Retrospective commit.

These are the original changes made by Kenichi Handa on the old
pre Emacs 22 emacs-bidi branch.

1 files changed, 85 insertions, 0 deletions

diff --git a/src/dispextern.h b/src/dispextern.h
index f28cae6d8b3..0b3310c8f69 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -1702,6 +1702,79 @@ struct face_cache
 
 extern int face_change_count;
 
+/* For BIDI */
+#define BIDI_MAXLEVEL 64
+
+/* Data type for describing the bidirectional character types.  */
+typedef enum {
+  UNKNOWN_BT,
+  STRONG_L,     /* strong left-to-right */
+  STRONG_R,     /* strong right-to-left */
+  STRONG_AL,    /* arabic right-to-left letter */
+  LRE,          /* left-to-right embedding */
+  LRO,          /* left-to-right override */
+  RLE,          /* right-to-left embedding */
+  RLO,          /* right-to-left override */
+  PDF,          /* pop directional format */
+  WEAK_EN,      /* european number */
+  WEAK_ES,      /* european number separator */
+  WEAK_ET,      /* european number terminator */
+  WEAK_AN,      /* arabic number */
+  WEAK_CS,      /* common separator */
+  WEAK_NSM,     /* non-spacing mark */
+  WEAK_BN,      /* boundary neutral */
+  NEUTRAL_B,    /* paragraph separator */
+  NEUTRAL_S,    /* segment separator */
+  NEUTRAL_WS,   /* whitespace */
+  NEUTRAL_ON    /* other neutrals */
+} bidi_type_t;
+
+/* The basic directionality data type.  */
+typedef enum { NEUTRAL_DIR, L2R, R2L } bidi_dir_t;
+
+/* Data type for storing information about characters we need to
+   remember.  */
+struct bidi_saved_info {
+  int bytepos, charpos;         /* character's buffer position */
+  bidi_type_t type;             /* character bidi type */
+  bidi_type_t orig_type;        /* original type of the character, after W1 */
+  bidi_type_t pristine_type;    /* type as we found it in the buffer */
+};
+
+/* Data type for keeping track of saved embedding levels and override
+   status information.  */
+struct bidi_stack {
+  int level;
+  bidi_dir_t override;
+};
+
+/* Data type for iterating over bidi text.  */
+struct bidi_it {
+  int bytepos;                  /* iterator's position in buffer */
+  int charpos;
+  int ch;                       /* the character itself */
+  int ch_len;                   /* the length of its multibyte sequence */
+  bidi_type_t type;             /* type of this character */
+  bidi_type_t orig_type;        /* original type, after overrides and W1 */
+  bidi_type_t pristine_type;    /* original type, as found in the buffer */
+  int resolved_level;           /* final resolved level of this character */
+  int invalid_levels;           /* how many PDFs should we ignore */
+  int invalid_rl_levels;        /* how many PDFs from RLE/RLO should ignore */
+  int new_paragraph;            /* if non-zero, a new paragraph begins here */
+  int prev_was_pdf;             /* if non-zero, prev char was PDF */
+  struct bidi_saved_info prev;  /* info about the previous character */
+  struct bidi_saved_info last_strong; /* last-seen strong directional char */
+  struct bidi_saved_info next_for_neutral; /* surrounding characters for... */
+  struct bidi_saved_info prev_for_neutral; /* ...resolving neutrals */
+  struct bidi_saved_info next_for_ws; /* character after sequence of ws */
+  int next_en_pos;              /* position of next EN char for ET */
+  int ignore_bn_limit;          /* position until which we should ignore BNs */
+  bidi_dir_t sor;               /* direction of start-of-run in effect */
+  int scan_dir;                 /* direction of text scan */
+  int stack_idx;                /* index of current data on the stack */
+  struct bidi_stack level_stack[BIDI_MAXLEVEL]; /* stack of embedding levels */
+};
+
 
 
 
@@ -2233,6 +2306,12 @@ struct it
 
   /* Face of the right fringe glyph.  */
   unsigned right_user_fringe_face_id : FACE_ID_BITS;
+
+  /* 1 means we need bidi processing.  */
+  int bidi_p;
+
+  /* For iterating over bidi text.  */
+  struct bidi_it bidi_it;
 };
 
 
@@ -2704,6 +2783,12 @@ extern EMACS_INT tool_bar_button_relief;
                           Function Prototypes
  ***********************************************************************/
 
+/* Defined in bidi.c */
+
+extern void bidi_init_it P_ ((int pos, bidi_dir_t dir,
+                              struct bidi_it *bidi_it));
+extern void bidi_get_next_char_visually P_ ((struct bidi_it *bidi_it));
+
 /* Defined in xdisp.c */
 
 struct glyph_row *row_containing_pos P_ ((struct window *, int,