mirror of https://github.com/GNOME/gimp.git
82c607d4a8
The previous PDB generation was losing pre-formatting inside triple-backticked blocks. In particular we were losing indentation (which was already ugly in C, but even syntactically wrong when displaying Python code samples). And it was also making us add double-newlines between every code lines, which was annoying. This updated code now leaves triple-backticked sections as-is. Unfortunately I was completely unable to do this by modifying the existing functions, which were modifying the input arg in-place. So I made them into functions returning the result. But then there is another part of code (niceargs()) where changing array contents doesn't work properly, and worse it seems to corrupt the array somehow (because I have generation breakage in completely-different pieces of the PDB generation code). I believe there is some passing-by reference/value concepts in perl which I don't quite get (they use `&`, `\` and other symbols and even searching for these, I don't quite understand how to use them the right way) but I've spent already too much time on this. So since I've got something working now by having duplicate functions, I'll let someone else from the future, who knows better perl, re-merge these functions if they know how. |
||
---|---|---|
.. | ||
groups | ||
README | ||
README_NEW_PDB_PROC | ||
app.pl | ||
enumcode.pl | ||
enumgen.pl | ||
enums-external.pl | ||
enums.pl | ||
groups.pl | ||
lib.pl | ||
meson-enumcode.sh | ||
meson-enumgen.sh | ||
meson-pdbgen.sh | ||
meson.build | ||
pdb.pl | ||
pdbgen.pl | ||
stddefs.pdb | ||
util.pl |
README
Some mostly unfinished docs are here. -Yosh This document describes the tool PDBGEN. If you added or modified .pdb files do not run this tool manually but run make instead! It will call pdbgen.pl then to generate the files into the right output directories. PDBGEN ------------------ What is this? PDBGEN is a tool to automate much of the drudge work of making PDB interfaces to GIMP internals. Right now, it generates PDB description records, argument marshallers (with sanity checking) for the app side, as well as libgimp wrappers for C plugins. It's written so that extending it to provide support for CORBA and other languages suited to static autogeneration. Invoking PDBGEN from the command line: 1. Change into the ./pdb directory. 2. $ ./pdbgen.pl DIRNAME where DIRNAME is either "lib" or "app", depending on which set of files you want to generate. The files are written into $destdir/app or $destdir/libgimp. $destdir is the environment variable destdir. If it's not set, then it's the ./pdb directory. Make sure the directories $destdir/app and $destdir/libgimp already exist and you have write permissions. Otherwise the code generator will fail and exit. It's up to you to diff the file you changed. When you're happy with the generated file, copy it into the actual ./app/ or ./libgimp/ directory where it finally gets built. Anatomy of a PDB descriptor: PDB descriptors are Perl code. You define a subroutine, which corresponds to the PDB function you want to create. You then fill certain special variables to fully describe all the information pdbgen needs to generate code. Since it's perl, you can do practically whatever perl lets you do to help you do this. However, at the simplest level, you don't need to know perl at all to make PDB descriptors. Annotated description: For example, we will look at gimp_display_new, specified in gdisplay.pdb. sub display_new { We start with the name of our PDB function (not including the "gimp_" prefix). $blurb = 'Create a new display for the specified image.'; This directly corresponds to the "blurb" field in the ProcRecord. $help = <<'HELP'; Creates a new display for the specified image. If the image already has a display, another is added. Multiple displays are handled transparently by the GIMP. The newly created display is returned and can be subsequently destroyed with a call to 'gimp-display-delete'. This procedure only makes sense for use with the GIMP UI. HELP This is the help field. Notice because it is a long string, we used HERE document syntax to split it over multiple lines. Any extra whitespace in $blurb or $help, including newlines, is automatically stripped, so you don't have to worry about that. &std_pdb_misc; This is the "author", "copyright", and "date" fields. Since S&P are quite common, they get a special shortcut which fills these in for you. Stuff like this is defined in stddefs.pdb. @inargs = ( &std_image_arg ); You specify arguments in a list. Again, your basic image is very common, so it gets a shortcut. @outargs = ( { name => 'display', type => 'display', desc => 'The new display', alias => 'gdisp', init => 1 } ); This is a real argument. It has a name, type, description at a minimum. "alias" lets you use the alias name in your invoker code, but the real name is still shown in the ProcRecord. This is useful not only as a shorthand, but for grabbing variables defined somewhere else (or constants), in conjunction with the "no_declare" flag. "init" simply says initialize this variable to a dummy value (in this case to placate gcc warnings) %invoke = ( headers => [ qw("gdisplay.h") ], These are the headers needed for the functions you call. vars => [ 'guint scale = 0x101' ], Extra variables can be put here for your invoker. code => <<'CODE' { if (gimage->layers == NULL) success = FALSE; else success = ((gdisp = gdisplay_new (gimage, scale)) != NULL); } CODE The actual invoker code. Since it's a multiline block, we put curly braces in the beginning.