From kde-commits  Mon Aug 25 15:04:01 2008
From: Jason Harris <kstars () 30doradus ! org>
Date: Mon, 25 Aug 2008 15:04:01 +0000
To: kde-commits
Subject: branches/KDE/4.1/kdelibs/kdeui/plotting
Message-Id: <1219676641.360550.4600.nullmailer () svn ! kde ! org>
X-MARC-Message: https://marc.info/?l=kde-commits&m=121967665106605

SVN commit 852217 by harris:

backporting fix from trunk (r851444): 

Improved "smart" placement of text labels for plotted points that have 
been named.  The previous method used a low-resolution "gridding" of the plot 
region into a 100x100 array (regardless of the plot widget's size) to serve as 
a mask to identify regions which already contain a plot element.  Now we use an 
actual image for the mask, matched to the size of the widget.  

In addition, we use a "downhill simplex" algorithm to search for an 
optimal  label position near the target point such that the label doesn't overlap with 
other plot elements.  Before we used a brute-force search.  

With the new method, the Solar System tool in KStars takes 85-95 msec to 
draw itself (compared to 250 ms with the old code, and 75-85 msec with no 
point labels).



 M  +234 -123  kplotwidget.cpp