vcl/source/gdi/scrptrun.cxx

   1 /*
   2  *******************************************************************************
   3  *
   4  *   Copyright (c) 1995-2013 International Business Machines Corporation and others
   5  *
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   9  *   this software and associated documentation files (the "Software"), to deal in
  10  *   the Software without restriction, including without limitation the rights to
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  12  *   Software, and to permit persons to whom the Software is furnished to do so,
  13  *   provided that the above copyright notice(s) and this permission notice appear
  14  *   in all copies of the Software and that both the above copyright notice(s) and
  15  *   this permission notice appear in supporting documentation.
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  17  *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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  23  *   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
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  26  *   Except as contained in this notice, the name of a copyright holder shall not be
  27  *   used in advertising or otherwise to promote the sale, use or other dealings in
  28  *   this Software without prior written authorization of the copyright holder.
  29  *
  30  *******************************************************************************
  31  *   file name:  scrptrun.cpp
  32  *
  33  *   created on: 10/17/2001
  34  *   created by: Eric R. Mader
  35  */
  36 /**
  37   * This file is largely copied from the ICU project,
  38   * under folder source/extra/scrptrun/scrptrun.cpp
  39   */
  40 #include <unicode/utypes.h>
  41 #include <unicode/uscript.h>
  42
  43 #include <scrptrun.h>
  44 #include <algorithm>
  45
  46 namespace {
  47
  48 struct PairIndices
  49 {
  50     int8_t ma00[0xff];
  51     int8_t ma20[0x7f];
  52     int8_t ma30[0x7f];
  53
  54     PairIndices()
  55     {
  56         std::fill_n(ma00, 0xff, -1);
  57         std::fill_n(ma20, 0x7f, -1);
  58         std::fill_n(ma30, 0x7f, -1);
  59
  60         // characters in the range 0x0000 - 0x007e (inclusive)
  61         // ascii paired punctuation
  62         ma00[0x28] =  0;
  63         ma00[0x29] =  1;
  64         ma00[0x3c] =  2;
  65         ma00[0x3e] =  3;
  66         ma00[0x5b] =  4;
  67         ma00[0x5d] =  5;
  68         ma00[0x7b] =  6;
  69         ma00[0x7d] =  7;
  70         // guillemets
  71         ma00[0xab] =  8;
  72         ma00[0xbb] =  9;
  73
  74         // characters in the range 0x2000 - 0x207e (inclusive)
  75         // general punctuation
  76         ma20[0x18] = 10;
  77         ma20[0x19] = 11;
  78         ma20[0x1c] = 12;
  79         ma20[0x1d] = 13;
  80         ma20[0x39] = 14;
  81         ma20[0x3a] = 15;
  82
  83         // characters in the range 0x3000 - 0x307e (inclusive)
  84         // chinese paired punctuation
  85         ma30[0x08] = 16;
  86         ma30[0x09] = 17;
  87         ma30[0x0a] = 18;
  88         ma30[0x0b] = 19;
  89         ma30[0x0c] = 20;
  90         ma30[0x0d] = 21;
  91         ma30[0x0e] = 22;
  92         ma30[0x0f] = 23;
  93         ma30[0x10] = 24;
  94         ma30[0x11] = 25;
  95         ma30[0x14] = 26;
  96         ma30[0x15] = 27;
  97         ma30[0x16] = 28;
  98         ma30[0x17] = 29;
  99         ma30[0x18] = 30;
 100         ma30[0x19] = 31;
 101         ma30[0x1a] = 32;
 102         ma30[0x1b] = 33;
 103     }
 104
 105     int32_t getPairIndex(UChar32 ch) const
 106     {
 107         if (ch < 0xff)
 108             return ma00[ch];
 109         if (ch >= 0x2000 && ch < 0x207f)
 110             return ma20[ch - 0x2000];
 111         if (ch >= 0x3000 && ch < 0x307f)
 112             return ma30[ch - 0x3000];
 113         return -1;
 114     }
 115
 116 };
 117
 118 // There are three Unicode script codes for Japanese text, but only one
 119 // OpenType script tag, so we want to keep them in one run as splitting is
 120 // pointless for the purpose of OpenType shaping.
