FBZOOM(1)

NAME

fbzoom - zoom and pan the view of a frame buffer

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SYNOPSIS
DESCRIPTION
OPTIONS
EXAMPLES
SEE ALSO
AUTHOR
COPYRIGHT
BUG REPORTS

SYNOPSIS

fbzoom [-T] [-F framebuffer] [-s|-S squarescrsize] [-w|-W scr_width] [-n|-N scr_height] [xPan yPan xZoom yZoom]

fbzoom interactively zooms and pans the view of a frame buffer using vi(1)- and/or emacs(1)-like keystrokes on a regular terminal. It changes only the way the frame buffer is viewed; the pixels stored in the frame buffer are not modified.

After opening the frame buffer, fbzoom displays the current view and reads single-character commands from the keyboard, updating the center pixel and zoom factor as it goes. The current center pixel, zoom factor, and pan mode are echoed on the status line.

If the four optional positional arguments xPan yPan xZoom yZoom are supplied, the view is initialized to that center pixel and zoom factor before interaction begins. Either zero or exactly four positional arguments must be given; the two zoom values must be positive.

OPTIONS

-T: Reverse the sense of the pan commands, so that the panning keys move the image rather than the window. This may also be toggled interactively with the T command.
-F framebuffer: Explicitly specify the frame buffer to open. Otherwise the environment variable FB_FILE selects the frame buffer; see brlcad(1).
-s (or -S) squarescrsize: Open the frame buffer as a square squarescrsize pixels on a side (default is 512).
-w (or -W) scr_width: Open the frame buffer scr_width pixels wide (default is 512).
-n (or -N) scr_height: Open the frame buffer scr_height pixels high (default is 512).

Once running, fbzoom responds to the following single-character commands (type ? at any time for this list):

b (or ^V): zoom bigger, both axes (x2)
s: zoom smaller, both axes (x0.5)
+ (or =): zoom bigger, both axes (+1)
-: zoom smaller, both axes (-1)
> / <: zoom x bigger (x2) / smaller (x0.5)
. / ,: zoom x bigger (+1) / smaller (-1)
) / (: zoom y bigger (x2) / smaller (x0.5)
0 / 9: zoom y bigger (+1) / smaller (-1)
h / l (or B / F): pan left / right by one
j / k (or N / P): pan down / up by one
H / L (or ^B / ^F): pan left / right by many
J / K (or ^N / ^P): pan down / up by many
T: toggle the sense of the pan commands
c: recenter the view (goto center)
z: reset the zoom to 1 1
r: reset both pan and zoom to normal
?: print the command list
q (or RETURN): exit

EXAMPLES

Example 1. Inspect a rendered image in detail

$ pix-fb -w 1024 -n 1024 render.pix
$ fbzoom -w 1024 -n 1024

Loads a 1024x1024 image into the frame buffer with pix-fb(1), then runs fbzoom on the same-sized frame buffer. Press b to magnify, the h/j/k/l keys to pan around the enlarged image, and q to quit.

Example 2. Start zoomed in on a region

$ fbzoom 256 256 4 4

Opens the default frame buffer with the view already centered on pixel (256, 256) and magnified 4x in both axes, then enters interactive mode.