icuSources/layout/ThaiLayoutEngine.cpp

   1
   2 /*
   3  * @(#)ThaiLayoutEngine.cpp     1.2 00/03/15
   4  *
   5  * (C) Copyright IBM Corp. 1998-2003 - All Rights Reserved
   6  *
   7  */
   8
   9 #include "LETypes.h"
  10 #include "LayoutEngine.h"
  11 #include "ThaiLayoutEngine.h"
  12 #include "ScriptAndLanguageTags.h"
  13
  14 #include "ThaiShaping.h"
  15
  16 U_NAMESPACE_BEGIN
  17
  18 const char ThaiLayoutEngine::fgClassID=0;
  19
  20 ThaiLayoutEngine::ThaiLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode)
  21     : LayoutEngine(fontInstance, scriptCode, languageCode)
  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*/, LEGlyphID *&glyphs, le_int32 *&charIndices, 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     charIndices = LE_NEW_ARRAY(le_int32, count * 2);
  78
  79     if (charIndices == NULL) {
  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, charIndices);
  86     mapCharsToGlyphs(outChars, 0, glyphCount, false, false, glyphs, charIndices, success);
  87
  88     LE_DELETE_ARRAY(outChars);
  89
  90     return glyphCount;
  91 }
  92
  93 U_NAMESPACE_END