This texture was generated in Filter Forge, a Photoshop plugin that allows you to create your own filters.
This snippet shows you how to take a control, e.g. a slider, and remap it through a curve. This allows you to change the response of a control in nonlinear fashion.
The method has a limitation: the control can only be connected to map inputs (and profile/curve inputs as well, though that has limited applications I believe)
The gray dot shows the normal linear response, the red shows a new circular arc mapped response. Notice how the origin and destination are the same, but the "travelling speed" is different.
The Response Sector control simply change the circular arc sector, and thereby the response.
Nonlinear Control Remapping , Control To Curve, Slider Response