#define		RED		0x08
#define		GREEN		0x04
#define		BLUE		0x02
#define		HI_INTENSITY	0x01

/* demo program to draw solid boxes with different colors on screen */

Main( argc, argv)
	int argc;
	char *argv[];
{
	int offset;
	char	c;
	int	Set_16_colors();

	Cputs("Graphics Solution 640 x 200 with 16 colors demo program\r\n");
	Cputs("Press any key to continue  \r\n");
	Getch(c);

/*====> This is the routine used to program the Graphics Solution */
/*      to 16 colors either in color or emulation mode */
	if( Set_16_colors()  > 0 )
		/* Draw the solid boxes */
		/* this part is demo only */
		for( offset = 0; offset < 600; offset += 20)
			{
			Fill_box( 21, 21 + offset, 30, 40 + offset, 0x00);
			Fill_box( 31, 21 + offset, 40, 40 + offset, 0x02);
			Fill_box( 41, 21 + offset, 50, 40 + offset, 0x04);
			Fill_box( 51, 21 + offset, 60, 40 + offset, 0x06);
			Fill_box( 61, 21 + offset, 70, 40 + offset, 0x08);
			Fill_box( 71, 21 + offset, 80, 40 + offset, 0x0a);
			Fill_box( 81, 21 + offset, 90, 40 + offset, 0x0c);
			Fill_box( 91, 21 + offset, 100, 40 + offset, 0x0e);

			Fill_box( 101, 21 + offset, 110, 40 + offset, 0x01);
			Fill_box( 111, 21 + offset, 120, 40 + offset, 0x03);
			Fill_box( 121, 21 + offset, 130, 40 + offset, 0x05);
			Fill_box( 131, 21 + offset, 140, 40 + offset, 0x07);
			Fill_box( 141, 21 + offset, 150, 40 + offset, 0x09);
			Fill_box( 151, 21 + offset, 160, 40 + offset, 0x0b);
			Fill_box( 161, 21 + offset, 170, 40 + offset, 0x0d);
			Fill_box( 171, 21 + offset, 180, 40 + offset, 0x0f);
			}
	else
		Cputs("Invalid mode setting\r\n");

	/* Wait for keyboard input  before clear screen */
	Getch();

	/* Switch back to text mode */
	Text_mode();

}
Set_16_colors()
{
	/* return 1 if set to emulation mode */
	/* return 2 if set to color mode */
	/* return -1 if nothing is set because in monochrome mode or */
	/*        cannot determine which mode is in */

	/* the CRT controller is programmed accordingly */

	int	Terminal_type();
	int	t_type;

	t_type = Terminal_type();
	if ( t_type == -1 )
		return(-1);
	else
		{
		if ( t_type == 1 )
			{
			Emul_640x200_16_colors();
			return(1);
			}
		else
			{
			if ( t_type == 2 )
				{
				Color_640x200_16_colors();
				return(2);
				}
			else
				return(-1);
			}
		}
}
Terminal_type()
{
	/* return 1 if set to emulation mode */
	/* return 2 if set to color mode */
	/* return -1 if nothing is set because in monochrome mode or */
	/*        cannot determine which mode is in */

	int	Get_word(), Iabs();
	int	Inp();
	unsigned	a;
	long	t1, t2;
	int	count;
	int	vr1;
	static	t_type = -1;

	if( t_type > 0 ) return( t_type);
	if ( Get_word( 0x40, 0x63 ) != 0x03d4 ) return( t_type);

	Time_1A( &a, &t1);
	for( t2 = t1; t2 == t1 ; Time_1A( &a, &t2));

	count = 0;
	vr1 = Inp( 0x03da) & 0x08;
	for( t1 = t2; (t2 - t1 ) <= 18; Time_1A( &a, &t2))
		{
		for( ;  vr1 != 0; vr1 = Inp( 0x03da) & 0x0008);
		for( ;  vr1 == 0; vr1 = Inp( 0x03da) & 0x0008);
		++count;
		}


	if( Iabs( count - 50) <= 5 )
		t_type = 1;
	if( Iabs( count - 60) <= 5 )
		t_type = 2;

	return(t_type);

}
Emul_640x200_16_colors()
{
	static	int	parms[16] = { 0x61, 0x50, 0x52, 0x08,
				      0x32, 0x06, 0x32, 0x32,
				      0x02, 0x07, 0x06, 0x07,
				      0x00, 0x00, 0x00, 0x00 };
	int	i;
	/* Set the Graphics Solution to 640 x 200 with 16 colors in 
	   Emulation Mode */

	Outp( 0x03d8, 0x02);
	/* Set extended graphics registers */
	Outp( 0x03dd, 0x80);

