Add a framework for saving and restoring internal data objects, in
gimp-internal-data.c. Internal data objects are saved in separate
files under a new "internal-data" subdirectory of the user's gimp
directory. The internal data is saved, restored, and cleared
together with the tool options.
Use this to save and restore the custom gradient. In the future,
we might add similar writable internal data objects that we'd want
to save.
Add a specialized propgui constructor for gegl:color-to-alpha-plus.
This op is currently in the workshop, but is set to be merged with
the existing gegl:color-to-alpha, so we omit the '-plus' from file-
and function-names.
The new op adds a pair of properties to control the radii, relative
to the selected color, below which colors become fully transparent,
and above which colors remain fully opaque. Allow these properties
to be set by picking a color from the image, and calculating the
radius accordingly.
Add a boolean "modify active gradient" option to the blend tool.
when checked, the active gradient is modified in-place while edited.
When unchecked, the active gradient is copied to the internal
"custom" gradient upon editing, and the custom gradient becomes
subsequently active.
Show a hint when the option is checked, but the active gradient is
non-writable, and can't be edited directly.
This commit adds the new gimpblendtool-editor.[hc] files, which are
where the gradient-editing related functionality of the blend tool
is going to go.