experiment with sample volume settings

src/config.ba0.c

 #include "sound.h"
 #include "config.h"
 
-struct config_mem {
-    struct config config;
-    struct scores scores[SCORE_NUM * 2];
-
-    uint32_t crc; // needs to be last
-};
-
-static struct config_mem mem;
+struct config_mem mem;
 
 BANKREF(config)
 
 
     if (calc_crc() != mem.crc) {
         mem.config.debug_flags = 0;
-        mem.config.sfx_vol = 0x0F;
+        mem.config.sfx_vol = 0x03;
         mem.config.music_vol = 0x07;
         score_reset();
     }
-
-    snd_vol_sfx = mem.config.sfx_vol;
-    snd_vol_music = mem.config.music_vol;
 }
 
 void conf_write_crc(void) BANKED {
     mem.crc = calc_crc();
 }
-
-struct scores *conf_scores(void) BANKED {
-    return mem.scores;
-}
-
-struct config *conf_get(void) BANKED {
-    return &mem.config;
-}

src/config.h

 
 void conf_init(void) BANKED;
 void conf_write_crc(void) BANKED;
-struct scores *conf_scores(void) BANKED;
-struct config *conf_get(void) BANKED;
 
 BANKREF_EXTERN(config)
 
+struct config_mem {
+    struct config config;
+    struct scores scores[SCORE_NUM * 2];
+
+    uint32_t crc; // needs to be last
+};
+
+extern struct config_mem mem;
+#define conf_scores() (mem.scores)
+#define conf_get() (&mem.config)
+
 #endif // __CONFIG_H__

src/main.c

 BANKREF(main)
 
 const struct conf_entry conf_entries[CONF_ENTRY_COUNT] = {
-    { .name = "sfx-vol",  .var = &snd_vol_sfx,   .max = 0x0F }, // 0
-    { .name = "musi-vol", .var = &snd_vol_music, .max = 0x0F }, // 1
+    //{ .name = "sfx-vol",  .var = &mem.config.sfx_vol,   .max = 3 },
+    { .name = "musi-vol", .var = &mem.config.music_vol, .max = 15 },
 };
 
 const struct debug_entry debug_entries[DEBUG_ENTRY_COUNT] = {
 static void conf_screen(void) NONBANKED {
     HIDE_WIN;
 
+    debug_menu_index = 0;
+
     move_win(MINWNDPOSX, MINWNDPOSY);
     hide_sprites_range(SPR_NUM_START, MAX_HARDWARE_SPRITES);
     win_conf();
 
     SHOW_WIN;
 
-    debug_menu_index = 0;
-
     while (1) {
         key_read();
 
                 } else {
                     *conf_entries[debug_menu_index].var = conf_entries[debug_menu_index].max;
                 }
-                conf_get()->music_vol = snd_vol_music;
-                conf_get()->sfx_vol = snd_vol_sfx;
                 conf_write_crc();
             END_ROM_BANK();
             win_conf();
                 } else {
                     *conf_entries[debug_menu_index].var = 0;
                 }
-                conf_get()->music_vol = snd_vol_music;
-                conf_get()->sfx_vol = snd_vol_sfx;
                 conf_write_crc();
             END_ROM_BANK();
             win_conf();

src/main.h

 
 BANKREF_EXTERN(main)
 
-#define CONF_ENTRY_COUNT 2
+#define CONF_ENTRY_COUNT 1
 extern const struct conf_entry conf_entries[CONF_ENTRY_COUNT];
 
 extern uint8_t debug_menu_index;

src/maps.c

                   title_map_map, 0, BANK(title_map), title_map_MAP_ATTRIBUTES, BANK(title_map));
 
     // TODO paging when more options added
+    uint8_t off = (10 - DEBUG_ENTRY_COUNT) / 2;
 
     str_center("Debug Menu", 0, 0);
 
             n_len += 2;
         END_ROM_BANK();
 
-        str(name_buff, (LINE_WIDTH - n_len) * 2, (i * 2) + 3, (debug_menu_index == i) ? 1 : 0);
+        str(name_buff, (LINE_WIDTH - n_len) * 2, (i * 2) + 3 + off, (debug_menu_index == i) ? 1 : 0);
     }
 }
 
                   title_map_map, 0, BANK(title_map), title_map_MAP_ATTRIBUTES, BANK(title_map));
 
