5 pixles wide by 10 pixles tall
how may bytes are in each row?	16
how may bytes are in the image data?160
how may bytes are in the file header? 14
how may bytes are in the info header? 40
how may bytes are in the whole file? 214

#include<iostream>
#include<fstream>

using namespace std;

const unsigned int HEADER_SIZE = 54;
const unsigned int BYTES_PER_PIXEL = 3;

struct FileHeader
{
	char bfType[3];
	unsigned int bfSize;
	unsigned short bfReserved1;
	unsigned short bfReserved2;
	unsigned int bfOffBits;
};

struct InfoHeader
{
	unsigned int biSize;
	unsigned int biWidth;
	unsigned int biHeight;
	unsigned short biPlanes;
	unsigned short biBitCount;
	unsigned int biCompression;
	unsigned int biSizeImage;
	unsigned int biXPelsPerMeter;
	unsigned int biYPelsPerMeter;
	unsigned int biClrUsed;
	unsigned int biClrImportant;
};

struct Pixel
{
	unsigned char blue;
	unsigned char green;
	unsigned char red;
};

struct BitmapFile
{
	FileHeader fileHeader;
	InfoHeader infoHeader;
	Pixel* pixels;
};

int paddingBytesNeededPerRow(int width);
int bytesPerRow(int width);


void writeFileHeader(ofstream& fout, const FileHeader& fileHeader)
{
	fout.write(fileHeader.bfType, 2); // this should read BM
	fout.write((char*)&fileHeader.bfSize,4);
	fout.write((char*)&fileHeader.bfReserved1,2);
	fout.write((char*)&fileHeader.bfReserved2,2);
	fout.write((char*)&fileHeader.bfOffBits,4);
}

void writeInfoHeader(ofstream& fout, const InfoHeader& infoHeader)
{
	fout.write((char*)&infoHeader.biSize,4);
	fout.write((char*)&infoHeader.biWidth,4);
	fout.write((char*)&infoHeader.biHeight,4);
	fout.write((char*)&infoHeader.biPlanes,2);
	fout.write((char*)&infoHeader.biBitCount,2);
	fout.write((char*)&infoHeader.biCompression,4);
	fout.write((char*)&infoHeader.biSizeImage,4);
	fout.write((char*)&infoHeader.biXPelsPerMeter,4);
	fout.write((char*)&infoHeader.biYPelsPerMeter,4);
	fout.write((char*)&infoHeader.biClrUsed,4);
	fout.write((char*)&infoHeader.biClrImportant,4);
}
void writePixels(ofstream& fout, const Pixel* pixels, const InfoHeader& infoHeader)
{
	int i = 0;
	for(int row = 0; row < infoHeader.biHeight; row++)
	{
		for(int column = 0;column < infoHeader.biWidth; column++)
		{
			fout.write((char*)&pixels[i].blue, 1);
			fout.write((char*)&pixels[i].green, 1);
			fout.write((char*)&pixels[i].red, 1);
			i++;
		}
		//may need to write extra bytes
		fout.write((char*)&padding,paddingBytesNeededPerRow(width));
	}
}

void writeBitmapFile(ofstream& fout, const BitmapFile& bitmapFile)
{
	writeFileHeader(fout,bitmapFile.fileHeader);
	writeInfoHeader(fout,bitmapFile.infoHeader);
	writePixels(fout, bitmapFile.pixels, bitmapFile.infoHeader);
}

void readFileHeader(ifstream& fin, FileHeader& fileHeader)
{
	fin.read(fileHeader.bfType, 2); // this should read BM
	fin.read((char*)&fileHeader.bfSize,4);
	fin.read((char*)&fileHeader.bfReserved1,2);
	fin.read((char*)&fileHeader.bfReserved2,2);
	fin.read((char*)&fileHeader.bfOffBits,4);
}

void readInfoHeader(ifstream& fin, InfoHeader& infoHeader)
{
	fin.read((char*)&infoHeader.biSize,4);
	fin.read((char*)&infoHeader.biWidth,4);
	fin.read((char*)&infoHeader.biHeight,4);
	fin.read((char*)&infoHeader.biPlanes,2);
	fin.read((char*)&infoHeader.biBitCount,2);
	fin.read((char*)&infoHeader.biCompression,4);
	fin.read((char*)&infoHeader.biSizeImage,4);
	fin.read((char*)&infoHeader.biXPelsPerMeter,4);
	fin.read((char*)&infoHeader.biYPelsPerMeter,4);
	fin.read((char*)&infoHeader.biClrUsed,4);
	fin.read((char*)&infoHeader.biClrImportant,4);
}
void readPixels(ifstream& fin, Pixel* pixels, InfoHeader& infoHeader)
{
	int i = 0;
	for(int row = 0; row < infoHeader.biHeight; row++)
	{
		for(int column = 0;column < infoHeader.biWidth; column++)
		{
			fin.read((char*)&pixels[i].blue, 1);
			fin.read((char*)&pixels[i].green, 1);
			fin.read((char*)&pixels[i].red, 1);
			i++;
		}
		//may need to read extra bytes
		fin.read((char*)&padding,paddingBytesNeededPerRow(width));
	}
}

void readBitmapFile(ifstream& fin, BitmapFile& bitmapFile)
{
	readFileHeader(fin,bitmapFile.fileHeader);
	readInfoHeader(fin,bitmapFile.infoHeader);

	//asking form memory at runtime (dynamic memeory allocation)
	bitmapFile.pixels = new Pixel[bitmapFile.infoHeader.biWidth * bitmapFile.infoHeader.biHeight];
	
	readPixels(fin, bitmapFile.pixels, bitmapFile.infoHeader);
}


int bytesPerRow(int width)
{
	int result = width * 3;
	
	while(result % 4 != 0)
	{
		result ++;
	}

	return result;
}


int paddingBytesNeededPerRow(int width)
{
	return ( bytesPerRow(width) - (width * 3));
}

void main()
{
	char fileName[100];
	cout << "Enter the name of the bitmap file you want to edit\n";
	cin.getline(fileName,100);

	BitmapFile bitmapFile;

	ifstream fin(fileName,ios_base::binary);
	readBitmapFile(fin,bitmapFile);
	fin.close();

	//do the menu stuff


	ofstream fout(fileName,ios::binary);
	writeBitmapFile(fout,bitmapFile);
	fout.close();
}




	//int height;
	//int width;

	//cout << "Height? ";
	//cin >> height;
	//cout << "Width? ";
	//cin >> width;

	//writeFileHeader(fout, height, width);
	//writeInfoHeader(fout, height, width);

	//unsigned char red = 0;
	//unsigned char blue = 0;
	//unsigned char green = 0;
	//unsigned int padding = 0;

	//for(int row = 0; row < height; row++)
	//{
	//	for(int column = 0;column < width; column++)
	//	{
	//		fout.write((char*)&blue, 1);
	//		fout.write((char*)&green, 1);
	//		fout.write((char*)&red, 1);
	//	}
	//	//may need to write extra bytes
	//	fout.write((char*)&padding,paddingBytesNeededPerRow(width));
	//}