add wav file conversion and playback

Makefile

@@ -32,10 +32,17 @@ SRCS += $(GIT)
 
 OBJS := $(SRCS:%.c=$(BUILD_DIR)/%.o)
 
-ASSETS := $(wildcard $(DATA_DIR)/*.png)
-SPRITES := $(ASSETS:%.png=$(BUILD_DIR)/%.c)
+IMAGES := $(wildcard $(DATA_DIR)/*.png)
+SPRITES := $(IMAGES:%.png=$(BUILD_DIR)/%.c)
 OBJS += $(SPRITES:%.c=%.o)
 
+WAVES := $(wildcard $(DATA_DIR)/*.wav)
+SOUNDS := $(WAVES:%.wav=$(BUILD_DIR)/%.c)
+OBJS += $(SOUNDS:%.c=%.o)
+
+ASSETS := $(SPRITES)
+ASSETS += $(SOUNDS)
+
 LCC := $(GBDK_HOME)/bin/lcc
 PNGA := $(GBDK_HOME)/bin/png2asset
 ROMU := $(GBDK_HOME)/bin/romusage
@@ -104,9 +111,14 @@ bgb_run: $(BUILD_DIR)/$(BIN)
 	@$(BGB_EMU) $(BGB_EMUFLAGS)
 
 flash: $(BIN)
-	@echo Flasing $<
+	@echo Flashing $<
 	@$(FLASHER) $(FLASHFLAGS) $<
 
+$(BUILD_DIR)/$(DATA_DIR)/%.c $(BUILD_DIR)/$(DATA_DIR)/%.h: $(DATA_DIR)/%.wav
+	@mkdir -p $(@D)
+	@echo Converting sound $<
+	@util/cvtsample.py $< "(None)" GBDK $(BUILD_DIR)/$(DATA_DIR)
+
 $(BUILD_DIR)/$(DATA_DIR)/%.c $(BUILD_DIR)/$(DATA_DIR)/%.h: $(DATA_DIR)/%.png
 	@mkdir -p $(@D)
 	$(eval SPRFLAG = $(shell echo "$<" | sed -n 's/.*_spr\([0-9]\+\).*/\-sw \1 \-sh \1/p'))
@@ -130,18 +142,18 @@ $(BUILD_DIR)/$(DATA_DIR)/%.c $(BUILD_DIR)/$(DATA_DIR)/%.h: $(DATA_DIR)/%.png
 		$(PNGA) $< -o $@ -spr8x8                                                        \
 	)))))
 
-$(BUILD_DIR)/%.o: %.c $(SPRITES)
+$(BUILD_DIR)/%.o: %.c $(ASSETS)
 	@mkdir -p $(@D)
 	@echo Compiling Code $<
 	$(eval BAFLAG = $(shell echo "$<" | sed -n 's/.*\.ba\([0-9]\+\).*/\-Wf-ba\1/p'))
 	@$(LCC) $(LCCFLAGS) $(BAFLAG) -c -o $@ $<
 
-$(BUILD_DIR)/%.o: $(BUILD_DIR)/%.c $(SPRITES)
+$(BUILD_DIR)/%.o: $(BUILD_DIR)/%.c $(ASSETS)
 	@mkdir -p $(@D)
 	@echo Compiling Asset $<
 	@$(LCC) $(LCCFLAGS) -c -o $@ $<
 
-$(BUILD_DIR)/%.o: %.s $(SPRITES)
+$(BUILD_DIR)/%.o: %.s $(ASSETS)
 	@mkdir -p $(@D)
 	@echo Assembling $<
 	@$(LCC) $(LCCFLAGS) -c -o $@ $<

README.md

@@ -88,6 +88,8 @@ The files `sgb_border.c` and `sgb_border.h` are copied directly from their `sgb_
 
     See <http://www.gnu.org/licenses/>.
 
+The `util/cvtsample.py` script is based on a [GBDK example](https://github.com/gbdk-2020/gbdk-2020/blob/develop/gbdk-lib/examples/gb/wav_sample/utils/cvtsample.py).
+
 The included cartridge label graphic in `artwork/cart_label.xcf` is based on the ['Cartridge-Label-Templates' by Dinierto](https://github.com/Dinierto/Cartridge-Label-Templates) licensed as CC0.
 