 121 UScriptCode getScript(UChar32 ch, UErrorCode* status)
 122 {
 123     UScriptCode script = uscript_getScript(ch, status);
 124     if (U_FAILURE(*status))
 125         return script;
 126     if (script == USCRIPT_KATAKANA || script == USCRIPT_KATAKANA_OR_HIRAGANA)
 127         return USCRIPT_HIRAGANA;
 128     return script;
 129 }
 130
 131 }
 132
 133 static const PairIndices gPairIndices;
 134
 135
 136 namespace vcl {
 137
 138 const char ScriptRun::fgClassID=0;
 139
 140 static bool sameScript(int32_t scriptOne, int32_t scriptTwo)
 141 {
 142     return scriptOne <= USCRIPT_INHERITED || scriptTwo <= USCRIPT_INHERITED || scriptOne == scriptTwo;
 143 }
 144
 145 UBool ScriptRun::next()
 146 {
 147     int32_t startSP  = parenSP;  // used to find the first new open character
 148     UErrorCode error = U_ZERO_ERROR;
 149
 150     // if we've fallen off the end of the text, we're done
 151     if (scriptEnd >= charLimit) {
 152         return false;
 153     }
 154
 155     scriptCode = USCRIPT_COMMON;
 156
 157     for (scriptStart = scriptEnd; scriptEnd < charLimit; scriptEnd += 1) {
 158         UChar   high = charArray[scriptEnd];
 159         UChar32 ch   = high;
 160
 161         // if the character is a high surrogate and it's not the last one
 162         // in the text, see if it's followed by a low surrogate
 163         if (high >= 0xD800 && high <= 0xDBFF && scriptEnd < charLimit - 1)
 164         {
 165             UChar low = charArray[scriptEnd + 1];
 166
 167             // if it is followed by a low surrogate,
 168             // consume it and form the full character
 169             if (low >= 0xDC00 && low <= 0xDFFF) {
 170                 ch = (high - 0xD800) * 0x0400 + low - 0xDC00 + 0x10000;
 171                 scriptEnd += 1;
 172             }
 173         }
 174
 175         UScriptCode sc = getScript(ch, &error);
 176         int32_t pairIndex = gPairIndices.getPairIndex(ch);
 177
 178         // Paired character handling:
 179
 180         // if it's an open character, push it onto the stack.
 181         // if it's a close character, find the matching open on the
 182         // stack, and use that script code. Any non-matching open
 183         // characters above it on the stack will be popped.
 184         if (pairIndex >= 0) {
 185             if ((pairIndex & 1) == 0) {
 186                 ++parenSP;
 187                 int32_t nVecSize = parenStack.size();
 188                 if (parenSP == nVecSize)
 189                     parenStack.resize(nVecSize + 128);
 190                 parenStack[parenSP].pairIndex = pairIndex;
 191                 parenStack[parenSP].scriptCode  = scriptCode;
 192             } else if (parenSP >= 0) {
 193                 int32_t pi = pairIndex & ~1;
 194
 195                 while (parenSP >= 0 && parenStack[parenSP].pairIndex != pi) {
 196                     parenSP -= 1;
 197                 }
 198
 199                 if (parenSP < startSP) {
 200                     startSP = parenSP;
 201                 }
 202
 203                 if (parenSP >= 0) {
 204                     sc = parenStack[parenSP].scriptCode;
 205                 }
 206             }
 207         }
 208
 209         if (sameScript(scriptCode, sc)) {
 210             if (scriptCode <= USCRIPT_INHERITED && sc > USCRIPT_INHERITED) {
 211                 scriptCode = sc;
 212
 213                 // now that we have a final script code, fix any open
 214                 // characters we pushed before we knew the script code.
 215                 while (startSP < parenSP) {
 216                     parenStack[++startSP].scriptCode = scriptCode;
 217                 }
 218             }
 219
 220             // if this character is a close paired character,
 221             // pop it from the stack
 222             if (pairIndex >= 0 && (pairIndex & 1) != 0 && parenSP >= 0) {
 223                 parenSP -= 1;
 224                 /* decrement startSP only if it is >= 0,
 225                    decrementing it unnecessarily will lead to memory corruption
 226                    while processing the above while block.
 227                    e.g. startSP = -4 , parenSP = -1
 228                 */
 229                 if (startSP >= 0) {
 230                     startSP -= 1;
 231                 }
 232             }
 233         } else {
 234             // if the run broke on a surrogate pair,
 235             // end it before the high surrogate
 236             if (ch >= 0x10000) {
 237                 scriptEnd -= 1;
 238             }
 239
 240             break;
 241         }
 242     }
 243
 244     return true;
 245 }
 246
 247 }