TODO

This repository will contain a proof of concept for a possible WebGL backend for VisPy.

The general idea is to stream GL commands from Python to Javascript through WebSockets and a custom JSON-based messaging protocol. Javascript acquires a GL context, and Python handles the conversion from a visualization application written by the user to a stream of OpenGL commands responding to user input.

We try to design an architecture that is close to the IPython notebook architecture.

This is just a proof of concept, to see if this idea is feasible.

Things to do:

• [DONE] Install Tornado and look at the documentation.
• [DONE] Write a toy example with bidirectional communication between Javascript and Tornado, through WebSockets, to get a feeling about how Python and Javascript can play with each other.
• [DONE] Building on this example, write a toy WebGL example with a simple object moving in response to commands sent by Python.
• Design a simple JSON-based messaging protocol, containing a GL command with arguments and data. It should also be able to contain user events (see event system in VisPy).
• Write standalone Python/Javascript libraries that can exchange NumPy arrays through JSON & base64.
  • Four things:
    • From NumPy to a JSON string
    • From a Javascript buffer to a JSON string
    • From a JSON string to a Javascript buffer
    • From a JSON string to a NumPy array
  • This library should support arbitrary complex datatypes.
  • Relevant links:
    • http://stackoverflow.com/questions/16887278/webgl-vertex-buffer-with-more-than-4-dimensional-coordinates
    • https://developer.mozilla.org/en-US/docs/Code_snippets/StringView
    • https://developer.mozilla.org/en-US/docs/Web/JavaScript/Typed_arrays?redirectlocale=en-US&redirectslug=JavaScript%2FTyped_arrays
    • https://developer.mozilla.org/en-US/docs/Web/JavaScript/Base64_encoding_and_decoding#Appendix.3A_Decode_a_Base64_string_to_Uint8Array_or_ArrayBuffer
    • https://developer.mozilla.org/en-US/docs/Mozilla/js-ctypes?redirectlocale=en-US&redirectslug=js-ctypes
• Javascript can be executed from Python with pyv8, might be useful for unit tests.
• Final goal: Write a Python library that takes GL commands as input and sends them to Javascript, which executes them in a WebGL canvas.