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<p>Hey Alessandro,<br>
<br>
I think there is a bug in this section of your code:<br>
<br>
<font face="monospace"> // Let's now iterate over the
structs and print the encoding (which is problematic)<br>
MemorySegment arrPointer =
FT_FaceRec.charmaps$get(faceMemory);<br>
arrPointer.get(POINTER, 0)<br>
.reinterpret(FT_CharMapRec_.$LAYOUT().byteSize() *
num)<br>
.elements(FT_CharMapRec_.$LAYOUT())<br>
.forEach(Test::printCharMap);</font></p>
<p>Looking at the documentation: [1], [2]. The 'charmaps' field of a
face is an array of _pointers_ to FT_CharMapRec_ (note that
FT_CharMap is a pointer to a FT_CharMapRec_), not an array of
FT_CharMapRec_. Your code, however, is getting the pointer to the
first struct from the array, and then reinterpreting that pointer
as an array of structs, while it's actually just a pointer to a
single FT_CharMapRec_ struct (not an array). That explains why the
first element looks valid, but the second doesn't.<br>
<br>
Treating the array as an array of pointers instead, I think this
should work:<br>
<br>
<font face="monospace"> // Let's now iterate over the
structs and print the encoding (which is problematic)<br>
MemorySegment arrPointer =
FT_FaceRec.charmaps$get(faceMemory);<br>
arrPointer<br>
.reinterpret(POINTER.byteSize() * num) // it's an
array of pointers<br>
.elements(</font><font face="monospace">POINTER</font><font face="monospace">) // the elements are pointers<br>
.map(s -> s.get(POINTER, 0)) // 's' is a slice of
the array. Get a pointer to a struct from the array<br>
.forEach(Test::printCharMap);</font><br>
</p>
<p>HTH,<br>
Jorn</p>
<p>[1]:
<a class="moz-txt-link-freetext" href="https://freetype.org/freetype2/docs/reference/ft2-face_creation.html#ft_facerec">https://freetype.org/freetype2/docs/reference/ft2-face_creation.html#ft_facerec</a><br>
[2]:
<a class="moz-txt-link-freetext" href="https://freetype.org/freetype2/docs/reference/ft2-character_mapping.html#ft_charmap">https://freetype.org/freetype2/docs/reference/ft2-character_mapping.html#ft_charmap</a><br>
</p>
<div class="moz-cite-prefix">On 13/11/2023 11:11, Alessandro Parisi
wrote:<br>
</div>
<blockquote type="cite" cite="mid:CAFpXZFzgZtZco-+k+5ORoohpm33wDnL=qGHY2E-bnT3M1KpcHQ@mail.gmail.com">
<div dir="ltr">Hello everyone,<br>
In the recent weeks, I've been experimenting with Project Panama
on JDK 21. I'm trying to create a wrapper for the Freetype font
library written in C, but I'm having some issues, probably
because I still don't understand very well the FFM API.
<div>While using the code generated by JExtract, I noticed that
it fails to parse the <i>charmaps</i> array from the <a href="https://freetype.org/freetype2/docs/reference/ft2-face_creation.html#ft_facerec" moz-do-not-send="true">FT_FaceRec</a> struct. With the TTF
font, I'm testing, there are two <i>charmaps</i>, the values
of the first one are the same printed by the native code too,
but for the second, the values are completely randomic</div>
<div>Here is a little reproducer: <a href="https://www.dropbox.com/scl/fi/gitugnyxe3kyomm4m0pke/FreetypeMRE.zip?rlkey=tvnrsb5ernwasmxj6cgrjyqqq&dl=0" moz-do-not-send="true">FreetypeMRE</a></div>
<div>Running the Test class will print the two <i>charmaps</i>.
There is also a little .exe I built to check the output of
native code, it's located in the src/native directory (there
is also the C src code)<br>
Am I doing something wrong, or is this a bug?</div>
</div>
</blockquote>
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