source/layout/HanLayoutEngine.cpp

/*
 * HanLayoutEngine.cpp: OpenType processing for Han fonts.
 *
 * (C) Copyright IBM Corp. 1998-2003 - All Rights Reserved.
 *
 * $Source: /xsrl/Nsvn/icu/icu/source/layout/HanLayoutEngine.cpp,v $ $Date: 2003/10/07 02:23:19 $ $Revision: 1.5 $
 */

#include "LETypes.h"
#include "LEScripts.h"
#include "LELanguages.h"

#include "LayoutEngine.h"
#include "OpenTypeLayoutEngine.h"
#include "HanLayoutEngine.h"
#include "ScriptAndLanguageTags.h"

U_NAMESPACE_BEGIN

const char HanOpenTypeLayoutEngine::fgClassID=0;

HanOpenTypeLayoutEngine::HanOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
                        const GlyphSubstitutionTableHeader *gsubTable)
    : OpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, gsubTable)
{
    // nothing else to do...
}

HanOpenTypeLayoutEngine::~HanOpenTypeLayoutEngine()
{
    // nothing to do
}

const LETag emptyTag = 0x00000000;

const LETag loclFeatureTag = LE_LOCL_FEATURE_TAG;
const LETag smplFeatureTag = LE_SMPL_FEATURE_TAG;
const LETag tradFeatureTag = LE_TRAD_FEATURE_TAG;

const LETag features[] = {loclFeatureTag, emptyTag};

le_int32 HanOpenTypeLayoutEngine::characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool /*rightToLeft*/,
        LEUnicode *&/*outChars*/, le_int32 *&/*charIndices*/, const LETag **&featureTags, LEErrorCode &success)
{
    if (LE_FAILURE(success)) {
        return 0;
    }

    if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
        success = LE_ILLEGAL_ARGUMENT_ERROR;
        return 0;
    }

    featureTags = LE_NEW_ARRAY(const LETag *, count);

    if (featureTags == NULL) {
        success = LE_MEMORY_ALLOCATION_ERROR;
        return 0;
    }

    // FIXME: do we want to add the 'trad' feature for 'ZHT' and the
    // 'smpl' feature for 'ZHS'? If we do this, we can remove the exact
    // flag from the language tag lookups, so we can use these features
    // with the default LangSys...
    for (le_int32 i = 0; i < count; i += 1) {
        featureTags[i] = features;
    }

    return count;
}

U_NAMESPACE_END