On Wed, Nov 19, 2008 at 03:10:52PM +0000, Andrew Ross wrote: > On Wed, Nov 19, 2008 at 03:38:37PM +0100, Werner Smekal wrote: > > Hi all, > > > > so I commited the change to the cairo driver by adding a new function > > filled_polygon(). You can play around with the width of the stroke by > > changing this line: > > > > cairo_set_line_width(aStream->cairoContext, 1.0); > > > > A width of 1.0 is good for shade plots without transparency. Example 30 > > doesn't look that good (but not worse than before). I couldn't find a > > good width for example 30. > > > > Actually the solution to this problem should be > > > > http://www.cairographics.org/manual/cairo-context.html#cairo-push-group > > > > where our case is described. Here we draw the fill and the stroke opaque > > in the same color in an intermediate buffer and then draw this buffer > > with a transparency into the image. Sounds nice, but has some > > disadvantages: > > > > 1) the driver gets unbearable slow > > 2) example 30 doesn't look better because of this :) > > 3) the pdf file size of example 30 increases from 8 to 200kB. > > > > I commited the code, but commented it. In order to test it in cairo.c > > you would need to comment line 795 and uncomment line 796. Also > > uncomment line 798, 801, 802. So in theory this should solve our problem > > but actually it does not. Now we need to discuss if we keep this stroke > > around the polygons or revert to the old code. > > Werner, > > I've tested your fix, which works fine and solves all the problems for > the examples I've looked at, except example 30 which suffers from the > transparency problem. The only downside is that is seems to roughly > double the size of the postscript files. This seems an awful lot, but is > probably a price worth paying for better results.
I've also committed a similar fix for the postscript driver. This makes only a small difference to the file size, which suggests cairo is not doing things in an optimal way. There is probably little we can do about that though. Andrew ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
