Remove redundant writes to support reverse stereo. Define FOREVER_FORWARD_STEREO.

5 files changed, 47 insertions, 4 deletions

diff --git a/source/snaporig.cpp b/source/snaporig.cpp
index 219f67f..ac2045c 100644
--- a/source/snaporig.cpp
+++ b/source/snaporig.cpp
@@ -386,10 +386,17 @@ static int ReadOrigSnapshot (STREAM snap)
 				 sizeof (SOrigSoundData), snap)) != SUCCESS)
 	    return (result);
 
+#ifndef FOREVER_FORWARD_STEREO
 	SoundData.master_volume_left = OrigSoundData.master_volume_left;
 	SoundData.master_volume_right = OrigSoundData.master_volume_right;
 	SoundData.echo_volume_left = OrigSoundData.echo_volume_left;
 	SoundData.echo_volume_right = OrigSoundData.echo_volume_right; 
+#else
+	SoundData.master_volume [0] = OrigSoundData.master_volume_left;
+	SoundData.master_volume [1] = OrigSoundData.master_volume_right;
+	SoundData.echo_volume [0] = OrigSoundData.echo_volume_left;
+	SoundData.echo_volume [1] = OrigSoundData.echo_volume_right; 
+#endif
 	SoundData.echo_enable = OrigSoundData.echo_enable;
 	SoundData.echo_feedback = OrigSoundData.echo_feedback;
 	SoundData.echo_ptr = OrigSoundData.echo_ptr;
diff --git a/source/snapshot.cpp b/source/snapshot.cpp
index 8dd7f8c..c31d3ac 100644
--- a/source/snapshot.cpp
+++ b/source/snapshot.cpp
@@ -377,10 +377,17 @@ static FreezeData SnapAPURegisters [] = {
 #define OFFSET(f) Offset(f,SSoundData *)
 
 static FreezeData SnapSoundData [] = {
+#ifndef FOREVER_FORWARD_STEREO
     {OFFSET (master_volume_left), 2, INT_V},
     {OFFSET (master_volume_right), 2, INT_V},
     {OFFSET (echo_volume_left), 2, INT_V},
     {OFFSET (echo_volume_right), 2, INT_V},
+#else
+    {OFFSET (master_volume [0]), 2, INT_V},
+    {OFFSET (master_volume [1]), 2, INT_V},
+    {OFFSET (echo_volume [0]), 2, INT_V},
+    {OFFSET (echo_volume [1]), 2, INT_V},
+#endif
     {OFFSET (echo_enable), 4, INT_V},
     {OFFSET (echo_feedback), 4, INT_V},
     {OFFSET (echo_ptr), 4, INT_V},
diff --git a/source/snes9x.h b/source/snes9x.h
index ebcf5e3..6c93855 100644
--- a/source/snes9x.h
+++ b/source/snes9x.h
@@ -331,7 +331,9 @@ struct SSettings{
 #ifndef FOREVER_STEREO
     bool8  Stereo;
 #endif
+#ifndef FOREVER_FORWARD_STEREO
     bool8  ReverseStereo;
+#endif
 #ifndef FOREVER_16_BIT_SOUND
     bool8  SixteenBitSound;
 #endif
diff --git a/source/soundux.cpp b/source/soundux.cpp
index c1a01c6..6f41f64 100644
--- a/source/soundux.cpp
+++ b/source/soundux.cpp
@@ -261,8 +261,10 @@ void S9xSetMasterVolume (short volume_left, short volume_right)
 {
     if (Settings.DisableMasterVolume || SNESGameFixes.EchoOnlyOutput)
     {
+#ifndef FOREVER_FORWARD_STEREO
 		SoundData.master_volume_left = 127;
 		SoundData.master_volume_right = 127;
+#endif
 		SoundData.master_volume [0] = SoundData.master_volume [1] = 127;
     }
     else
@@ -271,10 +273,15 @@ void S9xSetMasterVolume (short volume_left, short volume_right)
 		if (!so.stereo)
 			volume_left = (ABS (volume_right) + ABS (volume_left)) / 2;
 #endif
+#ifndef FOREVER_FORWARD_STEREO
 		SoundData.master_volume_left = volume_left;
 		SoundData.master_volume_right = volume_right;
 		SoundData.master_volume [Settings.ReverseStereo] = volume_left;
 		SoundData.master_volume [1 ^ Settings.ReverseStereo] = volume_right;
+#else
+		SoundData.master_volume [0] = volume_left;
+		SoundData.master_volume [1] = volume_right;
+#endif
     }
 }
 
