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