x4 zoom in/out slower

[Xhris]

In the Apr 2 version, each wheel scroll results in the complete redraw of the screen before the next wheel zoom notch is started. 4.0 is slightly faster than 3.2 (due to multi-core) but Xara 2.0 is much faster at wheel zooming than either of them (and it's not related to the increased number of zoom notches in 3.2/4.0). In 2.0, the wheel zooming takes priority over the screen redraw; the next zoom notch begins before the previous screen redraw completes. This makes it 'flicker', but it's much faster. (Tested using the "lines test.xar" above.)

Another good test file is the microscope file: just zoom in and out to the specimen slide. In 2.0, it is tremendously quick to get to full zoom (independently of the increased zoom step sizes); 3.2 and 4.0 require a full screen redraw before moving to the next zoom level.