Digital differential analyzer( DDA Algorithm)

                         DDA ALGORITHM

DDA Algorithm: DDA Algorithm stand for Digital Differential Analyzer Algorithm. DDA Algorithm is the simple line generation algorithm. Let’s what is DDA algorithm on simple way

Algorithm:

Step1 : Get Input of two end point A(X0 , Y0) and B(X1 , Y1)

Step2 : Calculate the Difference Between two point dx and dy

dx = X1 – X0

dy = Y1 – Y0

step 3 : if dx > dy , then you need move step in X Coordinate, otherwise in Y coordinate

if ( dx>dy)

    step=dx ;

else

    step = dy ;

step4 : Calculate the increment X and Y coordinate 

Xinc = dx / step ;

Yinc = dy / step ;

step5 : put the X coordinate and Y coordinate accordingly

for ( int v = 0 ; v< step; v++)

X= X+ Xinc ;

Y = Y + Yinc;

put Pix (Round(x), Round(y));

}

Advantage Of DDA Algorithm 

1) it is simplest algorithm

2) it does not require special skills for implementation

3) It is a faster method for calculating pixel positions

Disadvantage of DDA Algorithm

 

1) Floating point arithmetic in DDA algorithm is still time consuming. 

2) The algorithm is orientation dependent. Hence end point accuracy is poor.

3) Although DDA is fast, the accumulation of round-off error in successive additions of floating point increment, however can cause the calculation pixel position to drift away from the true line path for long line segment. 

4)Rounding-off in DDA is time consuming.