2.7.1 Chattering
Chattering tends to occur more when the Nintendo 3DS Touch Screen is pressed with light pressure that is below the prescribed force recognized as input. Chattering occurs with greater frequency in the following situations.
- The user presses the Touch Screen with light pressure
- The user flicks the surface of the Touch Screen using the stylus
- The user draws a line with light pressure
- The user taps the Touch Screen repeatedly at high speed
One way of dealing with chattering is to read a touch determination flag only once every 1/60th of a second or so.
Chattering or other such factors may also cause the library to return Touch Screen coordinates that are different from the actual values. One effective way to prevent chattering is to compare the current value with the previous coordinate value, and then treat the current value as invalid if there is too much difference between the two values.
No required guideline items.
2.7.2 Requiring Touches Accurate to the Nearest Few Pixels
Nintendo recommends that developers design Nintendo 3DS applications so that users who have lost their stylus can use their finger instead. For example, when implementing a simple “yes/no” selection screen, try to avoid designs in which the effective selection areas for the two options are only separated by a few pixels. Game elements designed to require interaction with small areas of the screen just a few pixels wide would be outside the scope of this recommendation.
No required guideline items.
2.7.3 Obtaining Input Coordinates
We recommend designing your application to make it clear to the user that stylus input is disabled within five pixels from the edge of the screen, where the application cannot get input. This helps prevent the user from thinking that the inability to use the stylus within this range might mean that the program has a bug or that the system is broken.
For instance, for an application allowing the user to draw within the area of the screen, one way of making this limitation clear would be to display a five-pixel-wide frame around the drawable area.
No required guideline items.
2.7.4 Touch Screen Durability
The roughly 10-pixel periphery of the touch screen is comparatively less durable than the central section.
As such, operations which involve forceful input to this 10-pixel area can shorten the CTR's useful lifetime or cause failures. Avoid any specifications which could conceivably result in such operations being likely to occur.
No required guideline items.