[OpenJDK 2D-Dev] [9] Review request for 8023794: [macosx] LCD Rendering hints seems not working without FRACTIONALMETRICS=ON

Denis S. Fokin denis.fokin at gmail.com
Wed Nov 5 13:57:44 UTC 2014


Hi Andrew,

I have noticed an issue with quartz (at list with our way to use it). 

This is a simple project that allows to illustrate the issue with a pure Quartz and Cocoa.

https://github.com/denis-fokin/OffscreenVsQuartzFontRendering <https://github.com/denis-fokin/OffscreenVsQuartzFontRendering>

Below you can see results.

I used the same MBP with an external Thunderbolt display.

Rendering of a glyph in the view and in the offscreen bitmap is the same for non-retina display.

http://imgur.com/Y33C0tF,vnn5Ajt#0 <http://imgur.com/Y33C0tF,vnn5Ajt#0>

In case of retina, it seems that the image uses improper number of pixels.

http://imgur.com/Y33C0tF,vnn5Ajt#1 <http://imgur.com/Y33C0tF,vnn5Ajt#1>

I see the same effect in the java-2d sub pixel rendering implementation.

Right now I am not sure, how to handle this properly.

Thank you,
   Denis.


> On 24 Oct 2014, at 21:56, Andrew Brygin <andrew.brygin at oracle.com> wrote:
> 
> Hello,
> 
>  please take a look to updated version of the fix:
> 
> http://cr.openjdk.java.net/~bae/8023794/9/webrev.03/ <http://cr.openjdk.java.net/~bae/8023794/9/webrev.03/>
> 
>  TODOs were removed:
>  * CGLSurfaceData.java
>       the condition for lcd rendering is inherited from OGL surface data, but
>       here we have to remove the check for the transparency, because we always
>       create transparent  volatile images for swing backbuffers on macosx in order
>       to support shaped windows.
> 
>  * CGGlyphImages.m and AWTStrike.m
>       NSException is used to  handle invalid (unevaluated) text antialising hint values.
>       We actually have already used NSException to handle memory allocation failure,
>       so this change just makes usage of get/release of primitive arrays a bit more safe.
> 
> 
> Known differences comparing to apple jdk6:
> 
> a) we do not interpret TEXT_ANTIALIASING_ON as lcd text.
> 
> b) we do not render lcd text in a case of non-opaque paint. This behavior is common for 
>      all cases (software loops, OGL, and D3D), so it seems to deserve a separate bug if we
>      want to handle this case.
> 
> Thanks,
> Andrew
> 
> On 10/14/2014 3:39 AM, Phil Race wrote:
>> On 10/13/2014 05:41 AM, Andrew Brygin wrote:
>>> Hello Phil,
>>> 
>>>  please see my comments inline.
>>> 
>>> On 10/13/2014 12:05 AM, Phil Race wrote:
>>>> 373         fontHints.put(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
>>>> 374         fontHints.put(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_LCD_HBGR);
>>>> 
>>>> 
>>>> I am not sure why we have the graphics AA hint "ON" set here.
>>>> Its not truly a font hint even though if its set it implcitly triggers font AA to be on too.
>>>> If you remove that first line do you notice any problems with Swing apps ?
>>> I failed to spot any difference in the SwingSet2 demo after removal the line 373.
>> 
>> Hmm .. Sergey seemed to suggest it was needed.
>> I was concerned that it might subvert the text rendering hint
>> as it used to cause us to do everything via the graphics AA loops.
>> So I guess I am not sure what the impact of removing it will be
>> You probably should check if it changes Metal & Nimbus rendering
>> in SwingSet as it looks to be read by those but I don't see anywhere
>> Aqua is reading these hints which is puzzling as you'd think that's
>> where they were wanted.
>> 
>>> 
>>>> 
>>>> 
>>>> The logic in the following code looks odd to me ..
>>>> 310 static CGGI_GlyphInfoDescriptor grey =
>>>>  311     { 1, &CGGI_CopyImageFromCanvasToAlphaInfo };
>>>>  312 static CGGI_GlyphInfoDescriptor rgb =
