Bresenham Line Algorithm(http://www.edepot.com)

The following is the source for the Bresenham Algorithm

Return to Line Algorithms

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// Bresenham Line Algorithm

// used by myLine
void myPixel(SURFACE* surface, int x,int y) {
	// PLOT x,y point on surface

}


// Bresenham Line Algorithm
void myLine(SURFACE* surface, int x1, int y1, int x2, int y2) {
	int		x, y;
	int		dx, dy;
	int		incx, incy;
	int		balance;


	if (x2 >= x1)
	{
		dx = x2 - x1;
		incx = 1;
	}
	else
	{
		dx = x1 - x2;
		incx = -1;
	}

	if (y2 >= y1)
	{
		dy = y2 - y1;
		incy = 1;
	}
	else
	{
		dy = y1 - y2;
		incy = -1;
	}

	x = x1;
	y = y1;

	if (dx >= dy)
	{
		dy <<= 1;
		balance = dy - dx;
		dx <<= 1;

		while (x != x2)
		{
			myPixel(surface,x, y);
			if (balance >= 0)
			{
				y += incy;
				balance -= dx;
			}
			balance += dy;
			x += incx;
		} myPixel(surface,x, y);
	}
	else
	{
		dx <<= 1;
		balance = dx - dy;
		dy <<= 1;

		while (y != y2)
		{
			myPixel(surface,x, y);
			if (balance >= 0)
			{
				x += incx;
				balance -= dy;
			}
			balance += dx;
			y += incy;
		} myPixel(surface,x, y);
	}
}


출처 : http://www.edepot.com/linebresenham.html