/*
 * 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.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */


/*
 *
 * (C) Copyright IBM Corp. 1998-2005 - All Rights Reserved
 *
 */

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

#include "ThaiShaping.h"

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

    // Figure out which presentation forms the font uses
    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;
}