[cairo] [PATCH pixman 02/11] pixman-filter: Correct Simpsons integration

Bill Spitzak spitzak at gmail.com
Thu Sep 11 11:22:23 PDT 2014

Actually the previous version did 1,2,6,6...6,6,2,1. Since it divided by 
3 it produced almost 2x the correct integration, though this was fixed 
by the normalization later. It also did not do Simpsons integration, 
instead it was much more like adding evenly-spaced samples.

On 09/10/2014 07:01 PM, Bill Spitzak wrote:
> Samples are multiplied in a 1,4,2,4,2,4,1 pattern, previous version
> did 1,2,4,4,4,2,1.
> I also reduced the number of samples greatly as there is no
> numerical difference with the filter functions.

More information about the cairo mailing list