Mobile Screen Resolution

[cesutherland]

CSS currently supports device viewport resolution but the canvas element should render respecting the screen resolution. Use screen.width and screen.height to get the proper resolution.

[cesutherland]

Resolution in flotr2 has been patched. We want to use window.devicePixelRatio as the resolution.

This will cause a performance hot spot in flotr where the context is scaled. We should scale the context once, then cache it as we do the canvas element.