Re: unified FLTK & Gnuplot printing

[Shai Ayal]

2010/8/30 Ben Abbott <address@hidden>:
> On Aug 30, 2010, at 1:16 AM, Jordi Gutiérrez Hermoso wrote:
>
>> On 23 August 2010 20:13, Ben Abbott <address@hidden> wrote:
>>> I've prepared a changeset to unify the printing for both the FLTK
>>> and Gnuplot backends.
>>>
>>> For both backends, ghostscript is relied upon more heavily than
>>> before.
>>
>> I've been meaning to comment on this.
>>
>> It's nice that you've found a unified method for all formats. I still
>> think, however, that we could profitably use a bitmap method for
>> bitmap output formats. Vector graphics aren't good for getting a
>> picture of a colourful surface with shading at an interesting angle.
>> It would also be nice to generate an exact screenshot of what's shown
>> on the screen in a bitmap format, which at least Søren has wished for.
>>
>> I have no idea how much work this will be, but I want to get started
>> on it, as an option or alternative to gl2ps at least for some output
>> formats. Maybe not for the 3.4 release, but soonish.
>>
>> - Jordi G. H.
>
> I've occasionally noticed the on screen rendering looks better than the 
> printed version. However, I don't have a deep enough understanding the 
> technical details to conclude why.
>
> The two cases for the FLTK backend
>
> (1) OpenGL -> bitmap (on screen may have anti-aliasing, or may not).
>
> (2) OpenGL -> Postscript -> bitmap (usign gs with anti-aliasing)
>
> I assumed any visible difference would depend upon which anti-aliasing method 
> is superior (assuming each image is the same size and resolution).
>
Also, way (1) is limited to screen resolution (i.e. if you have a
400x300 pixel figure window, you'll have a 400x300 image, while way
(2) can be any resolution you like (using the -r flag to gs and print)

Shai