![DSSSP frequency-response graph screenshot](https://raw.githubusercontent.com/NumberOneBot/dsssp/main/assets/screenshot.png)
![DSSSP animated filter-curve transitions](https://raw.githubusercontent.com/NumberOneBot/dsssp/main/assets/transition.gif)

# DSSSP

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## React Library for Audio Equalizers & Filter Visualization

[DSSSP](https://dsssp.io) is a React component library for visualizing and editing audio filters. These components are designed to serve as the core UI elements of audio production tools and interfaces, enabling users to interactively configure all filter parameters. Essentially, it is a conversion of proprietary audio processing and visualization tools from professional desktop software to a web-based environment.

The library's rendering system is based on SVG and provides a logarithmic frequency graph for audio spectrum representation, a set of components to render and manipulate biquad filters, and mathematical functions to calculate the resulting signal curve. Filters support **drag-and-drop** and **mouse wheel** interactions, direct property updates (**Gain**, **Frequency**, **Q-Factor**), **animated transitions** between curves, and implement common audio filter types.

## Features

- **SVG frequency-response graph** — logarithmic frequency axis and dB gain grid
- **Interactive biquad filters** — drag-and-drop and mouse-wheel control of **Gain**, **Frequency**, and **Q**
- **Full set of filter types** — peaking, low/high shelf, low/high pass, band-pass, notch, and gain
- **Composite curve** — the summed response of all filters, updated in real time
- **Animated transitions** between filter curves (`animate` / `easing` / `duration` props)
- **Themeable** and **TypeScript-first**
- Works with **React 18 and 19** (the only peer dependency)

## Components

- **`FrequencyResponseGraph`** — SVG container and context (scale, theme, dimensions) for everything below
- **`FilterCurve`** — the response curve of a single filter
- **`CompositeCurve`** — the summed response of all filters
- **`FilterPoint`** — draggable control point for a filter's frequency, gain and Q
- **`FilterGradient`** — gradient fill under a curve
- **`FilterIcon`** — filter-type icon glyph
- **`FrequencyResponseCurve`** — render a precomputed magnitude array
- **`PointerTracker`** — crosshair readout that follows the cursor

## Use cases

Parametric EQ interfaces, audio-plugin and DAW-style tools, crossover and filter designers, and teaching DSP — anywhere you need an interactive frequency-response graph on the web.

## Installation

Install the package in your project directory with:

```bash
npm install dsssp
```

## Quick start

```tsx
import {
  FrequencyResponseGraph,
  FilterCurve,
  CompositeCurve,
  type GraphFilter
} from 'dsssp'
import 'dsssp/font'

const filters: GraphFilter[] = [
  { freq: 400, gain: 6, q: 1, type: 'PEAK' },
  { freq: 600, gain: -8, q: 3, type: 'PEAK' },
  { freq: 1200, gain: 2, q: 0.7, type: 'HIGHSHELF2' }
]

const App = () => (
  <FrequencyResponseGraph
    width={800}
    height={480}
  >
    <FilterCurve
      filter={filters[0]}
      color="#FF9966"
    />
    <FilterCurve
      filter={filters[1]}
      color="#6699FF"
    />
    <FilterCurve
      filter={filters[2]}
      color="#66FF66"
    />
    <CompositeCurve filters={filters} />
  </FrequencyResponseGraph>
)
```

## Documentation

Visit [dsssp.io/docs](https://dsssp.io/docs/) to view the full documentation.

## Examples

Our documentation includes a full-scale [demo project](https://github.com/NumberOneBot/dsssp-demo) that showcases each library component across various use cases and provides a starting point for your own projects.

Visit the [dsssp.io/demo](https://dsssp.io/demo/) to see it live.

## License

[MIT](LICENSE) © Oleksiy Strelets — free to use in personal, open-source, and commercial projects.

## Contact

If you have any questions or feedback, reach out to the author at [alex.strelets@gmail.com](mailto:alex.strelets@gmail.com).