>>>>  313     { 3, &CGGI_CopyImageFromCanvasToRGBInfo };
>>>>  314 
>>>>  315 static inline CGGI_RenderingMode
>>>>  316 CGGI_GetRenderingMode(const AWTStrike *strike)
>>>>  317 {
>>>>  318     CGGI_RenderingMode mode;
>>>>  319     mode.cgFontMode = strike->fStyle;
>>>>  320 
>>>>  321     switch (strike->fAAStyle) {
>>>> 
>>>>  322     case sun_awt_SunHints_INTVAL_TEXT_ANTIALIAS_OFF:
>>>>  323     case sun_awt_SunHints_INTVAL_TEXT_ANTIALIAS_ON:
>>>> 
>>>> 
>>>>  324         mode.glyphDescriptor = &grey;
>>>>  325         break;
>>>>  326     case sun_awt_SunHints_INTVAL_TEXT_ANTIALIAS_LCD_HRGB:
>>>>  327     case sun_awt_SunHints_INTVAL_TEXT_ANTIALIAS_LCD_HBGR:
>>>>  328     case sun_awt_SunHints_INTVAL_TEXT_ANTIALIAS_LCD_VRGB:
>>>>  329     case sun_awt_SunHints_INTVAL_TEXT_ANTIALIAS_LCD_VBGR:
>>>>  330         mode.glyphDescriptor = &rgb;
>>>>  331         break;
>>>>  332     case sun_awt_SunHints_INTVAL_TEXT_ANTIALIAS_GASP:
>>>>  333     case sun_awt_SunHints_INTVAL_TEXT_ANTIALIAS_DEFAULT:
>>>>  334     default:
>>>>  335         // TODO: generate an error?
>>>>  336         break;
>>>>  337     }
>>>> 
>>>> 
>>>> .. If we get to default does this mean aliased rendering ?
>>>> If so why would "OFF" go the grey path - seems it should go default
>>>> And "GASP" looks like there is no support to specify the intended meaning there
>>>> Given that OS X text  is unhinted I'd think "ON" is a better option here
>>>> even though most fonts would do "OFF" at typical screen sizes .. but that's
>>>> because they are expecting hinted rendering. So I think you need to get
>>>> hinted glyphs to default this to aliased ..
>>> 
>>> If my understanding is correct, we never get TEXT_ANTIALIAS_GASP and
>>> TEXT_ANTIALIAS_DEFAULT here, because these hints must be already evaluated
>>> and translated to either TEXT_ANTIALIAS_OFF, or TEXT_ANTIALIAS_ON.
>>> It should be done in SunGraphisc2D.checkFontInfo(), lines 699 - 775.
>> 
>>   this is probably right so its OK .. 
>> 
>> -phil.
>> 
>>> 
>>> At this point we have no enough info to evaluate these hints properly,
>>> and a best solution is probably to raise an error.
>>> 
>>> Thanks,
>>> Andrew
>>> 
>>>> 
>>>> -phil.
>>>> 
>>>> 
>>>> On 10/10/14 2:13 PM, Andrew Brygin wrote:
>>>>> Hello Phil,
>>>>> 
>>>>> please see my comments inline.
>>>>> 
>>>>> On 10/11/2014 12:49 AM, Phil Race wrote:
>>>>>> On 10/10/14 11:05 AM, Andrew Brygin wrote:
>>>>>>> Hello Phil,
>>>>>>> 
>>>>>>>  changes in SunGraphics2D and SurfaceData were made in order to
>>>>>>>  implement an approach 'LCD instead of greyscale AA if possible'.
>>>>>>> 
>>>>>>>  Without this part of change, we get results according to the hints:
>>>>>>>  greyscale for TEXT_ANTIALIAS_ON, and subpixels  for lcd hints:
>>>>>>> 
>>>>>>> http://cr.openjdk.java.net/~bae/8023794/9/webrev.01/ <http://cr.openjdk.java.net/%7Ebae/8023794/9/webrev.01/>
>>>>>> 
>>>>>> So you are changing the meaning of application-specified "ON" across platforms ?
>>>>>> That sounds wrong - even for Mac ...
>>>>> 
>>>>> now I do not: the fix revision 01 does not change the meaning of the hints,
>>>>> and just makes text rendering on macosx to behave  in a similar manner as
>>>>> on windows.
>>>>> 
>>>>> Please take a look at the webrev.01.
>>>>> 
>>>>> Thanks,
>>>>> Andrew 
>>>>>> 
>>>>>>> 
>>>>>>>  I am not sure whether do we need to change the 'default' 
>>>>>>>  behavior: at the moment it produces aliased text.
>>>>>> 
>>>>>> default has meant aliased in all the non-mac sun/oracle implementations
>>>>>> since JDK 1.2. We have talked about changing it to something
>>>>>> more modern but should not do it lightly ..
>>>>>> 
>>>>>> -phil.
>>>>>> 
>>>>>>> 
>>>>>>> Thanks,
>>>>>>> Andrew
>>>>>>>  
>>>>>>> On 10/10/2014 8:54 PM, Phil Race wrote:
>>>>>>>> I don't have my head around all these changes but a lot of it seems to
