.TH APLOT 9.1
.SH NAME
aplot \- isometric plots of data arrays
.SH SYNOPSIS
.B fb/aplot
[
.B -a
]
[
.BI -l lightfile
] [
.BI -t type
] [
.BI -r range
] [
.B -w
.I x0 y0 x1 y1
]
.I file
.SH DESCRIPTION
.I Aplot
draws an anti-aliased isometric perspective plot of the square array of elevations that it
reads from
.IR file .
The output is a picture file, written on standard output.
.PP
Option
.B -t
specifies the type of the data in the binary file.  Possible
.I types
are
.IP
.EX
s	short
i	int
l	long
f	float
d	double
c	char
u	unsigned char
.EE
.PP
The default is
.BR "-t f" .
.PP
Option
.B -w
sets the
.B WINDOW=
attribute of the output image.
By default, the image is drawn in a 640\(mu512 window.
.PP
Normally, the data is scaled to make the plot fill the window.
This default scaling can be overridden by option
.BR -r ,
in which case the data is scaled so that
.I range
is the magnitude of data values that would make a plot that just
fills the window vertically.
.PP
Option
.B -l
gives the name of a file describing how to shade the surface and how
shiny the surface is.
By default, a not-at-all shiny surface is lit from above by a single light source.
The
.I lightfile
contains lines of the following forms:
.TP
.BI light " x y z brightness
specifies light source of the given brightness shining in direction
.RI ( x , y , z\f1).
There can be up to 16 light sources.
The default light is in direction (2,3,9) and has brightness 1.
.TP
.BI ambient " brightness
specifies the brightness of then ambient (non-directional) light.
The default is 0.02.
.TP
.BI diff " reflectance
sets the amount of diffuse reflection from the surface.
The default is 0.98.
.TP
.BI spec " reflectance
sets the amount of specular reflection from the surface.
The default is 0.
.TP
.BI bump " height
sets the width of the specular reflection bump.  Larger numbers
produce tighter (less diffuse) bumps.  The default is 80.
.PP
Option
.B -a
suppresses writing an
.I alpha
channel into the output file.
By default, the output has
.BR CHAN=ma .
.SH SOURCE
.B /sys/src/fb/aplot.c
.SH "SEE ALSO
.IR picfile (9.6),
.IR filters (9.1)
.SH BUGS
Input files are assumed to use native byte order and
floating point format, and so are not transportable,
except under option
.BR "-t u" .
