RE: [office-comment] draw:extrusion-first-light-harsh (ODF all versions)

["Alex Brown" <alexb@griffinbrown.co.uk>]

Rob hi

It is of course *entirely* within the TC's power to cherish whatever
vague terms and unknowable concepts it wants. By that logic harsh
lights, metallic surfaces and (from another world) autoSpaceLikeWord95
are all fine things.

At least then the text should be honest about it, and state that the
implementation of harsh lighting is application-defined.

> We are not obligated to specify the 
> exact radius of curvature when we say a text box has "rounded 
> edges"

Hmmmmmm -- ODF seems rather schizophrenic on this topic of graphical
specificity. If it only wanted to *gesture* in the direction of what an
implementation should do, I'd expect for @draw:sharpness something
_like_:

"this attribute's percentage value shall specify how sharp a polygon's
corners are".

But no, we get in actual fact:

----b
The draw:sharpness attribute specifies the radius of the ellipse on
which inner polygon corners are located. The value is a percentage,
where 0% means that all corners are located on a single ellipse, while
100% means that the inner corners are located at the center point of the
polygon. In general, if r is the radius of the polygon, and s is the
sharpness, the inner corners a [sic] located on a ellipse that's [sic]
radius is r(100-s)/100.

Note: This attribute is only meaningful only with a draw:concave
attribute with the value true.
----e

So (leaving aside the errors in this extract) it seems some aspects of
shape rendition are specified in really quite precise detail, others are
so underspecified as to be meaningless. 

> we do not need to specify the exact size, in 
> steradians, of a harsh light source.

No, but it's only you who who's talking about "steradians". Some plain
but brief description (maybe along the lines Bob suggested) would be
fine. Just something concrete for the implementer to implement.

As it is, this has been an interesting exchange. I think, after this,
that in fact there is no such thing as a "harsh light" as applied to a
light *source*; only harsh reflected light. So I'd recommend removing
these harsh lighting attributes from ODF.

BTW - has anybody actually implemented this feature? I'd like to see
some harsh lighting in action!

- Alex.