// imageLoader.cpp : Defines the entry point for the console application.
//

#include <windows.h>
#include <gl/GL.h>
#include <stdio.h>

#include <fstream>
#include <iostream>
#include <string>



using namespace std;

class RGBpixel {
public: 
	unsigned char r,g,b;

	RGBpixel() {
		r = g = b = 255;
	}
	RGBpixel(unsigned char r, unsigned char g, unsigned char b) {
		this->r = r;
		this->g = g;
		this->b = b;
	}
	friend bool operator==(const RGBpixel &left, const RGBpixel &right) {
		return left.r == right.r && left.g == right.g && left.b == right.b;
	}
	friend const RGBpixel operator+(const RGBpixel &left, const RGBpixel &right) {
		int c[3] = { left.r + right.r, left.g + right.g, left.b + right.b };
		for (int i = 0; i < 3; i++) {
			if (c[i] > 255) c[i] = 255;
		}
		RGBpixel sum(c[0], c[1], c[2]);
		return sum;
	}
	friend const RGBpixel operator-(const RGBpixel &left, const RGBpixel &right) {
		int c[3] = { left.r - right.r, left.g - right.g, left.b - right.b };
		for (int i = 0; i < 3; i++) {
			if (c[i] < 0) c[i] = 0;
		}
		RGBpixel sum(c[0], c[1], c[2]);
		return sum;
	}
};

class RGBimage {
private:

public:
	RGBpixel **map;
	char *data;
	int w;
	int h;

	RGBimage(int w, int h) {
		this->w = w;
		this->h = h;
		map = new RGBpixel*[h];
		for (int i = 0; i < h; i++) {
			map[i] = new RGBpixel[w];
		}
	}
	virtual ~RGBimage();
	void fill_data();
	void draw();
};
RGBimage::~RGBimage() {
	for (int i = 0; i < h; i++) {
		delete [] map[i];
	}
	delete [] map;
	delete [] data;
}
void RGBimage::fill_data() {
	int k = 0;
	while ((w + k)%4) k++;
	data = new char[h*(w + k)*3];

	for (int j = 0; j < h; j++) {
		for (int i = 0; i < w; i++) {
			int index = (i + j*(w + k))*3;
			data[index + 0] = map[j][i].r;
			data[index + 1] = map[j][i].g;
			data[index + 2] = map[j][i].b;
		}
	}
}
void RGBimage::draw() {
	fill_data();
	glDrawPixels(w, h, GL_RGB, GL_UNSIGNED_BYTE, data);
	//for (int i = 0; i < k; i++) data[h*(w + k)]
}


typedef unsigned short ushort;
typedef unsigned long ulong;

typedef unsigned short WORD;
typedef unsigned long DWORD;

#pragma pack(push, 1)
typedef struct bmpFileHeader 
{ 
  WORD    bfType;        // смещение 0 байт от начала файла
  DWORD   bfSize;        // смещение 2 байта от начала файла, длина 4 байта
  WORD    bfReserved1; 
  WORD    bfReserved2; 
  DWORD   bfOffBits;    // смещение 10 байт от начала файла, длина 4 байта
} BMPFILEHEADER;

typedef struct bmpInfoHeader
{
  DWORD  biSize; 
  int    biWidth; 
  int    biHeight; 
  WORD   biPlanes; 
  WORD   biBitCount; 
  DWORD  biCompression;  
} BMPINFOHEADER;
#pragma pack(pop)

class BMPimage {
private:
	void form_image();
public:
	
	string name;
	bmpFileHeader file_header;
	bmpInfoHeader info_header;
	RGBpixel *map;
	char *char_map;
	RGBimage *image;


	BMPimage() { name = ""; }
	virtual ~BMPimage();
	BMPimage(string fname) {
		loadBmp(fname);
	}
	void loadBmp(string fname);
};
BMPimage::~BMPimage() {
	delete [] map;
	delete [] char_map;
	delete image;
}
void BMPimage::form_image() {
	int w = info_header.biWidth;
	int h = info_header.biHeight;
	int k = 0;
	while ((w + k)%4) k++;
	image = new RGBimage(w, h);
	for (int j = 0; j < h; j++) {
		for (int i = 0; i < w; i++) {
			int index = (i + j*(w + k))*3;
			image->map[j][i].b = char_map[index];
			image->map[j][i].g = char_map[index + 1];
			image->map[j][i].r = char_map[index + 2];
		}
	}
}
void BMPimage::loadBmp(string fname) {
	FILE *pFile;
	pFile = fopen (fname.c_str(), "r");
	if (pFile!=NULL)
	{	
		fread((void*)&file_header, sizeof(bmpFileHeader), 1, pFile);
		fread((void*)&info_header, sizeof(bmpInfoHeader), 1, pFile);
		int w = info_header.biWidth;
		int h = info_header.biHeight;
		int offset = file_header.bfOffBits - sizeof(bmpFileHeader) - sizeof(bmpInfoHeader);
		char dummy;
		for (int i = 0; i < offset; i++) fread((void*)&dummy, sizeof(char), 1, pFile);
		//printf("ptr = %d\n", ptr);
		map = new RGBpixel[w*h];
		for (int j = 0; j < h; j++) {
			for (int i = 0; i < w; i++) {
				fread((void*)&map[i+j*w], sizeof(RGBpixel), 1, pFile);
				char t = map[i+j*w].r;
				map[i+j*w].r = map[i+j*w].b, map[i+j*w].b = t;
				for (int k = 0; k < (4 - (w*3)%4)%4; k++) fread((void*)&dummy, sizeof(char), 1, pFile);
			}
		}
		fseek ( pFile , file_header.bfOffBits , SEEK_SET );
		while (w % 4 != 0) w++;
		char_map = new char[w*h*3];
		//for (int i = 0; i < w*h*3; i++) {
		fread((void*)char_map, sizeof(char), w*h*3+4, pFile);
		//}
		fclose (pFile);

		form_image();
	} else {
		cout << "cannot open file for reading!" << endl;
	}
}