Re: strange box-offset

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

Timoth=E9e Lecomte wrote:
> Mojca Miklavec wrote:
>  =20
>> Hello,
>>
>> Can you please take a look at http://pub.mojca.org/gnuplot/bug/box-off=
set.png?
>>
>> The source is available in the same folder. Some boxes have an
>> additional frame offset by 1 pixel, which seems pretty strange to me.
>> This only happens at some specific sizes and some specific plots.
>>
>> When I tried the same example with the ConTeXt terminal (might be just
>> any text-based terminal) I spotted the following in the output:
>>
>> fill unitsquare xyscaled (2.04,32.09) shifted (52.15,18.03);
>> draw (52.15,18.03)--(52.15,50.11)--(54.18,50.11)--(54.18,18.03)
>> 	--(52.15,18.03)--cycle;
>>
>> 32.09+18.03=3D50.12, but the rectangle is filled up to 50.11
>>
>> There seems to be a round-off problem.
>>
>> Mojca
>>  =20
>>    =20
> I think I have seen the same problem when trying to make the wxWidgets=20
> terminal handle fillboxes correctly. I could not make 'test' and 'load=20
> "fillstyle.dem"' work correctly at the same time. I chose to make 'test=
'=20
> not to work, i.e. give the offset as you see in your graph, but make=20
> fillstyle.dem work, as the latter is the real use case. (To see it in=20
> the wxWidgets terminal, you have to disable the oversampling, otherwise=
=20
> the offset is a decimal and is negligible in the output).
>
> Best regards,
>
> Timoth=E9e
>  =20
And these offsets are also present in the X11 terminal. They are just=20
hidden most of the time by the two-pixels-thick lines. Look closely at=20
fillstyle.dem when it is using the one-pixel-thick lines, and you will=20
see them.

Timoth=E9e