The D Algorithm  If 1 does not fit within the triangle the angle is chosen along the steepest edge or diagonal resulting in a slope and direction equivalent to D8

Example 49 48 47 55 67 52 45 42 56 48 49 42 56 1 47 45 56 42 45 55 67 52 11 3 15o 11.4

Example 49 48 47 55 67 52 45 42 56 48 49 42 56 42 49 2 56 47 45 55 67 52 7 45o 9.9

Example 49 48 47 55 67 52 45 42 56 48 49 42 3 56 49 48 56 47 45 3 55 67 52 1 7 8.1o 7.1 98.1o

Example 49 48 47 55 67 52 45 42 56 48 49 42 4 56 47 45 4 55 67 52 48 180o Pick Slope Along Edge 9 1 47 56

Example 49 48 47 55 67 52 45 42 56 48 49 42 56 47 45 5 5 55 67 52 180o Pick Slope Along Edge 8 47 9 56 55

Example 49 48 47 55 67 52 45 42 56 48 49 42 56 47 45 6 6 55 67 52 225o 11 12 56 Pick Slope Along Edge 55 67

Example 49 48 47 55 67 52 45 42 56 48 49 42 56 47 45 7 55 67 52 7 315o 11 56 15 Pick Slope Along Edge 67 52

Example 49 48 47 55 67 52 45 42 56 48 49 42 56 47 45 8 55 67 52 8 0o 7 45 56 11 Pick Slope Along Edge 52

Example 45 42 49 48 47 55 67 52 56 49 48 47 55 67 52 45 42 56