CODEWITHSUNDEEP
javascriptandroidhtmlcanvasmulti-touch
user2386652
user2386652

Reputation: 81

HTML5 canvas, palm rejection

We are trying to use html5 canvas with tablet stylus, but we have a problem with palm touching with multitouch tablets. When a person try to draw something and touch the display surface with the palm, lines occurs because of the multitouch.

Do you know how to disable multitouch on tablet through js or canvas option, or do you know if there is a html5 canvas palm rejection techonology.

Upvotes: 6

Views: 2334

Answers (2)

wes24
wes24

Reputation: 43

There are some newer web APIs available in current browsers. In particular, the radiusX and radiusY of the touches from a touch event can be used to compute the area of touch. The areas larger than that of a finger, or stylus, could be ignored.

Upvotes: 3

chillichief
chillichief

Reputation: 1212

The palm rejection feature must be implemented in the browser itself or the operating system on the tablet. In HTML5 and Javascript there is no way of knowing how big the "Finger" is, that touches the canvas.

Palm rejection works fine on tablets that have a dedicated stylus, like the galaxy note series.

As to disabling the Multitouch functionality: There is no way of knowing for the browser, which touchpoint belongs to the stylus and wich one belongs to your palm.

Upvotes: 1

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