This patch introduces non linear sliders. That means, that the movement
of the mouse doesn't map linearly to the value of the slider.
The following changes have been made.
- Free logarithmic sliders with maximum range of (`0 <= x < inf`)
- Logarithmic sliders with correct value indication bar.
- Free cubic sliders with maximum range of (`-inf < x < inf`)
- Cubic sliders with correct value indication bar.
Cubic mapping has been added as well, because it's used for brush sizes
in other applications (Krita for e.g.).
To make a slider have a different scale type use following line in RNA:
`RNA_def_property_ui_scale_type(prop, PROP_SCALE_LOGARITHMIC);`
or:
`RNA_def_property_ui_scale_type(prop, PROP_SCALE_CUBIC);`
Test the precision, step size and soft-min if you change the scale type
of a property as it will feel very different and may need tweaking.
Ref D9074
0447aedb96