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Re: [Public WebGL] Should GLfloat and GLclampf be typedefs for "unrestricted float"?



On 2012/11/20 0:35, Benoit Jacob wrote:
For many WebGL functions taking GLfloat, it is actually very important
to _not_ throw, because these floats are often the result of nontrivial
arithmetic, and nontrivial floating-point arithmetic does produce
non-finite values, and good floating-point API design is to handle such
non-finite values gracefully.

So it's actually very important to make GLfloat unrestricted.
+1

For GLclampf, I don't know. Since GLfloat must be unrestricted, and IIUC
current browsers implement unrestricted anyways, it may be simpler to
keep it unrestricted. That may also be a good idea as GLclampf's too may
be the result of nontrivial floating point operations.
If GLfloat is unrestricted GLclampf should also be.

But note that the ES 2.0 spec says using NaN or infinity will produce unspecified results; it also says that these values should not result in "GL interruption or termination."

The WebGL spec. does not specify what the results should be either so I would hardly say that non-finite values are handled "gracefully." Graceful handling would probably require that the values be propagated as specified in IEEE 754. But I think throwing an exception would be akin to "GL interruption" so I come down on the side of unrestricted.

Regards

    -Mark

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