stfu/Source/Maker/main.c

#include <stdio.h>

#define SOKOL_IMPL
#define SOKOL_GLCORE
#include "sokol_app.h"
#include "sokol_audio.h"
#include "sokol_log.h"

#include "../config.h"
#include "../oscillators.c"
#include "../phaser.c"

static struct stfu_sinewave sine0;
static struct stfu_phaser phaser0;
static struct stfu_phaser phaser1;

static float key_frequency = STFU_C4_FREQUENCY;

static void stream(float *buffer, int num_frames, int num_channels) {
  for (int i = 0; i < num_frames; ++i) {
    // sine0 = stfu_pump_sinewave(sine0); // Carrier
    phaser0 = stfu_pump_phaser(phaser0);
    phaser1 = stfu_pump_phaser(phaser1);
    buffer[2 * i + 0] = sinf(phaser0.v + sinf(phaser1.v));
    buffer[2 * i + 1] = sinf(phaser0.v + sinf(phaser1.v));
  }
}

static void init(void) {
  saudio_setup(&(saudio_desc){
      .sample_rate = STFU_AUDIO_FRAME_RATE,
      .num_channels = STFU_AUDIO_CHANNEL_COUNT,
      // .stream_cb = stream,
  });

  // sine0 = stfu_init_sinewave(STFU_A4_FREQUENCY / 2.0f, 0.0f, 0.8f);
  phaser0 = stfu_init_phaser(key_frequency);
  phaser1 = stfu_init_phaser(key_frequency * 0.25);
}

static void cleanup(void) { saudio_shutdown(); }

static void event(const sapp_event *e) {
  switch (e->type) {
  case SAPP_EVENTTYPE_KEY_DOWN: {
    if (e->key_repeat)
      break;

    switch (e->key_code) {
    case SAPP_KEYCODE_Z:
      key_frequency = STFU_C4_FREQUENCY;
      break;
    case SAPP_KEYCODE_X:
      key_frequency = STFU_C4_FREQUENCY * STFU_NOTE_UPSCALE_FACTOR;
      break;
    case SAPP_KEYCODE_C:
      key_frequency = STFU_C4_FREQUENCY * STFU_NOTE_UPSCALE_FACTOR *
                      STFU_NOTE_UPSCALE_FACTOR;
      break;
    case SAPP_KEYCODE_V:
      key_frequency = STFU_C4_FREQUENCY * STFU_NOTE_UPSCALE_FACTOR *
                      STFU_NOTE_UPSCALE_FACTOR * STFU_NOTE_UPSCALE_FACTOR;
      break;
    case SAPP_KEYCODE_B:
      key_frequency = STFU_C4_FREQUENCY * STFU_NOTE_UPSCALE_FACTOR *
                      STFU_NOTE_UPSCALE_FACTOR * STFU_NOTE_UPSCALE_FACTOR *
                      STFU_NOTE_UPSCALE_FACTOR;
      break;
    case SAPP_KEYCODE_N:
      key_frequency = STFU_A4_FREQUENCY * STFU_NOTE_DOWNSCALE_FACTOR *
                      STFU_NOTE_DOWNSCALE_FACTOR * STFU_NOTE_DOWNSCALE_FACTOR *
                      STFU_NOTE_DOWNSCALE_FACTOR;
      break;
    case SAPP_KEYCODE_M:
      key_frequency = STFU_A4_FREQUENCY * STFU_NOTE_DOWNSCALE_FACTOR *
                      STFU_NOTE_DOWNSCALE_FACTOR * STFU_NOTE_DOWNSCALE_FACTOR;
      break;
    case SAPP_KEYCODE_COMMA:
      key_frequency = STFU_A4_FREQUENCY * STFU_NOTE_DOWNSCALE_FACTOR *
                      STFU_NOTE_DOWNSCALE_FACTOR;
      break;
    case SAPP_KEYCODE_PERIOD:
      key_frequency = STFU_A4_FREQUENCY * STFU_NOTE_DOWNSCALE_FACTOR;
      break;
    case SAPP_KEYCODE_SLASH:
      key_frequency = STFU_A4_FREQUENCY;
      break;
    default:
      break;
    }

    phaser0 = stfu_set_phaser_frequency(phaser0, key_frequency);
    phaser1 = stfu_set_phaser_frequency(phaser1, key_frequency * 0.25);

    break;
  }
  default:
    break;
  }
}

static void frame(void) {
  int frames = (int)(sapp_frame_duration() * (float)STFU_AUDIO_FRAME_RATE);
  int expected = saudio_expect();
  frames = frames > expected ? expected : frames;
  // todo: Prevent drifting apart.
  static float buffer[STFU_AUDIO_FRAME_RATE * STFU_AUDIO_CHANNEL_COUNT];
  while (frames > 0) {
    int now = frames > STFU_AUDIO_FRAME_RATE ? STFU_AUDIO_FRAME_RATE : frames;
    stream(buffer, now, STFU_AUDIO_CHANNEL_COUNT);
    saudio_push(buffer, now);
    frames -= now;
  }
}

sapp_desc sokol_main(int argc, char *argv[]) {
  return (sapp_desc){
      .width = 640,
      .height = 480,
      .init_cb = init,
      .frame_cb = frame,
      .cleanup_cb = cleanup,
      .event_cb = event,
      .logger.func = slog_func,
      .gl_major_version = 2,
      .gl_minor_version = 0,
      // .swap_interval = 0,
  };
}