private int nextNBits()

in src/main/java/org/apache/xmlgraphics/image/codec/tiff/TIFFFaxDecoder.java [1339:1408]


    private int nextNBits(int bitsToGet) {
        byte b;
        byte next;
        byte next2next;
        int l = data.length - 1;
        int bp = this.bytePointer;

        if (fillOrder == 1) {
            b = data[bp];

            if (bp == l) {
                next = 0x00;
                next2next = 0x00;
            } else if ((bp + 1) == l) {
                next = data[bp + 1];
                next2next = 0x00;
            } else {
                next = data[bp + 1];
                next2next = data[bp + 2];
            }
        } else if (fillOrder == 2) {
            b = flipTable[data[bp] & 0xff];

            if (bp == l) {
                next = 0x00;
                next2next = 0x00;
            } else if ((bp + 1) == l) {
                next = flipTable[data[bp + 1] & 0xff];
                next2next = 0x00;
            } else {
                next = flipTable[data[bp + 1] & 0xff];
                next2next = flipTable[data[bp + 2] & 0xff];
            }
        } else {
            throw new RuntimeException(PropertyUtil.getString("TIFFFaxDecoder7"));
        }

        int bitsLeft = 8 - bitPointer;
        int bitsFromNextByte = bitsToGet - bitsLeft;
        int bitsFromNext2NextByte = 0;
        if (bitsFromNextByte > 8) {
            bitsFromNext2NextByte = bitsFromNextByte - 8;
            bitsFromNextByte = 8;
        }

        bytePointer++;

        int i1 = (b & table1[bitsLeft]) << (bitsToGet - bitsLeft);
        int i2 = (next & table2[bitsFromNextByte]) >>> (8 - bitsFromNextByte);

        int i3 = 0;
        if (bitsFromNext2NextByte != 0) {
            i2 <<= bitsFromNext2NextByte;
            i3 = (next2next & table2[bitsFromNext2NextByte])
                >>> (8 - bitsFromNext2NextByte);
            i2 |= i3;
            bytePointer++;
            bitPointer = bitsFromNext2NextByte;
        } else {
            if (bitsFromNextByte == 8) {
                bitPointer = 0;
                bytePointer++;
            } else {
                bitPointer = bitsFromNextByte;
            }
        }

        int i = i1 | i2;
        return i;
    }