[Tutorial] SketchUp Ruby C Extension

[chyn2000]

Hi Guys.

First, I want to say that this project you have started is awesome. I had just decided I needed a ruby extension to get a speed boost for a plug-in project. I found a lot of tutorials on making extensions, but most were for either linux or for MS Visual Studio 6 on Windows. I'm not using either environment. I am on Windows 7 (64bit).

Sooooo, I have followed TBD's example program the best I can.

• I have downloaded the SUExt files.
• I have downloaded the Ruby Installer and Source per the SUExt readme file and installed Ruby.
• I have installed Pelles C.

I tried to open suext.ppj file and Pelles C kept throwing an error about "suext.obj is wrongly located in -path_to_project-". So I tried suext6.ppj and it seemed to be fine. It even seemed to build once I pointed Pelles C to where my Ruby installation was at.

From here I'm a little lost. Am I done? I brought up the irb and typed in: require 'path_to_project/suext.so'
The results were as follows:

LoadError: 127: The specified procedure could not be found. - Init_path_to_project\suext
path_to_project\suext.so
from path_to_project\suext.so
from path_to_ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from (irb):1
from :0

What am I missing?

Thanks
-Chyn

[thomthom]

When you require a C Extension, do not include the file extension.

So instead of:
require 'path_to_project/suext.so'

do:
require 'path_to_project/suext'

[chyn2000]

Ok. That certainly changed things a little.

I type:
irb(main):002:0> require 'path_to_project\suext'

and get back:
LoadError: 127: The specified procedure could not be found. - Init_path_to_project\suext
path_to_project\suext.so
from path_to_project\suext.so
from path_to_ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from (irb):2
from :0

[TIG]

or
/
?

[chyn2000]

Both. The '/'s and ''s that are in the post were copied and pasted. I didn't change any of them. Let me know if you want the original output. I just shortened the paths for readability.

-Chyn

[Jim]

TIG means try using this --> / <-- instead of that --> ** <-- in your require statement.

[chyn2000]

Ah. Gotchya now.

Nirg. Same result...

Anything else? Maybe is one of you guys have successfully built the example you could post it for download. That would make sure I've got my environment set up correctly.

-Chyn

[thomthom]

How did you build it? Seems something has gotten confused and the path has gotten mixed into the name of the initializing procedure for the C Extension.

@chyn2000 said:

LoadError: 127: The specified procedure could not be found. - Init_path_to_project\suext

It tries to call a function named Init_path_to_project\suext - where, given the name suext it should be trying to call Init_suext.

[chyn2000]

I built in Pelles C.

So, the path isn't hard coded in the program. I can place a copy of the suext.so on my d:\ and it changes the error out put to match:

irb(main):002:0> require 'D:\suext'
LoadError: 127: The specified procedure could not be found. - Init_D:\suext
D:\suext.so
from D:\suext.so
from d:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from (irb):2
from :0

Is there a specific directory I should have the file at?

[Dan Rathbun]

%(#BF8000)[path_to_ruby/lib/ruby/site_ruby/1.8/rubygems/**custom_require.rb**]

Why are you customizing the require() method ?

Try it WITHOUT loading this custom script...

[Jim]

@dan rathbun said:

Why are you customizing the require() method ?

He isn't - this is something done by RubyGems.

[Dan Rathbun]

OK.. my bad.. N/M

[Jim]

@chyn2000 said:

irb(main):002:0> require 'D:\suext'

You did it again.

Use:

require "D:/suext"

irb(main);001;0> require 'C;\SX_Basics'
LoadError; 127; The specified procedure could not be found.   - Init_C;\SX_Basics
C;\SX_Basics.so
        from C;\SX_Basics.so
        from (irb);1
irb(main);002;0> require 'C;/SX_Basics'
=> true
irb(main);003;0>

[Jim]

Ok, I just built TBD's suext example using Visual Studio Express 2010.

In order to get the extension to require properly, I had to use:

require "SUExt" <-- note case

require "suext" failed.

[chyn2000]

@jim said:

Ok, I just built TBD's suext example using Visual Studio Express 2010.

In order to get the extension to require properly, I had to use:

require "SUExt" <-- note case

require "suext" failed.

Yep Jim. That was exactly it!

Thanks everyone. Let me know if there is anything I can do to help.

Actually, it occurs to me that we may want to start making a small library of math and geometry ruby extensions very targeted towards SU. Thoughts?

-Chyn

[thomthom]

@chyn2000 said:

Actually, it occurs to me that we may want to start making a small library of math and geometry ruby extensions very targeted towards SU. Thoughts?

Not a bad idea. I had plans of doing some bezier functions.

[Jim]

@chyn2000 said:

Actually, it occurs to me that we may want to start making a small library of math and geometry ruby extensions very targeted towards SU. Thoughts?

Maybe wrapping up an existing library for SketchUp/Ruby would be a way to go? Here's some interesting ones:

[1] http://vcg.sourceforge.net/index.php/Main_Page
[2] http://www.cgal.org/
[3] http://ptex.us/
[4] http://code.google.com/p/ruby-sketchup-sdk/
[5] http://www.visilibity.org/

[jefftrull]

I was so excited to discover that someone was building Sketchup extensions with Visual Studio 2010 - that's exactly what I need to do - unfortunately, after going through the whole process, I can't seem to successfully load the SX_HelloWorld module:

require 'SX_HelloWorld'
Error; #<LoadError; C;/Program Files/Google/Google SketchUp 8/Plugins/SX_HelloWorld.so; 126; The specified module could not be found.   - C;/Program Files/Google/Google SketchUp 8/Plugins/SX_HelloWorld.so>
(eval)
(eval);0

Notice this is not a situation where the file is missing - that produces a similar but different error message.

After some Googling it seemed like missing .so's are sometimes the culprit, so I tried copying over some from my Ruby build directory (win32ole.so and Win32API.so), but it didn't help. Finally I tried running Sketchup from the VS2010 command line shell - this resulted in the infamous "bugsplat".

I'm at my wit's end here... any ideas?

Thanks,
Jeff
PS: My Ruby install gives RUBY_PLATFORM=i386-mswin32_100, RUBY_VERSION=1.8.6; Sketchup gives RUBY_PLATFORM=i386-mswin32 and the same version

[Dan Rathbun]

FYI: When require loads a shared object library file (and not a ruby script,)
the require(filepath) method looks for a C function named:
"Init_" + File.basename( filepath, File.extname(filepath) )
and runs it after loading the shared library.

This means that named C function must exist (even if it does nothing,) and must be named exactly as the file is named (CASE SENSITIVE.) If an enduser renames the so (or dll, dylib, etc.,) file later (including changing the case of any characters,) then loading the library file with require() will fail. (usually resulting in a "entry point not found" error.)

[jefftrull]

Thanks for the quick response! Unfortunately, I don't think that's the issue, for three reasons:

1. The error message is "The specified module could not be found", rather than "entry point not found"
2. I'm using the example file from bitbucket unchanged... the name of the relevant function there is "Init_SX_HelloWorld", vs filename "SX_HelloWorld.so"
3. I can use this module OK in Ruby standalone (whichever one I built with)

I do think it's got to be something simple... I just can't see what it might be. The error message isn't terribly helpful