• Well, after two days of not being able to work on this due to Comps prep and trouble with a significant fraction of my vehicles, maybe I can get something working today.
• Added everything from How to: Integrate X3DAudio with XAudio2, and definitely got a result – when the emitter position moved off of center, the sound cut out. Now you might think that’s a bad thing, but my guess is that I have some variable that either being set with zero or junk, which is messing up the sound matrix calculations.
• Using the XAudio2Sound3D project as a source of code to mine, I pulled over the (much more extensive) emitter setup and now have things working, although not as clearly as I’d like. Next is to clean up and package the code into the SampleSound-derived classes.
• And by the way, this might be a good hard hat to try the rig on: http://www.amazon.com/ERB-19224-Americana-Full-Ratchet/dp/B001LYB7JW
• Cleared a lot of nonessential (i.e. listening cone)code out of the emitter
• Realized that I could probably use voice->SetOutputMatrix() to set the channels directly. I added a method that cleans out the dspSettings.matrixCoefficients and then sets a single value in the matrix. Whadaya know – it worked 🙂
• Need to do some packaging of the code, but I now have enough to do tests for the situational awareness system and to get rid of the MIDI boards for the vibrotactile controller.

• Finished rolling up the SampleSounds(s) into BasicAudio.
• Starting on 3D audio, using How to: Integrate X3DAudio with XAudio2
  • Adding the 3D calls to the main() in ConsoleSound2, just after the BasicAudio class has been initialized.
  • Had to add x3daudio.lib to the project and <x3daudio.h> to the #includes.
  • This looks to be the meat of the calculation. It looks like X3DCalculate() works on the relative position of an Emitter and the Listener and uses that to populate a DSP. Once that’s done, then the Audio2 source is manipulated appropriately.

  •         X3DAudioCalculate( g_audioState.x3DInstance, &g_audioState.listener, &g_audioState.emitter, dwCalcFlags,
                               &g_audioState.dspSettings );
    
            IXAudio2SourceVoice* voice = g_audioState.pSourceVoice;
            if( voice )
            {
                // Apply X3DAudio generated DSP settings to XAudio2
                voice->SetFrequencyRatio( g_audioState.dspSettings.DopplerFactor );
                voice->SetOutputMatrix( g_audioState.pMasteringVoice, INPUTCHANNELS, g_audioState.nChannels,
                                        g_audioState.matrixCoefficients );
    
                voice->SetOutputMatrix(g_audioState.pSubmixVoice, 1, 1, &g_audioState.dspSettings.ReverbLevel);
    
                XAUDIO2_FILTER_PARAMETERS FilterParametersDirect = { LowPassFilter, 2.0f * sinf(X3DAUDIO_PI/6.0f * g_audioState.dspSettings.LPFDirectCoefficient), 1.0f }; // see XAudio2CutoffFrequencyToRadians() in XAudio2.h for more information on the formula used here
                voice->SetOutputFilterParameters(g_audioState.pMasteringVoice, &FilterParametersDirect);
                XAUDIO2_FILTER_PARAMETERS FilterParametersReverb = { LowPassFilter, 2.0f * sinf(X3DAUDIO_PI/6.0f * g_audioState.dspSettings.LPFReverbCoefficient), 1.0f }; // see XAudio2CutoffFrequencyToRadians() in XAudio2.h for more information on the formula used here
                voice->SetOutputFilterParameters(g_audioState.pSubmixVoice, &FilterParametersReverb);
            }

Today’s work. Just solid satisfying programming, though I am playing fast and loose with pointers because of headaches getting const to behave properly.

• Working on getting multi buffer support. Done! Also got repeating sound working.
• Going to put a basic Audio class together to manage SampleSounds.
• Done. BasicAudio (awesome name, huh?) is pretty wrapped up. Once all this is clean and commented, I’ll post the files.
• Start on 3D/multichannel tomorrow?

Today, I was going to extend the audio app to do some simple 3D sound. Nope. Aside from a lot of distractions that really only allowed me to get a couple of hours work done, the C++ documentation for this capability is getting harder and harder to find. And for some reason, Microsoft does not seem to believe in producing samples of code that actually do something. Instead, there are lots of nested pages, each pointing to a tidbit of information. Sigh. Anyway, here’s today’s struggles.

• I thought this tutorial would be the best way to get positional information, but it appears to be stale. The New Way seems to be this.
• Close, but it’s actually part of the Windows API now?
  • Programming Guide
  • Programming Reference
• Nope that’s C#. Still looking. Since I have xact3.h working, trying to stay in this space…
  • 3D XACT using C++
  • Which references How To: Integrate X3DAudio with XACT
  • Still looking for what headers to include. Got it. It’s <xact3d3.h>. Don’t confuse this with <xact3.h>
• Ok, at least for now (and yet again!) I think I know what’s going on and what I should do next. For tomorrow, I start writing a 3D version of Audio.h/Audio.cpp and then try calling that from the ConsoleSoundApp.