file.lua

   1 -- primitives for saving to file and loading from file
   2 function file_exists(filename)
   3   local infile = App.open_for_reading(filename)
   4   if infile then
   5     infile:close()
   6     return true
   7   else
   8     return false
   9   end
  10 end
  11
  12 function load_from_disk(State)
  13   local infile = App.open_for_reading(State.filename)
  14   State.lines = load_from_file(infile)
  15   if infile then infile:close() end
  16 end
  17
  18 function load_from_file(infile)
  19   local result = {}
  20   if infile then
  21     local infile_next_line = infile:lines()  -- works with both Lua files and LÖVE Files (https://www.love2d.org/wiki/File)
  22     while true do
  23       local line = infile_next_line()
  24       if line == nil then break end
  25       if line == '```lines' then  -- inflexible with whitespace since these files are always autogenerated
  26         table.insert(result, load_drawing(infile_next_line))
  27       else
  28         table.insert(result, {mode='text', data=line})
  29       end
  30     end
  31   end
  32   if #result == 0 then
  33     table.insert(result, {mode='text', data=''})
  34   end
  35   return result
  36 end
  37
  38 function save_to_disk(State)
  39   local outfile = App.open_for_writing(State.filename)
  40   if not outfile then
  41     error('failed to write to "'..State.filename..'"')
  42   end
  43   for _,line in ipairs(State.lines) do
  44     if line.mode == 'drawing' then
  45       store_drawing(outfile, line)
  46     else
  47       outfile:write(line.data)
  48       outfile:write('\n')
  49     end
  50   end
  51   outfile:close()
  52 end
  53
  54 function load_drawing(infile_next_line)
  55   local drawing = {mode='drawing', h=256/2, points={}, shapes={}, pending={}}
  56   while true do
  57     local line = infile_next_line()
  58     assert(line, 'drawing in file is incomplete')
  59     if line == '```' then break end
  60     local shape = json.decode(line)
  61     if shape.mode == 'freehand' then
  62       -- no changes needed
  63     elseif shape.mode == 'line' or shape.mode == 'manhattan' then
  64       local name = shape.p1.name
  65       shape.p1 = Drawing.find_or_insert_point(drawing.points, shape.p1.x, shape.p1.y, --[[large width to minimize overlap]] 1600)
  66       drawing.points[shape.p1].name = name
  67       name = shape.p2.name
  68       shape.p2 = Drawing.find_or_insert_point(drawing.points, shape.p2.x, shape.p2.y, --[[large width to minimize overlap]] 1600)
  69       drawing.points[shape.p2].name = name
  70     elseif shape.mode == 'polygon' or shape.mode == 'rectangle' or shape.mode == 'square' then
  71       for i,p in ipairs(shape.vertices) do
  72         local name = p.name
  73         shape.vertices[i] = Drawing.find_or_insert_point(drawing.points, p.x,p.y, --[[large width to minimize overlap]] 1600)
  74         drawing.points[shape.vertices[i]].name = name
  75       end
  76     elseif shape.mode == 'circle' or shape.mode == 'arc' then
  77       local name = shape.center.name
  78       shape.center = Drawing.find_or_insert_point(drawing.points, shape.center.x,shape.center.y, --[[large width to minimize overlap]] 1600)
  79       drawing.points[shape.center].name = name
  80     elseif shape.mode == 'deleted' then
  81       -- ignore
  82     else
  83       assert(false, ('unknown drawing mode %s'):format(shape.mode))
  84     end
  85     table.insert(drawing.shapes, shape)
  86   end
  87   return drawing
  88 end
  89
  90 function store_drawing(outfile, drawing)
  91   outfile:write('```lines\n')
  92   for _,shape in ipairs(drawing.shapes) do
  93     if shape.mode == 'freehand' then
  94       outfile:write(json.encode(shape))
  95       outfile:write('\n')
  96     elseif shape.mode == 'line' or shape.mode == 'manhattan' then
  97       local line = json.encode({mode=shape.mode, p1=drawing.points[shape.p1], p2=drawing.points[shape.p2]})
  98       outfile:write(line)
  99       outfile:write('\n')
 100     elseif shape.mode == 'polygon' or shape.mode == 'rectangle' or shape.mode == 'square' then
 101       local obj = {mode=shape.mode, vertices={}}
 102       for _,p in ipairs(shape.vertices) do
