Get the gain of an audio device.
The gain of a device is its volume; a larger gain means a louder output, with a gain of zero being silence.
Audio devices default to a gain of 1.0f (no change in output).
Physical devices may not have their gain changed, only logical devices, and this function will always return -1.0f when used on physical devices.
the audio device to query.
the gain of the device or -1.0f on failure; call SDL_GetError() for more information.
Threadsafety: It is safe to call this function from any thread.
SDL_SetAudioDeviceGain
See Implementation
Get the gain of an audio device.
The gain of a device is its volume; a larger gain means a louder output, with a gain of zero being silence.
Audio devices default to a gain of 1.0f (no change in output).
Physical devices may not have their gain changed, only logical devices, and this function will always return -1.0f when used on physical devices.