>>>>>>>> imply we really weren't asking for LCDon Mac when we could/should.
>>>>>>>> 
>>>>>>>> The change in the shared SurfaceData.javais something I want to
>>>>>>>> ask about as you have commented out as follows ..
>>>>>>>> ;
>>>>>>>>  749 
>>>>>>>>  750         // TODO: we have to take into account aaHint on macosx
>>>>>>>>  751         //case SunHints.INTVAL_TEXT_ANTIALIAS_ON:
>>>>>>>>  752         //    return aaTextRenderer;
>>>>>>>> 
>>>>>>>> ...
>>>>>>>> 
>>>>>>>> that looks like the case where the application code has *explicitly*
>>>>>>>> specified greyscale (ON==greyscale) so I don't see why you need
>>>>>>>> to go check the fontinfo in this case ?
>>>>>>>> 
>>>>>>>> -phil.
>>>>>>>> 
>>>>>>>> On 10/10/2014 07:34 AM, Andrew Brygin wrote:
>>>>>>>>> Hello Denis,
>>>>>>>>> 
>>>>>>>>>  could you please take a look at a preliminary version of the fix?
>>>>>>>>>  
>>>>>>>>>  http://cr.openjdk.java.net/~bae/8023794/9/webrev.00/ <http://cr.openjdk.java.net/%7Ebae/8023794/9/webrev.00/>
>>>>>>>>> 
>>>>>>>>>  This fix promotes the text antialiasing from grayscale to LCD if
>>>>>>>>>  destination surface data is able to render LCD, and provides
>>>>>>>>>  selection of an appropriate text pipeline for both cases.
>>>>>>>>>  It also separates production of gatyscale and LCD glyph images.
>>>>>>>>> 
>>>>>>>>> Thanks,
>>>>>>>>> Andrew
>>>>>>>>> 
>>>>>>>>> On 10/9/2014 4:13 PM, Denis Fokin wrote:
>>>>>>>>>> Hi Andrew,
>>>>>>>>>> 
>>>>>>>>>> I am happy about you participation in this work!
>>>>>>>>>> 
>>>>>>>>>> Looks like, I have missed this letter, while being sick. Sorry about this.
>>>>>>>>>> 
>>>>>>>>>> I signed OCA, but I have not gotten access to cr.openjdk.java.net <http://cr.openjdk.java.net/> yet. This is the reason why I have not updated the webrev.
>>>>>>>>>> 
>>>>>>>>>> I think that an API that is consistent with other platforms is a great solution. It just requires more efforts and multi-platform testing. On the other hand, a property could be a safe start.
>>>>>>>>>> 
>>>>>>>>>> As for the offscreen rendering, I have some kind of a workaround with the next approach.
>>>>>>>>>> 
>>>>>>>>>> In BufImgSurfaceData.getRenderLoops() I always return super.getRenderLoops(sg2d), and never solid loops.
>>>>>>>>>> 
>>>>>>>>>> In case if “useQuartz" flag is specified, I return only lcdTextRenderer from SurfaceData.getTextPipe()
>>>>>>>>>> 
>>>>>>>>>> Of course it is a brute force approach, but it allows producing a legible text in case of offscreen rendering.
>>>>>>>>>> 
>>>>>>>>>> Thank you,
>>>>>>>>>>    Denis.
>>>>>>>>>> 
>>>>>>>>>> On 29 Sep 2014, at 19:30, Andrew Brygin <andrew.brygin at oracle.com <mailto:andrew.brygin at oracle.com>> wrote:
>>>>>>>>>> 
>>>>>>>>>>> Hello Denis,
>>>>>>>>>>> 
>>>>>>>>>>>  I am not sure whether we should use 'apple.awt.graphics.UseQuartz' property.
>>>>>>>>>>>  Probably we have to change the text antialiasing defaults for macosx instead.
>>>>>>>>>>> 
>>>>>>>>>>>  I am working on the issue with software loops. I will update the thread
>>>>>>>>>>>  with my findings.
>>>>>>>>>>> 
>>>>>>>>>>> Thanks,
>>>>>>>>>>> Andrew
>>>>>>>>>>>   
>>>>>>>>>>> On 9/3/2014 3:32 PM, Denis Fokin wrote:
>>>>>>>>>>>> Hi Sergey and 2d team,
>>>>>>>>>>>> 
>>>>>>>>>>>> I have rewritten the fix. It works fine for text rendered on window using OpenGL.
>>>>>>>>>>>> 
>>>>>>>>>>>> http://web-dot.ru/openjdk/8023794/webrev.00/index.html <http://web-dot.ru/openjdk/8023794/webrev.00/index.html>
>>>>>>>>>>>> 
>>>>>>>>>>>> It is incomplete though. It does not work for rendering in a buffered image.
>>>>>>>>>>>> 
>>>>>>>>>>>> Additionally, I have not tested the code on other platforms except MacOS X.
>>>>>>>>>>>> 
>>>>>>>>>>>> To enable the antialiasing you should pass
>>>>>>>>>>>> 
