Constants promoted to double on atanHelper

[harrison3000]

The float literals on the atanHelper function are lacking the f and are therefore being promoted to double
Just by adding the f on the literals I was able to save around 8us on a bluepill STM32

[RobTillaart]

Thanks for reporting this.
Will update it in the library as I expect there is a gain for more boards.

[RobTillaart]

@harrison3000

There are a couple more places that need an "f".

[RobTillaart]

@harrison3000

Created a develop branch with the fixes and some more.
If you have time, can you check if the performance is now on par with your patches?
or did I miss some?

[RobTillaart]

@harrison3000
There were a few minor issues in the build, these are fixed now.

[harrison3000]

Just tested the development branch, same performance as my local changes (but I am only using atan2Fast)
I also noticed that the M_PI and M_PI / 2 constants are also being promoted

[RobTillaart]

Noticed the latter one too, thanks.
I might need to (re)define then

const float  __PI__  = 3.14159265;
const float __PI_DIV_2__ = __PI__ / 2;

[RobTillaart]

@harrison3000

updated the develop branch with const float PI = 3.14159265; in the .cpp file.

[RobTillaart]

Released 0.3.4

Thanks again for reporting!