Re: imagemagick support on W32

[Christoph <cschol2112@googlemail.com>]

On 9/30/2010 9:16 PM, Juanma Barranquero wrote:

> Yes, something like that, assuming you're trying to use ImageMagick
> DLLs and not linking statically.

For now, I will go on with the dlls. On a side note: would Emacs require 
to use the .dlls or could the library also be statically linked in?

> On HAVE_NTGUI, macros DEF_IMGLIB_FN and LOAD_IMGLIB_FN create and set
> such pointers. On ! HAVE_NTGUI, such pointers are simply redefined to
> refer to the original, statically linked functions.
>
> So, the code that currently calls ImageMagick functions directly, like
> NewMagickWand, MagickPingImage, etc, should be changed to call
> fn_NewMagickWand, fn_MagickPingImage, etc.

That's what I figured. Thanks.

> One issue:
>
>    /* Try loading ImageMagick library under probable names.  */
>    if (!(library = w32_delayed_load (libraries, Qimagemagick)))
>      return 0;
>
> You'll have to add the imagemagick libraries to image-library-alist,
> of course. But, what is the intention of ImageMagick here? To
> substitute libpng, jpeglib, etc? If so, something will have to be done
> with respect to image-type-available-p (or, more specifically,
> init-image-library) so Emacs "knows" that png, jpeg, tiff, etc are
> really available.
>
> But perhaps I'm misinterpreting the intention of ImageMagick?

I assumed that that was the intention of the inclusion of the 
ImageMagick branch in the first place. Maybe there are other use cases 
though that I am not aware of.

Thanks for the image-library-alist hint.

Right now, everything compiles fine (with the addition of my own 
init_imagemagick_functions function, but when I run 
(imagemagick-register-types) Emacs crashes.

Run under gdb from the src/ directory the output is:

Program received signal SIGSEGV, Segmentation fault.
0x6d043295 in GetLastValueInLinkedList ()
    from 
D:\devel\emacs\emacs-bzr\imagemagick\src\oo-spd\i386\CORE_RL_magick_.dll

I try to dig around some more.

Christoph