spm-fb [-s] [-F framebuffer] [-S squarescrsize] [-W scr_width] [-N scr_height] vsize [filename]SPM-FB(1)
NAME
spm-fb - display a sphere map on a framebuffer
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SYNOPSIS
DESCRIPTION
spm-fb reads a sphere map (an equal-area spherical sampling, as produced and consumed by the libbn bn_spm routines) and displays it on a framebuffer. The required vsize argument is the number of latitude bins ("v" size) used when the map was created; it determines how the bytes in the input are partitioned into scanlines. If filename is omitted the map is read from standard input.
By default each latitude bin is written directly to the framebuffer as one scanline, so the displayed image has the natural ragged width of an equal-area sphere map. With -s the map is instead resampled into a rectangular image that fills the framebuffer, mapping framebuffer pixel coordinates back onto the sphere.
OPTIONS
- -s
-
Display the map as a square (rectangular) image that fills the framebuffer, resampling the sphere map with bn_spm_read instead of writing each bin as a raw scanline.
- -F framebuffer
-
Use the specified framebuffer device instead of the default.
- -S squarescrsize
-
Set both the framebuffer width and height to squarescrsize pixels.
- -W scr_width
-
Set the framebuffer width to scr_width pixels.
- -N scr_height
-
Set the framebuffer height to scr_height pixels.
EXAMPLES
Example 1. Display a sphere map produced from an environment image
pix-spm world.pix 512 > world.spm
spm-fb -s -S 512 512 world.spmConvert a pix(5) image into a 512-bin sphere map with pix-spm(1), then resample that map onto a 512x512 framebuffer. The -s option fills the whole framebuffer rather than drawing the ragged equal-area bins directly.
SEE ALSO
brlcad(1), pix-spm(1), fbserv(1), pix(5)
AUTHOR
BRL-CAD Team
COPYRIGHT
This software is Copyright (c) 1989-2026 by the United States Government as represented by U.S. Army Research Laboratory.
BUG REPORTS
Reports of bugs or problems should be submitted via electronic mail to devs@brlcad.org