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Re: [Public WebGL] Some WebGL draft feedback

Tim Johansson wrote:
On 2010-01-13 20:43, Kenneth Russell wrote:

Incorrect rendering. The exception checks would have the same performance and tentacle-spreading issues I raised before.

I don't think incorrect rendering results are an acceptable alternative. I also dispute whether the check to see if the given rendering context is "current" upon each graphics call would have any perceptible performance impact. We currently have and need such checks in the WebGL implementations for Safari and Chrome and they are negligible in cost.

I agree that incorrect rendering is not good as it is not well specified. If an implementation manages to get it looking right without calling the sync function that behavior will quickly become required since many authors will forget to call the sync functions.

That means the check is required and I don't see any real benefit of requiring a sync function to be called instead of just syncing implicitly. IMO we should not add functions to make authors think about everything that might be slow in some implementations.

The only implementation that would render correctly without synchronization is one where all graphics API's are implemented in software running on a single processor together with the application, i.e. no parallelism possible. This is also the only kind of implementation where everything would not slow down when mixing APIs. Such an implementation is extremely unlikely.


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