/*
 * LCD Image Converter. Converts images and fonts for embedded applications.
 * Copyright (C) 2012 riuson
 * mailto: riuson@gmail.com
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/
 */

#include "bitstream.h"
//-----------------------------------------------------------------------------
#include <QVector>
#include "preset.h"
#include "prepareoptions.h"
#include "matrixoptions.h"
#include "imageoptions.h"
//-----------------------------------------------------------------------------
BitStream::BitStream(Preset *preset, QVector<quint32> *data, int start, int count)
{
    this->mPreset = preset;
    this->mData = data;
    this->mStart = start;
    this->mCount = count;

    this->init();
}
//-----------------------------------------------------------------------------
void BitStream::init()
{
    this->mCurrentPixel = 0;
    this->mMaskCurrent = this->mMaskSource = this->mPreset->matrix()->maskUsed();
    this->mBlockSize = ((int)this->mPreset->image()->blockSize() + 1) << 3;
    this->mBitsReaded = 0;
    this->mSetOnesByDefault = this->mPreset->image()->blockDefaultOnes();
}
//-----------------------------------------------------------------------------
bool BitStream::eof() const
{
    if (this->mStart + this->mCurrentPixel >= this->mData->size())
        return true;

    if (this->mCurrentPixel >= this->mCount)
        return true;

    return false;
}
//-----------------------------------------------------------------------------
quint32 BitStream::next()
{
    quint32 result;

    if (this->mSetOnesByDefault)
        result = 0xffffffff;
    else
        result = 0;

    // Number of bits
    int i = this->mBlockSize - 1;
    // '1' bit - filled output bit
    quint32 fill = this->mPreset->matrix()->maskFill();

    while (i >= 0)
    {
        result = result << 1;

        if (this->mSetOnesByDefault)
            result |= 0x00000001;

        // Loop until filled '1' bit
        if ((fill & (0x00000001 << i)) == 0)
        {
            i--;
            continue;
        }

        // If bits available
        if (!this->eof())
        {
            // Get next bit from stream and put to result
            if (this->nextBit())
                result |= 0x00000001;
            else
                result &= 0xfffffffe;
        }
        i--;
    }
    return result;
}
//-----------------------------------------------------------------------------
bool BitStream::nextBit()
{
    if (this->eof())
        return false;

    bool result = false;
    // Initial pixel data
    quint32 data = this->mData->at(this->mStart + this->mCurrentPixel);

    // Loop bits...
    for (int i = 0; i < 32; i++)
    {
        // From MSB to LSB
        quint32 mask = 0x80000000 >> i;

        // If bit is used
        if (this->mMaskCurrent & mask)
        {
            result = (data & mask) != 0;

            // Reset processed pixel's bit in mask
            this->mMaskCurrent &= ~mask;

            this->mBitsReaded++;

            // If pixel completed
            if (this->mMaskCurrent == 0)
            {
                // Reload mask
                this->mMaskCurrent = this->mMaskSource;
                // Go to next pixel in source data array
                this->mCurrentPixel++;

                if (this->eof())
                    data = 0;
                else
                    data = this->mData->at(this->mStart + this->mCurrentPixel);
            }

            break;
        }
    }

    return result;
}
//-----------------------------------------------------------------------------
int BitStream::remain() const
{
    int result = 0;
    for (int i = 0; i < 32; i++)
    {
        if (this->mMaskCurrent & (0x00000001 << i))
            result++;
    }
    return result;
}
//-----------------------------------------------------------------------------