aboutsummaryrefslogtreecommitdiff
path: root/src/field.nim
blob: 3f419f420fd26325f9fd06a98e8b1b927897be38 (plain)
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
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
type
  Line = object
    x: int
    columns: seq[int]

  Field* = object
    x, y: int
    lx: int
    lines: seq[Line]

func Blank*(f: var Field, x, y: int) =
  let ly = f.lines.len
  if y < f.y or y >= f.y+ly: # outside the field
    return
  var l = addr f.lines[y-f.y]
  let ll = l.columns.len
  if x < l.x or x >= l.x+ll: # outside the field
    return
  if x > l.x and x < l.x+ll-1: # just set the value
    l.columns[x-l.x] = int(' ')
    return
  if ll == 1: # this was the last character on the line
    if y == f.y: # we need to trim the leading lines
      var i = 1
      while f.lines[i].columns.len == 0:
        inc i
      f.y += i
      f.lines = f.lines[i..<ly]
    elif y == f.y+ly-1: # we need to trim the trailing lines
      var i = ly-2
      while f.lines[i].columns.len == 0:
        dec i
      f.lines = f.lines[0..i]
    else: # it was a line in the middle
      l.columns = @[]
  elif x == l.x: # we need to remove leading spaces
    var i = 1
    while l.columns[i] == int(' '):
      inc i
    l.x += i
    l.columns = l.columns[i..<ll]
  elif x == ll+l.x-1: # we need to remove trailing spaces
    var i = ll-2
    while l.columns[i] == int(' '):
      dec i
    l.columns = l.columns[0..i]
  # we now need to calculate the new field limits
  f.x = f.lines[0].x
  var x2 = f.lines[0].columns.len + f.lines[0].x
  for i in 1..<f.lines.len:
    if f.lines[i].columns.len == 0:
      continue
    if f.x > f.lines[i].x:
      f.x = f.lines[i].x
    if x2 < f.lines[i].x + f.lines[i].columns.len:
      x2 = f.lines[i].x + f.lines[i].columns.len
  f.lx = x2-f.x

func Get*(f: Field, x, y: int): int =
  if y >= f.y and y < f.y+f.lines.len:
    let l = f.lines[y-f.y]
    if x >= l.x and x < l.x+l.columns.len:
      return l.columns[x-l.x]
  return int(' ')

func IsIn*(f: Field, x, y: int): bool =
  return x >= f.x and y >= f.y and x < f.x+f.lx and y < f.y+f.lines.len

proc Load*(filename: string): ref Field =
  var file: File
  if not open(file, filename):
    return nil
  defer: file.close()
  var f: ref Field
  new(f)
  var l: ptr Line
  var leadingSpaces = 0
  var trailingSpaces = 0
  var data: array[4096, char]
  var lastReadIsCR = false
  while true:
    let n = file.readChars(data, 0, 4096)
    if n <= 0:
      if f.lines.len == 0:
        if l == nil: # we got en empty file!
          return nil
        f.x = l.x
      if l != nil:
        if f.lx < l.columns.len+l.x-f.x:
          f.lx = l.columns.len+l.x-f.x
      break
    var i = 0
    while i < n:
      if data[i] == char(12):
        inc i
        continue
      if lastReadIsCR and data[i] == '\n':
        inc i
        lastReadIsCR = false
        continue
      if data[i] == '\n' or data[i] == '\r':
        if f.lines.len == 0:
          return nil
        if f.lines.len == 1:
          f.x = l.x
        if l != nil:
          if f.x > l.x:
            f.x = l.x
          if f.lx < l.columns.len+l.x-f.x:
            f.lx = l.columns.len+l.x-f.x
        else:
          f.lines.add(Line())
        l = nil
        trailingSpaces = 0
        if data[i] == '\r':
          if i+1 < n and data[i+1] == '\n':
            inc i
          else:
            lastReadIsCR = true
      else:
        if data[i] == ' ':
          if l == nil: # trim leading spaces
            inc leadingSpaces
          else:
            inc trailingSpaces
        else:
          if l == nil:
            f.lines.add(Line())
            l = addr f.lines[^1]
            l.x = leadingSpaces
            leadingSpaces = 0
          if trailingSpaces > 0:
            let oldL = l.columns.len
            l.columns.setlen(oldL+trailingSpaces+1)
            for j in oldL..<l.columns.len-1:
              l.columns[j] = int(' ')
            l.columns[^1] = int(data[i])
            trailingSpaces = 0
          else:
            l.columns.add(int(data[i]))
      inc i
  return f

func Set*(f: var Field, x, y, v: int) =
  if v == int(' '):
    f.Blank(x, y)
  elif y >= f.y:
    if y < f.y+f.lines.len: # the line exists
      var l = addr f.lines[y-f.y]
      if l.columns.len == 0: # An empty line is a special case
        l.x = x
        l.columns = @[v]
        if f.x > x:
          f.lx = f.lx+f.x-x
          f.x = x
        if f.lx < x-f.x+1:
          f.lx = x-f.x+1
      elif x >= l.x:
        if x < l.x+l.columns.len: # just set the value
          l.columns[x-l.x] = v
        else: # append columns
          let oldL = l.columns.len
          l.columns.setlen(x-l.x+1)
          for i in oldL..<l.columns.len-1:
            l.columns[i] = int(' ')
          l.columns[^1] = v
          if f.lx < l.columns.len+l.x-f.x:
            f.lx = l.columns.len+l.x-f.x
      else: # preprend columns
        var newline = newSeqUninitialized[int](l.columns.len+l.x-x)
        newline[0] = v
        for i in 1..<l.x-x:
          newline[i] = int(' ')
        for i in l.x-x..<newline.len:
          newline[i] = l.columns[i-l.x+x]
        l.columns = newline
        l.x = x
        if f.x > x:
          f.lx = f.lx + f.x - x
          f.x = x
    else: # append lines
      f.lines.setlen(y-f.y+1)
      f.lines[y-f.y] = Line(x: x, columns: @[v])
      if f.x > x:
        f.lx = f.lx + f.x - x
        f.x = x
      if f.lx < x-f.x+1:
        f.lx = x-f.x+1
  else: # prepend lines
    var newlines = newSeq[Line](f.lines.len+f.y-y)
    newlines[0] = Line(x: x, columns: @[v])
    for i in f.y-y..<newlines.len:
      newlines[i] = f.lines[i-f.y+y]
    f.lines = newlines
    f.y = y
    if f.x > x:
      f.lx = f.lx+f.x-x
      f.x = x
    if f.lx < x-f.x+1:
      f.lx = x-f.x+1

func Step*(f: Field, v: tuple[x, y: int], d: tuple[x, y: int]): (int, int) =
  var x = v.x + d.x
  var y = v.y + d.y
  if f.IsIn(x, y):
    return (x, y)
  # We are stepping outside, we need to wrap the Lahey-space
  x = v.x
  y = v.y
  while true:
    let x2 = x - d.x
    let y2 = y - d.y
    if not f.IsIn(x2, y2):
      return (x, y)
    x = x2; y = y2

func GetSize*(f: Field): (int, int, int, int) =
  return (f.x, f.y, f.lx, f.lines.len)