5dbd3ebfb6
- Custom terminal canvas: one buffer, one write() per frame - Threaded audio via Nim channels (20fps → 60fps) - 6 phosphor palettes (green, amber, cyan, blue, white, red) - All tuning constants at top of osc.nim - No illwill dependency, binary 352KB → 200KB - CRT effects use same palette as trace Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
75 lines
2.3 KiB
Markdown
75 lines
2.3 KiB
Markdown
# terminal-oscilloscope
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A terminal-based oscilloscope with CRT phosphor physics, written in Nim. Zero dependencies — 200KB binary, just libc.
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## Features
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- **CRT boot/shutdown animations** — phosphor ramp, beam sweep, vertical collapse, dot fade
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- **Y-T and X-Y modes** — time-domain waveform or Lissajous figures
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- **Phosphor persistence** — beam bloom, decay trails, intensity-based shading
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- **Half-block rendering** — 2x vertical resolution using Unicode `▀▄█` characters
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- **Live audio capture** — direct libav bindings via dlopen, zero install
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- **Threaded audio** — 60fps rendering, audio capture on separate thread
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- **6 CRT phosphor palettes** — green, amber, cyan, blue, white, red
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## Install
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Requires [Nim](https://nim-lang.org/) 2.x.
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```bash
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git clone https://github.com/rolandnsharp/terminal-oscilloscope.git
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cd terminal-oscilloscope
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nim c -d:release --threads:on -o:osc src/osc.nim
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./osc
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```
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## Controls
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| Key | Action |
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|-----|--------|
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| `m` | Toggle Y-T / X-Y mode |
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| `+` / `-` | Increase / decrease gain (amplitude) |
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| `]` / `[` | Zoom in / out time axis |
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| `q` | Quit (with CRT shutdown effect) |
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## Configuration
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Edit the constants at the top of `src/osc.nim`:
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```nim
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const
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# Phosphor physics
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Decay = 0.85 # persistence per frame (0.0–1.0)
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Beam = 0.4 # intensity at beam impact
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Bloom = 0.08 # horizontal glow spread
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# Phosphor glow thresholds
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HotGlow = 0.7 # white-hot beam core
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WarmGlow = 0.4 # bright phosphor
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CoolGlow = 0.15 # dim persistence trail
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# Palette: green, amber, cyan, blue, white, red
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Palette = "green"
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```
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### Palettes
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| Name | Phosphor | Look |
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|------|----------|------|
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| `green` | P31 | classic oscilloscope |
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| `amber` | P12 | warm retro terminal |
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| `cyan` | P7 | Tektronix blue-green |
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| `blue` | P11 | cool/modern |
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| `white` | P4 | TV phosphor |
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| `red` | P22-R | radar display |
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## Audio
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Captures system audio by opening the PulseAudio/PipeWire monitor of your default output sink directly via libavformat and libavdevice. Libraries are loaded at runtime with `dlopen` — no dev packages, no subprocess, no extra dependencies.
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## Credits
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CRT turn-on/off animations inspired by [AetherTune](https://github.com/nevermore23274/AetherTune).
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