From kde-commits  Sat Aug 23 17:08:04 2008
From: Jason Harris <kstars () 30doradus ! org>
Date: Sat, 23 Aug 2008 17:08:04 +0000
To: kde-commits
Subject: KDE/kdelibs/kdeui/plotting
Message-Id: <1219511284.051167.17378.nullmailer () svn ! kde ! org>
X-MARC-Message: https://marc.info/?l=kde-commits&m=121951129428131

SVN commit 851444 by harris:

Having received no feedback on k-c-d when I announced this patch, I'll go ahead 
and commit it.

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