
+typedef float (*OscilatorFunc)(float phase);
+
float envelope_next(Envelope *env) {
- float value;
bool next_state = false;
env->counter++;
@@ -17,10 +69,10 @@ float envelope_next(Envelope *env) {
}
if (env->current_inc == 0) {
- env->current_inc = (1.0 - env->release_value) / (float)env->params.attack_time;
+ env->current_inc = (1.0 - env->current_value) / (float)env->params.attack_time;
}
- value = env->release_value + env->current_inc * (float)env->counter;
+ env->current_value += env->current_inc;
break;
}
case ENV_DECAY: {
@@ -32,26 +84,31 @@ float envelope_next(Envelope *env) {
env->current_inc = (1.0 - env->params.sustain_level) / (float)env->params.decay_time;
}
- value = 1.0 - env->current_inc * (float)env->counter;
+ env->current_value -= env->current_inc;
break;
}
case ENV_SUSTAIN: {
- value = env->params.sustain_level;
+ env->current_value = env->params.sustain_level;
break;
}
case ENV_RELEASE: {
if (env->counter >= env->params.release_time) {
env->state = ENV_OFF;
- env->counter = env->current_inc = 0;
+ env->counter = env->current_inc = env->current_value = 0;
return 0;
}
if (env->current_inc == 0) {
- env->current_inc = env->params.sustain_level / (float)env->params.release_time;
+ float from_level;
+ if (env->params.sustain_level > env->current_value) {
+ from_level = (env->params.sustain_level - env->current_value);
+ }else {
+ from_level = env->current_value;
+ }
+ env->current_inc = from_level / (float)env->params.release_time;
}
- value = env->params.sustain_level - env->current_inc * (float)env->counter;
- env->release_value = value;
+ env->current_value -= env->current_inc;
break;
}
}
@@ -60,18 +117,20 @@ float envelope_next(Envelope *env) {
env->counter = env->current_inc = 0;
env->state++;
}
- return value;
+ return env->current_value;
}
void envelope_note_on(EnvelopeParams params, Envelope *env) {
env->state = ENV_ATTACK;
env->counter = 0;
+ env->current_inc = 0;
env->params = params;
}
void envelope_note_off(Envelope *env) {
env->state = ENV_RELEASE;
env->counter = 0;
+ env->current_inc = 0;
}
float osc_sine_get(float phase) {
@@ -105,7 +164,6 @@ void set_note_on(SynthParams *params, SynthVoices *voices, size_t note_id) {
}
envelope_note_on(params->envelope_params, &voices->buffer[note_id].envelope);
voices->buffer[note_id].active = true;
- params->last_freq = voices->buffer[note_id].freq;
}
void set_note_off(SynthVoices *voices, size_t note_id) {
@@ -210,8 +268,28 @@ void prepare_output(float *scratch_buffer, short *output_buffer,
}
}
-void sound_loop_start(snd_pcm_t *pcm, MessageQueue *queue, WaveData *wave_data, SynthVoices *voices) {
- SynthParams params;
+void play_output_buffer(snd_pcm_t *pcm, short *output_buffer) {
+ int period_size = PERIOD_SIZE;
+ short *ptr = output_buffer;
+
+ while (period_size > 0) {
+ snd_pcm_sframes_t written = snd_pcm_writei(pcm, ptr, period_size);
+ if (written < 0) {
+ printf("xrun\n");
+ snd_pcm_prepare(pcm); // recover from xrun
+ break;
+ }
+ ptr += written;
+ period_size -= written;
+ }
+}
+
+void sound_loop(snd_pcm_t *pcm, SynthState *state) {
+ MessageQueue *queue = state->queue;
+ WaveData *wave_data = state->wave_data;
+ SynthVoices *voices = state->voices;
+ SynthParams params = state->params;
+
short output_buffer[PERIOD_SIZE];
float scratch_buffer[PERIOD_SIZE];
float display_buffer[DISPLAY_SAMPLES];
@@ -224,6 +302,7 @@ void sound_loop_start(snd_pcm_t *pcm, MessageQueue *queue, WaveData *wave_data,
case MSG_NOTE_ON: {
size_t note_id = msg.note.note_id;
set_note_on(&params, voices, note_id);
+ state->last_voice = &voices->buffer[note_id];
break;
}
case MSG_NOTE_OFF: {
@@ -255,33 +334,15 @@ void sound_loop_start(snd_pcm_t *pcm, MessageQueue *queue, WaveData *wave_data,
post_process(&params, scratch_buffer, PERIOD_SIZE);
prepare_output(scratch_buffer, output_buffer, PERIOD_SIZE);
- if (display_write_pos + PERIOD_SIZE > DISPLAY_SAMPLES) {
- size_t diff = DISPLAY_SAMPLES - display_write_pos;
- memcpy(&display_buffer[display_write_pos], scratch_buffer, diff * sizeof(float));
- memcpy(display_buffer, &scratch_buffer[diff], (PERIOD_SIZE - diff) * sizeof(float));
- } else {
- memcpy(&display_buffer[display_write_pos], scratch_buffer, PERIOD_SIZE * sizeof(float));
- }
-
+ memcpy(&display_buffer[display_write_pos], scratch_buffer, PERIOD_SIZE * sizeof(float));
display_write_pos = (display_write_pos + PERIOD_SIZE) % DISPLAY_SAMPLES;
- memcpy(wave_data->buffers[wave_data->write_index], display_buffer, DISPLAY_SAMPLES * sizeof(float));
- atomic_store(&wave_data->write_index, 1 - atomic_load(&wave_data->write_index));
- wave_data->freq = params.last_freq;
-
- int period_size = PERIOD_SIZE;
- short *ptr = output_buffer;
-
- while (period_size > 0) {
- snd_pcm_sframes_t written = snd_pcm_writei(pcm, ptr, period_size);
- if (written < 0) {
- printf("xrun\n");
- snd_pcm_prepare(pcm); // recover from xrun
- break;
- }
- ptr += written;
- period_size -= written;
+ if (display_write_pos == 0) {
+ memcpy(wave_data->buffers[atomic_load(&wave_data->write_index)], display_buffer, DISPLAY_SAMPLES * sizeof(float));
+ atomic_store(&wave_data->write_index, 1 - atomic_load(&wave_data->write_index));
}
+
+ play_output_buffer(pcm, output_buffer);
}
stop:
return;
@@ -302,15 +363,22 @@ void fill_voices(SynthVoice *voices, MidiNote *freqs, size_t freqs_amount) {
void *sound_thread_start(void *ptr) {
SoundThreadMeta *meta = ptr;
- SynthVoice buffer[12];
- fill_voices(buffer, &midi_freqs[49], 12);
+ SynthVoice buffer[24];
+ fill_voices(buffer, &midi_freqs[48], 24);
SynthVoices voices = {
.buffer = buffer,
- .size = 12,
+ .size = 24,
+ };
+
+ SynthState state = {
+ .params = {0},
+ .queue = meta->queue,
+ .wave_data = meta->wave_data,
+ .voices = &voices,
};
- sound_loop_start(meta->pcm, meta->queue, meta->wave_data, &voices);
+ sound_loop(meta->pcm, &state);
check(snd_pcm_drop(meta->pcm));
return NULL;
generated by cgit v1.2.3 (git 2.25.1) at 2026-03-24 02:12:57 +0000