Set the global gain of the specified haptic device.
int SDL_HapticSetGain(SDL_Haptic * haptic, int gain);
|haptic||the SDL_Haptic device to set the gain on|
|gain||value to set the gain to, should be between 0 and 100 (0 - 100)|
Returns 0 on success or a negative error code on failure; call SDL_GetError() for more information.
Device must support the SDL_HAPTIC_GAIN feature.
The user may specify the maximum gain by setting the environment variable
SDL_HAPTIC_GAIN_MAX which should be between 0 and
SDL_HAPTIC_GAIN_MAXas the maximum.
This function is available since SDL 2.0.0.