/*
* Do Arabic shaping on character "c". Returns the shaped character.
* out: "ccp" points to the first byte of the character to be shaped.
* in/out: "c1p" points to the first composing char for "c".
* in: "prev_c" is the previous character (not shaped)
* in: "prev_c1" is the first composing char for the previous char
* (not shaped)
* in: "next_c" is the next character (not shaped).
*/
int arabic_shape(int c, int *ccp, int *c1p, int prev_c, int prev_c1, int next_c)
{
int curr_c;
int shape_c;
int curr_laa;
int prev_laa;
/* Deal only with Arabic character, pass back all others */
if (!A_is_ok(c))
return c;
/* half-shape current and previous character */
shape_c = half_shape(prev_c);
/* Save away current character */
curr_c = c;
curr_laa = A_firstc_laa(c, *c1p);
prev_laa = A_firstc_laa(prev_c, prev_c1);
if (curr_laa) {
if (A_is_valid(prev_c) && !A_is_f(shape_c)
&& !A_is_s(shape_c) && !prev_laa)
curr_c = chg_c_laa2f(curr_laa);
else
curr_c = chg_c_laa2i(curr_laa);
/* Remove the composing character */
*c1p = 0;
} else if (!A_is_valid(prev_c) && A_is_valid(next_c))
curr_c = chg_c_a2i(c);
else if (!shape_c || A_is_f(shape_c) || A_is_s(shape_c) || prev_laa)
curr_c = A_is_valid(next_c) ? chg_c_a2i(c) : chg_c_a2s(c);
else if (A_is_valid(next_c))
curr_c = A_is_iso(c) ? chg_c_a2m(c) : chg_c_i2m(c);
else if (A_is_valid(prev_c))
curr_c = chg_c_a2f(c);
else
curr_c = chg_c_a2s(c);
/* Sanity check -- curr_c should, in the future, never be 0.
* We should, in the future, insert a fatal error here. */
if (curr_c == NUL)
curr_c = c;
if (curr_c != c && ccp != NULL) {
char_u buf[MB_MAXBYTES + 1];
/* Update the first byte of the character. */
(*mb_char2bytes)(curr_c, buf);
*ccp = buf[0];
}
/* Return the shaped character */
return curr_c;
}
/*
* A_is_ok returns TRUE if 'c' is an Arabic 10646 (8859-6 or Form-B)
*/
static bool A_is_ok(int c)
{
return A_is_iso(c) || A_is_formb(c);
}
