Derive the formula for initial decision parameter of Bresenham’s Line Drawingalgorithm.

Bresenham's Line Drawing Algorithm is a popular algorithm for drawing lines on a grid. The initial decision parameter (p) in Bresenham's algorithm is derived as follows:

Step 1: Define the variables Let's consider a line with initial point (x0, y0) and final point (x1, y1). The slope of the line is given by 'm' = (y1-y0)/(x1-x0).

Step 2: Calculate the difference in x and y coordinates dx = x1 - x0 dy = y1 - y0

Step 3: Derive the decision parameter The decision parameter 'p' at the start of the algorithm is given by 2*dy - dx.

This initial decision parameter is used to decide whether to move to the next pixel along the x-axis (E) or along both the x and y axes (NE). If p < 0, the next point is (x+1, y) and if p ≥ 0, the next point is (x+1, y+1). The decision parameter is updated for each pixel until the end point is reached.