From 1dcb04157c158fc22390dd99a89469a523dd0109 Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Sat, 26 Mar 2016 17:52:42 -0700
Subject: [PATCH] Add a config option for distance compensation

---
 Alc/bformatdec.c |  4 ++--
 Alc/bformatdec.h |  6 +++++-
 Alc/panning.c    | 10 ++++++++--
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/Alc/bformatdec.c b/Alc/bformatdec.c
index 7c202228..463a1969 100644
--- a/Alc/bformatdec.c
+++ b/Alc/bformatdec.c
@@ -233,7 +233,7 @@ int bformatdec_getOrder(const struct BFormatDec *dec)
     return 0;
 }
 
-void bformatdec_reset(BFormatDec *dec, const AmbDecConf *conf, ALuint chancount, ALuint srate, const ALuint chanmap[MAX_OUTPUT_CHANNELS])
+void bformatdec_reset(BFormatDec *dec, const AmbDecConf *conf, ALuint chancount, ALuint srate, const ALuint chanmap[MAX_OUTPUT_CHANNELS], int flags)
 {
     static const ALuint map2DTo3D[7] = {
         0,  1, 3,  4, 8,  9, 15
@@ -362,7 +362,7 @@ void bformatdec_reset(BFormatDec *dec, const AmbDecConf *conf, ALuint chancount,
         maxdist = maxf(maxdist, conf->Speakers[i].Distance);
 
     memset(dec->Delay, 0, sizeof(dec->Delay));
-    if(maxdist > 0.0f)
+    if((flags&BFDF_DistanceComp) && maxdist > 0.0f)
     {
         for(i = 0;i < conf->NumSpeakers;i++)
         {
diff --git a/Alc/bformatdec.h b/Alc/bformatdec.h
index 623e7b09..3ad06373 100644
--- a/Alc/bformatdec.h
+++ b/Alc/bformatdec.h
@@ -6,10 +6,14 @@
 struct AmbDecConf;
 struct BFormatDec;
 
+enum BFormatDecFlags {
+    BFDF_DistanceComp = 1<<0
+};
+
 struct BFormatDec *bformatdec_alloc();
 void bformatdec_free(struct BFormatDec *dec);
 int bformatdec_getOrder(const struct BFormatDec *dec);
-void bformatdec_reset(struct BFormatDec *dec, const struct AmbDecConf *conf, ALuint chancount, ALuint srate, const ALuint chanmap[MAX_OUTPUT_CHANNELS]);
+void bformatdec_reset(struct BFormatDec *dec, const struct AmbDecConf *conf, ALuint chancount, ALuint srate, const ALuint chanmap[MAX_OUTPUT_CHANNELS], int flags);
 
 /* Decodes the ambisonic input to the given output channels. */
 void bformatdec_process(struct BFormatDec *dec, ALfloat (*restrict OutBuffer)[BUFFERSIZE], ALuint OutChannels, ALfloat (*restrict InSamples)[BUFFERSIZE], ALuint SamplesToDo);
diff --git a/Alc/panning.c b/Alc/panning.c
index 1ac79449..90122550 100644
--- a/Alc/panning.c
+++ b/Alc/panning.c
@@ -620,9 +620,11 @@ ALvoid aluInitPanning(ALCdevice *device)
             { Aux5, { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f } },
             { Aux6, { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f } },
         };
+        const char *devname = al_string_get_cstr(device->DeviceName);
         ALuint speakermap[MAX_OUTPUT_CHANNELS];
         const char *fname = "";
         const char *layout;
+        int decflags = 0;
         AmbDecConf conf;
 
         ambdec_init(&conf);
@@ -630,9 +632,12 @@ ALvoid aluInitPanning(ALCdevice *device)
         layout = GetChannelLayoutName(device->FmtChans);
         if(!layout) goto ambi_fail;
 
-        if(!ConfigValueStr(al_string_get_cstr(device->DeviceName), "decoder", layout, &fname))
+        if(!ConfigValueStr(devname, "decoder", layout, &fname))
             goto ambi_fail;
 
+        if(GetConfigValueBool(devname, "decoder", "distance-comp", 1))
+            decflags |= BFDF_DistanceComp;
+
         if(!ambdec_load(&conf, fname))
         {
             ERR("Failed to load %s\n", fname);
@@ -677,7 +682,8 @@ ALvoid aluInitPanning(ALCdevice *device)
             (conf.ChanMask > 0xf) ? (conf.ChanMask > 0x1ff) ? "third" : "second" : "first",
             (conf.ChanMask & ~0x831b) ? " periphonic" : ""
         );
-        bformatdec_reset(device->AmbiDecoder, &conf, count, device->Frequency, speakermap);
+        bformatdec_reset(device->AmbiDecoder, &conf, count, device->Frequency,
+                         speakermap, decflags);
         ambdec_deinit(&conf);
 
         if(bformatdec_getOrder(device->AmbiDecoder) < 2)
-- 
2.11.4.GIT