[OpenJDK 2D-Dev] <AWT Dev> [9] Review request for 8076545 Text size is twice bigger under Windows L&F on Win 8.1 with HiDPI display

[Alexander Scherbatiy]

   Hello,

   Could you review the updated fix:
     http://cr.openjdk.java.net/~alexsch/8076545/webrev.02

   - round is used instead of ceil
   - inverted scales are used

   Thanks,
   Alexandr.


On 10/30/2015 10:40 PM, Jim Graham wrote:
> In this case round may be better.  ceil() is more for cases where you 
> needed "at least X amount of room", but I don't think a font size is 
> an "at least this much" kind of case.
>
> Also, I've been toying with the idea that use of ceil() and floor() in 
> any DPI-adjustment equations should really be "ceil(val - epsilon)" or 
> "floor(ceil + epsilon)" for some small value of epsilon chosen just 
> large enough to prevent various round-off errors from affecting the 
> outcome.  One idea is for 1/256 as the value of epsilon since that 
> could equate to the smallest measurable difference in terms of alpha 
> or interpolation results (or 1/512 for "half the smallest quantum")...
>
>             ...jim
>
> On 10/29/15 1:36 PM, Phil Race wrote:
>> size->cx = (int)ceil(size->cx / scale);
>>
>>
>> So if size->cx / scale works out to be 12.0001 you will round it up 
>> to 13?
>>
>> Can you check what pixel size windows gives you in such a case ?
>> I'd be a little surprised if they did that rather than round.
>>
>> Is the SetFontProperty that does not accept a scale parameter still used
>> somewhere ?
>>
>> -phil.
>>
>> On 10/29/2015 04:53 AM, Sergey Bylokhov wrote:
>>> On 17.07.15 16:27, Alexander Scherbatiy wrote:
>>>>>
>>>>> - Sergey's point about multi-mon should be checked out.
>>>>      Windows 8.1 has option "Let me choose one scaling level for 
>>>> all my
>>>> displays".
>>>>      If I unset it I am able to change the size of all items. However,
>>>> the DPI which returns GetDPIForMonitor is still 2 on HiDPI displays.
>>>
>>> This version looks fine, but I am sure it can be double checked on
>>> windows 10 at some moment as well.
>>>
>>>
>>