Rules for Claiming a Conformant WebGL Implementation ==================================================== The WebGL API is a web standard, and many web browser implementers deliver their browser on multiple operating systems (OSs). WebGL implementations also typically rely on the presence of an OpenGL or OpenGL ES implementation on the OS. It can be appreciated that a WebGL implementation therefore has many dependencies. This document attempts to clarify to potential implementers the rules the Khronos Group uses to judge whether a particular WebGL implementation is conformant. 1. Conformance on a particular operating system On a given OS, a WebGL implementation will be considered to conform to a particular version of the conformance suite if the suite passes with no test failures on at least two GPUs, each from a different vendor. If the OS only supports a GPU from one vendor, the two-GPU requirement is dropped. 2. Conformance across multiple operating systems A WebGL implementation will be considered to conform to a particular version of the conformance suite if it passes rule (1) on all of the OSs on which the WebGL implementation is intended to be supported. Discussion ========== A WebGL implementation might reach conformance on a particular OS, but a subsequent graphics driver release on that OS might introduce a regression causing failures of one or more of the WebGL conformance tests. In this situation it is not required that the browser revoke support for the "webgl" HTML Canvas context type. The browser vendor should work with the GPU vendor to ensure the driver regression is fixed. A situation like this would, however, prevent the WebGL implementer from conforming to a subsequent version of the test suite. A WebGL implementation intended to ship on three OSs may reach conformance on two of them, but due to graphics driver bugs, may be unable to reach conformance on the third. In this situation the implementation is not yet considered to be conformant. A web browser author developing a new WebGL implementation should not support the "webgl" HTML Canvas context type by default in a shipping version of the product until reaching conformance. It is acceptable to give end users an option to turn on WebGL support in a non-conformant implementation as long as the documentation for that option clearly indicates that the implementation is not yet conformant and may have compatibility issues. It is suggested that the Canvas context type "experimental-webgl" may be supported by default in such implementations. An existing WebGL implementation which conformed to an earlier version of the test suite is not required to remove support for the "webgl" HTML Canvas context type while in the process of conforming to a later version of the test suite. However, the implementer must not advertise conformance to the later version until it has been reached. It is acceptable for the implementer to advertise details of their conformance, for example number or percentage of passing or failing tests, or names of passing or failing tests. The WebGL API has strict security requirements. Even one failing test may indicate a serious security issue in the WebGL implementation. For this reason, no exceptions for failing conformance tests will be granted. The Khronos Group determines whether a particular WebGL implementation is conformant based on the implementer's conformance suite submissions, on multiple OSs and on multiple GPUs as necessary, using the rules above. An implementer shall not judge their own implementation conformant simply by applying the above rules.