Algorithm of DDA

Question

Write down the algorithm of DDA (Digital differential analyzer) scan conversion algorithm?

Answer 1

Algorithm:

Step 1: Input the line end-points and store the left end-point in (x1, y1) and right end-point in (x2, y2).

Step 2: Compute the values of Δx and Δy by using Δx = xb – xa, Δy = yb – ya

Step 3: When the values of Δx > Δy then assign values of steps as Δx or else the values of steps as Δy.

Step 4: Compute the values of X increment and Y increment and assign the value x= xa and y = ya.

Step 5: For k = 1 to steps do

X = X + X increment
Y= Y + Y increment

Putpixel(ceil(x), ceil(y),15)

Step 6: End