https://github.com/modlfo/vult-webaudio
Minimal example using Vult with WebAudio
https://github.com/modlfo/vult-webaudio
audio dsp effects synthesizer vult webaudio
Last synced: 6 months ago
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Minimal example using Vult with WebAudio
- Host: GitHub
- URL: https://github.com/modlfo/vult-webaudio
- Owner: modlfo
- Created: 2017-08-04T16:04:28.000Z (about 8 years ago)
- Default Branch: gh-pages
- Last Pushed: 2017-08-05T08:58:06.000Z (about 8 years ago)
- Last Synced: 2025-04-09T16:17:15.515Z (6 months ago)
- Topics: audio, dsp, effects, synthesizer, vult, webaudio
- Language: HTML
- Size: 3.91 KB
- Stars: 10
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Minimal example using Vult with WebAudio
Vult is a simple domain specific language with features that simplify developing of DSP algorithms. The generated code (C/++, Js and Lua) can be run efficiently on many platforms and microcontrollers.
You can find more information in the [Main Site](https://modlfo.github.io/vult/) and the [GitHub repository](https://github.com/modlfo/vult).
This example shows how to embed the Vult compiler in a Web page and generate a [ScriptProcessorNode](https://developer.mozilla.org/en-US/docs/Web/API/ScriptProcessorNode) to execute your Vult code with [WebAudio](https://developer.mozilla.org/en-US/docs/Web/API/Web_Audio_API) in a browser.
The full code is in the [`index.html`](https://github.com/modlfo/vult-webaudio/blob/gh-pages/index.html)
You can check the results in this link https://modlfo.github.io/vult-webaudio/
## Embedding Vult
The Vult compiler is available as JavaScript code in three different flavors:
- [Command line application (requires Node.js)](https://www.npmjs.com/package/vult)
- [Node.js library](https://www.npmjs.com/package/vultlib)
- [Web Browser library](https://github.com/modlfo/vult/releases)
In this case we are gonna use the Web Browser library. To embed the latest release in your page you can use the following address:
```
```
You can download or link an specific version from the compiler from the [releases](https://github.com/modlfo/vult/releases) page. For example:
```
```
When the script is loaded it provides the global `vult` which contains all the methods to call the compiler. The API is the same as in the [Node.js library](https://www.npmjs.com/package/vultlib), which provides all the functionality of the of the [command line application](https://github.com/modlfo/vult/wiki/Command-Line-Options).
## Generating ScriptProcessorNode
To generate code that is ready for WebAudio we can use the `webaudio` template available when generating JavaScrip. This is done by calling the function `vult.generateJs` and providing the appropriate options:
```
var result = vult.generateJs([
{
file: 'test.vult', // Name of the file
code: #code# // the code itself as a string
}
],
{
output: "Test", // output name (used to prefix the code)
template: 'webaudio' // here we specify the template
});
```
The result is an array with either errors or generated files. The errors are objects like this:
```
{
msg : String, // Error message
file : String, // File name
line : Number, // Line where it occurs
col : Number // Column where it occurs
}
```
If the code generation is successful we will get objects like this (same kind as the input files):
```
{
file : "foo.cpp", // File name or extension
code : ".. my code .." // Generated code
}
```
When generating Web Audio code we only get one file.
## Executing the code
The generated code is a string so we have to use `eval` in Javscript to execute it:
```
var code = result[0].code; // When generating Js there's only one file
var vultProcessor = eval(code);
```
The `vultProcessor` is a function that receives the `audioContext` and returns the `ScriptProcessorNode`.
```
var audioContext = new AudioContext();
var vultProcessorNode = vultProcessor(audioContext);
```
This node can be connected to your audio graph:
```
source = audioContext.createBufferSource();
source.connect(vultProcessorNode);
vultProcessorNode.connect(audioContext.destination);
```