On 24/06/11 09:01, Steve Thomas wrote:
How will we handle multi-touch in Etoys?
FYI: there's "touch", then 2-point fake-ish "multi-touch", then true "multi-point" multi-touch. Resistive touch screens are (typical) single touch although 2-point touch can be faked (a useful technique is looking for jump from left/right to middle corresponding to pressing one finger then another on opposite side of the screen). A surprising number of capacitive screens are fake-ish 2-point and shows their limitations in test sw that displays the actual touch points, which jump about under certain conditions. True (imo) multi-touch can cope with more than two fingers, number varies, I have one device with 10-point multi-touch.
- No Mouse Fat Fingers problem:
Two problems: the area in pixels under direct contact with the finger/thumb, which varies depending on resolution and physical screen size and the almost unavoidable roll of the finger/thumb as it comes into contact with the surface. The former complicates how to compensate for small controls (eg, buttons, and assuming UI not scaled-up massively). Multi-sampling around the touch point for nearest/top-most morph helps. The roll-problem results in a small movement which when measured in pixels could be large and may require implementing some dead-band to overcome (possibly reducing the effective resolution for touch).
-D