/*****************************************************************
 *     INCLUDE DIRECTIVES                                        *
 *****************************************************************/
#include<string.h>
#include<conio.h>
#include<stdlib.h>
#include<stdio.h>
#include<fstream.h>

/*****************************************************************
 *     UNIVERSAL DATA TYPES, CONSTANTS                           *
 *****************************************************************/
typedef unsigned char byte;

typedef struct {
	int X, Y;
} Point;


#define DEBUG 1
#define LOG(x) printf(x);


/*****************************************************************
 *     VIDEO DRIVER                                              *
 *****************************************************************/

// Used variables
byte far* VGAMem = (byte far *)0xA0000000L;
byte* Buffer;

// Used by cursor. Need to be initialized here
int SaveX, SaveY;

// Change video mode routine
void VideoMode(byte mode)
{
	asm {
		mov ah, 0
		mov al, mode
		int 0x10
	}
}

// Initialize graphic mode 0x13, use duble buffering if possible
void InitGraph()
{
	Buffer = (byte*)malloc(320 * 200);

	if (Buffer) memset(Buffer, 0, 320*200);

	#if DEBUG == 1
	if (!Buffer) LOG("Error: Not enough memory. Double buffering disabled.");
	#endif

	VideoMode(0x13);

	SaveX = SaveY = 400;
}

// Go back to normal text mode 0x03
void ExitGraph()
{
	free(Buffer);
	VideoMode(0x03);
}

// Put a pixel in specified position. Does not put it on the screen if double buffering.
void PutPixel(int x, int y, int c)
{
	if (y >= 200 || x >= 320) return;

	if (Buffer) Buffer[y*320 + x] = c;
	else VGAMem[y*320 + x] = c;
}

// Get a pixel from screen/double buffer
byte GetPixel(int x, int y)
{
	return (Buffer) ? Buffer[320*y + x] : VGAMem[320*y+x];
}

// Put double buffer on the screen. Should be called after e.g. displaying something new.
void Update()
{
	if (Buffer) memcpy(VGAMem, Buffer, 320*200);
}




/*****************************************************************
 *     MOUSE DRIVER                                              *
 *****************************************************************/

// Defines cursor size and array
#define cX 7
#define cY 7
byte Cursor[cY][cX] = { {1, 0, 0, 1, 1, 1, 1},
			{1, 0, 0, 1, 0, 0, 0},
			{1, 0, 0, 1, 0, 0, 0},
			{1, 1, 1, 1, 1, 1, 1},
			{0, 0, 0, 1, 0, 0, 1},
			{0, 0, 0, 1, 0, 0, 1},
			{1, 1, 1, 1, 0, 0, 1}};

// Save what is under the cursor
byte Save[cY][cX];
void SaveUnder(int x, int y)
{
	for (int i = 0; i < cX; i++)
		for (int j = 0; j < cY; j++)
			Save[i][j] = GetPixel(i+x, j+y);

	SaveX = x; SaveY = y;
}

// Restore what was under the cursor
void RestoreUnder ()
{
	for (int i = 0; i < cX; i++)
		for (int j = 0; j < cY; j++)
			PutPixel(i+SaveX, j+SaveY, Save[j][i]);
}

// Display the cursor 
void PutCursor(int x, int y, byte c)
{
	// restore old
	RestoreUnder();
	SaveUnder(x, y);
	for (int i = 0; i < cX; i++)
		for (int j = 0; j < cY; j++)
		{
			Save[j][i] = GetPixel(i+x, j+y);
			if (Cursor[j][i] == 1) PutPixel(i+x, j+y, Cursor[j][i] * c);
			if (Cursor[j][i] == 2) PutPixel(i+x, j+y, 256-(Cursor[j][i] * c));

		}

}

// Check if mouse cursor is in specified area
unsigned char MouseIsInArea (int MouseX, int MouseY, int left, int top, int right, int bottom)
{
	if (MouseX >= left && MouseX <= right
	    && MouseY >= top && MouseY <= bottom) return 1;
	return 0;
}

