1# -*- coding: utf-8 -*- 

2from math import ceil 

3 

4from qgis.core import * 

5from qgis.gui import * 

6#from PyQt4.QtGui import * 

7from PyQt5.QtWidgets import * 

8from PyQt5.QtCore import * 

9import os 

10from .utils import * 

11import numpy as np 

12 

13 

14def get_flow_layer(fd_layer, canvas, stream_layer,strFDType,_size): 

15 asc_file_fd = fd_layer.dataProvider().dataSourceUri() 

16 ascii_grid_fd = np.loadtxt(asc_file_fd, skiprows=6) # skip 6 . caution! 

17 

18 asc_file_st = stream_layer.dataProvider().dataSourceUri() 

19 ascii_grid_st = np.loadtxt(asc_file_st, skiprows=6) # skip 6 . caution! 

20 

21 xmin, ymin, xmax, ymax = fd_layer.extent().toRectF().getCoords() 

22 crs = fd_layer.crs().toWkt() 

23 point_layer = QgsVectorLayer('Point?crs=' + crs, 'flow_layer', 'memory') 

24 point_provider = point_layer.dataProvider() 

25 

26 resV = point_provider.addAttributes([QgsField("cellvalue", QVariant.Int)]) 

27 resS = point_provider.addAttributes([QgsField("stream", QVariant.Int)]) 

28 

29 gridWidth = fd_layer.rasterUnitsPerPixelX() 

30 gridHeight = fd_layer.rasterUnitsPerPixelY() 

31 

32 rows = ceil((ymax - ymin) / gridHeight) 

33 cols = ceil((xmax - xmin) / gridWidth) 

34 

35 point_layer.startEditing() # if omitted , setAttributes has no effect. 

36 

37 # Reference : GRM Manual page 25 a b c d . 2018.3 

38 if strFDType == 'StartsFromN': 

39 MyDirections = {1: 0, 2: 45, 4: 90, 8: 135, 16: 180, 32: 225, 64: 270, 128: 315} 

40 elif strFDType == 'StartsFromNE': 

41 MyDirections = {128: 0, 1: 45, 2: 90, 4: 135, 8: 180, 16: 225, 32: 270, 64: 315} # HyGIS(O) 

42 elif strFDType == 'StartsFromE': 

43 MyDirections = {64: 0, 128: 45, 1: 90, 2: 135, 4: 180, 8: 225, 16: 270, 32: 315} # HyGIS(x). TOPAZ 

44 elif strFDType == 'StartsFromE_TauDEM': 

45 MyDirections = {3: 0, 2: 45, 1: 90, 8: 135, 7: 180, 6: 225, 5: 270, 4: 315} # TauDEM 

46 else: 

47 print("FD Code is Wrong!") 

48 return 

49 

50 # strStylePath = "C:\GRM\sample\data\FD_Style_Template_v3.qml" # We Will change the path to relative path 

51 strStylePath = os.path.dirname(os.path.realpath(__file__)) 

52 strStylePath = strStylePath[:-6] + "DLL\FD_Style_Template_v5.qml" 

53 

54 lines = [] 

55 with open(strStylePath, 'r+') as f: 

56 lines = f.readlines() 

57 for i in [35, 61]: 

58# for i in [35, 60]: 

59 marker = lines[i] 

60 frist = marker.index('v=')+3 

61 last = marker.index('"', frist, len(marker)) 

62 

63 lines[i] = marker[:frist]+str(_size)+marker[last:] 

64 

65 with open(strStylePath, 'w') as f: 

66 f.writelines(lines) 

67 

68 

69 

70 

71 

72 point_layer.loadNamedStyle(strStylePath) 

73 

74 for i in range(int(cols)): 

75 for j in range(int(rows)): 

76 direction = get_direction(i, rows - j - 1, ascii_grid_fd, MyDirections) 

77 if not direction == None: 

78 ptCellCenter = QgsPointXY(xmin + i * gridWidth + gridWidth / 2.0, 

79 ymin + j * gridHeight + gridHeight / 2.0) 

80 feat = QgsFeature() 

81 feat.setGeometry(QgsGeometry().fromPointXY(ptCellCenter)) 

82 streamTag = 0 

83 if ascii_grid_st[rows - j - 1, i] > 0: streamTag = 1 

84 feat.setAttributes([direction, streamTag]) 

85 point_provider.addFeatures([feat]) 

86 point_layer.commitChanges() 

87 point_layer.updateExtents() 

88 point_layer.triggerRepaint() 

89 

90 

91 

92 

93 

94 

95 

96 

97 

98 

99 return point_layer 

100 

101 

102def get_direction(x, y, ascii_grid, directions): 

103 value = None 

104 try: 

105 value = ascii_grid[y][x] # order is [y][x]. top to bottom, zero base 

106 direction = directions.get(value) 

107 return direction 

108 

109 except IndexError: 

110 return "Intentional except"