icuSources/layout/IndicLayoutEngine.cpp

   1
   2 /*
   3  *
   4  * (C) Copyright IBM Corp. 1998-2009 - All Rights Reserved
   5  *
   6  */
   7
   8 #include "LETypes.h"
   9 #include "LayoutEngine.h"
  10 #include "OpenTypeLayoutEngine.h"
  11 #include "IndicLayoutEngine.h"
  12 #include "ScriptAndLanguageTags.h"
  13
  14 #include "GlyphSubstitutionTables.h"
  15 #include "GlyphDefinitionTables.h"
  16 #include "GlyphPositioningTables.h"
  17
  18 #include "GDEFMarkFilter.h"
  19 #include "LEGlyphStorage.h"
  20
  21 #include "IndicReordering.h"
  22
  23 U_NAMESPACE_BEGIN
  24
  25 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(IndicOpenTypeLayoutEngine)
  26
  27 IndicOpenTypeLayoutEngine::IndicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
  28                     le_int32 typoFlags, le_bool version2, const GlyphSubstitutionTableHeader *gsubTable, LEErrorCode &success)
  29     : OpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags, gsubTable, success), fMPreFixups(NULL)
  30 {
  31         if ( version2 ) {
  32                 fFeatureMap = IndicReordering::getv2FeatureMap(fFeatureMapCount);
  33         } else {
  34         fFeatureMap = IndicReordering::getFeatureMap(fFeatureMapCount);
  35         }
  36         fFeatureOrder = TRUE;
  37     fVersion2 = version2;
  38     fFilterZeroWidth = IndicReordering::getFilterZeroWidth(fScriptCode);
  39 }
  40
  41 IndicOpenTypeLayoutEngine::IndicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, le_int32 typoFlags, LEErrorCode &success)
  42     : OpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags, success), fMPreFixups(NULL)
  43 {
  44     fFeatureMap = IndicReordering::getFeatureMap(fFeatureMapCount);
  45     fFeatureOrder = TRUE;
  46         fVersion2 =  FALSE;
  47 }
  48
  49 IndicOpenTypeLayoutEngine::~IndicOpenTypeLayoutEngine()
  50 {
  51     // nothing to do
  52 }
  53
  54 // Input: characters, tags
  55 // Output: glyphs, char indices
  56 le_int32 IndicOpenTypeLayoutEngine::glyphProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
  57                     LEGlyphStorage &glyphStorage, LEErrorCode &success)
  58 {
  59     if (LE_FAILURE(success)) {
  60         return 0;
  61     }
  62
  63     if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
  64         success = LE_ILLEGAL_ARGUMENT_ERROR;
  65         return 0;
  66     }
  67
  68     le_int32 retCount = OpenTypeLayoutEngine::glyphProcessing(chars, offset, count, max, rightToLeft, glyphStorage, success);
  69
  70     if (LE_FAILURE(success)) {
  71         return 0;
  72     }
  73
  74     if (fVersion2) {
  75         IndicReordering::finalReordering(glyphStorage,retCount);
  76         IndicReordering::applyPresentationForms(glyphStorage,retCount);
  77         OpenTypeLayoutEngine::glyphSubstitution(count,max, rightToLeft, glyphStorage, success);
  78     } else {
  79         IndicReordering::adjustMPres(fMPreFixups, glyphStorage, success);
  80     }
  81     return retCount;
  82 }
  83
  84 // Input: characters
  85 // Output: characters, char indices, tags
  86 // Returns: output character count
  87 le_int32 IndicOpenTypeLayoutEngine::characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
  88         LEUnicode *&outChars, LEGlyphStorage &glyphStorage, LEErrorCode &success)
  89 {
  90     if (LE_FAILURE(success)) {
  91         return 0;
  92     }
  93
  94     if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
  95         success = LE_ILLEGAL_ARGUMENT_ERROR;
  96         return 0;
  97     }
  98
  99     le_int32 worstCase = count * IndicReordering::getWorstCaseExpansion(fScriptCode);
 100
 101     outChars = LE_NEW_ARRAY(LEUnicode, worstCase);
 102
 103     if (outChars == NULL) {
 104         success = LE_MEMORY_ALLOCATION_ERROR;
 105         return 0;
 106     }
 107
 108     glyphStorage.allocateGlyphArray(worstCase, rightToLeft, success);
 109     glyphStorage.allocateAuxData(success);
 110
 111     if (LE_FAILURE(success)) {
 112         LE_DELETE_ARRAY(outChars);
 113         return 0;
 114     }
 115
 116     // NOTE: assumes this allocates featureTags...
 117     // (probably better than doing the worst case stuff here...)
 118
 119     le_int32 outCharCount;
 120     if (fVersion2) {
 121         outCharCount = IndicReordering::v2process(&chars[offset], count, fScriptCode, outChars, glyphStorage);
 122     } else {
 123         outCharCount = IndicReordering::reorder(&chars[offset], count, fScriptCode, outChars, glyphStorage, &fMPreFixups, success);
 124     }
 125
 126     if (LE_FAILURE(success)) {
 127         LE_DELETE_ARRAY(outChars);
 128         return 0;
 129     }
 130
 131     glyphStorage.adoptGlyphCount(outCharCount);
 132     return outCharCount;
 133 }
 134
 135 U_NAMESPACE_END