I finally got to use LE Extended Standard Library plugin to get sound volume on Android, but I am not sure if it works correctly.
On Android Volume Up/Down (Pressed) input event in BP I execute Get Current System Volume (Percentages) and feed the Percentage float into Print String. What I get is range from 0 (no sound) to 0.15 (max volume) and when I adjust volume on the device, the value doesn’t change gradually. It goes from 0.0 to 0.000something for a while, then jumps to 0.1 and so on. Somehow it doesn’t increment linearly.
Even if I feed float into Normalize to Range node to map it to 0 - 1 range (so that my volume bar in the HUD fills properly) that non-linear volume change makes volume bar grow slowly at first (if I keep volume button on the device pressed), then jumps with large increments.
I e-mailed the author of the plugin and he said the following:
The “Get Current System Volume (Percentages)” blueprint doesn’t have any logic in it, it just uses the “FAndroidMisc::GetVolumeState(NULL)” function that is programmed inside of the Unreal Engine.
If it returns an incorrect result, the bug is in the “FAndroidMisc::GetVolumeState(NULL)” function.
Please advise and if it’s a bug indeed, please fix it.
It divides the integer by 100.0, which
causes it to have a value from 0.0 to
1.0. It is expected to return a float.
Although it might be better if it
returned an integer, it won’t make a
difference in the workings of the
blueprint. If it currently returns
0.15 instead of 1.0, it will also return 15 instead of 100 if I would
change it to return an integer.
The fact that the result is divided by
100.0 doesn’t mean the weird bug is caused by the blueprint.
Edit: Ow, I missed the part that the
max is supposedly 15. That is weird,
because in the code it says the max is
100. I’ll fix it asap haha
This does mean there is a mistake in
the internal code commenting, which
can also cause bugs to other
developers.
In the AndroidMisc.h it says this:
// Returns current volume, 0-100 (%)
static int GetVolumeState(double* OutTimeOfChangeInSec = nullptr);
As you can see, it says it returns 0
to 100, not 0 to 15.
Maybe it’s useful if Epic also knows
about this so they can fix it.
The comment in the header is bad; it always returned an integer in 0-15 range (this is passed straight from Java). If you want 0.0 to 1.0, you should divide by 15.0, not 100.0.
