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Date: -- (:)
From: Alexander V. Voinov <avv@q...>
Subject: Re: [Caml-list] Graphics frustration
Hi Matt,

I don't see ploticus in the list. But it is a good plot maker. However I use it 
from Python, not from OCaml, and the reflection capability of the former makes 
the interface tiny. But in all other respects there should not be any difference.

Alexander

Matt Gushee wrote:

> First of all, thanks to all who responded. And I have a few responses
> for the respondents. First, though, one general remark: although I am
> certainly interested in practical solutions to my current problem, in
> this instance I was trying to draw attention to what I see as a weak
> point in the selection of available libraries. Graphics are a common
> need, and I think better graphics libraries would help the popularity of
> OCaml.
> 
> 
> On Thu, Jul 24, 2003 at 11:22:03AM +0200, Olivier Andrieu wrote:
> 
>> Matt Gushee [Wednesday 23 July 2003] :
>> > So that's a quick summary of my situation. Do others agree with me that
>> > this is a significant problem? Are there any good solutions in the
>> > works?
>>
>>I agree with you that libplot isn't fully satisfactory. I haven't much
>>to suggest, though. GD seems to have all the features you need 
> 
> 
> I agree. However ...
> 
> 
>>(but I
>>don't know the state of the ocaml wrapper).
> 
> 
> That's the problem. It's far from being a complete GD interface. And
> I've contacted its author, and he doesn't expect to continue developing
> it. I may see if I can hack in the remaining functionality myself, but
> with my minimal C knowledge I'm not optimistic about that.
> 
> 
>>One solution I've been
>>thinking about is using libart together with Camlimages. Libart is a
>>library for rendering vector graphics (e.g. bezier paths) in
>>anti-aliased pixel buffers. It's written by the Ghostscipt maintainer
>>I think. It seems very good but it doesn't handle text rendering nor
>>saving pixel buffers to file. But I think it should be possible to
>>interface it with Camlimages : libart would do the primitives
>>rendering and camlimages the text rendering and saving.
> 
> 
> Interesting idea. I'd like to know if you do that. By the way, what in
> particular do you like about libart?
> 
> 
>>Writing a C wrapper seems the easiest and quicker way to do what you
>>want though ...
> 
> 
> I agree, and I actually would like to learn C. But there is so much to
> learn, and so little time to learn it ...
> 
> 
> On Thu, Jul 24, 2003 at 01:03:01PM +0100, Richard Jones wrote:
> 
>>I did something like this in C++ an eon ago. The program generated
>>Postscript directly and piped it into Ghostscript to render it into
>>the appropriate format. Postscript is a very powerful language for
>>this sort of thing once you get used to it.
> 
> 
> Well, I'm reasonably comfortable with PS, and that's pretty much the
> approach I'm taking already: as I explained, draw with MLgraph, convert
> with Camlimages (which uses Ghostscript to load PS). But the problem I'm
> having there is that the antialiasing in the output is unsatisfactory.
> If I use Camlimages out-of-the-box, there is no antialiasing, and curves
> come out looking horribly jagged. On the other hand, if I hack the
> Camlimages source such that Ghostscript is called with
> -dGraphicsAlphaBits=4, curves look fine, but vertical and horizontal
> lines look blurred and semi-transparent. I've also tried converting the
> Postscript with ImageMagick, with results very similar to the latter. So
> I'm afraid the root cause may be a limitation of Ghostscript, though I
> haven't thoroughly investigated yet.
> 
> 
> On Thu, Jul 24, 2003 at 02:25:38PM +0200, Daniel Bünzli wrote:
> 
>>Dear Matt,
>>
>>Did you consider using OpenGL ?
> 
> 
> What an appalling thought!
> 
> :-)
> 
> Seriously, though, I might end up doing this--when push comes to shove I
> care more about making things work than about doing them 'correctly.'
> Still, as a general solution to the problem of generating 2D raster
> graphics, OpenGL strikes me as being an ugly (and perhaps inefficient?)
> approach. But I don't understand OpenGL very well, and perhaps I'd
> change my mind if I did.
> 
> 
>>But it seems that the FreeType library can give you antialiased pixmaps 
>>of given fonts and that CamlImages provides an inteface to the FreeType 
>>library (never used that however). So maybe you can make both of them 
>>interact smoothly. So I suggest you (though I'm completly misinformed) 
>>CamlImages+lablGL.
> 
> 
> May be worth trying. How mature and stable is lablGL? I would have to
> learn OpenGL, and since I don't have much interest in OpenGL per se,
> before I take the time to learn it, I'd like to have some assurance that
> it is in fact a reliable means for producing high-quality 2D bitmaps.
> 
> 
> On Sat, Jul 26, 2003 at 10:37:20AM +0900, SooHyoung Oh wrote:
> 
>>What do you think about SVG (Selective Vector Graphics)?
> 
> 
> I'm very interested in SVG, but it's not an appropriate solution in this
> case. This is a front-end Web application, and I specifically intend it
> to render graphics in a form that is viewable with any mainstream
> browser--i.e., PNG, JPEG, and/or GIF. I think it will be several years
> before we can reasonably expect clients to have built-in SVG support.
> 
> 
>>It uses only text for graphics as postscript so it's not difficult to use
>>OCaml for SVG.
>>If you interested about that, I'll send you a few examples.
> 
> 
> If you mean examples of SVG images, I probably have enough already. But
> if you have written code for generating or processing SVG, I would be
> interested in seeing what you've done.
> 
> 
> On Sat, Jul 26, 2003 at 10:55:19AM +0900, SooHyoung Oh wrote:
> 
>>SVG (Scalable Vector Graphics)
>>
>>sorry...
> 
> 
> No worries. There are so many acronyms floating around these days, I
> would be a little scared of someone who could remember them all
> correctly.
> 



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