java2d performance java7 / java8

[Sergey Bylokhov]

Hello,
Yes you are right, in the opengl pipeline usage of ARGB_PRE is 
preferable, but other pipelines can use different formats. So it is 
better to use GraphicsConfiguration.createCompatibleImage()
http://docs.oracle.com/javase/8/docs/api/java/awt/GraphicsConfiguration.html#createCompatibleImage-int-int-int-

On 29.01.2015 3:35, DRC wrote:
> I discovered in my own testing that, at least for my application 
> (which is drawing large BufferedImages to the screen), using a 
> TYPE_INT_ARGB_PRE BufferedImage is in some cases 4-5x as fast as using 
> a TYPE_INT_RGB BufferedImage.  The reason is because, if the pixel 
> format isn't alpha-enabled, then OGLBlitSwToSurface() will call 
> glPixelTransferf() to set the alpha scale and bias.  This is basically 
> instructing glDrawPixels() to set the alpha components to a particular 
> value, which can be incredibly slow (probably not even 
> hardware-accelerated on a lot of platforms.)  It's much faster to set 
> the alpha components to opaque in my source image.

Note that you can rewrite this part of openjdk, sources are open, 
patches are welcome!

>
> On my 2009 Mac Mini, the difference this makes is about 4x (80 
> Mpixels/sec vs. 20.)  On my Linux machine with a high-end nVidia card, 
> using ARGB_PRE with -Dsun.java2d.opengl=true increases the performance 
> from 300 Mixels/sec to 400.  On my MacBook Pro, the performance 
> increase is also about 1/3.  So I think that, in general, using 
> ARGB_PRE BufferedImages is best when using OpenGL Java2d blitting.
>
> The Mac performance with Java 1.7 or 1.8 is still not as good as it 
> was under Apple Java 1.6 (which was about 120 Mpixels/sec on the Mac 
> Mini), but it's at least a lot better.
>
>
> On 10/7/14 12:01 PM, Hendrik Schreiber wrote:
>> On Aug 22, 2014, at 11:59, Hendrik Schreiber <hs at tagtraum.com> wrote:
>>
>>> On Aug 18, 2014, at 16:05, Florian Bruckner (3kraft) 
>>> <florian.bruckner at 3kraft.com> wrote:
>>>
>>> [...]
>>>
>>> Thanks for coming up with some sort of test.
>>>
>>> Hopefully the folks at Oracle find the time to look into this, 
>>> perhaps do their own performance testing, and find ways to improve 
>>> the 2D pipeline.
>>
>> Looks like we have something to look forward to:
>>
>> http://mail.openjdk.java.net/pipermail/2d-dev/2014-October/004870.html
>>
>> -hendrik


-- 
Best regards, Sergey.