1 2All code in this directory uses the OpenAL coordinate system for maximum 3useablity. The OpenAL coordinate system is equal to that of OpenGL with the 4main difference that objects behind the viewer can still be heard: 5 - positive x is to the right 6 - positive y is upwards 7 - positive z is towards the back of the viewer/listener 8 9see: http://www.falloutsoftware.com/tutorials/gl/cartesian.gif 10 11All positions are in cartesian space with a unit length of one meter. 12 13Velocities are three tuples indicating speed and direction in the same space 14as positions do (so they are not in the models local space). 15 16 17There is one SoundMgr that handles multiple SoundGroup classes. 18Each SoundGroup class handles multiple SoundSample classes. 19 20A SoundSample class defines the properties of each individual sound like 21pitch, volume, position, orientation, sound cone paramters, etc. This 22class can be created all over the code but *has* to be assigned to a 23SampelGroup before you can hear it. Current sample groups are "atc", 24"avionics" and "fx" for the master airplane effects. The position of a 25SoundSample is relative to (0,0,0) of the model and hence relative to 26the base position of the SampleGroup. 27 28A SampleGroup class has to be assigned to the SoundManager to be heard 29and holds data of a group of samples (maybe 'sample cloud' might be a 30good description). This class has to be created for each individual 31model that can produce one or more sounds. The SampleGroup class can be 32altered by modifying it's volume, position and orientation. 33Repositioning this class also means repositioning all it's associated 34samples. Altering it's orientation also means repositioning the absolute 35(real world) position (and orientation) of the associated sound samples. 36 37The SoundMaganer can be repositioned which basically means moving the 38listener around. It's also possible to alter the listener orientation en 39velocity with this class, together with the master volume. 40 41