 The included cartridge graphic in `artwork/cartridge.xcf` is based on the ['Front-End-Assets' by Duimon](https://github.com/Duimon/Front-End-Assets).

src/game.c

@@ -28,6 +28,7 @@
 #include "sound.h"
 #include "input.h"
 #include "main.h"
+#include "sample.h"
 #include "game.h"
 
 #define BAR_OFFSET_X (4 - 80)
@@ -315,7 +316,7 @@ int32_t game(void) NONBANKED {
             }
 
             if (ret == OBJ_ADDED) {
-                snd_shot();
+                sample_play_shoot();
 
                 if (score > 0) {
                     score--;

src/main.c

@@ -34,6 +34,7 @@
 #include "sgb_border.h"
 #include "border_sgb.h"
 #include "timer.h"
+#include "sample.h"
 #include "main.h"
 
 #ifdef DEBUG
@@ -150,7 +151,7 @@ static void splash_anim(uint8_t *hiwater) NONBANKED {
             spr_draw(SPR_SHIP, FLIP_NONE, -4, -42 - 1, 4, hiwater);
             if (frame == 0) {
                 obj_add(SPR_SHOT, SHIP_OFF, -42, SHOT_SPEED, 0);
-                snd_shot();
+                sample_play_shoot();
             }
             break;
 
@@ -182,7 +183,7 @@ static void splash_anim(uint8_t *hiwater) NONBANKED {
             spr_draw(SPR_SHIP, FLIP_X, 4, -42, 4, hiwater);
             if (frame == 0) {
                 obj_add(SPR_SHOT, -SHIP_OFF, -42, -SHOT_SPEED, 0);
-                snd_shot();
+                sample_play_shoot();
             }
             break;
     }

src/sample.c

@@ -0,0 +1,103 @@
+/*
+ * sample.c
+ * Duality
+ *
+ * Copyright (C) 2025 Thomas Buck <thomas@xythobuz.de>
+ *
+ * Based on examples from gbdk-2020:
+ * https://github.com/gbdk-2020/gbdk-2020/tree/develop/gbdk-lib/examples/gb/wav_sample
+ *
+ * And the docs for the DMG APU:
+ * https://gbdev.io/pandocs/Audio_Registers.html
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#include "sfx_shoot.h"
+#include "sample.h"
+
+static volatile uint8_t play_bank = 1;
+static volatile const uint8_t *play_sample = 0;
+static volatile uint16_t play_length = 0;
+
+void sample_play_shoot(void) NONBANKED {
+    CRITICAL {
+        play_bank = BANK(sfx_shoot);
+        play_sample = sfx_shoot;
+        play_length = sfx_shoot_SIZE >> 4;
+    }
+}
+
+void sample_isr(void) NONBANKED NAKED {
+    __asm
+    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;
+}

src/sample.h

@@ -0,0 +1,26 @@
+/*
+ * sample.h
+ * Duality
+ *
+ * Copyright (C) 2025 Thomas Buck <thomas@xythobuz.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __SAMPLE_H__
+#define __SAMPLE_H__
+
+void sample_play_shoot(void);
+void sample_isr(void);
+
+#endif // __SAMPLE_H__

src/sound.c

@@ -6,6 +6,7 @@
  *
  * Based on examples from gbdk-2020:
  * https://github.com/gbdk-2020/gbdk-2020/blob/develop/gbdk-lib/examples/gb/sound/sound.c
+ * https://github.com/gbdk-2020/gbdk-2020/tree/develop/gbdk-lib/examples/gb/wav_sample
  *
  * And the docs for the DMG APU:
  * https://gbdev.io/pandocs/Audio_Registers.html
@@ -53,7 +54,7 @@ static void play_note(enum notes note) NONBANKED {
         END_ROM_BANK();
 
         NR11_REG = 0x80 | 0x3F; // 50% duty, shortest initial length
-        NR12_REG = 0xF0; // max volume, no change
+        NR12_REG = 0x70; // half volume, no change
         NR13_REG = freq & 0xFF; // given frequency
         NR14_REG = 0x80 | ((freq >> 8) & 0x07); // trigger, upper freq bits
     } else {
@@ -173,14 +174,10 @@ void snd_play(void) NONBANKED {
     END_ROM_BANK();
 }
 
-void snd_shot(void) BANKED {
-    NR41_REG = 0x2F; // length timer, higher value is shorter time (up to 0x3F)
-    NR42_REG = 0xF0; // initially full volume, no volume changes over time
-    NR43_REG = 0x11; // frequency distribution
-    NR44_REG = 0xC0; // trigger and enable length
-}
-
 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

src/sound.h

@@ -73,7 +73,6 @@ void snd_game_music(void) BANKED;
 void snd_gameover_music(void) BANKED;
 void snd_play(void);
 
-void snd_shot(void) BANKED;
 void snd_explode(void) BANKED;
 
