git.y1.nz

commit 629647e0fd152ed8ae9a1d344459fec73c4eac0d
parent a4811f9fcedc93b0b2e23070642381860a530ab4
Author: bbbbbr <bbbbbr@users.noreply.github.com>
Date:   Mon, 14 Nov 2022 15:39:31 -0800

Merge pull request #450 from bbbbbr/Example_sound_megaduck

Examples: Sound test: Compat function naming
Diffstat:
M
gbdk-lib/examples/gb/sound/sound.c
53
++++++++++++++++++++++++++++++++---------------------

1 file changed, 32 insertions(+), 21 deletions(-)
diff --git a/gbdk-lib/examples/gb/sound/sound.c b/gbdk-lib/examples/gb/sound/sound.c
@@ -4,17 +4,28 @@
 #include <stdio.h>
 
 
-inline uint8_t nybble_swap_if_megaduck(uint8_t value) {
+inline uint8_t translate_envelope(uint8_t value) {
 	#ifdef MEGADUCK
+        // Mega Duck has nybbles swapped for NR12, NR22, NR42 audio envelope registers
 		return ((uint8_t)(value << 4) | (uint8_t)(value >> 4));
 	#else
 		return value;
 	#endif
 }
 
-inline uint8_t NR32_swap_volume_if_megaduck(uint8_t value) {
+inline uint8_t translate_frequency(uint8_t value) {
 	#ifdef MEGADUCK
-		// Translate NR32 volume. New Volume = ((0x00 - Volume) & 0x60)
+        // Mega Duck has nybbles swapped for NR43 frequency & randomness audio register
+        return ((uint8_t)(value << 4) | (uint8_t)(value >> 4));
+    #else
+        return value;
+    #endif
+}
+
+inline uint8_t translate_volume(uint8_t value) {
+	#ifdef MEGADUCK
+        // Mega Duck has bit values changed for NR32 volume register
+		// To translate the volume: New Volume = ((0x00 - Volume) & 0x60)
 		// GB: Bits:6..5 : 00 = mute, 01 = 100%, 10 = 50%, 11 = 25%
 		// MD: Bits:6..5 : 00 = mute, 11 = 100%, 10 = 50%, 01 = 25%
 		return ((~(uint8_t)value) + 1u) & (uint8_t)0x60u;
@@ -632,15 +643,15 @@ void update_value(uint8_t mode, uint8_t line, uint16_t value)
 	break;
       case 5: // envInitialValue
 	soundReg->mode1.envInitialValue = value;
-	NR12_REG = nybble_swap_if_megaduck( NR12() );
+	NR12_REG = translate_envelope( NR12() );
 	break;
       case 6: // envMode
 	soundReg->mode1.envMode = value;
-	NR12_REG = nybble_swap_if_megaduck( NR12() );
+	NR12_REG = translate_envelope( NR12() );
 	break;
       case 7: // envNbSweep
 	soundReg->mode1.envNbSweep = value;
-	NR12_REG = nybble_swap_if_megaduck( NR12() );
+	NR12_REG = translate_envelope( NR12() );
 	break;
       case 8: // frequency
       case FREQUENCY:
@@ -685,15 +696,15 @@ void update_value(uint8_t mode, uint8_t line, uint16_t value)
 	break;
       case 2: // envInitialValue
 	soundReg->mode2.envInitialValue = value;
-	NR22_REG = nybble_swap_if_megaduck( NR22() );
+	NR22_REG = translate_envelope( NR22() );
 	break;
       case 3: // envMode
 	soundReg->mode2.envMode = value;
-	NR22_REG = nybble_swap_if_megaduck( NR22() );
+	NR22_REG = translate_envelope( NR22() );
 	break;
       case 4: // envNbStep
 	soundReg->mode2.envNbStep = value;
-	NR22_REG = nybble_swap_if_megaduck( NR22() );
+	NR22_REG = translate_envelope( NR22() );
 	break;
       case 5: // frequency
       case FREQUENCY:
@@ -738,7 +749,7 @@ void update_value(uint8_t mode, uint8_t line, uint16_t value)
 	break;
       case 2: // selOutputLevel
 	soundReg->mode3.selOutputLevel = value;
-	NR32_REG = NR32_swap_volume_if_megaduck( NR32() );
+	NR32_REG = translate_volume( NR32() );
 	break;
       case 3: // frequency
       case FREQUENCY:
@@ -779,27 +790,27 @@ void update_value(uint8_t mode, uint8_t line, uint16_t value)
 	break;
       case 1: // envInitialValue
 	soundReg->mode4.envInitialValue = value;
-	NR42_REG = nybble_swap_if_megaduck( NR42() );
+	NR42_REG = translate_envelope( NR42() );
 	break;
       case 2: // envMode
 	soundReg->mode4.envMode = value;
-	NR42_REG = nybble_swap_if_megaduck( NR42() );
+	NR42_REG = translate_envelope( NR42() );
 	break;
       case 3: // envNbStep
 	soundReg->mode4.envNbStep = value;
-	NR42_REG = nybble_swap_if_megaduck( NR42() );
+	NR42_REG = translate_envelope( NR42() );
 	break;
       case 4: // polyCounterFreq
 	soundReg->mode4.polyCounterFreq = value;
-	NR43_REG = nybble_swap_if_megaduck( NR43() );
+	NR43_REG = translate_frequency( NR43() );
 	break;
       case 5: // polyCounterStep
 	soundReg->mode4.polyCounterStep = value;
-	NR43_REG = nybble_swap_if_megaduck( NR43() );
+	NR43_REG = translate_frequency( NR43() );
 	break;
       case 6: // polyCounterDiv
 	soundReg->mode4.polyCounterDiv = value;
-	NR43_REG = nybble_swap_if_megaduck( NR43() );
+	NR43_REG = translate_frequency( NR43() );
 	break;
       case 7: // counter_ConsSel
 	soundReg->mode4.counter_ConsSel = value;
@@ -1067,24 +1078,24 @@ void main()
   soundReg = &s;
   NR10_REG = NR10();
   NR11_REG = NR11();
-  NR12_REG = nybble_swap_if_megaduck( NR12() );
+  NR12_REG = translate_envelope( NR12() );
   NR13_REG = NR13();
   NR14_REG = NR14();
 
   NR21_REG = NR21();
-  NR22_REG = nybble_swap_if_megaduck( NR22() );
+  NR22_REG = translate_envelope( NR22() );
   NR23_REG = NR23();
   NR24_REG = NR24();
 
   NR30_REG = NR30();
   NR31_REG = NR31();
-  NR32_REG = NR32_swap_volume_if_megaduck( NR32() );
+  NR32_REG = translate_volume( NR32() );
   NR33_REG = NR33();
   NR34_REG = NR34();
 
   NR41_REG = NR41();
-  NR42_REG = nybble_swap_if_megaduck( NR42() );
-  NR43_REG = nybble_swap_if_megaduck( NR43() );
+  NR42_REG = translate_envelope( NR42() );
+  NR43_REG = translate_frequency( NR43() );
   NR44_REG = NR44();
 
   NR50_REG = NR50();

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