Pitch Scaling for Doppler Effect

The Doppler Effect depends on the velocities of Source and Listener relative to the medium, and the propagation speed of sound in that medium. The application might want to emphasize or de-emphasize the Doppler Effect as physically accurate calculation might give the desired results. The amount of frequency shift (pitch change) is proportional to the speed of listener and source along their line of sight. The application can increase or decrease that frequency shift by specifying the scaling factor OpenAL should apply to the result of the calculation.

A negative or zero scale will result in an INVALID_VALUE error, the command is then ignored. The default value is 1. The current setting can be queried using GetFloatv and DOPPLER_SCALE.

Calculation of the velocity-dependend Doppler Effect is controlled by using the Enable/Disable commands with the DOPPLER_SHIFT parameter, which can also be used with the IsEnabled query.