Design.ContextLost - lidavidm/jsglet GitHub Wiki

Uses

• Handle webglcontextlost event (http://www.khronos.org/webgl/wiki/HandlingContextLost)

  • Preserve the state if so

Needs and Considerations

• When context is restored, bring back OpenGL state
• Need a way of recording what state was changed
• Need a way to determine what resources to recreate
• Let application override/augment this functionality (e.g. to display a pause screen)

Implementation

• Each object that has OpenGL state/resources needs to register a context restored handler (in jsglet.common?)

  • This handler should restore/recreate OpenGL objects

  • Problem: object may depend on external resources such as images that may also need to be reloaded

    • Integrate with resource system?

• Keep a stack of OpenGL state changes (similar to Pyglet's Group, but for permanent, global state changes)

  • Let applications push functions onto stack
  • On context restore, call each function
  • Have a 'push-and-call' method to make it convenient