[Lazarus] TAChart with transparent background
werner.pamler at freenet.de
Tue Sep 16 00:07:29 CEST 2014
I added some simple time measuring code (using GetTickCount) to the
background image tutorial to see the speed loss that you mention:
Without the backgrounds (Lazarus logo and gradient) the GetTickCount
reports 0 ms between the OnBeforeDrawBackground and OnAfterPaint events,
while with the backgrounds it reports 16 ms, sometimes 0 ms. Replacing
the StretchDraw by a simple Draw in the painting of the logo, brings
down the time also to 0. Therefore I'd guess that the background
painting is not perceivable unless you squeeze a 20 mega-pixel photo
into the chart area or load the image during the painting event.
What exactly are you doing?
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