#include <stdio.h>
#include <dos.h>

#define VIDEO_SEGMENT 0XA0000000
#define SCREEN_WIDTH 320
#define SCREEN_HEIGHT 200
// 64k palette index 0xA0000000-0xA000FFFF (upper left to lower right)
char far *vram = MK_FP(0xA000, 0x0000);


unsigned char car_sprite[] = {21, 0, 6, 0,
    0, 0, 0, 0, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 4, 4, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0,
    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 0,
    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
    0, 4, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 4, 0, 0,
    0, 0, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 0, 0
};

unsigned char ball_sprite[] = {5, 0, 5, 0,        /* width 5, height 5 */
      0,  11,  11,  11,   0,
     11,  14,   3,   3,   9,
     11,   3,   3,   3,   9,
     11,   3,   3,   3,   9,
      0,   9,   9,   9,   0
};



/*
INT 10h, Service 0h
Set Screen Mode

Input:   AH = 0h
         AL = Mode Number (see below)
Output:  The video mode is changed.

Mode Number  Text Res.  Graphics Res.   Description  Adapters  Max. Pages
---------------------------------------------------------------------------
         0h      40x25         ------   B&W Text     CGA+               8
         1h      80x25         ------   B&W Text     MDPA+              8
	 2h      40x25         ------   Color Text   CGA+          4 or 8
         3h      80x25         ------   Color Text   (MDPA?)/CGA+  4 or 8
         4h      40x25        320x200   4 colors     CGA+               1
         5h      40x25        320x200   2 colors     CGA+               1
         6h      80x25        640x200   2 colors     CGA+               1
         7h      80x25         ------   B&W          MDPA (CGA+?)       1
         8h to Ch -- PCjr or other adapters; no longer used
         Dh      40x25        320x200   16 colors    EGA+               8
         Eh      80x25        640x200   16 colors    EGA+               4
         Fh      80x25        640x350   2 colors     EGA+               2
        10h      80x25        640x350   16 colors    EGA+               2
        11h      80x25        640x480   2 colors     VGA+               1
	12h      80x25        640x480   16 colors    VGA+               1
        13h      40x25        320x200   256 colors   VGA+               1
*/


void r_mode(int mode)
{
    union REGS in_reg, out_reg;
    struct SREGS segreg;

    segread(&segreg);
    in_reg.h.ah = (unsigned char)0x0;
    in_reg.h.al = (unsigned char)mode;
    int86x(0x10, &in_reg, &out_reg, &segreg);
}



void PutPixel (int x, int y, unsigned char color)
{
    pokeb (VIDEO_SEGMENT, (y * SCREEN_WIDTH) + x, color);
}

unsigned char ReadPixel (int x, int y)
{
    return peekb(VIDEO_SEGMENT, (y * SCREEN_WIDTH) + x);
}


void PutSprite (int x, int y, unsigned char sprite[])
{
    int x_count, y_count;
    int width, height;

    /* Extract the width from the first two bytes of the array, and the
       height from the third and fourth bytes of the array: */
    width = sprite[0] + (sprite[1] << 8);
    height = sprite[2] + (sprite[3] << 8);

    /* Loop through the rows: */
    for (y_count = 0; y_count <= height - 1; y_count++)
        /* Loop through the columns: */
        for (x_count = 0; x_count <= width - 1; x_count++)
            PutPixel (x + x_count, y + y_count,
                sprite[4 + (y_count * width) + x_count]);
}



void clear(unsigned char color)
{
	unsigned int i;
	int x = 0;
	int y = 0;
	for(i = 0; i < 0xFFFF; i++)
	{
		vram[(y * SCREEN_WIDTH) + x++] =  color;
	
		if (x >= 320)
		{
			y++;
			x = 0;
		}
	}
}


// mouse cursors made with 2L8 Cursor editor
// downloaded from http://ftp.gnome.org/mirror/archive/ftp.sunet.se/pub/simtelnet/msdos/mouse/

int POINT[32] = {
	0x3fff, 0x1fff, 0x0fff, 0x07ff, 0x03ff, 0x01ff, 0x00ff, 0x007f,
	0x003f, 0x003f, 0x01ff, 0x10ff, 0x30ff, 0xf87f, 0xf87f, 0xfc7f,
	0x0000, 0x4000, 0x6000, 0x7000, 0x7800, 0x7c00, 0x7e00, 0x7f00,
	0x7f80, 0x7c00, 0x6c00, 0x4600, 0x0600, 0x0300, 0x0300, 0x0000
};

short Mouse_Init (void)
{
    union REGS in_reg, out_reg;
    struct SREGS segreg;

    segread(&segreg);
    in_reg.x.ax = (unsigned char)0x0;
    int86x(0x33, &in_reg, &out_reg, &segreg);

    // return # of mouse buttons (-1 if no mouse)
    return out_reg.x.bx;
}

void Mouse_Show (void)
{
    union REGS in_reg, out_reg;
    struct SREGS segreg;

    segread(&segreg);
    in_reg.x.ax = (unsigned char)0x1;
    int86x(0x33, &in_reg, &out_reg, &segreg);
}

void Mouse_Hide (void)
{
    union REGS in_reg, out_reg;
    struct SREGS segreg;

    segread(&segreg);
    in_reg.x.ax = (unsigned char)0x2;
    int86x(0x33, &in_reg, &out_reg, &segreg);

}

void Mouse_Status( int *x, int *y, int *b )
{
    union REGS in_reg, out_reg;
    struct SREGS segreg;

    segread(&segreg);
    in_reg.x.ax = 0x3;
    in_reg.x.bx = 0;
    in_reg.x.cx = 0;
    in_reg.x.dx = 0;

    int86x(0x33, &in_reg, &out_reg, &segreg);
    *b = out_reg.x.bx;
    *x = out_reg.x.cx;
    *y = out_reg.x.dx;
}


void Mouse_Cursor(int *shape, int x, int y)
{
    union REGS inreg, outreg;
    struct SREGS s;

    inreg.x.ax = 0x9;
    inreg.x.bx = x;
    inreg.x.cx = y;
    inreg.x.dx = (unsigned)shape;
    segread(&s);
    s.es = s.ds;
    int86x(0x33,&inreg,&outreg,&s);
}


void main(void)
{
    int x = 0;
    int y = 0;
    int j = 0;

    printf("Entering mode 13\n");
    delay(500);
    r_mode(0x13);
    x = 0;
    y = 0;


    Mouse_Init();
    Mouse_Show();
    Mouse_Cursor(POINT, 0, 0);

    clear(0);
    while (j < 60 * 10)
    {
	j++;
	PutSprite(50 + x, 100 + x, car_sprite);
	PutSprite(150 + y, 100 + 2*y, ball_sprite);
	x++;
	y++;
	delay(15);
	clear(0);
    }
    r_mode(0x3);
    printf("Exiting mode 13\n");
    delay(500);
}