From: "Alex R. Mosteo" <alejandro@mosteo.invalid>
Subject: Re: Color gradients lib
Date: Tue, 08 Feb 2011 15:52:24 +0100
Date: 2011-02-08T15:52:24+01:00 [thread overview]
Message-ID: <iirlbk$mfc$1@news.eternal-september.org> (raw)
In-Reply-To: op.vqk5tbwlule2fv@garhos
Yannick Duchêne (Hibou57) wrote:
> Hi Alex,
>
> Any graphic capabilities requires an output “device”, either memory
> bitmap, screen, image file, and the latter may be bitmap, PNG, JPEG. I
> feel you miss to provide a context here. Are you seeking for a library to
> generate shapes filled with gradient to which kind of output ? This is
> important to know.
Yes, I was a bit scarce on details.
For the output device I have an abstract layer that can output to GTK or a
simulator or any other backend I could need, so that's not the issue.
I want a function mapping from some arbitrary values (my data, with its
minimum and maximum values) into the RGB triplets giving that cold-hot
representation. Let's say:
type My_Data is float range 0.0 .. 100.0;
type RGB_Component is float range 0.0 .. 1.0;
type RGB_Color is record R, G, B : RGB_Component; end record;
function Gradient (Value : My_Data) return RGB_Color;
And that's it. Hope this helps, and thanks for the interest.
Alex.
> Do not know anything about the context, however an idea : is SVG a valid
> option for you ? For graphs, pies, and other formal representations and
> plotted images, SVG is rather good (if no dynamic features is required),
> and it has gradient capabilities:
> http://www.w3.org/TR/SVG/pservers.html
>
> Otherwise, please tell more about the context and any relevant technical
> details.
>
>
> Le Tue, 08 Feb 2011 11:58:00 +0100, Alex R. Mosteo
> <alejandro@mosteo.invalid> a écrit:
>
>> Hello,
>>
>> I need to plot some data (2D maps) and I have everything in my drawing
>> library except some readily usable gradients. I was wondering if some Ada
>> library out there has this before making my custom one.
>>
>> I would need one to represent bad/good ranges (e.g. the default gradient
>> blue-cold to red-hot in matlab), and another to show a density of samples
>> (perhaps simple shades of gray).
>>
>> The second one is straightforward, but the first one seems like something
>> pretty standard, so I wouldn't like to create one that is similar but not
>> the same.
>>
>> (e.g. the first example in
>> http://www.mathworks.com/help/techdoc/visualize/f0-18164.html#f0-5919 )
>>
>> Thanks for any suggestions.
>
>
next prev parent reply other threads:[~2011-02-08 14:52 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-08 10:58 Color gradients lib Alex R. Mosteo
2011-02-08 13:16 ` Yannick Duchêne (Hibou57)
2011-02-08 14:52 ` Alex R. Mosteo [this message]
2011-02-08 15:18 ` Yannick Duchêne (Hibou57)
2011-02-08 15:21 ` Yannick Duchêne (Hibou57)
2011-02-08 16:27 ` Alex R. Mosteo
2011-02-08 19:30 ` Yannick Duchêne (Hibou57)
2011-02-08 18:00 ` Dmitry A. Kazakov
2011-02-08 19:27 ` Yannick Duchêne (Hibou57)
2011-02-08 19:36 ` Yannick Duchêne (Hibou57)
2011-02-08 19:54 ` Dmitry A. Kazakov
2011-02-09 8:53 ` Alex R. Mosteo
2011-02-08 20:26 ` Gautier write-only
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