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+# Horizont
+
+A stereo algorithmic reverb audio plugin (VST3 / AU) for macOS, built with
+JUCE and C++17.
+
+It pairs a Schroeder/Moorer-style reverb core — a diffusion allpass section and
+a bank of parallel damped combs whose gains are derived from an RT60 time — with
+a **feedback pitch-shifting loop**: each pass through the reverb is recirculated
+through a granular crossfade pitch shifter, so the tail climbs or descends in
+pitch on every echo. The UI is a dark teal hardware-rack style skin with
+skeuomorphic rotary knobs and a live wet-spectrum analyser.
+
+## Features
+
+- 9 fully automatable, host-saveable parameters in an `AudioProcessorValueTreeState`
+- Stable, self-scaling reverb: comb gains are computed from RT60 so the loop
+  never diverges, and every delay length / filter / window scales with sample rate
+- Per-sample parameter smoothing (`juce::SmoothedValue`) — no clicks, no allocation
+  in the audio callback
+- Granular pitch shifter with seamless crossfade; bypasses transparently at 0 semitones
+- Feedback loop routing the wet signal back through the pitch shifter and diffusers
+- Dark themed GUI: skeuomorphic knobs, glass panel highlights, animated spectrum display
+- Factory presets exposed through the host's program mechanism
+- VST3 and Audio Unit formats; plain `make` build + install on macOS
+
+## Controls
+
+| Control    | Range           | Default | Notes                                      |
+|------------|-----------------|---------|--------------------------------------------|
+| Low Cut    | 20 – 500 Hz     | 40 Hz   | Input high-pass filter                     |
+| High Cut   | 800 Hz – 20 kHz | 14 kHz  | Input low-pass filter                      |
+| Decay      | 0.2 – 10 s      | 3.5 s   | RT60 of the comb bank                      |
+| Size       | 0.4 – 2.0       | 1.0     | Room size scaling of comb delays           |
+| Diffusion  | 0 – 1           | 0.6     | Input allpass diffusion depth              |
+| Brightness | 0 – 1           | 0.75    | High-frequency damping of the tail         |
+| Feedback   | 0 – 1           | 0.6     | Recirculation through the pitch shifter    |
+| Pitch      | -12 – +12 st    | 0 st    | Pitch shift applied per feedback pass      |
+| Dry/Wet    | 0 – 1           | 0.35    | Dry / wet mix                              |
+
+## DSP architecture
+
+```
+ input -> [low-cut HP] -> [high-cut LP] -----> feedback node
+                                                 |      ^
+                                        (pitch shifter) |
+                                                 |  wet tail
+                                    [2 cascaded allpass diffusers]
+                                                 |
+                                  8 parallel combs (damping + RT60 gain)
+                                                 |
+                                        wet sum -> dry/wet mix -> output
+```
+
+- **Diffusers** shape the early reflections before the diffuse tail.
+- **Combs** each use a different prime-based delay length; their loop gains are
+  `10^(-3 * delaySeconds / decaySeconds)` so the composite RT60 tracks *Decay*.
+- **Pitch shifter** runs on the wet feedback path. Grains are windowed and
+  crossfaded; the read point moves at a rate proportional to the shift, with
+  sample-rate-scaled window lengths and a 32-sample crossfade.
+- The wet output passes through a DC blocker, and the whole engine is
+  sample-rate independent.
+
+## Requirements
+
+- macOS with Xcode Command Line Tools (`xcode-select --install`)
+- CMake >= 3.22
+- `git`, `make`, `codesign` (all ship with the command line tools)
+
+## Build & install
+
+From the repository root:
+
+```
+make            # fetches JUCE 8.0.15 into ./JUCE, configures and builds
+make install    # installs into ~/Library/Audio/Plug-Ins/VST3 and .../Components
+```
+
+`make` is fully self-contained: if `./JUCE` is missing it clones a pinned,
+stable JUCE release into the current directory, then builds the plugin. The
+resulting bundles land in `build/Horizont_artefacts/Release/`.
+
+Other targets:
+
+```
+make uninstall  # remove installed copies
+make clean      # delete the build directory
+make help       # list targets
+```
+
+If you prefer to manage JUCE yourself, either check it out as `./JUCE` next to
+this repo, or point CMake at it with `-DJUCE_ROOT=/path/to/JUCE`.
+
+> **Note:** JUCE 9 / `master` refactored the LookAndFeel API and is not yet
+> supported — a JUCE 8.0.x release tag is required.
+
+After installing, ask your DAW / Audio Unit host to rescan plug-ins (or run
+`auval` to validate the component). Installed bundles are ad-hoc code-signed.
+
+## Project layout
+
+```
+CMakeLists.txt          build configuration
+Makefile                one-command build/install on macOS
+Source/
+  PluginProcessor.*     processor, APVTS, state save/load, program (preset) handling
+  PluginEditor.*        layout, panels, preset combo box
+  HorizontEngine.*        the reverb DSP core
+  PitchShifter.*        granular crossfade pitch shifter
+  HorizontLookAndFeel.*   dark teal theme, skeuomorphic rotary knobs
+  Knob.*                knob component (slider + caption + value readout)
+  SpectrumDisplay.*     animated wet-spectrum analyser
+  Presets.h             factory presets
+```
+
+## License
+
+This project is released under the GPL v3 — the standard license for JUCE
+projects that use the open-source JUCE distribution. You may additionally use
+it under the terms of a JUCE commercial license if you hold one.