gecko/gfx/thebes/public/gfxFontUtils.h

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Foundation code.
 *
 * The Initial Developer of the Original Code is Mozilla Foundation.
 * Portions created by the Initial Developer are Copyright (C) 2005
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Stuart Parmenter <stuart@mozilla.com>
 *   John Daggett <jdaggett@mozilla.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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#ifndef GFX_FONT_UTILS_H
#define GFX_FONT_UTILS_H

#include "gfxTypes.h"

#include "prtypes.h"
#include "gfxFont.h"
#include "prcpucfg.h"

#include "nsDataHashtable.h"

/* Bug 341128 - w32api defines min/max which causes problems with <bitset> */
#ifdef __MINGW32__
#undef min
#undef max
#endif

#include <bitset>

// code from gfxWindowsFonts.h

class gfxSparseBitSet {
private:
    enum { BLOCK_SIZE = 32 };
    enum { BLOCK_SIZE_BITS = BLOCK_SIZE * 8 };

    struct Block {
        Block(unsigned char memsetValue = 0) { memset(mBits, memsetValue, BLOCK_SIZE); }
        PRUint8 mBits[BLOCK_SIZE];
    };

public:
    PRBool test(PRUint32 aIndex) {
        PRUint32 blockIndex = aIndex/BLOCK_SIZE_BITS;
        if (blockIndex >= mBlocks.Length())
            return PR_FALSE;
        Block *block = mBlocks[blockIndex];
        if (!block)
            return PR_FALSE;
        return ((block->mBits[(aIndex/8) & (BLOCK_SIZE - 1)]) & (1 << (aIndex & 0x7))) != 0;
    }

    void set(PRUint32 aIndex) {
        PRUint32 blockIndex = aIndex/BLOCK_SIZE_BITS;
        if (blockIndex >= mBlocks.Length()) {
            nsAutoPtr<Block> *blocks = mBlocks.AppendElements(blockIndex + 1 - mBlocks.Length());
            if (NS_UNLIKELY(!blocks)) // OOM
                return;
        }
        Block *block = mBlocks[blockIndex];
        if (!block) {
            block = new Block;
            if (NS_UNLIKELY(!block)) // OOM
                return;
            mBlocks[blockIndex] = block;
        }
        block->mBits[(aIndex/8) & (BLOCK_SIZE - 1)] |= 1 << (aIndex & 0x7);
    }

    void SetRange(PRUint32 aStart, PRUint32 aEnd) {
        const PRUint32 startIndex = aStart/BLOCK_SIZE_BITS;
        const PRUint32 endIndex = aEnd/BLOCK_SIZE_BITS;

        if (endIndex >= mBlocks.Length()) {
            PRUint32 numNewBlocks = endIndex + 1 - mBlocks.Length();
            nsAutoPtr<Block> *blocks = mBlocks.AppendElements(numNewBlocks);
            if (NS_UNLIKELY(!blocks)) // OOM
                return;
        }

        for (PRUint32 i = startIndex; i <= endIndex; ++i) {
            const PRUint32 blockFirstBit = i * BLOCK_SIZE_BITS;
            const PRUint32 blockLastBit = blockFirstBit + BLOCK_SIZE_BITS - 1;

            Block *block = mBlocks[i];
            if (!block) {
                PRBool fullBlock = PR_FALSE;
                if (aStart <= blockFirstBit && aEnd >= blockLastBit)
                    fullBlock = PR_TRUE;

                block = new Block(fullBlock ? 0xFF : 0);

                if (NS_UNLIKELY(!block)) // OOM
                    return;
                mBlocks[i] = block;

                if (fullBlock)
                    continue;
            }

            const PRUint32 start = aStart > blockFirstBit ? aStart - blockFirstBit : 0;
            const PRUint32 end = PR_MIN(aEnd - blockFirstBit, BLOCK_SIZE_BITS - 1);

            for (PRUint32 bit = start; bit <= end; ++bit) {
                block->mBits[bit/8] |= 1 << (bit & 0x7);
            }
        }
    }

    PRUint32 GetSize() {
        PRUint32 size = 0;
        for (PRUint32 i = 0; i < mBlocks.Length(); i++)
            if (mBlocks[i])
                size += sizeof(Block);
        return size;
    }


    nsTArray< nsAutoPtr<Block> > mBlocks;
};

class THEBES_API gfxFontUtils {

public:

    // for reading big-endian font data on either big or little-endian platforms
    
    static inline PRUint16
    ReadShortAt(const PRUint8 *aBuf, PRUint32 aIndex)
    {
        return (aBuf[aIndex] << 8) | aBuf[aIndex + 1];
    }
    
    static inline PRUint16
    ReadShortAt16(const PRUint16 *aBuf, PRUint32 aIndex)
    {
        const PRUint8 *buf = (PRUint8*) aBuf;
        PRUint32 index = aIndex << 1;
        return (buf[index] << 8) | buf[index+1];
    }
    
    static inline PRUint32
    ReadLongAt(const PRUint8 *aBuf, PRUint32 aIndex)
    {
        return ((aBuf[aIndex] << 24) | (aBuf[aIndex + 1] << 16) | (aBuf[aIndex + 2] << 8) | (aBuf[aIndex + 3]));
    }
    
    static nsresult
    ReadCMAPTableFormat12(PRUint8 *aBuf, PRInt32 aLength, gfxSparseBitSet& aCharacterMap, std::bitset<128>& aUnicodeRanges);
    
    static nsresult 
    ReadCMAPTableFormat4(PRUint8 *aBuf, PRInt32 aLength, gfxSparseBitSet& aCharacterMap, std::bitset<128>& aUnicodeRanges);

    static nsresult
    ReadCMAP(PRUint8 *aBuf, PRUint32 aBufLength, gfxSparseBitSet& aCharacterMap, std::bitset<128>& aUnicodeRanges, PRPackedBool& aUnicodeFont, 
        PRPackedBool& aSymbolFont);

    static inline bool IsJoiner(PRUint32 ch) {
        return (ch == 0x200C ||
                ch == 0x200D ||
                ch == 0x2060);
    }

    static inline bool IsInvalid(PRUint32 ch) {
        return (ch == 0xFFFD);
    }

    static PRUint8 CharRangeBit(PRUint32 ch);

};

#endif /* GFX_FONT_UTILS_H */