Re: Drawing Single Pixel Lines
Dan Raymond <[email protected]>
| Newsgroups | gmane.comp.lib.cairo |
|---|---|
| Message-ID | <[email protected]> |
As I recall, integer coordinates will refer to positions between pixels. If you add 0.5 to your coordinates then you will draw the line at the center of the pixel and it will be possible to have a single pixel width line. On 12/29/2015 3:00 PM, Christos Sotiriou wrote: > Hello, > > for an application using GTK and Cairo for its back-end I am drawing > to *integer* *coordinates* (cairo scale is 1) for efficiency using > simple cairo function calls. > > I would like to draw single pixel lines. In Cairo version > cairo-1.14.0-2.fc20.x86_64, using a line width of *1 (or 1.0)* works fine. > > In Cairo version 1.8.8-2.1.48 (Suse) a line width of 1 does not draw > the line at all, or draws halfway. > > When I change the line width to *2 (or 2.0)*, the line is drawn. I > know that in the FAQ a line width of 2.0 is recommended : > http://cairographics.org/FAQ/#sharp_lines. > > Is this the only solution, i.e. to change the line width to 2.0? When > I do that the lines appear slightly thicker that I would like! > > Thank you for your help, > > Christos. > > -- > -------------------------------------------------------------------------- > Christos P. Sotiriou > email: [email protected] <mailto:[email protected]> > Cell (GR): +30 697 8984 222 > Cell (US): +1 858 247 9436 > > -- cairo mailing list [email protected] http://lists.cairographics.org/mailman/listinfo/cairo