[OpenJDK 2D-Dev] [9] Review Request: 8146042 Offscreen rendering is different from onscreen one

[Sergey Bylokhov]

On 01.02.16 12:23, Semyon Sadetsky wrote:
>
>
> On 1/21/2016 5:04 PM, Sergey Bylokhov wrote:
>> On 19/01/16 14:30, Semyon Sadetsky wrote:
>>> We are getting error because of incorrect fudge factor added to the "to"
>>> line coordinates (for line from - to).
>>> See the updated version of the fix in which test should work on OS X:
>>> http://cr.openjdk.java.net/~ssadetsky/8146042/webrev.02/
>>> Test fails on my mac book-pro with integrated i7 GPU - rectangle is
>>> drawn at wrong position.
>>
>> It will fail on any hdpi systems(including osx+retina), The reason is
>> that: when you create a VolatileImage it will take into account
>> default transform of the GraphicsConfiguration(on hdpi systems it will
>> be x2). When you draw a line to this VI and then take s spapshot then
>> you convert the big VI image to the small BI. you need to take into
>> account this scale and draw VI to BI 1-2-1, something like this:
>> BufferedImage capture = new BufferedImage(12x2, 12x2,
>> BufferedImage.TYPE_4BYTE_ABGR_PRE);
>> capture.createGraphics().drawImage(vi,0,0,12x2,12x2,null);
>>
>> Note that even in this case the line locations check is incorrect and
>> should be adjusted.
> I tried what you've proposed. The position of the up-scaled image is
> wrong as well 1-21 instead of 2-22.

Why wrong? this is correct result, the simple BufferedImage will produce 
the same:
         BufferedImage bi = new BufferedImage(12*2, 12*2, 
BufferedImage.TYPE_INT_ARGB_PRE);
         Graphics2D g1 = bi.createGraphics();
         g1.scale(2,2);
         g1.setColor(Color.black);
         g1.drawRect(1, 1, 9, 9);
         g1.dispose();
         ImageIO.write(bi,"png",new File("gold.png"));

When you draw a line you set the middle point of the line, not the left 
point. So the x=1px when scaled will cover the pixels 1 and 2, not the 2 
and 3.

> I think test may be remained the same.
>>
>>
>>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>> --Semyon
>>>>>>>>>
>>>>>>>>> On 1/14/2016 9:23 PM, Phil Race wrote:
>>>>>>>>>> This fudge factor was last adjusted in
>>>>>>>>>> https://bugs.openjdk.java.net/browse/JDK-6597822
>>>>>>>>>> way back before the D3D pipeline was released and the comments
>>>>>>>>>> seem to
>>>>>>>>>> indicate that
>>>>>>>>>> there was a fair amount of testing on different hardware.
>>>>>>>>>>
>>>>>>>>>> I don't know why this seems to be in un-specified
>>>>>>>>>> hardware-dependent
>>>>>>>>>> territory but
>>>>>>>>>> it seems quite possible that this could just as easily
>>>>>>>>>> introduce a
>>>>>>>>>> different artifact
>>>>>>>>>> on some other hardware.
>>>>>>>>>>
>>>>>>>>>> What exactly are you testing on ? And I think it needs to
>>>>>>>>>> include at
>>>>>>>>>> least one Nvidia
>>>>>>>>>> and one AMD/ATI card.
>>>>>>>>>>
>>>>>>>>>> -phil.
>>>>>>>>>>
>>>>>>>>>> On 1/14/2016 10:09 AM, Semyon Sadetsky wrote:
>>>>>>>>>>> Hello,
>>>>>>>>>>>
>>>>>>>>>>> Please review the fix for jdk9.
>>>>>>>>>>>
>>>>>>>>>>> bug: https://bugs.openjdk.java.net/browse/JDK-8146042
>>>>>>>>>>> webrev: http://cr.openjdk.java.net/~ssadetsky/8146042/webrev.00/
>>>>>>>>>>>
>>>>>>>>>>> The root cause is incorrect coordinate rounding in D3D
>>>>>>>>>>> renderer. To
>>>>>>>>>>> fix the issue one of fudge factors was adjusted.
>>>>>>>>>>>
>>>>>>>>>>> Another issue mentioning in the JIRA ticket is taken out as a
>>>>>>>>>>> separate bug.
>>>>>>>>>>>
>>>>>>>>>>> --Semyon
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>
>>
>>
>


-- 
Best regards, Sergey.