Investigate and implement the VR APIs

[MaxZhaloba]

This tasks consists of such steps:

1. Investigate the VR APIs and estimate if they would work for us better than the current approach
2. If that appears to be the case, implement the most suitable API

Technologies to consider:

1. WebVR API. Resources:

• description
• specification
• support in browsers
• manual on Mozilla Dev site

2. WebXR API which is designed as a replacement and successor of WebVR. Extended reality combines virtual reality, augmented reality and mixed reality (promo).

• What is WebXR API?
• specification
• GitHub spec page
• application from Mozilla

Disadvantages of current implementation:

1. Need to touch the screen and confirm the fullscreen mode.
2. Fullscreen mode in Android works only when vr.html is launched from desktop icon as HTML application.
3. No fullscreen mode in iOS. I tested the current code from B#99_Add_landscape_and_lockorientation branch and could not initialise the VR page under iOS in Chrome, Safari and Firefox. The fullscreen popup appeared on the screen, but when I confirmed it, all browsers remained in windowed mode.

[SystemDiagnosticss]

Hello. I am tested WebXR on this samples on 4 Android smartphones (Nubia z17 mini, Gionee elife e7 mini s, Huawei TRT-LX1, OnePlus 5).
WebXR required to install Google VR services

Nubia z17 mini (Android 6.0.1)
Opera(v 46.3.2246.127744): works fine
Firefox(v 60.02): works fine
Chrome(v 69.0.3457.4): kill my Chrome app :)))

Gionee elife e7 mini s (Android 4.4.2)
Opera(46.3.2246.127744): works good
Firefox(v 60.02): don't work
Chrome(v 67.0.3396.87): don't work

Huawei TRT-LX1 (Android 7.0)
Opera(v 46.3.2246.127744): very very slow read data from IMU
Firefox(60.0.2): very slow read data from IMU
Chrome(67.0.3396.87): cant fin'd Google Vr-services (Ваш пристрій не сумісний з цією версією)
but driver work in Firefox and Opera

OnePlus 5 (Android 8.1.0)
Opera(46.3.2246.127744) works fine
Firefox (60.0.2) works fine
Chrome (v 67.0.3396.87) works fine