OImageBmp.cpp

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/*
 * Copyright (C) <2012> <EDF-R&D> <FRANCE>
 * 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 2 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
/*
 *
 */
 
#include "OImageBmp.h"
#include <cassert>
#include <fstream>
#include <cstring>
 
OImageBmp::OImageBmp() : OImage() {}
 
OImageBmp::~OImageBmp() {}
 
bool OImageBmp::load(const std::string& filename)
{
    // Open file to read
    std::ifstream ifs;
    ifs.open(filename.c_str(), std::ios::in | std::ios::binary);
    if (!ifs)
    {
        return false;
    }
 
    // Read width and height
    ifs.seekg(18, std::ios::beg);
    ifs.read((char*)&_sizeX, sizeof(unsigned int));
    ifs.read((char*)&_sizeY, sizeof(unsigned int));
 
    // OImage size in BGR and RGBA
    unsigned int size3 = _sizeX * _sizeY * 3;
    unsigned int size4 = _sizeX * _sizeY * 4;
 
    // Check planes
    unsigned short planes = 0;
    ifs.read((char*)&planes, sizeof(unsigned short));
    if (planes != 1)
    {
        return false;
    }
 
    // Check bits per pixel
    ifs.read((char*)&_depth, sizeof(unsigned int));
    if (_depth != 24)
    {
        return false;
    }
 
    // Allocate memory
    _data = new unsigned char[size4];
    unsigned char* tempData = new unsigned char[size3];
 
    // Read BGR image
    ifs.seekg(22, std::ios::cur);
    ifs.read((char*)tempData, size3);
 
    // Convert BGR to RGBA
    unsigned int c1 = 0, c2 = 0;
    for (c1 = 0, c2 = 0; c1 < size4; c1 += 4, c2 += 3)
    {
        _data[c1] = tempData[c2 + 2];
        _data[c1 + 1] = tempData[c2 + 1];
        _data[c1 + 2] = tempData[c2];
        _data[c1 + 3] = 255;
    }
 
    // Free temporary memory
    delete[] tempData;
 
    _depth = 32;
 
    ifs.close();
 
    return true;
}
 
void OImageBmp::flipHorizontal()
{
    const unsigned int stride = _depth;
    const unsigned int w = _sizeX;
    const unsigned int h = _sizeY;
    const unsigned int m = h / 2;
    unsigned char* temp = new unsigned char[stride];
 
    for (unsigned int y = 0; y < m; ++y)
    {
        for (unsigned int x = 0; x < w; ++x)
        {
            unsigned int offset = (y * w + x) * stride;
            unsigned int offsetOpp = ((h - y - 1) * w + x) * stride;
 
            std::memcpy(temp, _data + offset, stride);
            std::memcpy(_data + offset, _data + offsetOpp, stride);
            std::memcpy(_data + offsetOpp, temp, stride);
        }
    }
    delete[] temp;
}
 
void OImageBmp::flipVertical()
{
    const unsigned int stride = _depth;
    const unsigned int w = _sizeX;
    const unsigned int h = _sizeY;
    const unsigned int m = w / 2;
    unsigned char* temp = new unsigned char[stride];
 
    for (unsigned int y = 0; y < h; ++y)
    {
        for (unsigned int x = 0; x < m; ++x)
        {
            unsigned int offset = (y * w + x) * stride;
            unsigned int offsetOpp = (y * w + (w - x - 1)) * stride;
 
            std::memcpy(temp, _data + offset, stride);
            std::memcpy(_data + offset, _data + offsetOpp, stride);
            std::memcpy(_data + offsetOpp, temp, stride);
        }
    }
    delete[] temp;
}