1 by using digital differential analyzer

Question

1. By using Digital Differential Analyzer algorithm draw line segments from point (1,1) to (9,7).

Ans. We see that the usual equation of the line is specified by:

y = mx+c, here m = (y₁ - y₀/( x₁ - x₀)

Specified (x₀, y₀) → (1, 1) ; (x₁, y₁) → (9, 7)

⇒ m = (7-1)/(9-1) =6/8

C = y₁ - mx₁ = 7 - (6/8) *9 = 1/4

Consequently, by equation of line (y = mx + c) we contain: 

 y = (6/8)x+(1/4)

  Digital Differential Analyzer Algorithm Two case:

Case 1:   m < 1   

x_{i + 1} = x_i + 1

 y_{i + 1} = y_i + m

Case 2: m > 1   

x_{i + 1} = x_i + (1/m)

y_{i + 1} = y_i + 1

Here m < 1 so as per to Digital Differential Analyzer algorithm case 1

x_{i + 1} = xi + 1; y_{i + 1} = y_i + m

Specified (x₀, y₀) = (1, 1)

1) x₁ = x₀ + 1 = 2

y₁ = y₀ + m = 1+ (6/8) = 7/4

Place pixel (x₀, round y, colour)

That is, put on (2, 2)

Likewise, go on until (9, 7) is arrived at.