     // TODO paging when more options added
+    uint8_t off = (10 - CONF_ENTRY_COUNT) / 2;
 
     str_center("Conf Menu", 0, 0);
 
             n_len += 2;
         END_ROM_BANK();
 
-        str(name_buff, (LINE_WIDTH - n_len) * 2, (i * 2) + 3, (debug_menu_index == i) ? 1 : 0);
+        str(name_buff, (LINE_WIDTH - n_len) * 2, (i * 2) + 3 + off, (debug_menu_index == i) ? 1 : 0);
     }
 }
 

src/sample.c

  * See <http://www.gnu.org/licenses/>.
  */
 
+#include "banks.h"
+#include "config.h"
+#include "gb/hardware.h"
 #include "sfx_shoot.h"
 #include "sfx_expl_orb.h"
 #include "sfx_expl_ship.h"
 
 BANKREF(sample)
 
-static volatile uint8_t play_bank = 1;
-static volatile const uint8_t *play_sample = 0;
-static volatile uint16_t play_length = 0;
-static volatile uint8_t playing = 0;
-
-uint8_t snd_vol_sfx = 0x00;
+static uint8_t play_bank = 1;
+static const uint8_t *play_sample = 0;
+static uint16_t play_length = 0;
 
 struct sfxs {
     uint8_t bank;
     if (sfx >= SFX_COUNT) {
         return;
     }
+    if (conf_get()->sfx_vol == 0) {
+        return;
+    }
 
     CRITICAL {
         play_bank = sfxs[sfx].bank;
         play_sample = sfxs[sfx].smp;
         play_length = sfxs[sfx].len;
-        playing = 1;
     }
 }
 
 uint8_t sample_running(void) BANKED {
-    return playing;
+    return (play_length > 0) ? 1 : 0;
 }
 
+#if 1
+
+// TODO C version has a slight 'beep' always? and much worse at lower volumes?
+
+void sample_isr(void) NONBANKED {
+    if (play_length == 0) {
+        return;
+    }
+
+    NR51_REG = 0xBB; // turn CH3 off in left and right pan
+    NR30_REG = 0x00; // turn DAC off
+
+    START_ROM_BANK(play_bank);
+        // load waveforms
+        for (uint8_t i = 0; i < 16; i++) {
+            _AUD3WAVERAM[i] = *(play_sample++);
+        }
+    END_ROM_BANK();
+
+    NR30_REG = 0x80; // turn DAC on
+    NR31_REG = 0xFE; // length of wave, 2nd shortest
+    NR32_REG = (4 - conf_get()->sfx_vol) << 5;
+    NR33_REG = 0x00; // low freq bits are zero
+    NR34_REG = 0xC7; // start, no loop, high freq bits are 111
+    NR51_REG = 0xFF; // turn all channels on
+
+    play_length--;
+}
+
+#else
+
+// TODO ASM version has less beep at full volume, but also beeping at lower volumes?
+
 void sample_isr(void) NONBANKED NAKED {
     __asm
-    ld hl, #_play_length    ; something left to play?
-    ld a, (hl+)
-    or (hl)
-    jp z, done
-
-    ld hl, #_play_sample
-    ld a, (hl+)
-    ld h, (hl)
-    ld l, a                 ; HL = current position inside the sample
-
-    ; load new waveform
-    ld a, (#__current_bank) ; save bank and switch
-    ld e, a
-    ld a, (#_play_bank)
-    ld (_rROMB0), a
-
-    ldh a, (_NR51_REG)
-    ld c, a
-    and #0b10111011
-    ldh (_NR51_REG), a
-
-    xor a
-    ldh (_NR30_REG), a
-
-    .irp ofs,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
-    ld a, (hl+)
-    ldh (__AUD3WAVERAM+ofs), a
-    .endm
-
-    ld a, #0x80
-    ldh (_NR30_REG), a
-    ld a, #0xFE             ; length of wave
-    ldh (_NR31_REG), a
-    ld a, (_snd_vol_sfx)    ; volume
-    swap a                  ; shift vol to upper bits
-    ldh (_NR32_REG), a
-    xor a                   ; low freq bits are zero
-    ldh (_NR33_REG), a
-    ld a, #0xC7             ; start; no loop; high freq bits are 111
-    ldh (_NR34_REG), a
-
-    ld a, c
-    ldh (_NR51_REG), a
-
-    ld a, e                 ; restore bank
-    ld (_rROMB0), a
-
-    ld a, l                 ; save current position
-    ld (#_play_sample), a
-    ld a, h
-    ld (#_play_sample+1), a
-
-    ld hl, #_play_length    ; decrement length variable
-    ld a, (hl)
-    sub #1
-    ld (hl+), a
-    ld a, (hl)
-    sbc #0
-    ld (hl), a
-    ret
-
-done:
-    ld a, #0
-    ld (_playing), a
-    ret z
+        ld hl, #_play_length    ; something left to play?
+        ld a, (hl+)
+        or (hl)
+        ret z
+
+        ld hl, #_play_sample
+        ld a, (hl+)
+        ld h, (hl)
+        ld l, a                 ; HL = current position inside the sample
+
+                                ; load new waveform
+        ld a, (#__current_bank) ; save bank and switch
+        ld e, a
+        ld a, (#_play_bank)
+        ld (_rROMB0), a
+
+        ldh a, (_NR51_REG)
+        ld c, a
+        and #0b10111011
+        ldh (_NR51_REG), a
+
+        xor a
+        ldh (_NR30_REG), a
+
+        .irp ofs,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
+            ld a, (hl+)
+            ldh (__AUD3WAVERAM+ofs), a
+        .endm
+
+        ld a, #0x80
+        ldh (_NR30_REG), a
+        ld a, #0xFE             ; length of wave
+        ldh (_NR31_REG), a
+        ld a, #0x20             ; volume
+        ldh (_NR32_REG), a
+        xor a                   ; low freq bits are zero
+        ldh (_NR33_REG), a
+        ld a, #0xC7             ; start; no loop; high freq bits are 111
+        ldh (_NR34_REG), a
+
+        ld a, c
+        ldh (_NR51_REG), a
+
+        ld a, e                 ; restore bank
+        ld (_rROMB0), a
+
+        ld a, l                 ; save current position
+        ld (#_play_sample), a
+        ld a, h
+        ld (#_play_sample+1), a
+
+        ld hl, #_play_length    ; decrement length variable
+        ld a, (hl)
+        sub #1
+        ld (hl+), a
+        ld a, (hl)
+        sbc #0
+        ld (hl), a
+        ret
     __endasm;
 }
+#endif

