Commit 9c87e5c4 authored by Kenichi Handa's avatar Kenichi Handa

(reference-point-alist): Doc fixed.

(encode-composition-rule): Handle a rule (GREF NREF XOFF YOFF).
(decode-composition-rule): Likewise.
parent 62d89ee1
......@@ -73,7 +73,12 @@ follows (the point `*' corresponds to both reference points):
| | new |
| |glyph|
+----+-----+ <--- new descent
")
A composition rule may have the form \(GLOBAL-REF-POINT
NEW-REF-POINT XOFF YOFF), where XOFF and YOFF specifies how much
to shift NEW-REF-POINT from GLOBAL-REF-POINT. In this case, XOFF
and YOFF are integers in the range -100..100 representing the
shifting percentage against the font size.")
;; Encode composition rule RULE into an integer value. RULE is a cons
;; of global and new reference point symbols.
......@@ -84,17 +89,29 @@ follows (the point `*' corresponds to both reference points):
(if (and (integerp rule) (< rule 144))
;; Already encoded.
rule
(or (consp rule)
(error "Invalid composition rule: %S" rule))
(let ((gref (car rule))
(nref (cdr rule)))
(or (integerp gref)
(setq gref (cdr (assq gref reference-point-alist))))
(or (integerp nref)
(setq nref (cdr (assq nref reference-point-alist))))
(or (and (>= gref 0) (< gref 12) (>= nref 0) (< nref 12))
(error "Invalid composition rule: %S" rule))
(+ (* gref 12) nref))))
(if (consp rule)
(let ((gref (car rule))
(nref (cdr rule))
xoff yoff)
(if (consp nref) ; (GREF NREF XOFF YOFF)
(progn
(setq xoff (nth 1 nref)
yoff (nth 2 nref)
nref (car nref))
(or (and (>= xoff -100) (<= xoff 100)
(>= yoff -100) (<= yoff 100))
(error "Invalid compostion rule: %s" rule))
(setq xoff (+ xoff 128) yoff (+ yoff 128)))
;; (GREF . NREF)
(setq xoff 0 yoff 0))
(or (integerp gref)
(setq gref (cdr (assq gref reference-point-alist))))
(or (integerp nref)
(setq nref (cdr (assq nref reference-point-alist))))
(or (and (>= gref 0) (< gref 12) (>= nref 0) (< nref 12))
(error "Invalid composition rule: %S" rule))
(logior (lsh xoff 16) (lsh yoff 8) (+ (* gref 12) nref)))
(error "Invalid composition rule: %S" rule))))
;; Decode encoded composition rule RULE-CODE. The value is a cons of
;; global and new reference point symbols.
......@@ -102,13 +119,20 @@ follows (the point `*' corresponds to both reference points):
;; defined in composite.h.
(defun decode-composition-rule (rule-code)
(or (and (natnump rule-code) (< rule-code 144))
(or (and (natnump rule-code) (< rule-code #x1000000))
(error "Invalid encoded composition rule: %S" rule-code))
(let ((gref (car (rassq (/ rule-code 12) reference-point-alist)))
(nref (car (rassq (% rule-code 12) reference-point-alist))))
(let ((xoff (lsh rule-code -16))
(yoff (logand (lsh rule-code -8) #xFF))
gref nref)
(setq rule-code (logand rule-code #xFF)
gref (car (rassq (/ rule-code 12) reference-point-alist))
nref (car (rassq (% rule-code 12) reference-point-alist)))
(or (and gref (symbolp gref) nref (symbolp nref))
(error "Invalid composition rule code: %S" rule-code))
(cons gref nref)))
(if (and (= xoff 0) (= yoff 0))
(cons gref nref)
(setq xoff (- xoff 128) yoff (- yoff 128))
(list gref xoff yoff nref))))
;; Encode composition rules in composition components COMPONENTS. The
;; value is a copy of COMPONENTS, where composition rules (cons of
......
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