FBZOOM(1)

✨ NAME ✨

okay so fbzoom is the tool, and this page is FBZOOM(1) from the BRL-CAD manual set 💖. It's literally the interactive zoom-and-pan viewer for a frame buffer. Bestie, it's giving "look closer, but make it terminal" ✨.

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🎀 SYNOPSIS 🎀

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

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💅 DESCRIPTION 💅

fbzoom interactively zooms and pans the view of a frame buffer using vi(1)- and/or emacs(1)-like keystrokes on a regular terminal. The important vibe check: it changes only the way the frame buffer is viewed; the pixels stored in the frame buffer are not modified. No cap 🫶.

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. Live feedback? Obsessed 💅.

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. That's the rule, bestie — no in-between chaos 🙈.

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🌈 OPTIONS 🌈

Here's the whole flag menu — yes, all of it, no skipping 🫶:

• -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. Iconic little plot twist 💫.
• -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).

🎮 Single-character commands

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

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🍓 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. It's giving "detective mode" 🔍💅.

🦋 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. Main character energy from the very first frame 👑.

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💜 SEE ALSO 💜

go peek at these, iykyk: brlcad(1), bw-fb(1), fbgrid(1), gif-fb(1), pix-fb(1), plot3-fb(1).

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👑 AUTHOR 👑

BRL-CAD Team — periodt 💅.

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🧚 COPYRIGHT 🧚

This software is Copyright (c) 1989-2026 by the United States Government as represented by U.S. Army Research Laboratory.

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💀 BUG REPORTS 💀

Found a bug? Do not suffer in silence, bestie 😭. Reports of bugs or problems should be submitted via electronic mail to devs@brlcad.org.

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💖 from BRL-CAD, filed as FBZOOM(1), with copyright years 1989-2026 — that's the whole page, bestie, go zoom responsibly 🫶✨