1 files changed, 80 insertions, 7 deletions

diff --git a/src/main.c b/src/main.c
index ec2150a..30452e1 100644
--- a/src/main.c
+++ b/src/main.c
@@ -17,9 +17,6 @@
 // BIOS calls
 //
 
-int bios_vblank_wait();
-int bios_div(int num, int denom);
-
 int hblank_counter = 0;
 
 void
@@ -48,19 +45,95 @@ int main(void) {
 
     // Register interrupts.
     irq_init();
-    irs_set(IRQ_VBLANK, irq_stub);
+    irs_set(IRQ_VBLANK, irs_stub);
     irs_set(IRQ_HBLANK, irs_hblank_func);
 
+    // turn sound on
+    SOUND_STATUS = SOUND_ENABLE;
+    SOUND_DMG_MASTER = sound_volume(SOUND_SQUARE1 | SOUND_SQUARE2, 7);
+    SOUND_DSOUND_MASTER = SOUND_DMG100;
+
+    char *note_names[] = {
+        "C"  , "C#" , "D"  , "D#" ,
+        "E"  , "F"  , "F#" , "G"  ,
+        "G#" , "A"  , "A#" , "B"
+    };
     int frame_counter = 0;
+    Note active_note = NOTE_C;
+    u8 octave = 0;
+    bool playing = false;
+    bool new_note = false;
+    u8 interval = 1;
     while(true) {
         bios_vblank_wait();
         poll_keys();
 
         txt_position(0, 1);
         txt_clear_line();
-        txt_printf(" HBlank counter: %d\n", hblank_counter);
-        txt_clear_line();
-        txt_printf(" Frame counter: %d\n", frame_counter);
+
+        if (key_pressed(KEY_B)) {
+            active_note = NOTE_C;
+            new_note = true;
+            octave = 0;
+        } else if (key_pressed(KEY_A)) {
+            active_note = NOTE_D;
+            new_note = true;
+            octave = 0;
+        } else if (key_pressed(KEY_LEFT)) {
+            active_note = NOTE_E;
+            new_note = true;
+            octave = 0;
+        } else if (key_pressed(KEY_DOWN)) {
+            active_note = NOTE_F;
+            new_note = true;
+            octave = 0;
+        } else if (key_pressed(KEY_RIGHT)) {
+            active_note = NOTE_G;
+            new_note = true;
+            octave = 0;
+        } else if (key_pressed(KEY_UP)) {
+            active_note = NOTE_A;
+            new_note = true;
+            octave = 0;
+        } else if (key_pressed(KEY_L)) {
+            active_note = NOTE_B;
+            new_note = true;
+            octave = 0;
+        } else if (key_pressed(KEY_R)) {
+            active_note = NOTE_C;
+            new_note = true;
+            octave = 1;
+        }
+        if (key_pressed(KEY_START)) {
+            interval++;
+        }
+        if (key_pressed(KEY_SELECT)) {
+            interval--;
+        }
+
+        if (key_curr > 0) {
+            txt_printf(" Playing: %s + %s\n",
+                    note_names[active_note],
+                    (note_names[(active_note + interval) % 12]));
+            playing = true;
+        } else {
+            playing = false;
+        }
+
+        if (playing) {
+            if (new_note) {
+                SOUND_SQUARE1_CTRL = SOUND_SQUARE_ENV_VOL(4) | SOUND_SQUARE_ENV_TIME(0);
+                SOUND_SQUARE2_CTRL = SOUND_SQUARE_ENV_VOL(4) | SOUND_SQUARE_ENV_TIME(0);
+                SOUND_SQUARE1_FREQ = SOUND_SQUARE_RESET | sound_rate(active_note, octave);
+                SOUND_SQUARE2_FREQ = SOUND_SQUARE_RESET | sound_rate((active_note + interval) % 12, octave);
+            }
+            new_note = false;
+        } else {
+            SOUND_SQUARE1_CTRL = SOUND_SQUARE_ENV_VOL(0) | SOUND_SQUARE_ENV_TIME(0);
+            SOUND_SQUARE2_CTRL = SOUND_SQUARE_ENV_VOL(0) | SOUND_SQUARE_ENV_TIME(0);
+            SOUND_SQUARE1_FREQ = 0;
+            SOUND_SQUARE2_FREQ = 0;
+        }
 
         frame_counter++;
         update_button_sprites();