Forum: wxRuby Inserting RMagick RVG images in wxRuby

Hello, all -

I'm having a grand time making cpu stats for an embedded board show up 
in my
ruby app, but I have run into a roadblock. I used RMagick's RVG graphics 
to
create the graph, and it works fine when I just dump it to an image file
such as .png. I'm trying to eliminate that step and write it directly to 
a
panel in my Wx gui, but it appears -- and there's a statement in the 
docs
that confirms it -- that RVG::Image != Magick::Image. I experimented 
quite a
bit with the sample program that takes a RMagick image and inserts it, 
but I
haven't been able to make those techniques work for RVG. Is there a
conversion?

I've started looking at the Wx GraphicsContext methodology, but it isn't 
as
elegant. Suggestions?

wxRuby 2.0.1
RMagick 2.12.1
Ubuntu 9.10 32 bit
Ruby 1.87 p 302

On 24/11/10 00:48, Don Wilde wrote:
> I've started looking at the Wx GraphicsContext methodology, but it
> isn't as elegant. Suggestions?


I'm not completely sure I understand what you want to do - but I think
the easiest way is to Wx tell RVG to render the vector at a given
resolution in a well-known bitmap format (eg PNG), and then display that
in Wx.

You can bypass writing the rendered image to disk by using Image.read,
and a StringIO if necessary - so it can just be passed about in memory.
Re-render the image when the display size changes. You might find
something useful in my Ruby Quiz response for a Wx Mathematical Image
Generator:
http://rubyquiz.strd6.com/quizzes/191-mathematical...

alex

On Thu, Nov 25, 2010 at 7:13 AM, Alex Fenton <alex@pressure.to> wrote:

>> conversion?
> You can bypass writing the rendered image to disk by using Image.read, and
> a StringIO if necessary - so it can just be passed about in memory.
> Re-render the image when the display size changes. You might find something
> useful in my Ruby Quiz response for a Wx Mathematical Image Generator:
> http://rubyquiz.strd6.com/quizzes/191-mathematical...
>
> alex
>

Alex, thanks!

Your presentation and the sample file in wxruby samples were outstanding 
and
a heck of a lot of fun to play with. Some of the other demos get too 
cute
for their own good, but yours was very clear. I am using it to figure 
out
how to get my DC from point-painting to lines.

I have decided to rework my code so that the graph-drawing code is 
embedded
in the Window subclass and done completely in wx DC methodology. It's 
not as
straightforwardly obvious and Ruby idiomatic, but I'm making it work and 
the
code outside of the graph-drawing routine is getting much cleaner.

On Thu, Nov 25, 2010 at 9:02 AM, Don Wilde <dwilde1@gmail.com> wrote:

>>> bit with the sample program that takes a RMagick image and inserts it, but I
>> a well-known bitmap format (eg PNG), and then display that in Wx.
> Alex, thanks!
>
>
>
I should mention that I do know who Alonzo Church is, thanks to John
McCarthy. Am I dating myself from the LISPocene Era? :D