ff-bezier.1

.Dd 2024-04-02
.Dt FF-BEZIER 1
.Os farbfeld-utils
.Sh NAME
.Nm ff-bezier
.Nd farbfeld filter that draws one or more cubic Bezier curves
.Sh SYNOPSIS
.Nm
<colour> <x-pos> <y-pos> <x-pos> <y-pos> ...
.Sh DESCRIPTION
.Nm
reads a
.Xr farbfeld 5
image from stdin, draws one or more connected cubic Bezier curves on top of the image 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 first argument is the colour to draw. After that gives the coordinates of
each point, with one argument for X coordinate, one argument for Y coordinate,
and then again another X coordinate, another Y coordinate, etc.

The coordinate can have decimal values.

At least four points are needed. Any multiple of three points can be added
afterwards because the end points of each piece are shared, but the control
points are not shared.

The colour 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
.Sh EXAMPLES
$
.Nm
FF9090 0 50 40 30 80 20 120 140 < image.ff > image-bezier.ff
.Sh SEE ALSO
.Xr farbfeld 5 ,
.Xr farbfeld-utils 7