Performance impact of gesture recognition in Delphi?

Question

Delphi 2010 reportedly supports gestures for user interaction (mouse or touch interface), primarily through the Windows 7 gesture API.

Will supporting gestures inherently incur a major performance hit? In other words, is most of the gesture-related processing due to detection, or response to, the gesture? By "response to", I mean the animations related to inertia, etc.

Just wondering whether an already graphically-intensive application is going to take a big performance hit if I add gesture support. Hope I'll get a chance to give RAD2010 a spin soon and answer this question myself.

Answer 1

NO, it doesn't have any performance hit.

1. The 'data collecting' stage is triggered only when you start a gesture (ie. at a MouseDown event or similar) and it is just collecting the points in an array (or similar) hence no performance hit here.

2. In the 'recognition' stage, the recognition algorithm is pretty fast and has to deal with few data points, so nothing noticeable. Of course you will not use on your control many gestures because this is bad from usability pov.

3. If the gesture is recognized then an OnGesture event is fired. And here is your responsibility to write fast code. :-)

For a Gesture Engine overview perhaps you can have a look here.