pinch-zoom

[Martin Koller]

I'm using the MarbleWidget in a widget based app on a Desktop Computer using a TouchScreen.
No QML used.
What I see is that pinching does not work nicely - much too large jumps in zoom factor.

I'm wondering if this is simply a bug in the calculation of the zoomDelta Factor:
src/lib/marble/MarbleInputHandler.cpp
qreal zoomDelta = scaleFactor > 1.0 ? scaleFactor : -1.0/scaleFactor;

I get much better/smoother results when I simply use:
qreal zoomDelta = scaleFactor;
and pass
scaleFactor = scaleFactor > 1.0 ? 0.2 : -0.2;
in MarbleDefaultInputHandler::handleGesture

I'm not really clear how this is meant to be.
What shall the scaleFactor argument in MarbleDefaultInputHandler::handlePinch()
represent ?
Is this a delta value ?
What shall the value range be ?

-- 
Best regards/Schöne Grüße

Martin
A: Because it breaks the logical sequence of discussion
Q: Why is top posting bad?

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