Thanks Sergey,

Have you been following the rest of this thread? Any thoughts on how much the lack of PRE pixel format in the PNG loader might be hurting us?

                        ...jim

On 3/27/15 5:31 PM, Sergey Bylokhov wrote:
28.03.15 0:50, Jim Graham wrote:
On 3/27/15 3:48 AM, Hendrik Schreiber wrote:

That's an odd bug.  I'll note that it points out that we had missing
loops in the OpenGL pipeline to directly deal with the non-PRE data
and it links to a bug that adds those loops for more direct handling.
Actually not, the second bug adds a loop which transform non-PRE surface
to the PRE surface on the fly in software and scale it via OGL(before
that, conversion and scale were done in software via transformhelper).
In the JDK-8059943 we save one blit, which transform non_PRE BI to PRE.
Plus it saves one more blit when we try to cache non_PRE BI into vram
because this operation will be done via OGLGeneralBlit which also
convert non-PRE to PRE on the fly.
It's also not clear why those BufferedImage objects weren't cached. If
you create a BI and render to it and then blit from it a bunch of
times it should be cached in VRAM and the format shouldn't matter, but
if you are constantly rendering to the BI, then our cache never has
time to set up - and if you grab the data buffer for that BI, then it
will never be cached.  But the buffers we use in the
ImageRepresentations should be static and should be cached.

I'm not saying that I have all of the answers as to whether or not
changing the PNG decoder to use PRE buffers would help, I'm just
trying to delineate all of the considerations that affect whether this
is a practical issue or not.  We'd need test cases to test if any of
the mechanisms I'm describing are doing their job or not...

            ...jim


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