mirror of https://github.com/GNOME/gimp.git
1ff9c12b1e
… and gimp_brush_get_mask(). gimp_brush_get_pixels() was a bit crappy, returning raw data with only dimensions and bpp to go with (no color model/space, no bit depth…). So the assumption is that we work with 8-bit per channel data, possibly with alpha depending of number of channels as deduced from bpp, and very likely in sRGB color space. It might be globally ok with many of the brush formats (and historical brushes) but won't fare well as we improve brush capabilities. - gimp_brush_get_pixels() is in fact made private. - The 2 new functions are using this old PDB call _gimp_brush_get_pixels() to construct buffers. This has some limitations, in particular that it returns only 8-bit per channel sRGB data, but at least the signature won't change when we will improve things in the future (so if some day, we pass fancy brushes in high-bit depth, the method will stay the same). - This new implementation also allows scaling down the brush (keeping aspect ratio) which is useful when you need to fit a brush preview into a drawing widget. - Current implementation stores the buffers at native size in the libgimp's GimpBrush object, hence save re-querying the core every time you need an update. This can be improved as current implementation also means that you don't get updates if the brush changed. This should handle most common use cases for now, though. - Also with this change, I move GimpBrush class implementation into its own dedicated file. |
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.. | ||
groups | ||
README | ||
README_NEW_PDB_PROC | ||
app.pl | ||
enumcode.pl | ||
enumgen.pl | ||
enums-external.pl | ||
enums.pl | ||
groups.pl | ||
lib.pl | ||
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.