Hi
This is about the rendering of dashed and dash-dot lines. With the opengl plotting system being the default, maybe one could now think about the rendering quality of lines in plots and prints.
Here there are some -in my opinion- shortcomings of the current situation:
- The gaps in the dashed and dash-dot lines are too large (also compared to ML's plotting). In my personal octave build I actually replace the "0xF0F0" mask with "0xF8F8" for dashed and the "020F" mask for dash-dot lines with "0x27FF".
- The pattern doesn't scale with the linewidth. This makes very thick lines look strange when combined with some non solid line style.
- The lines have no caps, which makes especially dots look ugly (squares instead of circles).
- I have just realized that glLineStipple has been deprecated in recent versions of OpenGL.
Possible solutions:
Soon or later it will probably become necessary to go away from glLineStipple, so it might be useful to take a look at alternative and higher quality options already. For example the following work looks very interesting:
In any case one would also have to check what is supported by gl2ps.
Unfortunately, I don't see myself having the time to help with the coding of any new implementation soon but maybe you will find the above information useful.
Best regards
Kostas