icuSources/layout/IndicLayoutEngine.cpp

   1
   2 /*
   3  * @(#)IndicLayoutEngine.cpp    1.3 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 "OpenTypeLayoutEngine.h"
  12 #include "IndicLayoutEngine.h"
  13 #include "ScriptAndLanguageTags.h"
  14
  15 #include "GlyphSubstitutionTables.h"
  16 #include "GlyphDefinitionTables.h"
  17 #include "GlyphPositioningTables.h"
  18
  19 #include "GDEFMarkFilter.h"
  20
  21 #include "IndicReordering.h"
  22
  23 U_NAMESPACE_BEGIN
  24
  25 const char IndicOpenTypeLayoutEngine::fgClassID=0;
  26
  27 IndicOpenTypeLayoutEngine::IndicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
  28                     const GlyphSubstitutionTableHeader *gsubTable)
  29     : OpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, gsubTable), fMPreFixups(NULL)
  30 {
  31     fFeatureOrder = IndicReordering::getFeatureOrder();
  32 }
  33
  34 IndicOpenTypeLayoutEngine::IndicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode)
  35     : OpenTypeLayoutEngine(fontInstance, scriptCode, languageCode), fMPreFixups(NULL)
  36 {
  37     fFeatureOrder = IndicReordering::getFeatureOrder();
  38 }
  39
  40 IndicOpenTypeLayoutEngine::~IndicOpenTypeLayoutEngine()
  41 {
  42     // nothing to do
  43 }
  44
  45 // Input: characters, tags
  46 // Output: glyphs, char indices
  47 le_int32 IndicOpenTypeLayoutEngine::glyphProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft, const LETag **featureTags,
  48                 LEGlyphID *&glyphs, le_int32 *&charIndices, LEErrorCode &success)
  49 {
  50     if (LE_FAILURE(success)) {
  51         return 0;
  52     }
  53
  54     if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
  55         success = LE_ILLEGAL_ARGUMENT_ERROR;
  56         return 0;
  57     }
  58
  59     le_int32 retCount = OpenTypeLayoutEngine::glyphProcessing(chars, offset, count, max, rightToLeft, featureTags, glyphs, charIndices, success);
  60
  61     if (LE_FAILURE(success)) {
  62         return 0;
  63     }
  64
  65     IndicReordering::adjustMPres(fMPreFixups, glyphs, charIndices);
  66
  67     return retCount;
  68 }
  69
  70 // Input: characters
  71 // Output: characters, char indices, tags
  72 // Returns: output character count
  73 le_int32 IndicOpenTypeLayoutEngine::characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool /*rightToLeft*/,
  74         LEUnicode *&outChars, le_int32 *&charIndices, const LETag **&featureTags, LEErrorCode &success)
  75 {
  76     if (LE_FAILURE(success)) {
  77         return 0;
  78     }
  79
  80     if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
  81         success = LE_ILLEGAL_ARGUMENT_ERROR;
  82         return 0;
  83     }
  84
  85     le_int32 worstCase = count * IndicReordering::getWorstCaseExpansion(fScriptCode);
  86
  87     outChars = LE_NEW_ARRAY(LEUnicode, worstCase);
  88
  89     if (outChars == NULL) {
  90         success = LE_MEMORY_ALLOCATION_ERROR;
  91         return 0;
  92     }
  93
  94     charIndices = LE_NEW_ARRAY(le_int32, worstCase);
  95     if (charIndices == NULL) {
  96         LE_DELETE_ARRAY(outChars);
  97         success = LE_MEMORY_ALLOCATION_ERROR;
  98         return 0;
  99     }
 100
 101     featureTags = LE_NEW_ARRAY(const LETag *, worstCase);
 102
 103     if (featureTags == NULL) {
 104         LE_DELETE_ARRAY(charIndices);
 105         LE_DELETE_ARRAY(outChars);
 106         success = LE_MEMORY_ALLOCATION_ERROR;
 107         return 0;
 108     }
 109
 110     // NOTE: assumes this allocates featureTags...
 111     // (probably better than doing the worst case stuff here...)
 112     return IndicReordering::reorder(&chars[offset], count, fScriptCode, outChars, charIndices, featureTags, &fMPreFixups);
 113 }
 114
 115 U_NAMESPACE_END