On 2013-08-11 19:47, Ptyl Dragon wrote:
additionally, we are trying to get the zoom to be continuous, so to
follow a pinch gesture as native touch devices do. currently, i
believe zooming is done in integers, representing percentages. we need
to get it to work with float or double values, so to allow the
Zooming on mobile devices is tricky. To make it smooth, you will need to
implement a mobile-specific strategy.
Typically, the way that zooming on mobile devices works is this
- when zooming, the UI enters a special ZOOMING state
- when zooming in, the zoom code asks the underlying code to render a
bitmap target about twice the size of the current screen.
Then it uses the mobile device graphics framework, typically the
on-board GPU , to rescale as need be.
- it typically does the rendering to bitmap from outside the main thread
- only when the zooming is over, does the zooming code tell the UI to
resize properly to the new target size
This is why when zooming in or out slowly everything looks fine.
But when you zoom quickly, you sometimes see jagged lines for a while.
This is because the background did not have enough time to render a new
target bitmap, so the zooming code is stuck with rescaling the old bitmap.
HTH, Noel.
Disclaimer: http://www.peralex.com/disclaimer.html
Context
Privacy Policy |
Impressum (Legal Info) |
Copyright information: Unless otherwise specified, all text and images
on this website are licensed under the
Creative Commons Attribution-Share Alike 3.0 License.
This does not include the source code of LibreOffice, which is
licensed under the Mozilla Public License (
MPLv2).
"LibreOffice" and "The Document Foundation" are
registered trademarks of their corresponding registered owners or are
in actual use as trademarks in one or more countries. Their respective
logos and icons are also subject to international copyright laws. Use
thereof is explained in our
trademark policy.