From: Joe Van Dyk <joevandyk@...>
Date: 2005-04-05T00:17:13+09:00
Subject: Re: Extension question

On Apr 4, 2005 7:46 AM, Tom Copeland <tom@infoether.com> wrote:
> On Mon, 2005-04-04 at 23:19 +0900, Joe Van Dyk wrote:
> > Hi,
> >
> > I'm generating a fairly large image file (can be 10000x10000) pixels
> > by reading some binary data and setting each pixel.  As you can
> > imagine, pure Ruby is REALLY slow, I think because of the loops.  I've
> > written the program in C and it's literally hundreds to thousands of
> > times faster (depending on image size).
> >
> > So, I'd like to write my first C extension.  I'm using the GD library
> > for image manipulation.
> 
> You might be interested in this:
> 
> http://raa.ruby-lang.org/list.rhtml?name=ruby-gd
> 
> >From the example scripts:
> 
> require "GD"
> im = GD::Image.new(100,100)
> red = im.colorAllocate(255,0,0)
> im.rectangle(0,0,99,99,red)
> im.png STDOUT
> 
> Yours,

Hi,

I was using Ruby-GD before.  The slowness is not the library, but the
looping 10 million times.  I have to set each pixel, so I can't use
the rectangle function.