[mapserver-dev] Precision about geotransform

[Mohamed Saâd HESSANE]

I don't think so. If it was, juste when a cos or a sin vanish.
My first thought was that mapserver have to calculate more pixels in a
rotated map than a normale map. But when i read the source code i found that
it's the projection which rotate, not the map. So why this discimination?
The same projection


2011/4/21 Stephen Woodbridge <woodbri at swoodbridge.com>

> On 4/21/2011 10:32 AM, Mohamed Saād HESSANE wrote:
>
>> Hy list,
>> I have a question. I'm doing a benchmarking test of a rotated map, and i
>> get the result in the attached file.
>> My question is why it take more time to draw a map rotated at 45° than a
>> map rotated at 90° or 183° ???
>> Thank you !
>>
>
> I'm only guessing here but could it be that the math required to compute
> cos and sin is more costly in cpu cycles at those angles.
>
> Regardless, this is an interesting question and I love the graphic, nice
> job on that.
>
> -Steve W
> _______________________________________________
> mapserver-dev mailing list
> mapserver-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/mapserver-dev/attachments/20110421/83f2a5a0/attachment.html