Re: gnuplot, wxterminal and antialiasing

[<tim...@en...>]

> On Friday 10 March 2006 03:10 pm, Timoth=E9e Lecomte wrote:
>
>> This problem comes from the terminal API, which works with integers
>> everywhere. That's why 'plot x', on all platforms, looks wobbly to
>> some extent instead of being a straight diagonal.
>
> I was able to mitigate this problem dramatically for the svg termimal
> simply by increasing the driver's internal scale by a factor of 10.
> Screen coordinates are still integers, but the resolution is 10x better=
,
> and the wobble is essentially eliminated.
>
>> Please take a look at this screeshot
>
> Here are a pair of screenshots, before and after increasing the
> svg internal scale by a factor of 10.
>
> http://www.bmsc.washington.edu/people/merritt/gnuplot/scale_1.png
> http://www.bmsc.washington.edu/people/merritt/gnuplot/scale_10.png

Ok, so this is the same method as what I called "oversampling". The only
difference is that I used a higher scale factor, 10000.

>> As for me, I prefer the rendering with the modified oversampling
>> wxterminal because it gets rid of the annoying aliased and wobbling
>> lines.
>
> Does it affect the speed?
> I'm already concerned that the wxterminal is slow compared to x11.

I see exaclty the same speed as without "oversampling", that is to say it
is still much slower than x11, but not worse than without oversampling.

Regarding the speed of the wxWidgets/Cairo rendering, there may be severa=
l
bottlenecks :
- first, my code is surely not optimised (a lot of mutex lock, etc.),
- then Cairo itself is still young so the upcoming 1.2 version may contai=
n
speed improvements,
- and finally I can use a backend drawing with Glitz, so that Cairo will
use  OpenGL and profit from the gpu acceleration

I sincerely think that the first point is the most pertinent, because eve=
n
if I disable antialiasing, the speed does not improve much...
However, in theory, the antialiasing makes the rendering slower, that's s=
ure.

Best regards,

Timoth=E9e