handle bg music in isr and add second pulse channel

src/game.c

 
 static uint8_t pause_screen(void) NONBANKED {
     snd_music_off();
+    snd_note_off();
 
     uint8_t n = 0;
 
 
 static void show_explosion(uint16_t power) NONBANKED {
     snd_music_off();
+    snd_note_off();
     sample_play_explosion_ship();
 
     for (uint8_t n = 0; n < (4 * 4 * 4); n++) {
 }
 
 int32_t game(void) NONBANKED {
+    snd_music_off();
+    snd_note_off();
+
     disable_interrupts();
     DISPLAY_OFF;
     map_game();
     DISPLAY_ON;
     enable_interrupts();
 
-    snd_music_off();
     snd_game_music();
 
     while(1) {
-        snd_play();
         key_read();
 
         enum ACCELERATION acc = 0;
                 break;
             }
 
+            // restart bg music
+            snd_game_music();
+
             // re-draw ship sprite
             redraw = 1;
         }

src/main.c

     }
 
     while (1) {
-        snd_play();
         key_read();
 
         if (key_pressed(J_A) || key_pressed(J_B)) {
     SHOW_WIN;
 
     while (1) {
-        snd_play();
         key_read();
 
         if (key_pressed(J_A) || key_pressed(J_B) || key_pressed(J_SELECT)) {
 }
 
 static void splash(void) NONBANKED {
+    snd_music_off();
+    snd_note_off();
+
     disable_interrupts();
     DISPLAY_OFF;
     map_title();
     DISPLAY_ON;
     enable_interrupts();
 
-    snd_music_off();
     snd_menu_music();
 
     while (1) {
-        snd_play();
         key_read();
 
         if (key_pressed(J_LEFT)) {
 }
 
 static uint16_t ask_name(int32_t score) NONBANKED {
+    snd_music_off();
+    snd_note_off();
+
     disable_interrupts();
     DISPLAY_OFF;
     map_title();
     DISPLAY_ON;
     enable_interrupts();
 
-    snd_music_off();
     snd_gameover_music();
 
     char name[3] = { 'a', 'a', 'a' };
     win_name_draw(convert_name(name[0], name[1], name[2]), score < 0, pos);
 
     while (1) {
-        snd_play();
         key_read();
 
         if (key_pressed(J_LEFT)) {

src/obj.c

                 break;
         }
 
+        if (!objs[i].active) {
+            continue;
+        }
+
         spr_draw(objs[i].sprite, FLIP_NONE, objs[i].off_x >> POS_SCALE_OBJS, objs[i].off_y >> POS_SCALE_OBJS, 0, hiwater);
     }
 

src/sound.c

     }
 }
 
+static void play_note2(enum notes note) NONBANKED {
+    if (note < SILENCE) {
+        START_ROM_BANK(BANK(sound));
+        uint16_t freq = frequencies[note];
+        END_ROM_BANK();
+
+        NR21_REG = 0x80 | 0x3F; // 50% duty, shortest initial length
+        NR22_REG = 0x70; // half volume, no change
+        NR23_REG = freq & 0xFF; // given frequency
+        NR24_REG = 0x80 | ((freq >> 8) & 0x07); // trigger, upper freq bits
+    } else {
+        NR21_REG = 0x80 | 0x3F; // 50% duty, shortest initial length
+        NR22_REG = 0x10; // 'lowest' volume without pop, no change
+        NR23_REG = 0x00; // lowest frequency
+        NR24_REG = 0x80 | 0x40 | 0x00; // trigger, enable length, upper freq bits
+    }
+}
+
 static void play_drum(enum drums drum) NONBANKED {
     switch (drum) {
         case dKick:
 }
 
 void snd_music_off(void) BANKED {
+    CRITICAL {
+        music = NULL;
+    }
+}
+
+void snd_note_off(void) BANKED {
     play_note(SILENCE);
+    play_note2(SILENCE);
 }
 
 static void play_current_note(void) NONBANKED {
     }
 
     START_ROM_BANK(bank);
-    if (music->notes) {
-        if (music->notes[off] != END) {
-            play_note(music->notes[off]);
+        if (music->notes) {
+            if (music->notes[off] != END) {
+                play_note(music->notes[off]);
+            }
         }
-    }
-    if (music->drums) {
-        if (music->drums[off] != dEND) {
-            play_drum(music->drums[off]);
+        if (music->notes2) {
+            if (music->notes2[off] != END) {
+                play_note(music->notes2[off]);
+            }
+        }
+        if (music->drums) {
+            if (music->drums[off] != dEND) {
+                play_drum(music->drums[off]);
+            }
         }
-    }
     END_ROM_BANK();
 }
 
 void snd_menu_music(void) BANKED {
-    music = &music_menu;
-    bank = BANK(sound_menu);
-    off = 0;
-    last_t = timer_get();
-    play_current_note();
+    // TODO
+    snd_gameover_music();
+    return;
+
+    CRITICAL {
+        music = &music_menu;
+        bank = BANK(sound_menu);
+        off = 0;
+        last_t = timer_get();
+        play_current_note();
+    }
 }
 
 void snd_game_music(void) BANKED {
-    music = &music_game;
-    bank = BANK(sound_game);
-    off = 0;
-    last_t = timer_get();
-    play_current_note();
+    // TODO
+    snd_music_off();
+    return;
+
+    CRITICAL {
+        music = &music_game;
+        bank = BANK(sound_game);
+        off = 0;
+        last_t = timer_get();
+        play_current_note();
+    }
 }
 
 void snd_gameover_music(void) BANKED {
-    music = &music_over;
-    bank = BANK(sound_over);
-    off = 0;
-    last_t = timer_get();
-    play_current_note();
+    CRITICAL {
+        music = &music_over;
+        bank = BANK(sound_over);
+        off = 0;
+        last_t = timer_get();
+        play_current_note();
+    }
 }
 
 void snd_play(void) NONBANKED {
     }
 
     START_ROM_BANK(bank);
+    CRITICAL {
         uint16_t diff = timer_get() - last_t;
         if (diff >= music->duration) {
             off++;
                 }
             }
 
