Re: [Rubycocoa-talk] NSBitmapImageRep#bitmapData

[Ralph B. <ra...@de...>]

Thanks Jonathan! I was able to get it to work.

If at all possible I would prefer not to link my C++ stuff against Ruby 
in order to keep it clean. It is a library meant for stand-alone 
distribution. I now handle the conversion in the SWIG layer:

// Convert bool from Ruby --> C with type check
%typemap(in) BitmapPointer {
	id ocobj = (id) NUM2UINT( rb_funcall($input, rb_intern("__ocid__"), 0) 
);
	$1 = [(NSBitmapImageRep*) ocobj bitmapData];
}

Three more things were needed to make it work.
1. Testinterface::Test(bitmapRep.bitmapData())   ->    
Testinterface::Test(bitmapRep)    (duh)
2. #include <AppKit/NSBitmapImageRep.h>    (in the SWIG .i file)
3. You're now mixing Objective-C and C/C++ (aptly termed 
Objective-C++), and the compiler needs to be made aware of this. This 
is done by changing the extension of the *_wrap.cxx file to .mm, ie. 
*_wrap.mm. Update your makefile.

Thanks again, Jonathan.

Ralph

On Jul 15, 2005, at 00:52, Jonathan Paisley wrote:

> On 14 Jul 2005, at 21:08, Ralph Brorsen wrote:
>
>> The main event here is of course "$1 = StringValuePtr($input);", 
>> which should, as I understand it return a char pointer to the string 
>> data which bitmapRep.bitmapData() returned. The reason it is 
>> converted to a Ruby string, I assume, is because RubyCocoa sees the 
>> char *, and thinks it is a string. Perhaps the string is copied to an 
>> internal buffer?
>
> As you've identified, the return value of bitmapData is being 
> converted to a ruby string. The easiest solution (since you're already 
> dealing with some native code) may be to pass the NSBitmapImageRep 
> pointer to your native code and get the pointer to the bitmapData from 
> within your native code.