<Swing Dev> [9] Review request for 8162350 RepaintManager shifts repainted region when the floating point UI scale is used

Wed Nov 30 23:59:41 UTC 2016

These results are good.  I'm for simplifying as well...

			...jim

On 11/30/16 3:57 PM, Sergey Bylokhov wrote:
> On 29.11.16 20:46, Alexandr Scherbatiy wrote:
>>   The result of running SwingMark 2 with the following JDK is:
>>   1. without the fix
>>     1st test run [1]: 92373
>>     2nd test run [2]: 92156
>>
>>    average: (92373 + 92156) / 2 = 92264.5
>>
>>   2. paintDoubleBufferedImp() method is always used
>>     1st test run [3]: 92476    // (92476 - 92264.5) / 92264.5 / 100 =
>> 0.000023%
>>     2nd test run [4]: 90800  // (90800 - 92264.5) / 92264.5 / 100 =
>> -0.000159%
>>
>>   3.paintDoubleBufferedFPScales () method is always used
>>     1st test run [5]: 91053    // (91053 - 92264.5) / 92264.5 / 100 =
>> -0.000131%
>>     2nd test run [6]: 92900    // (92900 - 92264.5) / 92264.5 / 100 =
>> 0.000069%
>
> So it seems we can simplify the this codepath and always use the new method? Do we have some arguments against it?
>
>> [1]
>> http://cr.openjdk.java.net/~alexsch/8162350/swingmark2/repaint-manager-fp-scale-base_00.txt
>>
>> [2]
>> http://cr.openjdk.java.net/~alexsch/8162350/swingmark2/repaint-manager-fp-scale-base_01.txt
>>
>> [3]
>> http://cr.openjdk.java.net/~alexsch/8162350/swingmark2/repaint-manager-fp-scale-int_00.txt
>>
>> [4]http://cr.openjdk.java.net/~alexsch/8162350/swingmark2/repaint-manager-fp-scale-int_01.txt
>>
>> [5]
>> http://cr.openjdk.java.net/~alexsch/8162350/swingmark2/repaint-manager-fp-scale-fp_00.txt
>>
>> [6]
>> http://cr.openjdk.java.net/~alexsch/8162350/swingmark2/repaint-manager-fp-scale-fp_01.txt
>>
>>>
>>> On 21.11.16 16:59, Alexandr Scherbatiy wrote:
>>>>
>>>> Hello,
>>>>
>>>> Could you review the updated fix:
>>>>   http://cr.openjdk.java.net/~alexsch/8162350/webrev.04
>>>>
>>>>  - isFloatingPointScale(AffineTransform) is moved from the SunGraphics2D
>>>> to the SwingUtilities2 class.
>>>>
>>>>   Thanks,
>>>>   Alexandr.
>>>>
>>>> On 11/18/2016 11:23 PM, Jim Graham wrote:
>>>>> Hi ALexandr,
>>>>>
>>>>> This looks great.
>>>>>
>>>>> BTW, when I suggested moving the FPscale test into SG2D I was
>>>>> suggesting that to avoid having to copy the transform out of it via
>>>>> getTransform(), but you've found a different solution to that issue
>>>>> (i.e. the new getTransform(g) method) so it no longer matters where
>>>>> that utility static function is located.  You can move it back to one
>>>>> of the Swing classes.
>>>>>
>>>>> In terms of the logic of choosing which repaint function to use, it
>>>>> looks like you use the old-style function if the scales don't match,
>>>>> but won't that cause rendering anomalies?  The new code is still an
>>>>> improvement for the standard HiDPI case, and I'm guessing that
>>>>> mismatched scales probably never tends to happen, but we might want to
>>>>> flag it for further investigation.
>>>>>
>>>>> +1 relative to whether you want to move the FPscale test back out of
>>>>> SG2D or not...
>>>>>
>>>>>             ...jim
>>>>>
>>>>> On 11/18/16 1:44 AM, Alexandr Scherbatiy wrote:
>>>>>>
