galdr 0.1.0: terminal grid synthesizer (MIDI in, PipeWire out)

Signal flows downward through single-glyph unit generators; each MIDI note
voices the whole grid; the mix renders low-latency to PipeWire (reusing the
native path from spectrust). Grid edits recompile and hot-swap without
dropping audio. Pairs with orca (note/CC source) and spectrust (visualizer).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GLUwWE2KmFPzhKaf67tWbx

README.md

@@ -0,0 +1,58 @@
+# galdr
+
+A terminal **grid synthesizer**. Signal flows downward through a field of
+single-glyph unit generators; every incoming MIDI note voices the whole grid;
+the mix is rendered low-latency to PipeWire. It is orca's voice — the same
+esoteric, spatial approach to programming, but for making sound instead of
+sending events.
+
+```
+orca-rs  ──MIDI/OSC/UDP──▶  galdr  ──PipeWire──▶  speakers
+   compose the pattern       voice it       (spectrust -p visualizes it)
+```
+
+## The grid
+
+Signal flows **down**: each cell takes the sample from the cell above as its
+input. The left and right neighbour glyphs are parameters — a digit `0`–`9` is
+a constant, a letter `a`–`z` reads MIDI CC (`a` = CC 0).
+
+| glyph | unit generator |
+|---|---|
+| `~` | sine (ratio ← left) |
+| `^` | saw (ratio ← left) |
+| `_` | pulse (width ← left) |
+| `v` | triangle |
+| `*` | noise |
+| `f` | lowpass (cutoff ← left) |
+| `e` | envelope, attack/release ← left/right, gated by the note |
+| `s` | shaper / drive ← left |
+| `!` | output to master |
+
+Each `!` sums into the master, so parallel columns stack timbres or voices.
+A note plays every column at once.
+
+Example — a filtered saw with an envelope:
+
+```
+^        saw at the note pitch
+f        lowpass, cutoff from the digit to its left...
+e        ...enveloped by the note gate
+!        ...to master
+```
+
+Editing the grid recompiles and hot-swaps the running program without dropping
+audio.
+
+## Usage
+
+```
+galdr [--latency <frames>] [--poly <n>] [--rate <hz>] [--midi-name <s>]
+```
+
+galdr creates a virtual MIDI input port named **galdr**; connect orca or any
+sequencer/DAW to it. `--midi-name` connects to an existing port instead.
+Cursor keys move; type a glyph to place it; Backspace clears; Esc quits.
+
+Runtime deps: PipeWire and ALSA (MIDI). Built in Rust; reuses the native
+PipeWire path from spectrust.