>
> Hi Jim,
>
> The acceleration of 8-bit source images for the upcoming release of 1.3 is very good
>news. Just curious, will loading, manipulating and displaying 24-bit, true color
>images be faster as well? Bug# 4276423 refers to the "drawImage of an offscreen image
>to the screen" being slow. Is this part of what you have previously discussed and has
>been fixed in Java2D in the upcoming JDK 1.3 release?
>
> I haven't really compared image performance to the earlier JDKs, but in simple
>comparisons to native Win32 applications, loading large 24-bit images (say
>1280x1024x24bits, no transparency, BufferedImage: TYPE_INT_RGB) is between 6X and 10X
>slower depending on the host computer's memory configuration. I know the performance
>problem is primarily related to the fact that the offscreen image buffer is in normal
>memory instead of VRAM. The question I have is on what release of Java will this be
>addressed? Will it be the final release of 1.3 or a later version?
>
> Thank you,
> Julian L Brown
> Opinion One
> [EMAIL PROTECTED]
>
>
I must agree that RGB images (no alpha) are a real problem.
There is a bug which refers to stating 32-bits in the DirectColorModel,
when the mask is only 24-bits for normal drawImage() operations.
It causes Java2D to re-create temporary buffers every time. Changing the
non-alpha DirectColorModel to 24-bits is a work-around to this bug.
However, even with this work-around, the speeds on MOST graphics cards is
terrible in JDK1.2.2 . And, there is no specific bug identified, or
statement made about this problem.
On my NVIDIA ZX 8Meg, I get about 230ms to do drawImage() on an 800x600
DirectColor 24-bit, no alpha image. That is not good, but I might be able
to live with it. It is about the same in 8-bit and 24-bit depth screen.
However, on every Matrox and ATI card in our company (on 450+ MHz PII and PIII),
I get 800ms for all screen depths. This is with or without double buffering.
This is ridiculous. Native code could go 10x times this fast. This is clearly
a bug, and I am worried that it will go unfixed in JDK1.3 .
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