kicad-developers team mailing list archive

["vladimir_uryvaev" <vovanius@...>]

--- In kicad-devel@xxxxxxxxxxxxxxx, "Lorenzo" <lomarcan@...> wrote:
> I could agree with arc usage, it could be useful sometimes, but you'll need to keep an option to approximate it with lines since there are photoplotters out there that doesn't handle G2 and G3 codes (circular interpolation)... cairo is still way too slow to be used confortably. I mean, 90% of the lines in a schematic is horizontal or vertical, so antialiasing is not an issue. Text drawing with antialiasing on screen could maybe a good thing IF it isn't too slow. Practical example: gerbv using cairo is simply unuseable. I always use it in 'fast with xor mode' because having to wait seconds just for a pan simply is not acceptable.

Large angle arcs a very rare in fonts, so no arc support woultn't be great disadvantage.
Also graphics is interesting to me, so I will look how to improve it.
 
> On a 1024x768 I find legibility pretty good at usable zoom levels. And remember that silks are usually done with a fairly coarse grid mesh: our process guarantees only 0,2mm line width, which means 2mm character height using ISO fonts. We also generate the silk as a pdf for documentation purposes (to check component placement). I usually use 0,6mm character height for these (works good up to 0603 components).

Practical limit on fonts height is about 5 times of plotter resolution/accuracy (using font like found on SMD resistors). I tested it on PCB, when tried to fit SMD components very dense. I've designed very simple font for that purpose. For more dense design i could even use not ordinary fonts, but some very compact representation like barcode/dotcode (only problem is how to make it still readable by human).

> So, at the end we need a plotter font anyway for final output. As a compromise we could offer, as an option, pango plotting just on screen to have antialiasing and stuff (this would be subjective, I actually prefer no antialiasing at 1024x768 and more because contrast is better).

It is a matter of taste, to use antialiasing or not. As I see non hinted vector characters usually more readable (better say recognisable) at very lowresolution when antialiased.