// Bit masks for mouse buttons
const byte MouseLeftB = 1, MouseRightB = 2, MouseMiddleB = 4;

// Initialize mouse driver
int MouseInit(int *NumberOfButtons)
{
	int r;
	int tmp;
	asm {
		mov ax, 0
		int 0x33
		mov tmp, ax
		mov r, bx
		}

	*NumberOfButtons = tmp;
	return r;
}

// Get the status of the mouse (buttons, etc)
byte MouseGetStatus()
{
	byte re;
	asm {
		mov ax, 3
		int 0x33
		mov re, bl
	}
	return re;
}

// Get movement
void MouseGetDirection (int *x, int *y)
{
	int tx, ty;
	asm {
		mov ax, 0x0B
		int 0x33
		mov tx, cx
		mov ty, dx
	}
	*x = tx; *y = ty;
}



/*****************************************************************
 *     FONT MANAGER                                              *
 *****************************************************************/

class Font {
	char Path[256];
	ifstream file;

  public:
	byte Error;
	Font(char* c);
	Font();

	~Font() {
		file.close();
		}

	Point PutChar(int x, int y, char c);

	void PutString(int x, int y, char* str);

	void OpenNew(char* c);
};

Font::Font(char* c) {
	int len = strlen(c);

	for (int i = 0; i < len && i<256; i++)
		Path[i] = c[i];

	file.open(c);

	if (!file) Error = 1;
	else Error = 0;
}

Font::Font() {
	Path[0] = 0;
}

void Font::OpenNew(char* c)
{
	int len = strlen(c);
	for (int i = 0; i < len && i<256; i++)
		Path[i] = c[i];
	file.open(c);
	if (!file) Error = 1;
	else Error = 0;
}


Point Font::PutChar(int x, int y, char c)
{
    Point ret;
    int cSizeX, cSizeY;
    if (Error) return ret;

    int tmp = 0;
    file.seekg(0, ios::beg);

    for (int i = 0; i < c; i++) {
	file>>cSizeX>>cSizeY;
	  for (int j = 0; j < cSizeX * cSizeY; j++) file>>tmp;
	  }

    file>>cSizeX>>cSizeY;
    for (int yy=0; yy<cSizeY; yy++)
      for (int xx=0; xx<cSizeX; xx++)
      {
		file>>tmp;
		if (tmp) PutPixel(xx+x, yy+y, c);
      }

      ret.X = cSizeX;
      ret.Y = cSizeY;
      return ret;
}

void Font::PutString(int x, int y, char* str)
{
    if (Error) return;

    Point temp; int sum = 0;

    // Use a default kerning value of 1 pixels.
    int len = strlen(str);
    for (int i=0; i < len; i++) {

	  temp = PutChar(x+sum, y, str[i]);
	  sum += temp.X+1;
	  }
}





/*****************************************************************
 *     WINDOW MANAGER                                            *
 *****************************************************************/

class Window
{
	byte Visible;

	char Title[256];
	Font Fnt;

public:
	Point Pos, Size;

	Window(char* s);
	Window();
	Window(Point pos, Point siz, char* s);

	void Show();
	void Hide();

	void DrawPixel(int x, int y, int c)
	{
	    if (x < this->Size.X && y < this->Size.Y)
	    PutPixel (x+this->Pos.X, y+this->Pos.Y, c);
	}

	void Update();

  void MouseAction(int X, int Y, byte Buttons)
  {
    if (Buttons & MouseLeftB) DrawPixel(5,5, 150);
    else DrawPixel(5, 5, 0);

  }


};

Window::Window(char* s)
{
	memcpy(Title, s, 256);
	Visible = 0;
	Size.X = 0; Size.Y = 0; Pos.X = 0; Pos.Y = 0;

	Fnt.OpenNew("font.txt");
}

Window::Window()
{
	Visible = 0;
	Size.X = 0; Size.Y = 0; Pos.X = 0; Pos.Y = 0;
	Title[0] = 0;