>>>>>> Thank you. I see that using the integer device-pixel translations
>>>>>> preserves the component painting in the same way for
>>>>>> floating point scales.
>>>>>>
>>>>>> Could you review the updated fix:
>>>>>>   http://cr.openjdk.java.net/~alexsch/8162350/webrev.03
>>>>>>
>>>>>>   - translation adjustment is removed
>>>>>>   - Region.clipRound() is used for pixels coordinates rounding.
>>>>>>
>>>>>>   Thanks,
>>>>>>   Alexandr.
>>>>>>
>>>>>> On 11/16/2016 1:52 AM, Jim Graham wrote:
>>>>>>> Let me clarify something...
>>>>>>>
>>>>>>> On 11/15/16 2:49 AM, Alexandr Scherbatiy wrote:
>>>>>>>>   Let's consider the following use case:
>>>>>>>>   scale = 1.5
>>>>>>>>   A component calls fillRect(1, 1, 1, 1).
>>>>>>>>   This is (1.5, 1.5, 3.0, 3.0) in the device space
>>>>>>>>   which fills  (1, 1, 3, 3) and covers 2x2 pixels
>>>>>>>
>>>>>>> Agreed.
>>>>>>>
>>>>>>>>   Now the area (1, 1, 1, 1) needs to be repainted
>>>>>>>>     create a backbuffer
>>>>>>>>     translate(-1, -1) // move the top left corner of the area to
>>>>>>>> the zero point
>>>>>>>>     draw the component into the backbuffer:
>>>>>>>>       fillRect(1, 1, 1, 1) -> after translation fillRect(0, 0, 1,
>>>>>>>> 1) -> after scaling  (0.0, 0.0, 1.5, 1.5 ) in the
>>>>>>>> device space
>>>>>>>>       which fills (0, 0, 1, 1) and covers 1x1 pixels
>>>>>>>
>>>>>>> If you did g.setTransform(identity), g.translate(-1, -1), (then
>>>>>>> restore the scale) then the analysis is as follows:
>>>>>>>
>>>>>>> g.setTransform(identity) => [1 0 0] [0 1 0]
>>>>>>> g.translate(-1, -1) => [1 0 -1] [0 1 -1]
>>>>>>> g.scale(1.5, 1.5) => [1.5 0 -1] [0 1.5 -1]
>>>>>>> g.fillRect(1, 1, 1, 1)
>>>>>>>     => coordinates are (1.5-1, 1.5-1, 3-1, 3-1)
>>>>>>>     => (.5, .5, 2, 2)
>>>>>>>     => fills (0, 0, 2, 2)
>>>>>>>     => which covers 2x2 pixels
>>>>>>>
>>>>>>> If you did g.translate(-1, -1) on the scaled transform then the
>>>>>>> analysis is as follows:
>>>>>>>
>>>>>>> g.transform is [1.5 0 0] [0 1.5 0]
>>>>>>> g.translate(-1, -1) is [1.5 0 -1.5] [0 1.5 -1.5]
>>>>>>> g.fillRect(1, 1, 1, 1)
>>>>>>>     => coordinates are (1.5-1.5, 1.5-1.5, 3-1.5, 3-1.5)
>>>>>>>     => (0, 0, 1.5, 1.5)
>>>>>>>     => fill (0, 0, 1, 1)
>>>>>>>     => covers 1x1 pixels
>>>>>>>
>>>>>>> The second operation is what you are describing above and that would
>>>>>>> be an inappropriate way to perform damage repair
>>>>>>> because you used a scaled translation which did not result in an
>>>>>>> integer coordinate translation.
>>>>>>>
>>>>>>> Please re-read my previous analysis that shows what happens when you
>>>>>>> use integer device-pixel translations which are
>>>>>>> translations that happen using integers on a non-scaled transform.
>>>>>>> Note that you can add a scale *AFTER* you apply
>>>>>>> the integer device pixel translation and it will not affect the
>>>>>>> integer-ness of the translation.  You can see above
>>>>>>> that the difference in how the translate command is issues affects
>>>>>>> where the translation components of the matrix end
>>>>>>> up being -1,-1 or -1.5,-1.5...
>>>>>>>
>>>>>>>             ...jim
>>>>>>
>>>>
>>>
>>>
>>
>
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