[cairo] MIPMAPPING cairo.
frederic.plourde at polymtl.ca
Thu Oct 16 06:45:13 PDT 2008
Jeff Muizelaar a écrit :
> On Wed, Oct 15, 2008 at 09:14:04AM -0400, Frédéric Plourde wrote:
>>> Are you sure this bilinear sample is correct? It looks far worse than
>>> anything I have seen. Looks more like the image was scaled to 50% and
>>> the binlinearly scaled up. The current algorithim only fails if the
>>> scale is less than 60% or so.
>> Mhh.. yep, pretty sure. What's happening maybe is that the source image
>> "http://img58.imageshack.us/img58/8669/src1231x1504np1.png" gets
>> automatically resized in FF3 (and other browsers ?), but is really
>> bigger than it seems. So, we're really talking about downscaling with a
>> large factor.... which kills text image as you've seen.
> It looks to me like
> is the wrong image. Bilinear filtering shouldn't look that, and it
> doesn't match what I get when I run the test program myself.
Finally guys, you were all right ! ;-)
I don't know what happened, I think ImageShack has screwed up that
bilinear image... weird !
so here it is as it should be :
and I just realized I showed you images that were downscaled less than
2X ! duh !
To really see the differences between bilinear and mipmapping perf,
let's see those other ones :
* Former 'nearest' and 'bilinear" modes :
* New mipmaping modes :
The improved quality here is really clear! One can even see that
trilinear (linear_MM_linear) is not - in that case - so different from
the linear_MM_nearest one. This is because the target scale is "close"
to mipmap levels.
The really iinteresting mode is LINEAR_MIPMAP_NEAREST.
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