Which of the following algorithms is not used for line clipping?
Southerland-Hodgeman algorithm
Sutherland–Hodgman is a polygon-clipping algorithm: it clips a polygon successively against the clipping-window boundaries. Cohen–Sutherland, Liang–Barsky and Nicholl–Lee–Nicholl are line-clipping algorithms.
Important Questions from Two Dimensional Geometric
Consider the midpoint (or Bresenham) algorithm for rasterizing lines given below:
(1) Input (x 1, y 1) and (x 2, y 2)
(2) y = y 1
(3) d = f(x 1+ 1, y 1+ ½) // f is the implicit form of a line
(4) for x = x 1 to x 2
(5) do
(6) plot(x,y)
(7) if(d<0)
(8) then
(9) y = y + 1
(10) d = d + (y 1- y 2) + (x 2- x 1)
(11) else
(12) d = d + (y 1- y 2)
(13) end
(14) end
Which statements are true?
P: For a line with slope m>1, we should change the outer loop in line (4) to be over y.
Q: Lines (10) and (12) update the decision variable d through an incremental evaluation of the line equation f.
R: The algorithm fails if d is ever 0.