@@ -284,10 +291,15 @@ void S9xSetEchoVolume (short volume_left, short volume_right)
     if (!so.stereo)
 		volume_left = (ABS (volume_right) + ABS (volume_left)) / 2;
 #endif
+#ifndef FOREVER_FORWARD_STEREO
     SoundData.echo_volume_left = volume_left;
     SoundData.echo_volume_right = volume_right;
     SoundData.echo_volume [Settings.ReverseStereo] = volume_left;
     SoundData.echo_volume [1 ^ Settings.ReverseStereo] = volume_right;
+#else
+    SoundData.echo_volume [0] = volume_left;
+    SoundData.echo_volume [1] = volume_right;
+#endif
 }
 
 void S9xSetEchoEnable (uint8 byte)
@@ -378,10 +390,12 @@ void S9xFixSoundAfterSnapshotLoad ()
 		SoundData.channels [i].previous [0] = (int32) SoundData.channels [i].previous16 [0];
 		SoundData.channels [i].previous [1] = (int32) SoundData.channels [i].previous16 [1];
     }
+#ifndef FOREVER_FORWARD_STEREO
     SoundData.master_volume [Settings.ReverseStereo] = SoundData.master_volume_left;
     SoundData.master_volume [1 ^ Settings.ReverseStereo] = SoundData.master_volume_right;
     SoundData.echo_volume [Settings.ReverseStereo] = SoundData.echo_volume_left;
     SoundData.echo_volume [1 ^ Settings.ReverseStereo] = SoundData.echo_volume_right;
+#endif
     IAPU.Scanline = 0;
 }
 
@@ -1157,12 +1171,19 @@ void MixStereo (int sample_count)
 			}
 
 			if (pitch_mod & (1 << (J + 1)))
-			wave [I / 2] = ch->sample * ch->envx;
+				wave [I / 2] = ch->sample * ch->envx;
 
+#ifndef FOREVER_FORWARD_STEREO
 			MixBuffer [I      ^ Settings.ReverseStereo] += VL;
 			MixBuffer [I + (1 ^ Settings.ReverseStereo)] += VR;
 			ch->echo_buf_ptr [I      ^ Settings.ReverseStereo] += VL;
 			ch->echo_buf_ptr [I + (1 ^ Settings.ReverseStereo)] += VR;
+#else
+			MixBuffer [I    ] += VL;
+			MixBuffer [I + 1] += VR;
+			ch->echo_buf_ptr [I    ] += VL;
+			ch->echo_buf_ptr [I + 1] += VR;
+#endif
 		}
 stereo_exit: ;
 	}
@@ -1840,10 +1861,12 @@ void S9xResetSound (bool8 full)
 	
     if (full)
     {
+#ifndef FOREVER_FORWARD_STEREO
 		SoundData.master_volume_left = 0;
 		SoundData.master_volume_right = 0;
 		SoundData.echo_volume_left = 0;
 		SoundData.echo_volume_right = 0;
+#endif
 		SoundData.echo_enable = 0;
 		SoundData.echo_write_enabled = 0;
 		SoundData.echo_channel_enable = 0;
@@ -1857,9 +1880,11 @@ void S9xResetSound (bool8 full)
 		SoundData.echo_volume[1] = 0;
 		SoundData.noise_hertz = 0;
     }
-	
+
+#ifndef FOREVER_FORWARD_STEREO
     SoundData.master_volume_left = 127;
     SoundData.master_volume_right = 127;
+#endif
     SoundData.master_volume [0] = SoundData.master_volume [1] = 127;
     if (so.playback_rate)
 		so.err_rate = (uint32) (FIXED_POINT * SNES_SCANLINE_TIME / (1.0 / so.playback_rate));
diff --git a/source/soundux.h b/source/soundux.h
index 9bb2a22..5484e89 100644
--- a/source/soundux.h
+++ b/source/soundux.h
@@ -188,10 +188,12 @@ typedef struct {
 
 typedef struct
 {
+#ifndef FOREVER_FORWARD_STEREO
     short master_volume_left; /* range is -128 .. 127 */
     short master_volume_right; /* range is -128 .. 127 */
     short echo_volume_left; /* range is -128 .. 127 */
     short echo_volume_right; /* range is -128 .. 127 */
+#endif
     int echo_enable;
     int echo_feedback; /* range is -128 .. 127 */
     int echo_ptr;
@@ -203,8 +205,8 @@ typedef struct
     uint32 dummy [3];
     Channel channels [NUM_CHANNELS];
     bool8 no_filter;
-    int master_volume [2]; /* for reverse stereo */
-    int echo_volume [2]; /* for reverse stereo */
+    int master_volume [2]; /* range is -128 .. 127 */
+    int echo_volume [2]; /* range is -128 .. 127 */
     int noise_hertz;
 } SSoundData;