From 4a88f486775592cf5655256be8b758beeb9e0776 Mon Sep 17 00:00:00 2001
From: Barry Harris <44396066+barry65536@users.noreply.github.com>
Date: Wed, 23 May 2012 08:49:07 +0000
Subject: [PATCH] Added support to itemga20.cpp for volume and left/right
 selection for each route. Updated necessary drivers to support.

---
 src/burn/drv/irem/d_m92.cpp |  1 +
 src/burn/snd/iremga20.cpp   | 35 +++++++++++++++++++++++++++++++++--
 src/burn/snd/iremga20.h     |  1 +
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/src/burn/drv/irem/d_m92.cpp b/src/burn/drv/irem/d_m92.cpp
index 841d47635..dedf7fead 100644
--- a/src/burn/drv/irem/d_m92.cpp
+++ b/src/burn/drv/irem/d_m92.cpp
@@ -1752,6 +1752,7 @@ static INT32 DrvInit(INT32 (*pRomLoadCallback)(), const UINT8 *sound_decrypt_tab
 	BurnYM2151SetAllRoutes(0.40, BURN_SND_ROUTE_BOTH);
 
 	iremga20_init(0, DrvSndROM, 0x100000, 3579545);
+	itemga20_set_route(0, 1.00, BURN_SND_ROUTE_BOTH);
 
 	MSM6295Init(0, 1000000 / 132, 0); // ppan
 	MSM6295SetRoute(0, 1.00, BURN_SND_ROUTE_BOTH);
diff --git a/src/burn/snd/iremga20.cpp b/src/burn/snd/iremga20.cpp
index 649e7db89..3a1860b20 100644
--- a/src/burn/snd/iremga20.cpp
+++ b/src/burn/snd/iremga20.cpp
@@ -54,6 +54,8 @@ struct _ga20_state
 	UINT16 regs[0x40];
 	struct IremGA20_channel_def channel[4];
 	INT32 frequency;
+	double gain;
+	INT32 output_dir;
 };
 
 static struct _ga20_state chips[MAX_GA20];
@@ -130,8 +132,21 @@ void iremga20_update(INT32 device, INT16 *buffer, INT32 length)
 		}
 
 		sampleout >>= 2;
-		buffer[0] += sampleout;
-		buffer[1] += sampleout;
+
+		INT32 nLeftSample = 0, nRightSample = 0;
+		
+		if ((chip->output_dir & BURN_SND_ROUTE_LEFT) == BURN_SND_ROUTE_LEFT) {
+			nLeftSample += (INT32)(sampleout * chip->gain);
+		}
+		if ((chip->output_dir & BURN_SND_ROUTE_RIGHT) == BURN_SND_ROUTE_RIGHT) {
+			nRightSample += (INT32)(sampleout * chip->gain);
+		}
+		
+		nLeftSample = BURN_SND_CLIP(nLeftSample);
+		nRightSample = BURN_SND_CLIP(nRightSample);
+		
+		buffer[0] += nLeftSample;
+		buffer[1] += nRightSample;
 	}
 
 	/* update the regs now */
@@ -247,6 +262,9 @@ void iremga20_init(INT32 device, UINT8 *rom, INT32 rom_size, INT32 frequency)
 	chip->rom = rom;
 	chip->rom_size = rom_size;
 	chip->frequency = (frequency / 4) / 60;
+	
+	chip->gain = 1.00;
+	chip->output_dir = BURN_SND_ROUTE_BOTH;
 
 	iremga20_reset(device);
 	
@@ -255,6 +273,19 @@ void iremga20_init(INT32 device, UINT8 *rom, INT32 rom_size, INT32 frequency)
 	nNumChips = device;
 }
 
+void itemga20_set_route(INT32 device, double nVolume, INT32 nRouteDir)
+{
+#if defined FBA_DEBUG
+	if (!DebugSnd_IremGA20Initted) bprintf(PRINT_ERROR, _T("itemga20_set_route called without init\n"));
+	if (device > nNumChips) bprintf(PRINT_ERROR, _T("itemga20_set_route called with invalid chip %x\n"), device);
+#endif
+
+	chip = &chips[device];
+	
+	chip->gain = nVolume;
+	chip->output_dir = nRouteDir;
+}
+
 void iremga20_exit()
 {
 #if defined FBA_DEBUG
diff --git a/src/burn/snd/iremga20.h b/src/burn/snd/iremga20.h
index 118bda7e0..0d45885d8 100644
--- a/src/burn/snd/iremga20.h
+++ b/src/burn/snd/iremga20.h
@@ -3,6 +3,7 @@ UINT8 iremga20_read(INT32 device, INT32 offset);
 
 void iremga20_reset(INT32 device);
 void iremga20_init(INT32 device, UINT8 *rom, INT32 rom_size, INT32 frequency);
+void itemga20_set_route(INT32 device, double nVolume, INT32 nRouteDir);
 void iremga20_update(INT32 device, INT16 *buffer, INT32 length);
 void iremga20_exit();