[doc] Type1 GX (sfnt-wrapped Type1) is not supported.
* docs/formats.txt: Clarify the reference of Type1 GX,
and state that this format is not supported. This
is because the content `TYP1' table is not exactly same
with the Type1 font format specification; no eexec
encryption is used. For detail and concrete examples,
see the analysis on:
https://gitlab.freedesktop.org/freetype/freetype/-/issues/1231
diff --git a/docs/formats.txt b/docs/formats.txt
index 4b2f32e..3d03c01 100644
--- a/docs/formats.txt
+++ b/docs/formats.txt
@@ -77,8 +77,8 @@
--- BDF --- --- bdf 5005.BDF_Spec.pdf, X11
- SFNT PS TYPE_1 --- type1 Type 1 GX Font Format
- (for the Mac) [3]
+ SFNT PS TYPE_1 --- type1 Type 1 GX Font Format [7]
+ (for the Mac; not supported)
SFNT PS TYPE_1 CID cid 5180.sfnt.pdf (for the Mac) [3]
SFNT PS CFF --- cff OT spec, 5176.CFF.pdf
(`OTTO' format)
@@ -198,6 +198,12 @@
[6] Supported font formats are TrueType and OpenType fonts as
defined in the OpenType specification 1.6 and newer.
+[7] `The Type 1 GX Font Format' (dated 1995-09-27) was distributed in
+ Apple Developer CD-ROM in those days. The content of `TYP1' table
+ is a PostScript Type 1 font without the eexec encryption. Current
+ versions of FreeType don't not support this format, but FontForge
+ can load it.
+
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