diff options
| -rw-r--r-- | doc/lispref/internals.texi | 2 | ||||
| -rw-r--r-- | src/composite.h | 17 |
2 files changed, 18 insertions, 1 deletions
diff --git a/doc/lispref/internals.texi b/doc/lispref/internals.texi index 4150a2b21b8..0e250d0f59b 100644 --- a/doc/lispref/internals.texi +++ b/doc/lispref/internals.texi @@ -1429,7 +1429,7 @@ other words, if a module function wants to call Lisp functions or Emacs primitives, convert @code{emacs_value} objects to and from C datatypes (@pxref{Module Values}), or interact with Emacs in any other way, some call from Emacs to @code{emacs_module_init} or to a module -function must be in the call stack. Module function may not interact +function must be in the call stack. Module functions may not interact with Emacs while garbage collection is running; @pxref{Garbage Collection}. They may only interact with Emacs from Lisp interpreter threads (including the main thread) created by Emacs; @pxref{Threads}. diff --git a/src/composite.h b/src/composite.h index 660b1fa1b9e..67e87201bf2 100644 --- a/src/composite.h +++ b/src/composite.h @@ -246,6 +246,11 @@ composition_valid_p (ptrdiff_t start, ptrdiff_t end, Lisp_Object prop) /* Macros for lispy glyph-string. This is completely different from struct glyph_string. */ +/* LGSTRING is a string of font glyphs, LGLYPHs. It is represented as + a Lisp vector, with components shown below. Once LGSTRING was + processed by a shaping engine, it holds font glyphs for one or more + grapheme clusters. */ + #define LGSTRING_HEADER(lgs) AREF (lgs, 0) #define LGSTRING_SET_HEADER(lgs, header) ASET (lgs, 0, header) @@ -259,6 +264,10 @@ composition_valid_p (ptrdiff_t start, ptrdiff_t end, Lisp_Object prop) #define LGSTRING_ID(lgs) AREF (lgs, 1) #define LGSTRING_SET_ID(lgs, id) ASET (lgs, 1, id) +/* LGSTRING_GLYPH_LEN is the maximum number of LGLYPHs that the + LGSTRING can hold. This is NOT the actual number of valid LGLYPHs; + to find the latter, walk the glyphs returned by LGSTRING_GLYPH + until the first one that is nil. */ #define LGSTRING_GLYPH_LEN(lgs) (ASIZE ((lgs)) - 2) #define LGSTRING_GLYPH(lgs, idx) AREF ((lgs), (idx) + 2) #define LGSTRING_SET_GLYPH(lgs, idx, val) ASET ((lgs), (idx) + 2, (val)) @@ -278,6 +287,14 @@ enum lglyph_indices LGLYPH_SIZE }; +/* Each LGLYPH is a single font glyph, whose font code is in + LGLYPH_CODE. + LGLYPH_FROM and LGLYPH_TO are indices into LGSTRING; all the + LGLYPHs that share the same values of LGLYPH_FROM and LGLYPH_TO + belong to the same grapheme cluster. + LGLYPH_CHAR is one of the characters, usually the first one, that + contributed to the glyph (since there isn't a 1:1 correspondence + between composed characters and the font glyphs). */ #define LGLYPH_NEW() make_nil_vector (LGLYPH_SIZE) #define LGLYPH_FROM(g) XFIXNUM (AREF ((g), LGLYPH_IX_FROM)) #define LGLYPH_TO(g) XFIXNUM (AREF ((g), LGLYPH_IX_TO)) |