	Outp( 0x03df, 0xa2);

	Outp( 0x03d8, 0x02);
	/* Program 6845 crt controlller */
	for( i =0; i < 16; ++i)
		{
		Outp( 0x03d4, i);
		Outp( 0x03d5, parms[i]);
		}
	Outp( 0x03d8, 0x0a);
	Outp( 0x03d9, 0x30);

	Outp( 0x03df, 0xa0);
	Outp( 0x03dd, 0x80);

	/* Clear video memory */
	Fill_ram( 0xb000, 0, 0x4000, 0);
	Fill_ram( 0xb800, 0, 0x4000, 0);

}
Color_640x200_16_colors()
{
	static	int	parms[16] = { 0x70, 0x50, 0x58, 0x0a,
				      0x40, 0x06, 0x32, 0x38,
				      0x02, 0x03, 0x06, 0x07,
				      0x00, 0x00, 0x00, 0x00 };
	int	i;

	/* Set the Graphics Solution to 640 x 200 with 16 colors in 
	   Color Mode */
	Outp( 0x03d8, 0x02);

	/* Set extended graphics registers */
	Outp( 0x03dd, 0x80);

	Outp( 0x03d8, 0x02);
	/* Program 6845 crt controlller */
	for( i =0; i < 16; ++i)
		{
		Outp( 0x03d4, i);
		Outp( 0x03d5, parms[i]);
		}
	Outp( 0x03d8, 0x0a);
	Outp( 0x03d9, 0x30);

	Outp( 0x03dd, 0x80);

	/* Clear video memory */
	Fill_ram( 0xb000, 0, 0x4000, 0);
	Fill_ram( 0xb800, 0, 0x4000, 0);

}
Text_mode()
{
	static	int	parms[16] = { 0x71, 0x50, 0x5a, 0x0a,
				      0x1f, 0x06, 0x19, 0x1c,
				      0x02, 0x07, 0x06, 0x07,
				      0x00, 0x00, 0x00, 0x00 };
	int	i;

	/* Set the Graphics Solution to 80 x 25 Text Mode */
	Outp( 0x03d8, 0x02);

	/* Set extended graphics registers */
	Outp( 0x03dd, 0x00);

	Outp( 0x03d8, 0x25);
	/* Program 6845 crt controlller */
	for( i =0; i < 16; ++i)
		{
		Outp( 0x03d4, i);
		Outp( 0x03d5, parms[i]);
		}
	Outp( 0x03d8, 0x2d);
	Outp( 0x03d9, 0x30);

	Outp( 0x03dd, 0x00);

	/* Clear video memory */
	Fill_ram( 0xb800, 0, 0x2000, ' ' + 0x0700);

}
Fill_box(from_row,from_col,to_row,to_col,color)
	int	from_row, from_col, to_row, to_col;
	unsigned	color;
{
	int	row ,col;

	/* Routine to draw a solid box */	
	for( row = from_row; row <= to_row; ++row)
		for( col = from_col; col <= to_col; ++col)
			Putpixel(row,col,color);
}
Mem_loc( g_row, g_col, offset_loc, shr, mask)
	int g_row, g_col;
	unsigned	*offset_loc, *shr;
	unsigned	*mask;

{
	static	unsigned	mmmmmm = 0xc000;

	/* Convert a ( x, y ) coordinate into a offset and mask into
	   the video memory */

	*offset_loc =	( g_row >> 2 ) * 160 +
			( g_row & 0x03 ) * 0x2000 +
			( ( g_col * 2 ) >> 3 );
	*shr = ( g_col * 2 ) & 0x0007;
	*mask = mmmmmm >> *shr;
}
Putpixel( g_row, g_col, color)
	int	g_row, g_col;
	unsigned	color;
{
	int	offset, shr;
	unsigned	valuex, value, mask;
	unsigned	Get_bb();

	/* calculate the offset of the ( x, y) in the video memory */
	Mem_loc( g_row, g_col, &offset, &shr, &mask);

	color = color << 12;

	/* Update the pixel value in plane 0 */
	valuex = Get_bb( 0xb000, offset);
	value = ( valuex & (~mask) ) |
		( ( color >> shr ) & mask);
	Str_bb( 0xb000, offset, value);

	/* Update the pixel value in plane 1 */
	valuex = Get_bb( 0xb800, offset);
	value = ( valuex & (~mask) ) |
		( ( ( color << 2 ) >> shr ) & mask);
	Str_bb( 0xb800, offset, value);

}
Iabs( i1)
	int	i1;
{
	if ( i1 > 0 ) return( i1);
	return( -i1);
}