From 7d239fe4ac7af88c7a4c11c6355adae18fbf9171 Mon Sep 17 00:00:00 2001
From: curt <curt>
Date: Wed, 28 Apr 2004 03:57:13 +0000
Subject: [PATCH] Expose the ability to specify how the sound volume fades
 relative to distance from the listener.  This let's us configure "interior"
 cockpit sounds versus "exterior" engine type sounds.

---
 simgear/sound/sample_openal.cxx | 12 ++++++++++--
 simgear/sound/sample_openal.hxx | 21 +++++++++++++++++++++
 simgear/sound/xmlsound.cxx      |  9 ++++++++-
 3 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/simgear/sound/sample_openal.cxx b/simgear/sound/sample_openal.cxx
index 6d3739dc..d2242d3c 100644
--- a/simgear/sound/sample_openal.cxx
+++ b/simgear/sound/sample_openal.cxx
@@ -66,6 +66,8 @@ SGSoundSample::SGSoundSample( const char *path, const char *file,
     data(NULL),
     pitch(1.0),
     volume(1.0),
+    reference_dist(500.0),
+    max_dist(3000.),
     loop(AL_FALSE)
 {
     SGPath samplepath( path );
@@ -131,8 +133,8 @@ SGSoundSample::SGSoundSample( const char *path, const char *file,
     alSourcei( source, AL_LOOPING, loop );
 
     alSourcei( source, AL_SOURCE_RELATIVE, AL_TRUE );
-    alSourcef( source, AL_REFERENCE_DISTANCE, 500.0f );
-    alSourcef( source, AL_MAX_DISTANCE, 3000.0f );
+    alSourcef( source, AL_REFERENCE_DISTANCE, reference_dist );
+    alSourcef( source, AL_MAX_DISTANCE, max_dist );
 }
 
 
@@ -141,6 +143,8 @@ SGSoundSample::SGSoundSample( unsigned char *_data, int len, int _freq ) :
     data(NULL),
     pitch(1.0),
     volume(1.0),
+    reference_dist(500.0),
+    max_dist(3000.),
     loop(AL_FALSE)
 {
     SG_LOG( SG_GENERAL, SG_DEBUG, "In memory sounds sample" );
@@ -176,6 +180,10 @@ SGSoundSample::SGSoundSample( unsigned char *_data, int len, int _freq ) :
     alSourcefv( source, AL_POSITION, source_pos );
     alSourcefv( source, AL_VELOCITY, source_vel );
     alSourcei( source, AL_LOOPING, loop );
+
+    alSourcei( source, AL_SOURCE_RELATIVE, AL_TRUE );
+    alSourcef( source, AL_REFERENCE_DISTANCE, reference_dist );
+    alSourcef( source, AL_MAX_DISTANCE, max_dist );
 }
 
 
diff --git a/simgear/sound/sample_openal.hxx b/simgear/sound/sample_openal.hxx
index 90d4baeb..e0488979 100644
--- a/simgear/sound/sample_openal.hxx
+++ b/simgear/sound/sample_openal.hxx
@@ -81,6 +81,8 @@ private:
 
     double pitch;
     double volume;
+    double reference_dist;
+    double max_dist;
     ALboolean loop;
 
 public:
@@ -210,6 +212,25 @@ public:
         alSourcefv( source, AL_VELOCITY, source_vel );
     }
 
+
+    /**
+     * Set reference distance of sound (the distance where the gain
+     * will be half.)
+     */
+    inline void set_reference_dist( ALfloat dist ) {
+        reference_dist = dist;
+        alSourcef( source, AL_REFERENCE_DISTANCE, reference_dist );
+    }
+
+
+    /**
+     * Set maximume distance of sound (the distance where the sound is
+     * no longer audible.
+     */
+    inline void set_max_dist( ALfloat dist ) {
+        max_dist = dist;
+        alSourcef( source, AL_MAX_DISTANCE, max_dist );
+    }
 };
 
 
diff --git a/simgear/sound/xmlsound.cxx b/simgear/sound/xmlsound.cxx
index 79d441e7..5708486b 100644
--- a/simgear/sound/xmlsound.cxx
+++ b/simgear/sound/xmlsound.cxx
@@ -180,7 +180,11 @@ SGXmlSound::init(SGPropertyNode *root, SGPropertyNode *node, SGSoundMgr *sndmgr,
 
    }
 
-
+   float reference_dist = node->getDoubleValue("reference-dist", 500.0);
+   float max_dist = node->getDoubleValue("max-dist", 3000.0);
+   SG_LOG(SG_GENERAL,SG_ALERT, "ref-dist = " << reference_dist );
+   SG_LOG(SG_GENERAL,SG_ALERT, "max-dist = " << max_dist );
+ 
    //
    // set pitch properties
    //
@@ -241,10 +245,13 @@ SGXmlSound::init(SGPropertyNode *root, SGPropertyNode *node, SGSoundMgr *sndmgr,
        _sample = new SGSoundSample( path.c_str(),
                                     node->getStringValue("path", ""),
                                     true );
+
        _mgr->add( _sample, _name );
    }
 
    _sample->set_volume(v);
+   _sample->set_reference_dist( reference_dist );
+   _sample->set_max_dist( max_dist );
    _sample->set_pitch(p);
 }
 
-- 
2.39.5