Algorithm of Bresenhams line drawing

Question

Write down the Bresenhams line drawing algorithm?

Answer 1

Step 1: Input the line end-points and store the left end-point in (X0, Y0)

Step 2: Load the (X0, Y0) to the frame buffer.

Step 3: Compute constants Δx, Δy, 2 Δy, -2 Δx, and get the decision parameters as:
P0 = 2 Δy – Δx

Step 4: At all Xk all along the line, beginning at k = 0, execute the following test

If Pk < 0, then the next point to plot is (X_k+1, Y_k) and P_k+1 = P_k + 2 Δy.
Or else, next point to the plot is (X_k+1, Y_k+1) and P_k+1 = P_k+2 Δy - 2 Δx.

Step 5: Repeat the step 4 Δx times.