>>>>>>>>>>>> -Dapple.awt.graphics.UseQuartz=true
>>>>>>>>>>>> 
>>>>>>>>>>>> to java.
>>>>>>>>>>>> 
>>>>>>>>>>>> The current issue now is the glyph info bytes that are passed from CGGlyphImage to AATextRenderer.
>>>>>>>>>>>> 
>>>>>>>>>>>> To render data we use DEFINE_SOLID_DRAWGLYPHLIST* macros. Basing on the macros a set of functions is generated for the next loops.
>>>>>>>>>>>> 
>>>>>>>>>>>> sun/java2d/loops/ByteGray.c
>>>>>>>>>>>> sun/java2d/loops/ByteIndexed.c
>>>>>>>>>>>> sun/java2d/loops/FourByteAbgr.c
>>>>>>>>>>>> sun/java2d/loops/FourByteAbgrPre.c
>>>>>>>>>>>> sun/java2d/loops/Index12Gray.c
>>>>>>>>>>>> sun/java2d/loops/Index8Gray.c
>>>>>>>>>>>> sun/java2d/loops/IntArgb.c
>>>>>>>>>>>> sun/java2d/loops/IntArgbBm.c
>>>>>>>>>>>> sun/java2d/loops/IntArgbPre.c
>>>>>>>>>>>> sun/java2d/loops/IntBgr.c
>>>>>>>>>>>> sun/java2d/loops/IntRgb.c
>>>>>>>>>>>> sun/java2d/loops/IntRgbx.c
>>>>>>>>>>>> sun/java2d/loops/LoopMacros.h
>>>>>>>>>>>> sun/java2d/loops/ThreeByteBgr.c
>>>>>>>>>>>> sun/java2d/loops/Ushort555Rgb.c
>>>>>>>>>>>> sun/java2d/loops/Ushort555Rgbx.c
>>>>>>>>>>>> sun/java2d/loops/Ushort565Rgb.c
>>>>>>>>>>>> sun/java2d/loops/UshortGray.c
>>>>>>>>>>>> sun/java2d/loops/UshortIndexed.c
>>>>>>>>>>>> 
>>>>>>>>>>>> For instance, C preprocessor generates the next code for IntRgb.c
>>>>>>>>>>>> 
>>>>>>>>>>>> void IntRgbDrawGlyphListLCD(/*…*/){
>>>>>>>>>>>>   jint   glyphCounter, bpp;
>>>>>>>>>>>>   jint   scan = pRasInfo->scanStride;
>>>>>>>>>>>>   IntRgbDataType *pPix;
>>>>>>>>>>>>   fprintf(__stderrp, "NAME_SOLID_DRAWGLYPHLISTLC\n");
>>>>>>>>>>>>   jint   srcA;
>>>>>>>>>>>>   jint   srcR   , srcG, srcB;;;;
>>>>>>>>>>>>   do {
>>>>>>>>>>>>     (srcB) = (argbcolor) & 0xff;
>>>>>>>>>>>>     (srcG) = ((argbcolor) >> 8) & 0xff;
>>>>>>>>>>>>     (srcR) = ((argbcolor) >> 16) & 0xff;
>>>>>>>>>>>>     (srcA) = ((argbcolor) >> 24) & 0xff;
>>>>>>>>>>>>   } while (0);;
>>>>>>>>>>>> // and so on…
>>>>>>>>>>>> 
>>>>>>>>>>>> Looks like rgb loop expects to see 4 8-bit color channels per pixel.
>>>>>>>>>>>> 
>>>>>>>>>>>> For now, I do not understand which contract should be honoured to meet DEFINE_SOLID_DRAWGLYPHLIST* expectations, i.e. how should I place bytes in GlyphInfo.
>>>>>>>>>>>> 
>>>>>>>>>>>> May be it should be set somewhere in Java code.
>>>>>>>>>>>> 
>>>>>>>>>>>> Could anyone share this knowledge with me?
>>>>>>>>>>>> 
>>>>>>>>>>>> Thank you,
>>>>>>>>>>>>     Denis.
>>>>>>>>>>>> 
>>>>>>>>>>>> 
>>>>>>>>>>>> On 09 Jul 2014, at 19:22, Sergey Bylokhov <Sergey.Bylokhov at oracle.com <mailto:Sergey.Bylokhov at oracle.com>> wrote:
>>>>>>>>>>>> 
>>>>>>>>>>>>> Hello, Denis.
>>>>>>>>>>>>> Thanks for this research!
>>>>>>>>>>>>> On 09.07.2014 15:13, Denis Fokin wrote:
>>>>>>>>>>>>>> The current version consist of three parts.
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> 1. We are rendering glyphs in offscreen images using Quartz functions. This does not work without kCGBitmapByteOrder32Host mask.
>>>>>>>>>>>>> I assume LCD hint does not work? this looks good.
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> 2. We assume that subpixel antialiasing should not be  used on a non-opaque surface. As I understand the vImage  in CGLVolatileSurfaceManager is not related directly to our window. For a start, I have hardcoded Transparency.OPAQUE, but it requires much better understanding of the architecture to make a more proper solution.
>>>>>>>>>>>>> It is related to the CGLOffScreenSurfaceData, which is used as a surface for VolatileImages. I check this code and looks like we ignore type of the ColorModel and create a transparent native texture anyway.
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> 3. When I started using CGGI_CopyImageFromCanvasToRGBInfo as a rendering mode, I had found that the little endian mode should be undefined. Again, it might be an improper way to do this.
