diff options
Diffstat (limited to 'src/sounds.c')
| -rw-r--r-- | src/sounds.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/src/sounds.c b/src/sounds.c new file mode 100644 index 0000000..fe6b3d3 --- /dev/null +++ b/src/sounds.c @@ -0,0 +1,248 @@ +#include "sounds.h" + +int mqueue_get(message_queue *q, synth_message *msg) { + pthread_mutex_lock(&(q)->lock); + if ((q)->tail == (q)->head) { + pthread_mutex_unlock(&(q)->lock); + return 1; + } + + *(msg) = (q)->buffer[(q)->tail]; + (q)->tail = ((q)->tail + 1) % MESSAGE_QUEUE_SIZE; + + pthread_mutex_unlock(&(q)->lock); + return 0; +} + +/* osc_triangle_gen */ + +void osc_sine_gen(float *buffer, size_t sample_count, float *phase, + float phase_inc) { + for (size_t i = 0; i < sample_count; i++) { + buffer[i] += sinf(*phase); + *phase += phase_inc; + if (*phase >= 2 * M_PI) + *phase -= 2 * M_PI; + } +} + +void osc_square_gen(float *buffer, size_t sample_count, float *phase, + float phase_inc) { + for (size_t i = 0; i < sample_count; i++) { + buffer[i] += sinf(*phase) ? 1 : -1; + *phase += phase_inc; + if (*phase >= 2 * M_PI) + *phase -= 2 * M_PI; + } +} + +void osc_saw_gen(float *buffer, size_t sample_count, float *phase, + float phase_inc) { + for (size_t i = 0; i < sample_count; i++) { + buffer[i] += (*phase / M_PI) - 1; + *phase += phase_inc; + if (*phase >= 2 * M_PI) + *phase -= 2 * M_PI; + } +} + +oscilator_func osc_get(oscilator_type type) { + switch (type) { + case OSC_SINE: + return osc_sine_gen; + case OSC_SAW: + return osc_saw_gen; + case OSC_SQUARE: + return osc_square_gen; + default: + return osc_sine_gen; + } +} + +void set_note_on(synth_voices *voices, size_t note_id) { + if (note_id >= voices->size) { + return; + } + voices->buffer[note_id].active = true; +} + +void set_note_off(synth_voices *voices, size_t note_id) { + if (note_id >= voices->size) { + return; + } + voices->buffer[note_id].active = false; +} + +void set_all_notes_off(synth_voices *voices) { + for (size_t i = 0; i < voices->size; i++) { + if (voices->buffer[i].active) { + voices->buffer[i].active = false; + } + } +} + +void set_param(synth_params *params, param_type type, float value) { + switch (type) { + case PARAM_OSC: { + params->oscilator_type = (int)value; + break; + } + case PARAM_VOLUME: { + params->master_volume = value; + break; + } + } +} + +void generate_voices(synth_voices *voices, synth_params *params, float *buffer, + size_t buffer_size) { + oscilator_func oscilator = osc_get(params->oscilator_type); + for (size_t i = 0; i < voices->size; i++) { + synth_voice *voice = &voices->buffer[i]; + if (!voice->active) { + continue; + } + + if (voice->phase_inc == 0) { + voice->phase_inc = 2 * M_PI * voice->freq / SAMPLE_RATE; + } + oscilator(buffer, buffer_size, &voice->phase, voice->phase_inc); + } +} + +void post_process(synth_params *params, float *scratch_buffer, + size_t buffer_size) { + for (size_t i = 0; i < buffer_size; i++) { + scratch_buffer[i] *= params->master_volume; + } +} + +void prepare_output(float *scratch_buffer, short *output_buffer, + size_t buffer_size) { + for (size_t i = 0; i < buffer_size; i++) { + output_buffer[i] = scratch_buffer[i] * 0.2f * 32767; + } +} + +void sound_loop_start(snd_pcm_t *pcm, message_queue *queue, + synth_voices *voices, synth_params *params) { + bool should_stop = false; + + short output_buffer[PERIOD_SIZE]; + float scratch_buffer[PERIOD_SIZE]; + + while (!should_stop) { + synth_message msg; + while (mqueue_get(queue, &msg) == 0 && !should_stop) { + switch (msg.type) { + case MSG_NOTE_ON: { + size_t note_id = msg.note.note_id; + set_note_on(voices, note_id); + break; + } + case MSG_NOTE_OFF: { + size_t note_id = msg.note.note_id; + set_note_off(voices, note_id); + break; + } + case MSG_ALL_NOTES_OFF: { + set_all_notes_off(voices); + break; + } + case MSG_PARAM_CHANGE: { + param_type type = msg.param_change.param_type; + float value = msg.param_change.value; + set_param(params, type, value); + break; + } + case MSG_STOP: { + should_stop = true; + } + } + } + + memset(&output_buffer, 0, PERIOD_SIZE * sizeof(short)); + memset(&scratch_buffer, 0, PERIOD_SIZE * sizeof(float)); + + generate_voices(voices, params, scratch_buffer, PERIOD_SIZE); + + /* post_process(params, scratch_buffer, PERIOD_SIZE); */ + prepare_output(scratch_buffer, output_buffer, PERIOD_SIZE); + + snd_pcm_sframes_t written = snd_pcm_writei(pcm, output_buffer, PERIOD_SIZE); + if (written < 0) { + printf("xrun\n"); + snd_pcm_prepare(pcm); // recover from xrun + } + } +} + +void fill_voices(synth_voice *voices, float *freqs, size_t freqs_amount) { + for (size_t i = 0; i < freqs_amount; i++) { + voices[i] = (synth_voice){ + .active = false, + .freq = freqs[i], + .phase = 0, + .phase_inc = 0, + }; + } +} + +void *sound_thread_start(void *ptr) { + sound_thread_meta *meta = ptr; + + float freqs[12] = { + 261.63f, // c + 277.18f, // c# + 293.66f, // e + 311.13f, // e# + 329.63f, // d + 349.23f, // f + 369.99f, // f# + 392, // g + 415.3f, // g# + 440, // a + 466.16, // a# + 493.88, // b + }; + + synth_voice buffer[12]; + fill_voices(buffer, freqs, 12); + + synth_voices voices = { + .buffer = buffer, + .size = 12, + }; + synth_params params = { + .oscilator_type = OSC_SINE, + }; + + sound_loop_start(meta->pcm, meta->queue, &voices, ¶ms); + + check(snd_pcm_drop(meta->pcm)); + return NULL; +} + +int set_hw_params(snd_pcm_t *pcm) { + snd_pcm_hw_params_t *hw_params; + + snd_pcm_hw_params_alloca(&hw_params); + + check(snd_pcm_hw_params_any(pcm, hw_params)); + + unsigned int resample = 1; + check(snd_pcm_hw_params_set_rate_resample(pcm, hw_params, resample)); + check(snd_pcm_hw_params_set_access(pcm, hw_params, + SND_PCM_ACCESS_RW_INTERLEAVED)); + check(snd_pcm_hw_params_set_format(pcm, hw_params, SND_PCM_FORMAT_S16_LE)); + check(snd_pcm_hw_params_set_channels(pcm, hw_params, 1)); + check(snd_pcm_hw_params_set_rate(pcm, hw_params, SAMPLE_RATE, 0)); + snd_pcm_uframes_t period_size = PERIOD_SIZE; + check( + snd_pcm_hw_params_set_period_size_near(pcm, hw_params, &period_size, 0)); + snd_pcm_uframes_t buffer_size = period_size * 4; + check(snd_pcm_hw_params_set_buffer_size_near(pcm, hw_params, &buffer_size)); + check(snd_pcm_hw_params(pcm, hw_params)); + + return 0; +} |