 BANKREF_EXTERN(sound)

src/timer.c

@@ -17,12 +17,15 @@
  * See <http://www.gnu.org/licenses/>.
  */
 
+#include "sample.h"
 #include "timer.h"
-#include "gb/gb.h"
 
-static volatile uint16_t count;
+static volatile uint16_t count = 0;
 
 static void timer_isr(void) NONBANKED {
+    if ((count & 0x03) == 0) {
+        sample_isr();
+    }
     count++;
 }
 

util/cvtsample.py

@@ -0,0 +1,105 @@
+#!/usr/bin/env python3
+
+# based on the cvtsample.py included in the GBDK example:
+# https://github.com/gbdk-2020/gbdk-2020/blob/develop/gbdk-lib/examples/gb/wav_sample/utils/cvtsample.py
+
+import sys
+import wave
+import os
+
+sGBDK = """//AUTOGENERATED FILE FROM cvtsample
+#include <stdint.h>
+#include <gbdk/platform.h>
+BANKREF({:s})
+"""
+
+hGBDK = """//AUTOGENERATED FILE FROM cvtsample
+#ifndef WAVE_SOUND_{:s}_H
+#define WAVE_SOUND_{:s}_H
+#include <stdint.h>
+#include <gbdk/platform.h>
+
+#define {:s}_SIZE 0x{:x}
+extern const uint8_t {:s}[];
+
+BANKREF_EXTERN({:s})
+#endif
+"""
+
+def main(argv=None):
+    argv = argv or sys.argv
+    if len(argv) < 2:
+        sys.stderr.write("cvtsample.py: no filename; try cvtsample.py --help\n")
+        sys.exit(1)
+
+    infilename = argv[1]
+    ident = argv[2] if len(argv) > 2 else None
+    fmt = argv[3].upper() if len(argv) > 3 else "C"
+    outdir = argv[4] if len(argv) > 4 else os.getcwd()
+
+    if infilename in ('--help', '-h'):
+        print("usage: cvtsample.py SOURCE [IDENTIFIER] [FMT] [OUTDIR]")
+        return
+
+    if ident == "(None)":
+        ident = None
+    if ident == None:
+        ident = os.path.splitext(os.path.basename(infilename))[0]
+
+    if fmt == "C":
+        sHDR = "const UINT8 {:s}[] = {{\n"
+        sFOOT = "};\n"
+        sEMIT = "0x{:x}"
+        sNEW = ",\n"
+        sNONEW = ","
+    elif fmt == "GBDK":
+        outheader = os.path.join(outdir, f"{ident}.h")
+        outsource = os.path.join(outdir, f"{ident}.c")
+        sHDR = "const uint8_t {:s}[] = {{\n"
+        sFOOT = "};\n"
+        sEMIT = "0x{:x}"
+        sNEW = ",\n"
+        sNONEW = ","
+    elif fmt == "ASM":
+        sHDR = "{:s}::"
+        sFOOT = ""
+        sEMIT = "${:x}"
+        sNEW = "\n"
+        sNONEW = ","
+
+    with wave.open(infilename, mode="rb") as f:
+        p = f.getparams()        
+        if (p.nchannels == 1) and (p.sampwidth == 1) and (p.framerate >= 8000) and (p.framerate <= 8192) and (p.comptype == 'NONE'):
+            data = f.readframes(p.nframes)
+            c = 0
+            cnt = 0;
+            flag = False
+
+            s = sHDR.format(ident)
+            for i in range(len(data) - len(data) % 32):
+                c = ((c << 4) | (data[i] >> 4)) & 0xFF
+                if flag:
+                    s += sEMIT.format(c)
+                    cnt += 1
+                    s += sNEW if (cnt % 16 == 0) else sNONEW
+                        
+                flag = not flag
+            s += sFOOT
+
+            if fmt == "GBDK":
+                with open(outsource, "w") as o:
+                    o.write(sGBDK.format(ident))
+                    o.write(s)
+                with open(outheader, "w") as o:
+                    o.write(hGBDK.format(ident, ident, ident, cnt, ident, ident))
+            else:
+                sys.stdout.write(s)
+                sys.stdout.flush()
+        else:
+            sys.stderr.write("ERROR: Invalid wav file format\n")
+            sys.stderr.write("Requires - nChannels: 1, sampWidth: 1, rate: 8000 - 8192, compType: NONE\n")
+            sys.stderr.write("Found    - nChannels: %d, sampWidth: %d, rate: %d, compType: %s\n" % (p.nchannels, p.sampwidth, p.framerate, p.comptype))
+            sys.stderr.flush()
+
+if __name__=='__main__':
+    main()