#include "bitmap.h"

Bitmap::Bitmap()
{
	data = NULL;
	return;
}

Bitmap::~Bitmap()
{
	delete [] data;
	return;
}

void Bitmap::readBitmap(string fileName)
{
//	ifstream inFile(fileName.c_str());
	FILE* inFile;
	inFile = fopen(fileName.c_str(), "rb");
	if (!inFile)
	{
//		cout << "Failed to open " << fileName << endl;
		exit(1);
	}
	
//	char c = inFile.get();
	char c = getc(inFile);
	assert(c == 'B');
//	c = inFile.get();
	c = getc(inFile);
	assert(c == 'M');
	fileSize = readLong(inFile);
	readShort(inFile);
	readShort(inFile);
	offset = readLong(inFile);
	headerSize = readLong(inFile);
	width = readLong(inFile);
	height = readLong(inFile);
	trueW = width;
	trueH = height;
	readShort(inFile);
	bitsPerPixel = readShort(inFile);
	assert(bitsPerPixel == 1 || bitsPerPixel == 4 || bitsPerPixel == 8 || bitsPerPixel == 24);
	readLong(inFile);
	imageSize = readLong(inFile);
	readLong(inFile);
	readLong(inFile);
	numberOfColors = readLong(inFile);
	numberOfImpColors = readLong(inFile);

	switch (bitsPerPixel)
	{
		case 1:
//			cout << "Not implemented yet" << endl;
			break;
		case 4:
//			cout << "Not implemented yet" << endl;
			break;
		case 8:
//			cout << "Not implemented yet" << endl;
			break;
		case 24:
		{
			int bytesPerRow = ((3*width + 3) >> 2) << 2;
			delete[] data;
			data = new unsigned char[height*bytesPerRow];
			unsigned char* p = data;
			for (int i = 0; i < height; i++)
			{
				int j;
				for (j = 0; j < width; j++)
				{
//					*(p+2) = inFile.get();		// Read blue
//					*(p+1) = inFile.get();		// Read green
//					*p = inFile.get();			// Read red
					*(p+2) = getc(inFile);		// Read blue
					*(p+1) = getc(inFile);		// Read green
					*p = getc(inFile);			// Read red
					p += 3;
				}
				int k=3*j;
				for (int k = 3*j; k < bytesPerRow; k++)
				{
//					inFile.get();
					getc(inFile);
					*(p++) = 0;
				}
			}
			break;
		}
	}
//	inFile.close();
	fclose(inFile);
	return;
}

//short Bitmap::readShort(ifstream& in)
short Bitmap::readShort(FILE* in)
{
	unsigned char low, high;
//	low = in.get();
//	high = in.get();
	low = getc(in);
	high = getc(in);
	
	short value = high;
	value <<= 8;
	value |= low;
	return value;
}

//long Bitmap::readLong(ifstream& in)
long Bitmap::readLong(FILE* in)
{
	unsigned char byte0, byte1, byte2, byte3;
//	byte0 = in.get();
//	byte1 = in.get();
//	byte2 = in.get();
//	byte3 = in.get();
	byte0 = getc(in);
	byte1 = getc(in);
	byte2 = getc(in);
	byte3 = getc(in);

	long value = byte3;
	value <<= 8;
	value |= byte2;
	value <<= 8;
	value |= byte1;
	value <<= 8;
	value |= byte0;
	return value;
}

int Bitmap::powerOf2(int n)
{
	int power = 1;
	n--;
	while (n)
	{
		n >>= 1;
		power <<= 1;
	}
	return power;
}

void Bitmap::resizeToPowerOf2()
{
	int bytesPerRow = ((3*trueW + 3) >> 2) << 2;
	width = powerOf2(trueW);
	height = powerOf2(trueH);
	imageSize = 3*width*height;
	unsigned char* newData = new unsigned char[imageSize];
	unsigned char* p = data;
	unsigned char* q = newData;
	for (int j = 0; j < trueH; j++)
	{
		for (int i = 0; i < bytesPerRow; i++)
			*(q++) = *(p++);
		for (int i = bytesPerRow; i < 3*width; i++)
			*(q++) = 0;
	}
	for (int j = trueH; j < height; j++)
		for (int i = 0; i < 3*width; i++)
			*(q++) = 0;
	delete[] data;
	data = newData;
	return;
}