Re: fltk rendering problem

[Mike Miller]

On Fri, Oct 12, 2012 at 2:47 PM, Martin Helm wrote:
> Am 12.10.2012 20:38, schrieb Dmitri A. Sergatskov:
>> On Fri, Oct 12, 2012 at 10:41 AM, Martin Helm <address@hidden> wrote:
>> ...
>>> So it is not a problem of the graphics card driver or the mesa version.
>> ...
>>
>> FWIW:
>>
>> I see this problem on the computer with intel graphics (i7-2600k/DZ68 m/b) 
>> and
>> I do not see on the computer with an nvidia card (and nvidia driver).
>> (GF106GL [Quadro 2000])
>>
>> Dmitri.
>> --
> As I said I see exactly the same behavior (we have intel gpu and nvidia
> gpu machines at home, all GNU/Linux systems), it is still not a driver
> issue as my own test shows me.
> The issue seems to be that something in octave (I will investigate the
> details over the weekend) simply does not set proper state variables for
> opengl and instead relies on whatever the implementation on the machine
> does as default.
> This is rarely what one would like to have.
> So far I can also not understand what sense it makes to set a linewidth
> of 0.5 without at the same time enabling antialiasing, the behavior what
> an opengl implementation shall do in such a case seems to be undefined.
> The nvidia driver just renders it aliased with a line width of 1, the
> intel+mesa implementation seems to try to render "half" of the points.
> So if by default we want aliased rendering we should probably have a
> default line width which is an integer, not a fraction which cannot be
> rendered in a defined way.

Thanks for looking into this Martin. I guess I might as well post to
the bug tracker so we don't forget about this. Could you also share
the small opengl antialiasing test code you wrote?

-- 
mike