 103         table.insert(obj.vertices, drawing.points[p])
 104       end
 105       local line = json.encode(obj)
 106       outfile:write(line)
 107       outfile:write('\n')
 108     elseif shape.mode == 'circle' then
 109       outfile:write(json.encode({mode=shape.mode, center=drawing.points[shape.center], radius=shape.radius}))
 110       outfile:write('\n')
 111     elseif shape.mode == 'arc' then
 112       outfile:write(json.encode({mode=shape.mode, center=drawing.points[shape.center], radius=shape.radius, start_angle=shape.start_angle, end_angle=shape.end_angle}))
 113       outfile:write('\n')
 114     elseif shape.mode == 'deleted' then
 115       -- ignore
 116     else
 117       assert(false, ('unknown drawing mode %s'):format(shape.mode))
 118     end
 119   end
 120   outfile:write('```\n')
 121 end
 122
 123 -- for tests
 124 function load_array(a)
 125   local result = {}
 126   local next_line = ipairs(a)
 127   local i,line,drawing = 0, ''
 128   while true do
 129     i,line = next_line(a, i)
 130     if i == nil then break end
 131 --?     print(line)
 132     if line == '```lines' then  -- inflexible with whitespace since these files are always autogenerated
 133 --?       print('inserting drawing')
 134       i, drawing = load_drawing_from_array(next_line, a, i)
 135 --?       print('i now', i)
 136       table.insert(result, drawing)
 137     else
 138 --?       print('inserting text')
 139       table.insert(result, {mode='text', data=line})
 140     end
 141   end
 142   if #result == 0 then
 143     table.insert(result, {mode='text', data=''})
 144   end
 145   return result
 146 end
 147
 148 function load_drawing_from_array(iter, a, i)
 149   local drawing = {mode='drawing', h=256/2, points={}, shapes={}, pending={}}
 150   local line
 151   while true do
 152     i, line = iter(a, i)
 153     assert(i, 'drawing in array is incomplete')
 154 --?     print(i)
 155     if line == '```' then break end
 156     local shape = json.decode(line)
 157     if shape.mode == 'freehand' then
 158       -- no changes needed
 159     elseif shape.mode == 'line' or shape.mode == 'manhattan' then
 160       local name = shape.p1.name
 161       shape.p1 = Drawing.find_or_insert_point(drawing.points, shape.p1.x, shape.p1.y, --[[large width to minimize overlap]] 1600)
 162       drawing.points[shape.p1].name = name
 163       name = shape.p2.name
 164       shape.p2 = Drawing.find_or_insert_point(drawing.points, shape.p2.x, shape.p2.y, --[[large width to minimize overlap]] 1600)
 165       drawing.points[shape.p2].name = name
 166     elseif shape.mode == 'polygon' or shape.mode == 'rectangle' or shape.mode == 'square' then
 167       for i,p in ipairs(shape.vertices) do
 168         local name = p.name
 169         shape.vertices[i] = Drawing.find_or_insert_point(drawing.points, p.x,p.y, --[[large width to minimize overlap]] 1600)
 170         drawing.points[shape.vertices[i]].name = name
 171       end
 172     elseif shape.mode == 'circle' or shape.mode == 'arc' then
 173       local name = shape.center.name
 174       shape.center = Drawing.find_or_insert_point(drawing.points, shape.center.x,shape.center.y, --[[large width to minimize overlap]] 1600)
 175       drawing.points[shape.center].name = name
 176     elseif shape.mode == 'deleted' then
 177       -- ignore
 178     else
 179       assert(false, ('unknown drawing mode %s'):format(shape.mode))
 180     end
 181     table.insert(drawing.shapes, shape)
 182   end
 183   return i, drawing
 184 end
 185
 186 function is_absolute_path(path)
 187   local os_path_separator = package.config:sub(1,1)
 188   if os_path_separator == '/' then
 189     -- POSIX systems permit backslashes in filenames
 190     return path:sub(1,1) == '/'
 191   elseif os_path_separator == '\\' then
 192     if path:sub(2,2) == ':' then return true end  -- DOS drive letter followed by volume separator
 193     local f = path:sub(1,1)
 194     return f == '/' or f == '\\'
 195   else
 196     error('What OS is this? LÖVE reports that the path separator is "'..os_path_separator..'"')
 197   end
 198 end
 199
 200 function is_relative_path(path)
 201   return not is_absolute_path(path)
 202 end