[OpenJDK 2D-Dev] Provide a way to make MultiResolutionImage screen compatible

[Hendrik Schreiber]

> On Apr 1, 2015, at 16:32, Sergey Bylokhov <Sergey.Bylokhov at oracle.com> wrote:
> 
> Hi, Jim.
> 31.03.15 0:00, Jim Graham wrote:
>> Hi Sergey,
>> 
>> Slow us down where?
> Slowdown occurs before the images will be cached in the native texture. At least two times: for the first time "image->conversion->window" blit and for the second time "image->conversion->texture->window" blit. Plus we will get a slow down when we cannot create a texture for some reason(big/unsupported size, low vc memory on intel etc).
> Simple image copy on my osx 10.10 retina(J2DBench 1000x1000 BufferedImage to the screen):
> argb_pre: num-reps="1268"
> argb image: num-reps="539"
> cached image: num-reps="10362"
> 
> Not a big deal, but based on this I changed all image types in the swing to eliminate these unnecessary conversions.

Sergey,

do I understand this correctly, when I say, it seems that using the "wrong" image type there is a two time penalty, but once the image is cached (which happens, once we drew it), it will draw as quickly as any other VRAM-cached image?

In other words: the gain of adjusting PNGDecoder to produce pre-multiplied images is probably minimal?

Thanks,

-hendrik