Re: Bug report: Set exec->backward_compatibility flag before TT CV program re-execution

Alexei Podtelezhnikov <[email protected]> Wed, 15 Oct 2025 22:32:59 -0400
Newsgroups gmane.comp.fonts.freetype.devel
Message-ID <[email protected]>
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Werner,

Besides the change below or something similar. How should we handle the flag=
 *during* the CV execution? Right now the CV program does not change it unti=
l it is complete. In other wards, should we care about it while moving twili=
ght points in the  CV program? Right now we ignore the flag presumably.

Alexei

> On Oct 15, 2025, at 21:32, Honnesh Ramachandra <[email protected]> wr=
ote:
>=20
> =EF=BB=BF
> Great. Here is a diff of the proposed changes in that case in ttgload.c
>=20
> @@ -2201,7 +2201,6 @@
>        TT_Driver       driver    =3D (TT_Driver)FT_FACE_DRIVER( glyph->fac=
e );
>  #endif
> =20
> -
>        if ( size->bytecode_ready > 0 )
>          return size->bytecode_ready;
>        if ( size->bytecode_ready < 0 )
> @@ -2215,6 +2214,7 @@
>        }
> =20
>        exec =3D size->context;
> +      exec->backward_compatibility =3D 0;
> =20
>  #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
>        if ( driver->interpreter_version =3D=3D TT_INTERPRETER_VERSION_40 )=

> =20
>=20

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<html><head><meta http-equiv=3D"content-type" content=3D"text/html; charset=3D=
utf-8"></head><body dir=3D"auto"><div dir=3D"ltr">Werner,</div><div dir=3D"l=
tr"><br></div><div dir=3D"ltr">Besides the change below or something similar=
. How should we handle the flag *during* the CV execution? Right now the CV p=
rogram does not change it until it is complete. In other wards, should we ca=
re about it while moving twilight points in the &nbsp;CV program? Right now w=
e ignore the flag presumably.</div><div dir=3D"ltr"><br></div><div dir=3D"lt=
r">Alexei</div><div dir=3D"ltr"><br><blockquote type=3D"cite">On Oct 15, 202=
5, at 21:32, Honnesh Ramachandra &lt;[email protected]&gt; wrote:<br><b=
r></blockquote></div><blockquote type=3D"cite"><div dir=3D"ltr">=EF=BB=BF

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<div class=3D"WordSection1">
<p class=3D"p1"><span style=3D"font-size:11.0pt;font-family:&quot;Aptos&quot=
;,sans-serif;color:black">Great. Here is a diff of the proposed changes in t=
hat case in ttgload.c
</span><span style=3D"font-size:11.0pt;font-family:&quot;Aptos&quot;,sans-se=
rif"><br>
<br>
</span><span class=3D"s1">@@ -2201,7 +2201,6 @@</span><o:p></o:p></p>
<p class=3D"p2"><span class=3D"apple-converted-space">&nbsp;&nbsp; &nbsp; &n=
bsp; </span><span class=3D"s1">TT_Driver
</span><span class=3D"apple-converted-space">&nbsp; &nbsp; &nbsp; </span><sp=
an class=3D"s1">driver</span><span class=3D"apple-converted-space">&nbsp; &n=
bsp;
</span><span class=3D"s1">=3D (TT_Driver)FT_FACE_DRIVER( glyph-&gt;face );</=
span><o:p></o:p></p>
<p class=3D"p2"><span class=3D"apple-converted-space">&nbsp;</span><span cla=
ss=3D"s1">#endif</span><o:p></o:p></p>
<p class=3D"p3"><span class=3D"apple-converted-space">&nbsp;</span><o:p></o:=
p></p>
<p class=3D"p4"><span class=3D"s1">-</span><o:p></o:p></p>
<p class=3D"p2"><span class=3D"apple-converted-space">&nbsp;&nbsp; &nbsp; &n=
bsp; </span><span class=3D"s1">if ( size-&gt;bytecode_ready &gt; 0 )</span><=
o:p></o:p></p>
<p class=3D"p2"><span class=3D"apple-converted-space">&nbsp;&nbsp; &nbsp; &n=
bsp; &nbsp; </span><span class=3D"s1">return size-&gt;bytecode_ready;</span>=
<o:p></o:p></p>
<p class=3D"p2"><span class=3D"apple-converted-space">&nbsp;&nbsp; &nbsp; &n=
bsp; </span><span class=3D"s1">if ( size-&gt;bytecode_ready &lt; 0 )</span><=
o:p></o:p></p>
<p class=3D"p1"><span class=3D"s1">@@ -2215,6 +2214,7 @@</span><o:p></o:p></=
p>
<p class=3D"p2"><span class=3D"apple-converted-space">&nbsp;&nbsp; &nbsp; &n=
bsp; </span><span class=3D"s1">}</span><o:p></o:p></p>
<p class=3D"p3"><span class=3D"apple-converted-space">&nbsp;</span><o:p></o:=
p></p>
<p class=3D"p2"><span class=3D"apple-converted-space">&nbsp;&nbsp; &nbsp; &n=
bsp; </span><span class=3D"s1">exec =3D size-&gt;context;</span><o:p></o:p><=
/p>
<p class=3D"p5"><span class=3D"s1">+</span><span class=3D"apple-converted-sp=
ace">&nbsp; &nbsp; &nbsp; </span>
<span class=3D"s1">exec-&gt;backward_compatibility =3D 0;</span><o:p></o:p><=
/p>
<p class=3D"p3"><span class=3D"apple-converted-space">&nbsp;</span><o:p></o:=
p></p>
<p class=3D"p2"><span class=3D"apple-converted-space">&nbsp;</span><span cla=
ss=3D"s1">#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL</span><o:p></o:p></p>
<p class=3D"p2"><span class=3D"apple-converted-space">&nbsp;&nbsp; &nbsp; &n=
bsp; </span><span class=3D"s1">if ( driver-&gt;interpreter_version =3D=3D TT=
_INTERPRETER_VERSION_40 )</span><o:p></o:p></p>
<p class=3D"MsoNormal"><span style=3D"font-size:11.0pt"><o:p>&nbsp;</o:p></s=
pan></p>
<p class=3D"MsoNormal"><br></p><div id=3D"mail-editor-reference-message-cont=
ainer"><div><div><div><div>
</div>
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