Enum containing WebGL Constant values by name.
for use without an active WebGL context, or in cases where certain constants are unavailable using the WebGL context
(For example, in [Safari 9]{https://github.com/AnalyticalGraphicsInc/cesium/issues/2989}).
These match the constants from the [WebGL 1.0]{https://www.khronos.org/registry/webgl/specs/latest/1.0/}
and [WebGL 2.0]{https://www.khronos.org/registry/webgl/specs/latest/2.0/}
specifications.
Enum containing WebGL Constant values by name. for use without an active WebGL context, or in cases where certain constants are unavailable using the WebGL context (For example, in [Safari 9]{https://github.com/AnalyticalGraphicsInc/cesium/issues/2989}).
These match the constants from the [WebGL 1.0]{https://www.khronos.org/registry/webgl/specs/latest/1.0/} and [WebGL 2.0]{https://www.khronos.org/registry/webgl/specs/latest/2.0/} specifications.
see: https://github.com/AnalyticalGraphicsInc/cesium/blob/8328880c6a50e4fb735f68f8b87338eb477efb1f/Source/Core/WebGLConstants.js