Hi,
at the osg branch, the directional sound and doppler effects should work
since two days.
It seems that (at least) on windows there is a bug within OpenAL
calculating the Doppler effect.
Either there is no Doppler Effect (like I have) or it is totally wrong
(as aerotro has with the same executable than I have). Eventually it
affects the performance of flightgear.
The enclosed patch switches of the Doppler calculation of OpenAL and
adds a own Doppler calculation.
The patch is not designed for cvs (now). I first need the feedback, if
all windows builds or even other OS are affected.
With this patch Doppler effect should be ok at every OS. I hope, that
the performance issue is solved with that, too (or is independent from
the sound former sound patch).
Now that the Doppler effect works here I got aware of some bugs:
- the effect is wrong, if the aircraft changes its orientation (pitch
and heading)
- the sound is switched off for one frame if the fly-by view jumps to a
new eyepoint (and often some 3d models are loaded at this time this
frame can be noticeable long)
- the same happens, if you change the view
- if you move (rotate) the eye-point in an external view you hear
Doppler effects
I will try to make a patch for this within the next days.
Maik
Index: sound/sample_openal.cxx
===================================================================
RCS file: /var/cvs/SimGear-0.3/source/simgear/sound/sample_openal.cxx,v
retrieving revision 1.27
diff -u -p -r1.27 sample_openal.cxx
--- sound/sample_openal.cxx 21 Jun 2007 21:46:21 -0000 1.27
+++ sound/sample_openal.cxx 24 Jun 2007 00:06:53 -0000
@@ -75,6 +75,10 @@ SGSoundSample::SGSoundSample() :
reference_dist(500.0),
max_dist(3000.),
loop(AL_FALSE),
+#ifndef USE_OPEN_AL_DOPPLER
+ doppler_pitch_factor(1),
+ doppler_volume_factor(1),
+#endif
playing(false)
{
}
@@ -273,7 +277,7 @@ SGSoundSample::set_pitch( double p ) {
if ( p > 2.0 ) { p = 2.0; }
pitch = p;
if (playing) {
- alSourcef( source, AL_PITCH, pitch );
+ alSourcef( source, AL_PITCH, pitch * doppler_pitch_factor );
print_openal_error("set_pitch");
}
}
@@ -282,7 +286,7 @@ void
SGSoundSample::set_volume( double v ) {
volume = v;
if (playing) {
- alSourcef( source, AL_GAIN, volume );
+ alSourcef( source, AL_GAIN, volume * doppler_volume_factor );
print_openal_error("set_volume");
}
}
@@ -354,9 +358,35 @@ SGSoundSample::set_source_vel( ALfloat *
source_vel[0] = vel[0];
source_vel[1] = vel[1];
source_vel[2] = vel[2];
+#ifdef USE_OPEN_AL_DOPPLER
if (playing) {
alSourcefv( source, AL_VELOCITY, source_vel );
}
+#else
+ double doppler, msv, mfp;
+ sgVec3 final_pos;
+ sgAddVec3( final_pos, source_pos, offset_pos );
+ msv = sgLengthVec3(source_vel);
+ mfp = sgLengthVec3(final_pos);
+ if (mfp > 1e-6)
+ doppler = (msv < 339) ? (340 -
+ sgScalarProductVec3( source_vel, final_pos ) / mfp) / (340 - msv)
+ : 0;
+ else
+ doppler = 1;
+ if (doppler > 0.1) {
+ doppler_pitch_factor = doppler;
+ doppler_volume_factor = 1;
+ }
+ else {
+ doppler_pitch_factor = 0.1;
+ doppler_volume_factor = (doppler > 0) ? doppler * 10 : 0;
+ }
+ if (playing) {
+ alSourcef( source, AL_GAIN, volume * doppler_volume_factor );
+ alSourcef( source, AL_PITCH, pitch * doppler_pitch_factor );
+ }
+#endif
}
void
Index: sound/sample_openal.hxx
===================================================================
RCS file: /var/cvs/SimGear-0.3/source/simgear/sound/sample_openal.hxx,v
retrieving revision 1.17
diff -u -p -r1.17 sample_openal.hxx
--- sound/sample_openal.hxx 8 Mar 2006 18:16:09 -0000 1.17
+++ sound/sample_openal.hxx 24 Jun 2007 00:06:54 -0000
@@ -90,6 +90,10 @@ private:
double pitch;
double volume;
+#ifndef USE_OPEN_AL_DOPPLER
+ double doppler_pitch_factor;
+ double doppler_volume_factor;
+#endif
double reference_dist;
double max_dist;
ALboolean loop;
-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
Flightgear-devel mailing list
Flightgear-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/flightgear-devel
