ff-flood.1

.Dd 2024-05-07
.Dt FF-FLOOD 1
.Os farbfeld-utils
.Sh NAME
.Nm ff-flood
.Nd farbfeld filter that applies flood fill
.Sh SYNOPSIS
.Nm
<x> <y> <colour> <?border colour?> <?options?>
.Sh DESCRIPTION
.Nm
reads a
.Xr farbfeld 5
image from stdin, applies the flood filter and writes the result to stdout.
.Pp
In case of an error
.Nm
writes a diagnostic message to stderr.
.Sh EXIT STATUS
.Bl -tag -width Ds
.It 0
Image processed successfully.
.It 1
An error occurred.
.El
.Sh OPTIONS
The filter takes the following arguments:
   - X coordinate of flood
   - Y coordinate of flood
   - colour to fill with
   - (optional) border colour
   - (optional) extra options

The colours can be defined through one of the following patterns:
   rrggbb            three pairs of 8-bit hex values
   rrggbbaa          four pairs of 8-bit hex values
   rrrrggggbbbb      three pairs of 16-bit hex values
   rrrrggggbbbbaaaa  four pairs of 16-bit hex values

The extra options are a letter and equal sign and number.

The available options are:
   a -- if nonzero, this amount is added to the alpha channel each time the
        flood goes from one scanline to another one
   c -- specify how many channels to use for comparison, from 1 to 4
        (the default is to use all four channels)
   d -- set to 0 (default) for four directions only, or 1 to include diagonals
   h -- set nonzero to enable horizontal wrapping
   v -- set nonzero to enable vertical wrapping

Note that the border colour does not need to be defined to add extra options.

By default flood fill will replace the colours of all pixels that have the
exact same value. If the border colour is used then the flood fill will
replace all pixels that are not the same as either of the flood and border
colours. This can be used for example to fill an area that has a black
outline.
.Sh EXAMPLES
$
.Nm
20 20 906060 v=1 < image.ff > image-flood.ff
.Sh SEE ALSO
.Xr farbfeld 5 ,
.Xr farbfeld-utils 7