サイレンマシーンforGB proto

sirenmachine.c

/* use gbdk-2020 4.0.6 */
/* <path-to-gbdk-env>/bin/lcc -Wa-l -Wl-m -Wl-j -o sirenmachine.gb sirenmachine.c */

#include <gb/gb.h>
#include <stdio.h>
#include <gbdk/console.h>

UBYTE previous_keys;
BYTE keys;
#define UPDATE_KEYS() previous_keys = keys; keys = joypad()
#define KEY_ISPRESS(K) (keys & (K))
#define KEY_PUSHED(K) ((keys & (K)) && !(previous_keys & (K)))
#define KEY_RELEASED(K) (!(keys & (K)) && (previous_keys & (K)))
#define KEY_ANY_EVENT(K) (keys & (K)) ^ (previous_keys  & (K))

UWORD lfo_count_max;
UWORD lfo_count_up;
UBYTE lfo_dir;
UBYTE lfo_waveform;
UBYTE osc_pw;
UBYTE osc_freq;
UBYTE lfo_rate;
const UBYTE lfo_period = 6U;
const UWORD freq_base [3] = {1407U, 1729U, 1887U};

char lfo_waveform_name[4][8] = {
  "Square ",
  "Up     ",
  "Down   ",
  "Up-Down"
};

void print_bar(UBYTE val) {
  UBYTE i;
  printf("[");
  for (i = 0; i < 18; i++){
    if (i < val) {
      printf("-");
    } else if (i == val) {
      printf("*");
    } else {
      printf(" ");
    }
  }
  printf("]");
}

void tim() {
  __critical {
    if (lfo_count_up < lfo_count_max) {
      lfo_count_up += 1U << lfo_rate;
    } else {
      lfo_count_up = 0U;
      lfo_dir = ~lfo_dir;
    }
  }
}

void print_osc_pw() {
  gotoxy(0, 12);
  switch (osc_pw) {
    case 0 : printf("[--________________]"); break;
    case 1 : printf("[-----_____________]"); break;
    case 2 : printf("[---------_________]"); break;
  }
}

void print_lfo_event() {

  if (KEY_ANY_EVENT(J_DOWN | J_UP)) {
    gotoxy(0, 6);
    switch (lfo_rate) {
      case 0: print_bar(0); break;
      case 1: print_bar(9); break;
      case 2: print_bar(17); break;
    }
  }

  if (KEY_ANY_EVENT(J_LEFT | J_RIGHT)) {
    gotoxy(0, 9);
    switch (osc_freq) {
      case 0: print_bar(0); break;
      case 1: print_bar(9); break;
      case 2: print_bar(17); break;
    }
  }
}

void main() {
  __critical {
    lfo_count_max = 376U;
    lfo_count_up = 0U;
    lfo_dir = 0U;
    lfo_waveform = 0U;
    osc_pw = 2U;
    osc_freq = 1U;
    lfo_rate = 1U;
    add_TIM(tim);
  }

  UWORD freq = 0U;

  NR52_REG = 0x80U;  // Enable sound

  /* Sound channel 1 */
  // NR10_REG = 0x17U;
  // NR11_REG = 0x9FU;
  // NR12_REG = 0xF0U;
  // NR13_REG = 0x00FFU & freq_2;
  // NR14_REG = 0x40 | (freq_2 >> 8);

  /* Sound channel 2*/
  NR21_REG = (osc_pw & 0x03) << 6;
  NR22_REG = 0xF0U;

  /* Sound channel 3 */
  // NR30_REG = 0x00U;
  // NR31_REG = 0x00U;
  // NR32_REG = 0x20U;
  // NR33_REG = 0xD6U;
  // NR34_REG = 0x46U;

  NR50_REG = 0x77U;  // Set master volume
  NR51_REG = 0xFFU;

  gotoxy(0, 0);
  printf("Siren Machine for GB");
  gotoxy(1, 2);
  printf("LFO Waveform");
  gotoxy(1, 3);
  printf("- Square");
  gotoxy(1, 5);
  printf("LFO Rate");
  gotoxy(0, 6);
  print_bar(9);
  gotoxy(1, 8);
  printf("OSC Freq. Offset");
  gotoxy(0, 9);
  print_bar(9);
  gotoxy(1, 11);
  printf("OSC Pulse Width");
  print_osc_pw();
  gotoxy(1, 14);
  printf("OSC Sound Off/On");
  gotoxy(1, 15);
  printf("- Off");


  TMA_REG = 0xFFU - lfo_period;  // Interrupt rate : 5641.3 Hz
  TAC_REG = 0x07U;  // Timer enable, Clock at 16384 Hz
  set_interrupts(TIM_IFLAG);

  while (1) {

    if (KEY_PUSHED(J_A)) {
      NR22_REG = 0xF0U;  // max volume
      NR24_REG = 0x80U;  // restart sound
    }

    if (KEY_ISPRESS(J_A)) {
      gotoxy(3, 15);
      printf("On ");
    }

    if (KEY_RELEASED(J_A)) {
      NR22_REG = 0x00U;  // min volume, stop sound
      gotoxy(3, 15);
      printf("Off");
    }

    __critical {
      if (lfo_waveform == 0U) {
        if (lfo_dir) {
          freq = 0U;
        } else {
          freq = lfo_count_max;
        }
      } else if (lfo_waveform == 1U) {
        freq = lfo_count_up;
      } else if (lfo_waveform == 2U) {
        freq = lfo_count_max - lfo_count_up;
      } else {
        if (lfo_dir) {
          freq = lfo_count_up;
        } else {
          freq = lfo_count_max - lfo_count_up;
        }
      }

      if (KEY_PUSHED(J_LEFT) && osc_freq > 0U) {
        osc_freq--;
      } else if (KEY_PUSHED(J_RIGHT) && osc_freq < 2U) {
        osc_freq++;
      }
    }

    freq = freq_base[osc_freq] + (freq >> osc_freq);

    NR23_REG = 0x00FFU & freq;
    NR24_REG = (freq >> 8);

    if (KEY_PUSHED(J_B)) {
      if (lfo_waveform < 3) {
        lfo_waveform++;
      } else {
        lfo_waveform = 0U;
      }
      gotoxy(3, 3);
      printf("%s", lfo_waveform_name[lfo_waveform]);
    }

    if (KEY_PUSHED(J_SELECT)) {
      if (osc_pw < 2) {
        osc_pw++;
      } else {
        osc_pw = 0U;
      }
      NR21_REG = (osc_pw & 0x03) << 6;
      print_osc_pw();
    }

    __critical {
      if (KEY_PUSHED(J_DOWN) && lfo_rate > 0U) {
        lfo_rate--;
      } else if (KEY_PUSHED(J_UP) && lfo_rate < 2U) {
        lfo_rate++;
      }
    }

    print_lfo_event();

    UPDATE_KEYS();
  }
}