FilesExpand file tree

 master

/

FloodFill.js

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

103 lines (92 loc) · 3.76 KB

 master

/

FloodFill.js

Copy path

Top

File metadata and controls

• Code
• Blame

103 lines (92 loc) · 3.76 KB

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103

/**

* Flood fill.

*

* Flood fill, also called seed fill, is an algorithm that determines and alters the area connected to a given node in a

* multi-dimensional array with some matching attribute. It is used in the "bucket" fill tool of paint programs to fill

* connected, similarly-colored areas with a different color.

*

* (description adapted from https://en.wikipedia.org/wiki/Flood_fill)

* @see https://www.techiedelight.com/flood-fill-algorithm/

*/

const neighbors = [[-1, -1], [-1, 0], [-1, 1], [0, -1], [0, 1], [1, -1], [1, 0], [1, 1]]

/**

* Implements the flood fill algorithm through a breadth-first approach using a queue.

*

* @param rgbData The image to which the algorithm is applied.

* @param location The start location on the image.

* @param targetColor The old color to be replaced.

* @param replacementColor The new color to replace the old one.

*/

export function breadthFirstSearch (rgbData, location, targetColor, replacementColor) {

if (location[0] < 0 ||

location[0] >= rgbData.length ||

location[1] < 0 ||

location[1] >= rgbData[0].length) {

throw new Error('location should point to a pixel within the rgbData')

}

const queue = []

queue.push(location)

while (queue.length > 0) {

breadthFirstFill(rgbData, location, targetColor, replacementColor, queue)

}

}

/**

* Implements the flood fill algorithm through a depth-first approach using recursion.

*

* @param rgbData The image to which the algorithm is applied.

* @param location The start location on the image.

* @param targetColor The old color to be replaced.

* @param replacementColor The new color to replace the old one.

*/

export function depthFirstSearch (rgbData, location, targetColor, replacementColor) {

if (location[0] < 0 ||

location[0] >= rgbData.length ||

location[1] < 0 ||

location[1] >= rgbData[0].length) {

throw new Error('location should point to a pixel within the rgbData')

}

depthFirstFill(rgbData, location, targetColor, replacementColor)

}

/**

* Utility-function to implement the breadth-first loop.

*

* @param rgbData The image to which the algorithm is applied.

* @param location The start location on the image.

* @param targetColor The old color to be replaced.

* @param replacementColor The new color to replace the old one.

* @param queue The locations that still need to be visited.

*/

function breadthFirstFill (rgbData, location, targetColor, replacementColor, queue) {

const currentLocation = queue[0]

queue.shift()

if (rgbData[currentLocation[0]][currentLocation[1]] === targetColor) {

rgbData[currentLocation[0]][currentLocation[1]] = replacementColor

for (let i = 0; i < neighbors.length; i++) {

const x = currentLocation[0] + neighbors[i][0]

const y = currentLocation[1] + neighbors[i][1]

if (x >= 0 && x < rgbData.length && y >= 0 && y < rgbData[0].length) {

queue.push([x, y])

}

}

}

}

/**

* Utility-function to implement the depth-first loop.

*

* @param rgbData The image to which the algorithm is applied.

* @param location The start location on the image.

* @param targetColor The old color to be replaced.

* @param replacementColor The new color to replace the old one.

*/

function depthFirstFill (rgbData, location, targetColor, replacementColor) {

if (rgbData[location[0]][location[1]] === targetColor) {

rgbData[location[0]][location[1]] = replacementColor

for (let i = 0; i < neighbors.length; i++) {

const x = location[0] + neighbors[i][0]

const y = location[1] + neighbors[i][1]

if (x >= 0 && x < rgbData.length && y >= 0 && y < rgbData[0].length) {

depthFirstFill(rgbData, [x, y], targetColor, replacementColor)

}

}

}

}