1+ # Bresenham Line Algorithm (BLA) is one of the earliest algorithms developed
2+ # in computer graphics. It is used for drawing lines. It is an efficient method because
3+ # it involves only integer addition, subtractions, and multiplication operations.
4+ 5+ # These operations can be performed very rapidly so lines can be generated quickly.
6+ 7+ # Reference: http://floppsie.comp.glam.ac.uk/Southwales/gaius/gametools/6.html
8+ 9+ # Algorithm:
10+ # 1. We are given the starting and ending point (x1, y1) and (x2, y2)
11+ # 2. We compute the gradient m, using the formula: m = (y2-y1)/(x2-x1)
12+ # 3. The equation of the straight line is y = m*x+c. So the next thing we need to find is the intercept c
13+ # 4. Intercept can be derived using the formula c = y1 - m*x1
14+ # 5. To get the next point, we add dx to the x-cordinate and dy to the y cordinate
15+ 116def lineGenerator (x1 , y1 , x2 , y2 ):
217 dx = x2 - x1
318 dy = y2 - y1
@@ -26,25 +41,25 @@ def lineGenerator(x1, y1, x2, y2):
2641 slope = slope
2742
2843
29- lineGenerator (3 , 2 , 15 , 5 )
44+ # lineGenerator(3, 2, 15, 5)
3045
31- # if P1[0]==P2[0] and P1[1]==P2[1]:
32- # return 0
33- # #P1 is the point given. Initial point
34- # #P2 is the point to reach. Final point
35- # print(P1)
36- # #Check if the point is above or below the line.
37- # dx = P2[0]-P1[0]
38- # dy = P2[1]-P1[0]
46+ # # P1 is the point given. Initial point
47+ # # P2 is the point to reach. Final point
48+ # if P1[0] == P2[0] and P1[1] == P2[1]:
49+ # return 0
50+ # print(P1)
51+ # #Check if the point is above or below the line.
52+ # dx = P2[0]-P1[0]
53+ # dy = P2[1]-P1[0]
3954
40- # di = 2*dy - dx
55+ # di = 2*dy - dx
4156
42- # currX = P1[0]
43- # currY = P1[1]
57+ # currX = P1[0]
58+ # currY = P1[1]
4459
45- # if di > 0:
46- # P1 = (currX+1, currY+1)
47- # else:
48- # P1 = (currX+1, currY)
60+ # if di > 0:
61+ # P1 = (currX+1, currY+1)
62+ # else:
63+ # P1 = (currX+1, currY)
4964
50- # return lineGenerator(P1, P2)
65+ # return lineGenerator(P1, P2)
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