/webvr-polyfill-dpdb

An up-to-date Device Parameter Database for the WebVR Polyfill

Primary LanguageJavaScriptApache License 2.0Apache-2.0

webvr-polyfill-dpdb

Build Status (Travis CI) Package Info (npm)

This is a fork of the online cache of the Device Parameter Database (DPDB) for the webvr-polyfill.

Adding a Device

You'll need to update dpdb-formatted.json with your device's information in the following format:

{
  "devices": [
    {
      "type": "android",
      "rules": [
        {
          "mdmh": "asus/*/ASUS_Z00AD/*"
        },
        {
          "ua": "ASUS_Z00AD"
        }
      ],
      "dpi": [
        403,
        404.6
      ],
      "bw": 3,
      "ac": 1000
    }
  ]
}
  • type: Either "android" or "ios".
  • rules: An array of various rules that must be satisfied in order to use the configuration. See the Rules section below.
  • dpi: The DPI of the device's screen, either as a scalar value or as an array of X and Y DPI. Get this information via the Device Info App and look for Actual DPI X and Actual DPI Y values.
  • bw: The bezel width in millimeters, with many phones having between 3 or 4mm bezel widths. See the Calculating Bezel Width section below.
  • ac: The accuracy of this entry. This is not currently used in webvr-polyfill, but may in the future, and used to settle discrepencies between device reported information versus DPDB data, although this is more for Android apps that have may potentially have access to both API reporting and DPDB results. Can be one of the following values:
    • 0: measurements are speculative. Use as fallback only.
    • 500: measurements are based on the device's self-reported values, which is often inaccurate. Unless you're physically measuring a device, this is probably the value to use.
    • 1000: measurements are based on measuring a physical device.

Rules

The rules entry is an array of objects, each with one key/value pair, and matches if any of the rules match the device.

User-Agent

The ua rule is matched with the device's User-Agent string. It is not a regular expression, but just a simple substring match. Go to useragentstring.com and find something unique that looks like the device's name. Use this if device type is "android". Keep in mind of other models, where a string for the Nexus 5 could match the Nexus 5X, hence a string like "Nexus 5 " (note the extra space).

  { "ua": "ASUS_Z00AD" }

MDMH

The mdmh rule matches a device based on manufacturer, device, model, and hardware, as reported by the device's Android API. This rule is only applicable to Android devices running native apps, not the web.

  { "mdmh": "asus/*/ASUS_Z00AD/*" }

Resolution

The res rule matches a device based on its exact pixel resolution. This should normally only be used on iOS devices because there's a 1:1 mapping between exact resolution and phone model.

  { "res": [640, 960] }

Calculating Bezel Width

You can calculate the exact bezel width using this formula, where deviceWidth is in millimeters, screen is the screen's diagonal length in millimeters, and ratio is the screen resolution's width / height:

(deviceWidth - Math.sqrt((screen * screen) / (1 + (1 / (ratio * ratio))))) / 2;

Scripts

To generate the dpdb.json file from the dpdb-formatted.json source file, run this npm script from the command line:

npm run build

Or call this Node script directly:

node scripts/build.js --write

Change Log

The following devices were added (and/or corrections made):

2017-05-22

2017-01-19

  • Added format key to avoid 'unexpected format version' error (thanks to AdrienPoupa for spotting this oversight)

2017-01-12

2017-01-06