DDALine

#include <graphics.h>
#include <math.h>
void DDALine( int x1, int y1, int x2, int y2 );

int main( void )
{
	int	gdriver = DETECT, gmode, errorcode;
	int	bkcolor, midx, midy;
	initgraph( &gdriver, &gmode, "" );
	DDALine( 0, 100, 639, 479 );
	getch();
	closegraph();
	return(0);
}

void DDALine( int x1, int y1, int x2, int y2 )
{
	double	dx, dy, e, x, y;
	int	color;
	int	i;
	dx	= x2 - x1;
	dy	= y2 - y1;
	e	= (fabs( dx ) > fabs( dy ) ) ? fabs( dx ) : fabs( dy );
	dx	/= e;
	dy	/= e;
	x	= x1;
	y	= y1;
	color	= getcolor();
	for ( i = 0; i <= e; i++ )
	{
		putpixel( (int) (x + 0.5), (int) (y + 0.5), color );
		x	+= dx;
		y	+= dy;
	}
}