Fonts with embedded bitmaps are not always rotated

[Langer, Christoph]

Hi Mit,

first of all: Is this an issue with JDK8 only which requires a new patch or is it something that is fixed in a higher OpenJDK release and needs to be backported? If the latter is the case, please send us the bug URL in JBS = OpenJDK Bug system [0]. If not, can you please send a problem description by which one can open a bug.

Secondly, if you want to contribute your patch, the OpenJDK project requires you to sign a committers agreement (OCA). Do you have that? Further information can be found at [1], [2].

Thanks
Christoph

[0] https://bugs.openjdk.java.net/
[1] https://openjdk.java.net/contribute/
[2] http://www.oracle.com/technetwork/oca-405177.pdf


> -----Original Message-----
> From: jdk8u-dev <jdk8u-dev-bounces at openjdk.java.net> On Behalf Of
> Mitsuhiro Yamamoto
> Sent: Dienstag, 14. Mai 2019 06:57
> To: jdk8u-dev at openjdk.java.net
> Subject: Fonts with embedded bitmaps are not always rotated
>
> Hi there,
>
> I would like to fix a issue below, so I created a patch file for it.
> https://github.com/AdoptOpenJDK/openjdk-build/issues/945
>
> Can you help me with this?
>
> diff --git a/jdk/src/share/native/sun/font/freetypeScaler.c
> b/jdk/src/share/native/sun/font/freetypeScaler.c
> index 8c9207d9b2..59747cc860 100644
> --- a/jdk/src/share/native/sun/font/freetypeScaler.c
> +++ b/jdk/src/share/native/sun/font/freetypeScaler.c
> @@ -364,6 +364,19 @@
> Java_sun_font_FreetypeFontScaler_createScalerContextNative(
>      context->doBold = (boldness != 1.0);
>      context->doItalize = (italic != 0);
>
> +    /* freetype is very keen to use embedded bitmaps, even if it knows
> +     * there is a rotation or you asked for antialiasing.
> +     * In the rendering path we will check useSBits and disable
> +     * bitmaps unless it is set. And here we set it only if none
> +     * of the conditions invalidate using it.
> +     * Note that we allow embedded bitmaps for the LCD case.
> +     */
> +    if ((aa != TEXT_AA_ON) && (fm != TEXT_FM_ON) &&
> +        !context->doBold && !context->doItalize &&
> +        (context->transform.yx == 0) && (context->transform.xy == 0))
> +    {
> +        context->useSbits = 1;
> +    }
>      return ptr_to_jlong(context);
>  }
>
> @@ -685,9 +698,8 @@
> Java_sun_font_FreetypeFontScaler_getGlyphImageNative(
>          return ptr_to_jlong(getNullGlyphImage());
>      }
>
> -    /* if algorithmic styling is required then we do not request bitmap */
> -    if (context->doBold || context->doItalize) {
> -        renderFlags =  FT_LOAD_DEFAULT;
> +    if (!context->useSbits) {
> +            renderFlags |= FT_LOAD_NO_BITMAP;
>      }
>
>      /* NB: in case of non identity transform
>
> Mit