Line Drawing Algorithm: DDA Algorithm..!!

DDA Line ( X1, Y1, XN, YN):
Description: Here X1 and Y1 denote the starting x – coordinate  and y – coordinate  of the line
and XN and YN denote the ending x – coordinate and y – coordinate.

1.  Set M = (YN – Y1) / (XN – X1)    [Calculate slope of line]
2.  Repeat For I = X1 to XN
3.    If (M <= 1) Then
4.      Set DX = 1
5.      Set DY = M * DX
6.    Else
7.      Set DY = 1
8.      Set DX = DY / M
    [End of If]
9.    Set X1 = X1 + DX
10.    Set Y1 = Y1 + DY
11.    Call PutPixel(X1, Y1)
  [End of For]
12.  Exit