add explosion sfxs

src/game.c

 
 static void show_explosion(uint16_t power) NONBANKED {
     snd_music_off();
+    sample_play_explosion_ship();
 
-    snd_explode();
-
-    for (uint8_t n = 0; n < (4 * 4); n++) {
+    for (uint8_t n = 0; n < (4 * 4 * 4); n++) {
         uint8_t hiwater = SPR_NUM_START;
-        spr_draw(SPR_EXPL, FLIP_NONE, 0, 0, n >> 2, &hiwater);
+        if (n < (4 * 4)) {
+            spr_draw(SPR_EXPL, FLIP_NONE, 0, 0, n >> 2, &hiwater);
+        }
         status(0, power >> POWER_SHIFT, &hiwater);
         hide_sprites_range(hiwater, MAX_HARDWARE_SPRITES);
         vsync();

src/obj.c

 
 #include "sprites.h"
 #include "game.h"
+#include "sample.h"
 #include "obj.h"
 
 /*
 
                     if ((abs(objs[i].off_x - objs[j].off_x) <= SHOT_RANGE)
                             && (abs(objs[i].off_y - objs[j].off_y) <= SHOT_RANGE)) {
+                        sample_play_explosion_orbs();
+
                         objs[i].active = 0;
                         objs[j].active = 0;
 

src/sample.c

  */
 
 #include "sfx_shoot.h"
+#include "sfx_expl_orb.h"
+#include "sfx_expl_ship.h"
 #include "sample.h"
 
 static volatile uint8_t play_bank = 1;
     }
 }
 
+void sample_play_explosion_orbs(void) NONBANKED {
+    CRITICAL {
+        play_bank = BANK(sfx_expl_orb);
+        play_sample = sfx_expl_orb;
+        play_length = sfx_expl_orb_SIZE >> 4;
+    }
+}
+
+void sample_play_explosion_ship(void) NONBANKED {
+    CRITICAL {
+        play_bank = BANK(sfx_expl_ship);
+        play_sample = sfx_expl_ship;
+        play_length = sfx_expl_ship_SIZE >> 4;
+    }
+}
+
 void sample_isr(void) NONBANKED NAKED {
     __asm
     ld hl, #_play_length    ; something left to play?

src/sample.h

 #define __SAMPLE_H__
 
 void sample_play_shoot(void);
+void sample_play_explosion_orbs(void);
+void sample_play_explosion_ship(void);
 void sample_isr(void);
 
 #endif // __SAMPLE_H__

src/sound.c

         }
     END_ROM_BANK();
 }
-
-void snd_explode(void) BANKED {
-    // TODO use something more elaborate than noise
-    //return;
-
-    NR41_REG = 0x00; // length timer, higher value is shorter time (up to 0x3F)
-    NR42_REG = 0xF1; // initially full volume, then fade sound out
-    NR43_REG = 0x46; // frequency distribution
-    NR44_REG = 0xC0; // trigger and enable length
-}

src/sound.h

 void snd_gameover_music(void) BANKED;
 void snd_play(void);
 
-void snd_explode(void) BANKED;
-
 BANKREF_EXTERN(sound)
 
 #endif // __SOUND_H__