From ab8d342df06fdfcc1b630e318e121bcfb6a1cdfa Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Wed, 26 Dec 2007 23:01:22 -0800
Subject: [PATCH] Allow 5.1 channel output This doesn't use the center or LFE
 channel in spatial calculations, however

---
 Alc/ALu.c                 | 31 +++++++++++++++++++++++++++++--
 OpenAL32/Include/alMain.h |  4 +++-
 OpenAL32/Include/alu.h    |  2 +-
 OpenAL32/alExtension.c    |  2 ++
 4 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/Alc/ALu.c b/Alc/ALu.c
index 87764592..3e8ddd89 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -59,11 +59,13 @@ __inline ALuint aluBytesFromFormat(ALenum format)
         case AL_FORMAT_MONO8:
         case AL_FORMAT_STEREO8:
         case AL_FORMAT_QUAD8:
+        case AL_FORMAT_51CHN8:
             return 1;
 
         case AL_FORMAT_MONO16:
         case AL_FORMAT_STEREO16:
         case AL_FORMAT_QUAD16:
+        case AL_FORMAT_51CHN16:
             return 2;
 
         default:
@@ -87,6 +89,10 @@ __inline ALuint aluChannelsFromFormat(ALenum format)
         case AL_FORMAT_QUAD16:
             return 4;
 
+        case AL_FORMAT_51CHN8:
+        case AL_FORMAT_51CHN16:
+            return 6;
+
         default:
             return 0;
     }
@@ -340,6 +346,9 @@ static ALvoid CalcSourceParams(ALCcontext *ALContext, ALsource *ALSource,
                 break;
             case AL_FORMAT_QUAD8:
             case AL_FORMAT_QUAD16:
+            /* TODO: Add center/lfe channel in spatial calculations? */
+            case AL_FORMAT_51CHN8:
+            case AL_FORMAT_51CHN16:
                 // Apply a scalar so each individual speaker has more weight
                 PanningLR = 0.5f + (0.5f*Position[0]*1.41421356f);
                 PanningLR = __min(1.0f, PanningLR);
@@ -367,10 +376,14 @@ static ALvoid CalcSourceParams(ALCcontext *ALContext, ALsource *ALSource,
         drysend[1] = SourceVolume * 1.0f * ListenerGain;
         drysend[2] = SourceVolume * 1.0f * ListenerGain;
         drysend[3] = SourceVolume * 1.0f * ListenerGain;
+        drysend[4] = SourceVolume * 1.0f * ListenerGain;
+        drysend[5] = SourceVolume * 1.0f * ListenerGain;
         wetsend[0] = SourceVolume * 0.0f * ListenerGain;
         wetsend[1] = SourceVolume * 0.0f * ListenerGain;
         wetsend[2] = SourceVolume * 0.0f * ListenerGain;
         wetsend[3] = SourceVolume * 0.0f * ListenerGain;
+        wetsend[4] = SourceVolume * 0.0f * ListenerGain;
+        wetsend[5] = SourceVolume * 0.0f * ListenerGain;
 
