Java example source code file (ThaiLayoutEngine.cpp)

This example Java source code file (ThaiLayoutEngine.cpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

false, le_delete_array, le_failure, le_illegal_argument_error, le_memory_allocation_error, leerrorcode, leglyphstorage, leunicode, null, thailayoutengine, thailayoutengine\:\:adjustglyphpositions, thailayoutengine\:\:thailayoutengine, u_namespace_end, uobject_define_rtti_implementation

The ThaiLayoutEngine.cpp Java example source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */


/*
 *
 * (C) Copyright IBM Corp. 1998-2010 - All Rights Reserved
 *
 */

#include "LETypes.h"
#include "LayoutEngine.h"
#include "ThaiLayoutEngine.h"
#include "ScriptAndLanguageTags.h"
#include "LEGlyphStorage.h"

#include "KernTable.h"

#include "ThaiShaping.h"

U_NAMESPACE_BEGIN

UOBJECT_DEFINE_RTTI_IMPLEMENTATION(ThaiLayoutEngine)

ThaiLayoutEngine::ThaiLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, le_int32 typoFlags, LEErrorCode &success)
    : LayoutEngine(fontInstance, scriptCode, languageCode, typoFlags, success)
{
    fErrorChar = 0x25CC;

    // Figure out which presentation forms the font uses
    if (! fontInstance->canDisplay(0x0E01)) {
        // No Thai in font; don't use presentation forms.
        fGlyphSet = 3;
    } else if (fontInstance->canDisplay(0x0E64)) {
        // WorldType uses reserved space in Thai block
        fGlyphSet = 0;
    } else if (fontInstance->canDisplay(0xF701)) {
        // Microsoft corporate zone
        fGlyphSet = 1;

        if (!fontInstance->canDisplay(fErrorChar)) {
            fErrorChar = 0xF71B;
        }
    } else if (fontInstance->canDisplay(0xF885)) {
        // Apple corporate zone
        fGlyphSet = 2;
    } else {
        // no presentation forms in the font
        fGlyphSet = 3;
    }
}

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

// Input: characters (0..max provided for context)
// Output: glyphs, char indices
// Returns: the glyph count
// NOTE: this assumes that ThaiShaping::compose will allocate the outChars array...
le_int32 ThaiLayoutEngine::computeGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool /*rightToLeft*/, LEGlyphStorage &glyphStorage, 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;
    }

    LEUnicode *outChars;
    le_int32 glyphCount;

    // This is enough room for the worst-case expansion
    // (it says here...)
    outChars = LE_NEW_ARRAY(LEUnicode, count * 2);

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

    glyphStorage.allocateGlyphArray(count * 2, FALSE, success);

    if (LE_FAILURE(success)) {
        LE_DELETE_ARRAY(outChars);
        success = LE_MEMORY_ALLOCATION_ERROR;
        return 0;
    }

    glyphCount = ThaiShaping::compose(chars, offset, count, fGlyphSet, fErrorChar, outChars, glyphStorage);
    mapCharsToGlyphs(outChars, 0, glyphCount, FALSE, FALSE, glyphStorage, success);

    LE_DELETE_ARRAY(outChars);

    glyphStorage.adoptGlyphCount(glyphCount);
    return glyphCount;
}

// This is the same as LayoutEngline::adjustGlyphPositions() except that it doesn't call adjustMarkGlyphs
void ThaiLayoutEngine::adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool  /*reverse*/,
                                        LEGlyphStorage &glyphStorage, LEErrorCode &success)
{
    if (LE_FAILURE(success)) {
        return;
    }

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

    if (fTypoFlags & LE_Kerning_FEATURE_FLAG) { /* kerning enabled */
      LETableReference kernTable(fFontInstance, LE_KERN_TABLE_TAG, success);
      KernTable kt(kernTable, success);
      kt.process(glyphStorage, success);
    }

    // default is no adjustments
    return;
}

U_NAMESPACE_END