fastfetch: boxes for a screenshot, and a logo that tumbles like donut.c

Module: modules/home/shell/fastfetch/default.nix

fastfetch is run to screenshot the rice for r/NixOS and r/unixporn, so what it shows is picked for whoever looks at the picture: the nixpkgs pin, the Nix version and the closure size, the pieces of the rice that fastfetch cannot detect (bar, launcher, prompt, editor), and no network address.

The boxesCopy Anchor Link

Each section is a box closed on both sides. fastfetch has no per-line suffix, and its format padding counts bytes and not cells, so the right border is drawn from the key: save the cursor (ESC 7), jump over the value column, print the border, and restore (ESC 8). The value then prints in between. A value longer than the column (46 cells) overwrites the border, which is why the CPU, the displays and the themes use trimmed formats.

Every module prints exactly one line, so the module list's length is the boxes' height. That is what keeps the displays as one row per connector (fastfetch cannot sort displays, and the order comes from my.monitors) and the font as kitty's declared one (terminalfont prints nothing outside kitty, which shifted every row).

The tumbling logoCopy Anchor Link

The logo is drawn the way donut.c draws its torus, and fastfetch cannot animate a logo, so every frame is rendered at build time by spin-frames.py:

• The official snowflake becomes a solid slab: front and back faces, rounded off toward the outline so each face is a gradient and not a single glyph, plus a rim facing outward.
• It rotates about two axes at once at donut.c's pace (0.04 rad about X and 0.02 about Z per frame), which makes two turns about X for one about Z in 314 frames: the loop has no seam.
• Each surface point is projected with perspective into a z-buffer, and its brightness against a fixed light picks a character from donut.c's ramp, .,-~:;=!*#$@, with its L*8 mapping.
• The characters take the brand guide's signature blues, Afghani #4d6fb7 and Argentinian #5fb8f2. The PNG in nixos-icons still carries the older #5277c3 and #7ebae4, so each lambda is recolored by which of the two it is.
• A frame is as tall as the boxes and twice as wide, since a cell is about twice as tall as wide.

The zsh wrapper prints the boxes with the first frame as the logo, so fastfetch reserves exactly its space, and then redraws the frames over it from the bottom of the output until a key. The key goes on to the prompt.

The layout follows the terminalCopy Anchor Link

A logo taller than the window breaks fastfetch, which draws the logo first and climbs back up to print the boxes beside it; a scrolled screen cannot be climbed. Arguments (fastfetch --help) and a redirected output skip the animation.