>>>>>>>>>>>>> It seems __LITTLE_ENDIAN__usage in this file should be checked.
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> Thank you,
>>>>>>>>>>>>>>   Denis.
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> diff -r f87c5be90e01 src/macosx/classes/sun/java2d/opengl/CGLVolatileSurfaceManager.java
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> --- a/src/macosx/classes/sun/java2d/opengl/CGLVolatileSurfaceManager.javaFri Jun 20 10:15:30 2014 -0700
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> +++ b/src/macosx/classes/sun/java2d/opengl/CGLVolatileSurfaceManager.javaWed Jul 09 14:50:09 2014 +0400
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> @@ -108,7 +108,7 @@
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>             } else {
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>                 CGLGraphicsConfig gc =
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> (CGLGraphicsConfig)vImg.getGraphicsConfig();
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> -                ColorModel cm = gc.getColorModel(vImg.getTransparency());
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> +                ColorModel cm = gc.getColorModel(Transparency.OPAQUE);
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>                 int type = vImg.getForcedAccelSurfaceType();
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>                 // if acceleration type is forced (type != UNDEFINED) then
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>                 // use the forced type, otherwise choose one based on caps
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> diff -r f87c5be90e01 src/macosx/native/sun/font/CGGlyphImages.m
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> --- a/src/macosx/native/sun/font/CGGlyphImages.mFri Jun 20 10:15:30 2014 -0700
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> +++ b/src/macosx/native/sun/font/    .mWed Jul 09 14:50:09 2014 +0400
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> @@ -196,6 +196,8 @@
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> #pragma mark --- Font Rendering Mode Descriptors ---
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> +#undef __LITTLE_ENDIAN__
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> +
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> static inline void
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> CGGI_CopyARGBPixelToRGBPixel(const UInt32 p, UInt8 *dst)
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> {
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> @@ -366,7 +368,8 @@
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>     canvas->context = CGBitmapContextCreate(canvas->image->data,
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> width, height, 8, bytesPerRow,
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> colorSpace,
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> - kCGImageAlphaPremultipliedFirst);
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> + kCGImageAlphaPremultipliedFirst
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> +                                            | kCGBitmapByteOrder32Host);
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>> CGContextSetRGBFillColor(canvas->context, 0.0f, 0.0f, 0.0f, 1.0f);
>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>     CGContextSetFontSize(canvas->context, 1);
>>>>>>>>>>>>>> 
>>>>>>>>>>>>> 
>>>>>>>>>>>>> 
>>>>>>>>>>>>> -- 
>>>>>>>>>>>>> Best regards, Sergey.
>>>>>>>>>>>>> 
>>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>> 
>>>>>>>>> 
>>>>>>>> 
>>>>>>> 
>>>>>> 
>>>>> 
>>>> 
>>> 
>> 
> 

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