Computer Graphics with Photoshop - Plugin version problems (resource issue?)

Author

Plugin version problems (resource issue?)

skahil@gmail.com

2005-06-29, 7:16 pm

I am developing a Photoshop file format plugin to read a file format
called *.KAP using SDK version 5.0.

The problem I am having is that though Photoshop v5.0 will acknowledge
my plugin, newer versions of Photoshop (7.1) and Photoshop elements
(3.0) do not.
i.e. My file format does not show up in the OPEN dialog, and when I try
to open I get a "wrong file type" error.

Now as I understand it Photoshop scans the contents of the Plugins
directory and reads the resources of the files stored there looking for
PiPL resources.
This leads me to conclude that I have screwed up my resource file
somehow.
The format of the file that CnvtPiPL.exe accepts is a bit of a mystery
to me so I was hoping that someone could either enlighten me as to what
I have done wrong or point me to some documentation.

Alternatively, perhaps there is something more fundamental going on
like a type of resource that the newer Photoshop programs are looking
for that I don't know about or some lack of backward compatibility.

I would really appreciate any help you could offer on the subject.
Thanks,
Sean.

I have simply modified the example resource file it can be found here:
http://awh1.Apocgraphy.com/download/SimpleFormat.r

The PiPL section is as follows:
resource 'PiPL' (ResourceID, plugInName " PiPL", purgeable)
{
{
Kind { ImageFormat },
Name { plugInName },
Version { (latestFormatVersion << 16) | latestFormatSubVersion },

#if Macintosh
Code68K { ImageFormat, $$ID },
CodePowerPC { 0, 0, "" },
#endif

#if MSWindows
CodeWin32X86 { "ENTRYPOINT" },
#endif

// ClassID, eventID, aete ID, uniqueString:
HasTerminology { plugInClassID, plugInEventID, ResourceID, vendorName
" " plugInName },

SupportedModes
{
noBitmap, noGrayScale,
doesSupportIndexedColor, noRGBColor,
noCMYKColor, noHSLColor,
noHSBColor, noMultichannel,
noDuotone, noLABColor
},

EnableInfo { "true" },

FmtFileType { '8B1F', '8BIM' },
//ReadTypes { { '8B1F', ' ' } },
FilteredTypes { { '8B1F', ' ' } },
ReadExtensions { { 'KAP ' } },
WriteExtensions { { 'KAP ' } },
FilteredExtensions { { 'KAP ' } },
FormatFlags { fmtDoesNotSaveImageResources, fmtCanRead,
fmtCannotWrite, fmtCanWriteIfRead },
FormatMaxSize { { 32767, 32767 } },
FormatMaxChannels { { 1, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24 } }
}
};

toby

2005-06-30, 4:18 am

skahil@XXXXXXXXXX wrote:
> I am developing a Photoshop file format plugin to read a file format
> called *.KAP using SDK version 5.0.
>
> The problem I am having is that though Photoshop v5.0 will acknowledge
> my plugin, newer versions of Photoshop (7.1) and Photoshop elements
> (3.0) do not.

That is to be expected. The Mac versions of Photoshop 7.0 and CS
require code linked against CarbonLib. To distinguish such code from
plugins built for the older "classic" PowerPC runtime, a new code
property was defined. The Photoshop 5.0 SDK does not include this
property, but it is trivial to add. Once this is done, you can properly
identify code that's loadable under PS7's Carbon runtime. (Note, I have
never seen or used the PS7 or later SDKs; this information is from my
own investigations and was originally posted here:
http://groups-beta.google.com/group...2bde8aad0?hl=en
also noting a couple of other minor fixes to support Carbon building.)

Open the file Resources/PiPL.r, and find the "CodePowerPC" property.
Add a similar one after it like so:

case CodePowerPCbundle:
longint = '8BIM';
key longint = 'ppcb';
longint = 0;
#if DeRez
fill long;
#else
longint = (ppcbEnd[$$ArrayIndex(properties)] -
ppcbStart[$$ArrayIndex(properties)]) / 8;
#endif
ppcbStart:
longint;
longint;
pstring;
ppcbEnd:
align long;

(Photoshop 7 running under Classic will use the older plugin format, in
other words behaving just like an earlier version.)

You will also need to change the way your code is compiled and linked.
If you are using CodeWarrior, you can set your prefix file to
MacCarbonHeaders.h and link against CarbonLib (and MSL if you use it)
only. Note that the resulting code will *only* load in PS7 or CS; it is
not valid for any version of Photoshop running under MacOS 9 or
earlier. For those, you continue to build and link in the old way,
using the CodePowerPC property.

Likewise, Mac Photoshop CS2 introduces yet another property because its
plugins must be in Mach-O format:

case CodeMachO:
longint = '8BIM';
key longint = 'mach';
longint = 0;
#if DeRez
fill long;
#else
longint = (machEnd[$$ArrayIndex(properties)] -
machStart[$$ArrayIndex(properties)]) / 8;
#endif
machStart:
longint;
longint;
pstring;
machEnd:
align long;

This can be added to any SDK to build plugins for CS2. Instructions for
porting your code to the Mach-O/gcc build system are beyond the scope
of this post, but a complete example, including Makefile, is here:
http://www.telegraphics.com.au/svn/icoformat/trunk/ (Subversion
repository).

Plugin projects and source code for all configurations of Photoshop,
including Windows, are available on my site,
http://www.telegraphics.com.au/sw/

Don't hesitate to contact me with any further questions.

--Toby

> i.e. My file format does not show up in the OPEN dialog, and when I try
> to open I get a "wrong file type" error.

skahil@gmail.com

2005-06-30, 7:23 pm

Thanks for the detailed answer Toby!
That gives me a lot to chew on.

You rock!
Sean.