os/textandloc/fontservices/textshaperplugin/IcuSource/layout/ThaiLayoutEngine.cpp
author sl
Tue, 10 Jun 2014 14:32:02 +0200
changeset 1 260cb5ec6c19
permissions -rw-r--r--
Update contrib.
     1 
     2 /*
     3  *
     4  * (C) Copyright IBM Corp. 1998-2005 - All Rights Reserved
     5  *
     6  */
     7 
     8 #include "LETypes.h"
     9 #include "LayoutEngine.h"
    10 #include "ThaiLayoutEngine.h"
    11 #include "ScriptAndLanguageTags.h"
    12 #include "LEGlyphStorage.h"
    13 
    14 #include "ThaiShaping.h"
    15 
    16 U_NAMESPACE_BEGIN
    17 
    18 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(ThaiLayoutEngine)
    19 
    20 ThaiLayoutEngine::ThaiLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, le_int32 typoFlags)
    21     : LayoutEngine(fontInstance, scriptCode, languageCode, typoFlags)
    22 {
    23     fErrorChar = 0x25CC;
    24 
    25     // Figure out which presentation forms the font uses
    26     if (fontInstance->canDisplay(0x0E64)) {
    27         // WorldType uses reserved space in Thai block
    28         fGlyphSet = 0;
    29     } else if (fontInstance->canDisplay(0xF701)) {
    30         // Microsoft corporate zone
    31         fGlyphSet = 1;
    32 
    33         if (!fontInstance->canDisplay(fErrorChar)) {
    34             fErrorChar = 0xF71B;
    35         }
    36     } else if (fontInstance->canDisplay(0xF885)) {
    37         // Apple corporate zone
    38         fGlyphSet = 2;
    39     } else {
    40         // no presentation forms in the font
    41         fGlyphSet = 3;
    42     }
    43 }
    44 
    45 ThaiLayoutEngine::~ThaiLayoutEngine()
    46 {
    47     // nothing to do
    48 }
    49 
    50 // Input: characters (0..max provided for context)
    51 // Output: glyphs, char indices
    52 // Returns: the glyph count
    53 // NOTE: this assumes that ThaiShaping::compose will allocate the outChars array...
    54 le_int32 ThaiLayoutEngine::computeGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool /*rightToLeft*/, LEGlyphStorage &glyphStorage, LEErrorCode &success)
    55 {
    56     if (LE_FAILURE(success)) {
    57         return 0;
    58     }
    59 
    60     if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
    61         success = LE_ILLEGAL_ARGUMENT_ERROR;
    62         return 0;
    63     }
    64 
    65     LEUnicode *outChars;
    66     le_int32 glyphCount;
    67     
    68     // This is enough room for the worst-case expansion
    69     // (it says here...)
    70     outChars = LE_NEW_ARRAY(LEUnicode, count * 2);
    71 
    72     if (outChars == NULL) {
    73         success = LE_MEMORY_ALLOCATION_ERROR;
    74         return 0;
    75     }
    76 
    77     glyphStorage.allocateGlyphArray(count * 2, FALSE, success);
    78 
    79     if (LE_FAILURE(success)) {
    80         LE_DELETE_ARRAY(outChars);
    81         success = LE_MEMORY_ALLOCATION_ERROR;
    82         return 0;
    83     }
    84 
    85     glyphCount = ThaiShaping::compose(chars, offset, count, fGlyphSet, fErrorChar, outChars, glyphStorage);
    86     mapCharsToGlyphs(outChars, 0, glyphCount, FALSE, FALSE, glyphStorage, success);
    87 
    88     LE_DELETE_ARRAY(outChars);
    89 
    90     glyphStorage.adoptGlyphCount(glyphCount);
    91     return glyphCount;
    92 }
    93 
    94 U_NAMESPACE_END