third_party/harfbuzz/src/harfbuzz-thai.c

   1 /*
   2  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
   3  *
   4  * This is part of HarfBuzz, an OpenType Layout engine library.
   5  *
   6  * Permission is hereby granted, without written agreement and without
   7  * license or royalty fees, to use, copy, modify, and distribute this
   8  * software and its documentation for any purpose, provided that the
   9  * above copyright notice and the following two paragraphs appear in
  10  * all copies of this software.
  11  *
  12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  16  * DAMAGE.
  17  *
  18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  23  */
  24
  25 #include "harfbuzz-shaper.h"
  26 #include "harfbuzz-shaper-private.h"
  27 #include "harfbuzz-external.h"
  28
  29 #include <assert.h>
  30 #include <stdio.h>
  31
  32 typedef int (*th_brk_def)(const char*, int[], int);
  33 static th_brk_def th_brk = 0;
  34 static int libthai_resolved = 0;
  35
  36 static void resolve_libthai()
  37 {
  38     if (!th_brk)
  39         th_brk = (th_brk_def)HB_Library_Resolve("thai", 0, "th_brk");
  40     libthai_resolved = 1;
  41 }
  42
  43 static void to_tis620(const HB_UChar16 *string, hb_uint32 len, const char *cstr)
  44 {
  45     hb_uint32 i;
  46     unsigned char *result = (unsigned char *)cstr;
  47
  48     for (i = 0; i < len; ++i) {
  49         if (string[i] <= 0xa0)
  50             result[i] = (unsigned char)string[i];
  51         if (string[i] >= 0xe01 && string[i] <= 0xe5b)
  52             result[i] = (unsigned char)(string[i] - 0xe00 + 0xa0);
  53         else
  54             result[i] = '?';
  55     }
  56
  57     result[len] = 0;
  58 }
  59
  60 static void thaiWordBreaks(const HB_UChar16 *string, hb_uint32 len, HB_CharAttributes *attributes)
  61 {
  62     char s[128];
  63     char *cstr = s;
  64     int brp[128];
  65     int *break_positions = brp;
  66     hb_uint32 numbreaks;
  67     hb_uint32 i;
  68
  69     if (!libthai_resolved)
  70         resolve_libthai();
  71
  72     if (!th_brk)
  73         return;
  74
  75     if (len >= 128)
  76         cstr = (char *)malloc(len*sizeof(char) + 1);
  77
  78     to_tis620(string, len, cstr);
  79
  80     numbreaks = th_brk(cstr, break_positions, 128);
  81     if (numbreaks > 128) {
  82         break_positions = (int *)malloc(numbreaks * sizeof(int));
  83         numbreaks = th_brk(cstr, break_positions, numbreaks);
  84     }
  85
  86     for (i = 0; i < len; ++i) {
  87         attributes[i].lineBreakType = HB_NoBreak;
  88         attributes[i].wordBoundary = FALSE;
  89     }
  90
  91     for (i = 0; i < numbreaks; ++i) {
  92         if (break_positions[i] > 0) {
  93             attributes[break_positions[i]-1].lineBreakType = HB_Break;
  94             attributes[break_positions[i]-1].wordBoundary = TRUE;
  95         }
  96     }
  97
  98     if (break_positions != brp)
  99         free(break_positions);
 100
 101     if (len >= 128)
 102         free(cstr);
 103 }
 104
 105 void HB_ThaiAttributes(HB_Script script, const HB_UChar16 *text, hb_uint32 from, hb_uint32 len, HB_CharAttributes *attributes)
 106 {
 107     assert(script == HB_Script_Thai);
 108     attributes += from;
 109     thaiWordBreaks(text + from, len, attributes);
 110 }
 111