src/sample.h

 
 BANKREF_EXTERN(sample)
 
-extern uint8_t snd_vol_sfx;
-
 #endif // __SAMPLE_H__

src/sound.c

  */
 
 #include "banks.h"
+#include "config.h"
 #include "timer.h"
 #include "sound_menu.h"
 #include "sound_game.h"
 static volatile uint16_t off = 0;
 static volatile uint16_t last_t = 0;
 
-uint8_t snd_vol_music = 0x00;
-
 struct snds {
     uint8_t bank;
     struct music const * snd;
         END_ROM_BANK();
 
         NR11_REG = 0x80 | 0x3F; // 50% duty, shortest initial length
-        NR12_REG = (snd_vol_music << 4) | 0x00; // given volume, no change
+        NR12_REG = (conf_get()->music_vol << 4) | 0x00; // given volume, no change
         NR13_REG = freq & 0xFF; // given frequency
         NR14_REG = 0x80 | ((freq >> 8) & 0x07); // trigger, upper freq bits
     } else {
         END_ROM_BANK();
 
         NR21_REG = 0x80 | 0x3F; // 50% duty, shortest initial length
-        NR22_REG = (snd_vol_music << 4) | 0x00; // given volume, no change
+        NR22_REG = (conf_get()->music_vol << 4) | 0x00; // given volume, no change
         NR23_REG = freq & 0xFF; // given frequency
         NR24_REG = 0x80 | ((freq >> 8) & 0x07); // trigger, upper freq bits
     } else {

src/sound.h

 
 BANKREF_EXTERN(sound)
 
-extern uint8_t snd_vol_music;
-
 #endif // __SOUND_H__

src/timer.c

 #include "sound.h"
 #include "timer.h"
 
-static volatile uint16_t count = 0;
+static uint16_t count = 0;
 
 static void timer_isr(void) NONBANKED {
     if ((count & 0x03) == 0) {