[Pixman] [cairo] Floating point API in Pixman

M Joonas Pihlaja jpihlaja at cc.helsinki.fi
Tue Aug 10 23:00:16 PDT 2010

On Wed, 11 Aug 2010, Soeren Sandmann wrote:

> For the matrix in pixman_image_t, I think we need to just move to
> single precision floating point unconditionally. There are several
> cases where 16.16 fixed point simply doesn't have enough either range
> or precision.

Before deciding on the kind of floating point, could we think very 
hard about the precision and accuracy guarantees pixman would like to 
make for each of its operations?  Single precision floating point is 
not very far off from 16.16 after all, so I worry that we'll be in the 
same boat very quickly again if we're not careful.


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