	Fnt.OpenNew("font.txt");
}

Window::Window(Point pos, Point siz, char* s)
{
	Visible = 0;
	Size = siz; Pos = pos;
	memcpy(Title, s, 256);
}


void Window::Show()
{
	Visible = 1;
	for (int i = Pos.X; i < Size.X + Pos.X; i++) {
		for (int j = Pos.Y+10; j < Size.Y + Pos.Y; j++)
			PutPixel(i, j, 7);

		for (j = Pos.Y; j < Pos.Y+10; j++)
			PutPixel(i, j, 12);
		}
	Fnt.PutString(Pos.X+3, Pos.Y+2, Title);
}

void Window::Hide()
{
	Visible = 0;

	for (int i = Pos.X; i < Size.X + Pos.X; i++)
		for (int j = Pos.Y; j < Size.Y + Pos.Y; j++)
			PutPixel(i, j, 0);
}



/*****************************************************************
 *     MAIN FUNCTION                                             *
 *****************************************************************/

int main()
{
	int a;
	InitGraph();
	MouseInit(&a);

	Window alpha("AaBbCcXyZhSgGZz@,HEL");
	alpha.Pos.X = 320/2;
	alpha.Pos.Y = 200/2;
	alpha.Size.X = 140;
	alpha.Size.Y = 80;


	int MouseX = 320/2, MouseY = 200/2;
	int dx, dy, oldX, oldY;
	int Col = 15;

	for (;;)
	{
		if (oldX != MouseX || oldY != MouseY) {
			memset (Buffer, 0, 320*200);
			alpha.Show();
			PutCursor(MouseX, MouseY, Col);


			Update();

		}

		oldX = MouseX; oldY = MouseY;

		MouseGetDirection(&dx, &dy);
		MouseX+=dx;
		MouseY+=dy;

		if (MouseX > 320) MouseX = 320;
		if (MouseY > 200) MouseY = 200;
		if (MouseX < 0) MouseX = 0;
		if (MouseY < 0) MouseY = 0;

		int ok=0;

		if (MouseGetStatus() & MouseLeftB) {
			alpha.MouseAction(MouseX, MouseY, MouseGetStatus());

			// Check if bottom right corner => ok=2
			if (MouseIsInArea (oldX, oldY, alpha.Pos.X+alpha.Size.X-5, alpha.Pos.Y + alpha.Size.Y-5,
					alpha.Pos.X+alpha.Size.X, alpha.Pos.Y + alpha.Size.Y))
				ok = 2;

			else if (MouseIsInArea (oldX, oldY, alpha.Pos.X, alpha.Pos.Y,
					alpha.Pos.X+alpha.Size.X, alpha.Pos.Y + alpha.Size.Y))
				ok = 1;

			if (ok==1)
			{
				alpha.Pos.X += dx;
				alpha.Pos.Y += dy;

				if (alpha.Pos.X < 0) alpha.Pos.X = 0;
				if (alpha.Pos.Y < 0) alpha.Pos.Y = 0;
				if (alpha.Pos.X > 320 - alpha.Size.X) alpha.Pos.X = 320-alpha.Size.X;
				if (alpha.Pos.Y > 200 - alpha.Size.Y) alpha.Pos.Y = 200-alpha.Size.Y;

			}

			else if (ok==2)
			{
				alpha.Size.X += dx;
				alpha.Size.Y += dy;

				if (alpha.Size.X > 300) alpha.Size.X = 300;
				if (alpha.Size.X < 40) alpha.Size.X = 40;
				if (alpha.Size.Y > 150) alpha.Size.Y = 150;
				if (alpha.Size.Y < 30) alpha.Size.Y = 30;
			}
		}

		if (!(MouseGetStatus() & MouseLeftB)) ok=0;


		if(kbhit()) break;


	}


	ExitGraph();
	return 0;
}