Purr Data

Table of Contents

• Overview
• Developers
• Accomplished Milestones
• Setup
• Directory Structure
• Future Work
• Reporting Bugs

Overview

This document describes the work that was done under Google Summer of Code 2020 a.k.a. GSoC for organization Purr Data. The project idea was to make the native Purr Data run in a web browser by adding a WebAssembly target and HTML5 GUI framework.

Purr Data a.k.a. Pd-l2ork 2 is an improved version of Miller Puckette’s Pd.

Pd (Pure Data) is a graphical data-flow programming environment which is geared towards real-time interactive computer music and multimedia applications. It is a full-featured open-source alternative to its commercial sibling, Cycling74’s Max.

Purr Data serves the same purpose, but offers a new and much improved graphical user interface and includes many 3rd party plug-ins. Like Pd, it runs on Linux, macOS and Windows, and is open-source throughout.

The goal of this project is to make the graphical programming environment Purr Data run in a web browser so it can be more accessible to users.

You can try the latest version from https://purrdata.glitch.me/

Developers

• The backend part of the software has been mainly done by Zack Lee (cuinjune@gmail.com)
• The frontend part of the software has been mainly done by Hugo Carvalho (hugonvsc@gmail.com)

Accomplished Milestones

• Modified the native Purr Data and libpd codebase to make them compatible with Emscripten. (Zack)
• Modified and created Makefile to build for Emscripten and to generate WebAssembly(.wasm) binaries for external libraries. (Zack)
• Cleaned the backend codebase and organized the file system so the project can be easily maintained. (Zack)
• Modified the existing NW.js based source code to make them compatible with web browsers. (Hugo)
• Reimplemented some elements(menu, canvas, style) specifically for the web browser. (Hugo)
• Integrated the backend with the frontend. (Hugo, Zack)
• Fixed some major bugs and errors in the frontend. (Hugo, Zack)

Setup

Installing Dependencies (Linux)

sudo apt-get install git automake cmake fakeroot dpkg-dev libgconf-2-4

Installing Node.js (macOS, Linux)

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.37.2/install.sh | bash

Installing/Activating Emscripten (macOS, Linux)

git clone https://github.com/emscripten-core/emsdk.git
cd emsdk
git pull
./emsdk install latest
./emsdk activate latest
source ./emsdk_env.sh
cd ..

Building Purr Data for Emscripten (macOS, Linux)

git clone https://git.purrdata.net/jwilkes/purr-data.git
cd purr-data
git checkout emscripten
make emscripten

Setting up the project (Windows)

Method 1

- git clone https://git.purrdata.net/jwilkes/purr-data.git
- cd purr-data
- run command npm install.
- Change directory to purr-data/emscripten/project/purr-data.
- run command npm run build.
- run command npm start.

Method 2

- Follow the steps given in the link inorder to install Ubuntu LTS (https://docs.microsoft.com/en-us/windows/wsl/) .
- Then follow the steps mentioned in above sections for Linux.

Running Purr Data in a web browser

• After the building is successfully completed, visit http://localhost:5000 in your browser.
• You can run npm start under purr-data/emscripten/project/purr-data to run the app again.

Directory Structure

• components: Elements that are dynamically added to the page. (canvas, dialogs, menu)
• components/dialogs: Copied dialogs files from purr-data/pd/nw folder.
• css: Copied css files from purr-data/pd/nw/css folder.
• css/webapp: Styles created for the web browser.
• dist: Browserified Javascript files. (pdgui.js, pd_shortcuts.js, pd_canvas.js)
• libs: External dependencies.
• utils: Common functions used for this project.

Future Work

• Fix shortcuts so they can work identically in browsers as the native Purr Data.
• Fix getting stuck in the loading screen until a mouse/key event is triggered in Firefox/Safari.
• Fix the patch not responding to mouse event after the help file is opened and not being clicked.
• Fix wrong mouse coordinate issue that happens in some circumstances.
• Fix or disable some of the global menu items not working.
• Fix graphical arrays being opened if the patch font size changes.
• Ask for saving the patch when the user closes an edited patch.
• Make the GUI(e.g. bang, toggle) property dialog window work.
• Make the dialog windows(e.g. property, text) appear on the right side of the patch instead of the left sidebar.
• Merge the patch menu into the global menu and make it work depending on the focus of patches.
• Style the patch window menu bar so it can show the focus state and add some buttons (e.g. close) for convenience.
• Make the patch window resizable by dragging its border.
• Make the patch window rearrangeable by dragging its menu bar.
• Improve the file manager so the files/folders can be added/renamed/deleted.
• Clean the frontend codebase and organize the file system.
• Make the work storable and shareable between users.

Reporting Bugs

If you find any bugs, please let us know. You can contact using the mailing list or create an issue.