+            if (music->notes2) {
+                if (music->notes2[off] != END) {
+                    play_note2(music->notes2[off]);
+                } else {
+                    off = 0xFFFF;
+                }
+            }
+
             if (music->drums) {
                 if (music->drums[off] != dEND) {
                     play_drum(music->drums[off]);
                 }
             }
         }
+    }
     END_ROM_BANK();
 }

src/sound.h

 
 struct music {
     enum notes * const notes;
+    enum notes * const notes2;
     enum drums * const drums;
     uint16_t duration;
 };
 void snd_init(void) BANKED;
 
 void snd_music_off(void) BANKED;
+void snd_note_off(void) BANKED;
 void snd_menu_music(void) BANKED;
 void snd_game_music(void) BANKED;
 void snd_gameover_music(void) BANKED;

src/sound_game.c

 
 const struct music music_game = {
     .notes = game_music,
+    .notes2 = NULL,
     .drums = NULL,
     .duration = 200,
 };

src/sound_menu.c

 BANKREF(sound_menu)
 
 const enum notes menu_music[] = {
-    C3, C3, G3, G3, A3, A3, G3, SILENCE,
-    F3, F3, E3, E3, D3, D3, C3, SILENCE,
-    G3, G3, F3, F3, E3, E3, D3, D3,
-    G3, G3, F3, F3, E3, E3, D3, D3,
-    C3, C3, G3, G3, A3, A3, G3, SILENCE,
-    F3, F3, E3, E3, D3, D3, C3, SILENCE,
     SILENCE, SILENCE, END
 };
 
 const struct music music_menu = {
     .notes = menu_music,
+    .notes2 = NULL,
     .drums = NULL,
     .duration = 200,
 };

src/sound_over.c

     END
 };
 
+#define ADD_LOOP \
+    Ab2, SIL, Ab2, SIL, Ab2, SIL, Ab2, SIL, \
+    Ab2, SIL, Ab2, SIL, Ab2, SIL, Ab2, SIL
+
+#define ADD_LOOP_2 \
+     A2, SIL,  A2, SIL,  A2, SIL,  A2, SIL, \
+     A2, SIL,  A2, SIL,  A2, SIL,  A2, SIL
+
+#define ADD_LOOP_3 \
+     E2, SIL,  E2, SIL,  E2, SIL,  E2, SIL, \
+     E2, SIL,  E2, SIL,  E2, SIL,  E2, SIL
+
+const enum notes over_notes2[] = {
+    ADD_LOOP, ADD_LOOP_2,
+    ADD_LOOP, ADD_LOOP_3,
+    ADD_LOOP, ADD_LOOP_2,
+
+    Db3, Db3, Db3, Db3, Db3, Db3, Db3, Db3,
+    SIL, SIL, SIL, SIL, SIL, SIL, SIL, SIL,
+    SIL, SIL, SIL, SIL, SIL, SIL, SIL, SIL,
+    SIL, SIL, SIL, SIL, SIL, SIL, SIL, SIL,
+
+     D3,  D3,  D3,  D3,  D3,  D3,  D3,  D3,
+    SIL, SIL, SIL, SIL, SIL, SIL, SIL, SIL,
+    SIL, SIL, SIL, SIL, SIL, SIL, SIL, SIL,
+    SIL, SIL, SIL, SIL, SIL, SIL, SIL, SIL,
+
+    // repeat
+
+    ADD_LOOP, ADD_LOOP_2,
+    ADD_LOOP, ADD_LOOP_3,
+    ADD_LOOP, ADD_LOOP_2,
+
+    Db3, Db3, Db3, Db3, Db3, Db3, Db3, Db3,
+    SIL, SIL, SIL, SIL, SIL, SIL, SIL, SIL,
+    SIL, SIL, SIL, SIL, SIL, SIL, SIL, SIL,
+    SIL, SIL, SIL, SIL, SIL, SIL, SIL, SIL,
+
+    D3,  D3,  D3,  D3,  D3,  D3,  D3,  D3,
+    SIL, SIL, SIL, SIL, SIL, SIL, SIL, SIL,
+    SIL, SIL, SIL, SIL, SIL, SIL, SIL, SIL,
+    SIL, SIL, SIL, SIL, SIL, SIL, SIL, SIL,
+
+    // end
+
+    SILENCE, SILENCE, SILENCE, SILENCE,
+    SILENCE, SILENCE, SILENCE, SILENCE,
+    SILENCE, SILENCE, SILENCE, SILENCE,
+    SILENCE, SILENCE, SILENCE, SILENCE,
+    END
+};
+
 #define DRUM_LOOP \
     dKi, dSI, dSI, dSI, dSI, dSI, dKi, dSI, \
     dSn, dSI, dSI, dSI, dKi, dSI, dSI, dSI \
 
 const struct music music_over = {
     .notes = over_notes,
+    .notes2 = over_notes2,
     .drums = over_drums,
     .duration = 120,
 };

src/timer.c

  */
 
 #include "sample.h"
+#include "sound.h"
 #include "timer.h"
 
 static volatile uint16_t count = 0;
     if ((count & 0x03) == 0) {
         sample_isr();
     }
+    snd_play();
     count++;
 }