Multi-touch

The PowerPad is used to produce multi-touch, multi-color graphics.

Mr. Jobs seized on the multitouch technology after Apple product designers proposed it as a “safari pad,” a portable Web surfing appliance.

Its trackpad is multi-touch and quite comfortable, though we found its sensitivity too high.

The multi-touch support on the iPhone provides a series of touch events consisting of smaller, individual parts of a single multi-touch gesture. For example, placing your finger on the screen generates one event, placing a second finger on the screen generates another, and moving either finger generates yet another.

But the performance of multi-touch is not so impressive.

One incredible example comes from Thomas Robinson [. . .] ; he creates a virtual light table that pulls in Flickr photos, then uses multitouch to allow you to use two fingers to pinch, zoom, rotate, or simply move the images around on the screen (Figure 12–16).