         pitch[0] = Pitch;
     }
@@ -380,8 +393,8 @@ ALvoid aluMixData(ALCcontext *ALContext,ALvoid *buffer,ALsizei size,ALenum forma
 {
     static float DryBuffer[BUFFERSIZE][OUTPUTCHANNELS];
     static float WetBuffer[BUFFERSIZE][OUTPUTCHANNELS];
-    ALfloat DrySend[OUTPUTCHANNELS] = { 0.0f, 0.0f, 0.0f, 0.0f };
-    ALfloat WetSend[OUTPUTCHANNELS] = { 0.0f, 0.0f, 0.0f, 0.0f };
+    ALfloat DrySend[OUTPUTCHANNELS] = { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };
+    ALfloat WetSend[OUTPUTCHANNELS] = { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };
     ALuint BlockAlign,BufferSize;
     ALuint DataSize=0,DataPosInt=0,DataPosFrac=0;
     ALuint Channels,Bits,Frequency,ulExtraSamples;
@@ -641,6 +654,13 @@ ALvoid aluMixData(ALCcontext *ALContext,ALvoid *buffer,ALsizei size,ALenum forma
                         buffer = ((ALubyte*)buffer) + 1;
                     }
                     break;
+                case AL_FORMAT_51CHN8:
+                    for(i = 0;i < SamplesToDo*6;i++)
+                    {
+                        *((ALubyte*)buffer) = (ALubyte)((aluF2S(DryBuffer[i/6][i%6]+WetBuffer[i/6][i%6])>>8)+128);
+                        buffer = ((ALubyte*)buffer) + 1;
+                    }
+                    break;
                 case AL_FORMAT_MONO16:
                     for(i = 0;i < SamplesToDo;i++)
                     {
@@ -663,6 +683,13 @@ ALvoid aluMixData(ALCcontext *ALContext,ALvoid *buffer,ALsizei size,ALenum forma
                         buffer = ((ALshort*)buffer) + 1;
                     }
                     break;
+                case AL_FORMAT_51CHN16:
+                    for(i = 0;i < SamplesToDo*6;i++)
+                    {
+                        *((ALshort*)buffer) = aluF2S(DryBuffer[i/6][i%6]+WetBuffer[i/6][i%6]);
+                        buffer = ((ALshort*)buffer) + 1;
+                    }
+                    break;
             }
 
             size -= SamplesToDo;
diff --git a/OpenAL32/Include/alMain.h b/OpenAL32/Include/alMain.h
index 1f62b535..30dd068f 100644
--- a/OpenAL32/Include/alMain.h
+++ b/OpenAL32/Include/alMain.h
@@ -92,9 +92,11 @@ extern char _alDebug[256];
 #define AL_FORMAT_MONO_IMA4                      0x1300
 #define AL_FORMAT_STEREO_IMA4                    0x1301
 // These are from AL_EXT_MCFORMATS, which we don't support yet but the mixer
-// can use 4-channel formats
+// can use the extra formats
 #define AL_FORMAT_QUAD8                          0x1204
 #define AL_FORMAT_QUAD16                         0x1205
+#define AL_FORMAT_51CHN8                         0x120A
+#define AL_FORMAT_51CHN16                        0x120B
 
 #define SWMIXER_OUTPUT_RATE        44100
 //#define OUTPUT_BUFFER_SIZE         (32768*SWMIXER_OUTPUT_RATE/22050)
diff --git a/OpenAL32/Include/alu.h b/OpenAL32/Include/alu.h
index e4fe0dc3..ecf32e5c 100644
--- a/OpenAL32/Include/alu.h
+++ b/OpenAL32/Include/alu.h
@@ -5,7 +5,7 @@
 #define FRACTIONBITS 14
 #define FRACTIONMASK ((1L<<FRACTIONBITS)-1)
 #define MAX_PITCH 4
-#define OUTPUTCHANNELS 4
+#define OUTPUTCHANNELS 6
 
 #include "AL/al.h"
 #include "AL/alc.h"
diff --git a/OpenAL32/alExtension.c b/OpenAL32/alExtension.c
index 269590e9..24ea48db 100644
--- a/OpenAL32/alExtension.c
+++ b/OpenAL32/alExtension.c
@@ -156,6 +156,8 @@ static ALenums enumeration[]={
     { (ALchar *)"AL_FORMAT_STEREO_IMA4",                AL_FORMAT_STEREO_IMA4               },
     { (ALchar *)"AL_FORMAT_QUAD8",                      AL_FORMAT_QUAD8                     },
     { (ALchar *)"AL_FORMAT_QUAD16",                     AL_FORMAT_QUAD16                    },
+    { (ALchar *)"AL_FORMAT_51CHN8",                     AL_FORMAT_51CHN8                    },
+    { (ALchar *)"AL_FORMAT_51CHN16",                    AL_FORMAT_51CHN16                   },
 
     // Buffer attributes
     { (ALchar *)"AL_FREQUENCY",                         AL_FREQUENCY                        },