Recipe: Smoothing Drawings

Depending on the device in use and the amount of simultaneous processing involved, capturing user gestures may produce results that are rougher than desired. Touch events are often limited by CPU demands as well as by shaking hands. A smoothing algorithm can offset those limitations by interpolating between points. Figure 1-4 demonstrates the kind of angularity that derives from granular input and the smoothing that can be applied instead.


Figure 1-4 Catmull-Rom smoothing can be applied in real time to improve arcs between touch events. The images shown here are based on identical gesture input, with (right) and without ...

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