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function generate(mappath)
local getmapdata = require 'mapdata'
local map = getmapdata(mappath .. '.map')
local cases = {}
do
local bits = {}
for x = 0, map 'width' * 2 - 1 do
for y = 0, map 'height' * 2 - 1 do
local unwalkable = math.floor(map('tile_mode', map('tile', math.floor(x / 2), math.floor(y / 2), 'index')) / 10) ~= 1
if unwalkable then
bits[x + 1] = bits[x + 1] or {}
bits[x + 1][y + 1] = true
bits[x + 1][y + 2] = true
bits[x + 2] = bits[x + 2] or {}
bits[x + 2][y + 1] = true
bits[x + 2][y + 2] = true
end
end
end
for x = 1, map 'width' * 2 do
for y = 1, map 'height' * 2 do
local bit1 = not (bits[x] and bits[x][y])
local bit2 = not (bits[x + 1] and bits[x + 1][y])
local bit3 = not (bits[x + 1] and bits[x + 1][y + 1])
local bit4 = not (bits[x] and bits[x][y + 1])
local case = 0
if bit1 and bit2 and bit3 and not bit4 then
case = 1
elseif bit1 and bit2 and not bit3 and bit4 then
case = 2
elseif bit1 and bit2 and not bit3 and not bit4 then
case = 3
elseif bit1 and not bit2 and bit3 and bit4 then
case = 4
elseif bit1 and not bit2 and bit3 and not bit4 then
case = 5
elseif bit1 and not bit2 and not bit3 and bit4 then
case = 6
elseif bit1 and not bit2 and not bit3 and not bit4 then
case = 7
elseif not bit1 and bit2 and bit3 and bit4 then
case = 8
elseif not bit1 and bit2 and bit3 and not bit4 then
case = 9
elseif not bit1 and bit2 and not bit3 and bit4 then
case = 10
elseif not bit1 and bit2 and not bit3 and not bit4 then
case = 11
elseif not bit1 and not bit2 and bit3 and bit4 then
case = 12
elseif not bit1 and not bit2 and bit3 and not bit4 then
case = 13
elseif not bit1 and not bit2 and not bit3 and bit4 then
case = 14
elseif not (bit1 and bit2 and bit3 and bit4) then
case = 15
end
cases[x] = cases[x] or {}
cases[x][y] = case
end
end
end
do
local casematch = {
[1] = {
{ from = '%d-1,%d', [8] = true, [9] = true, [10] = true, [11] = true },
{ from = '%d,%d+1', [2] = true, [3] = true, [10] = true, [11] = true }
},
[2] = {
{ from = '%d,%d+1', [1] = true, [3] = true, [5] = true, [7] = true },
{ from = '%d+1,%d', [4] = true, [5] = true, [6] = true, [7] = true }
},
[3] = {
{ from = '%d-1,%d', [1] = true, [3] = true, [5] = true, [7] = true },
{ from = '%d+1,%d', [2] = true, [3] = true, [10] = true, [11] = true }
},
[4] = {
{ from = '%d,%d-1', [8] = true, [10] = true, [12] = true, [14] = true },
{ from = '%d+1,%d', [2] = true, [6] = true, [10] = true, [14] = true }
},
[5] = {
{ from = '%d-1,%d', [8] = true, [9] = true, [10] = true, [11] = true },
{ from = '%d,%d+1', [2] = true, [3] = true, [10] = true, [11] = true },
{ from = '%d,%d-1', [8] = true, [10] = true, [12] = true, [14] = true },
{ from = '%d+1,%d', [2] = true, [6] = true, [10] = true, [14] = true }
},
[6] = {
{ from = '%d,%d-1', [4] = true, [5] = true, [6] = true, [7] = true },
{ from = '%d,%d+1', [2] = true, [6] = true, [10] = true, [14] = true }
},
[7] = {
{ from = '%d-1,%d', [2] = true, [6] = true, [10] = true, [14] = true },
{ from = '%d,%d-1', [2] = true, [3] = true, [10] = true, [11] = true }
},
[8] = {
{ from = '%d-1,%d', [1] = true, [5] = true, [9] = true, [13] = true },
{ from = '%d,%d-1', [4] = true, [5] = true, [12] = true, [13] = true }
},
[9] = {
{ from = '%d,%d-1', [8] = true, [9] = true, [10] = true, [11] = true },
{ from = '%d,%d+1', [1] = true, [5] = true, [9] = true, [13] = true }
},
[10] = {
{ from = '%d-1,%d', [1] = true, [5] = true, [9] = true, [13] = true },
{ from = '%d,%d-1', [4] = true, [5] = true, [12] = true, [13] = true },
{ from = '%d,%d+1', [4] = true, [5] = true, [6] = true, [7] = true },
{ from = '%d+1,%d', [1] = true, [3] = true, [5] = true, [7] = true }
},
[11] = {
{ from = '%d,%d-1', [1] = true, [3] = true, [5] = true, [7] = true },
{ from = '%d+1,%d', [1] = true, [5] = true, [9] = true, [13] = true }
},
[12] = {
{ from = '%d-1,%d', [8] = true, [10] = true, [12] = true, [14] = true },
{ from = '%d+1,%d', [4] = true, [5] = true, [12] = true, [13] = true }
},
[13] = {
{ from = '%d,%d+1', [8] = true, [10] = true, [12] = true, [14] = true },
{ from = '%d+1,%d', [8] = true, [9] = true, [10] = true, [11] = true }
},
[14] = {
{ from = '%d-1,%d', [4] = true, [5] = true, [6] = true, [7] = true },
{ from = '%d,%d+1', [4] = true, [5] = true, [12] = true, [13] = true }
}
}
function GetFromWhere(x, y)
local case = cases[x + 1][y + 1]
if case == 0 or case == 15 then error('position must be in an outline', 2) end
local fromx, fromy
for _, n in ipairs({{-1, 0}, {0, -1}, {1, 0}, {0, 1}}) do
local nx, ny = unpack(n)
local ncase = cases[x + nx + 1][y + ny + 1]
for i = 1, #casematch[case] do
local frommatch = casematch[case][i]
fromx, fromy = loadstring('return ' .. frommatch.from:format(x, y))()
if fromx == nx and fromy == ny then
local tomatch = casematch[case][math.floor(i / 3) == 0 and (i == 1 and 2 or 1) or (i == 3 and 4 or 3)]
local tox, toy = loadstring('return ' .. tomatch.from:format(x, y))()
if tox == x and toy == y then
break
else
fromx, fromy = nil
end
end
end
if fromx and fromy then
break
end
end
return fromx, fromy
end
function MarchingSquares(x, y, x0, y0, ox, oy)
local case = cases[x + 1][y + 1]
local outline = {{x, y}}
if x == ox and y == oy then
return outline
end
if case == 0 or case == 15 then error('must define from an outline', 2) end
for i = 1, #casematch[case] do
local frommatch = casematch[case][i]
local fromx, fromy = loadstring('return ' .. frommatch.from:format(x, y))()
if fromx == x0 and fromy == y0 then
local tomatch = casematch[case][math.floor(i / 3) == 0 and (i == 1 and 2 or 1) or (i == 3 and 4 or 3)]
local tox, toy = loadstring('return ' .. tomatch.from:format(x, y))()
local tocase = cases[tox + 1] and cases[tox + 1][toy + 1]
if tocase then
if frommatch[tocase] then
local nextoutline = MarchingSquares(tox, toy, x, y, ox, oy)
for i = 1, #nextoutline do
outline[#outline + 1] = nextoutline[i]
end
end
else
error('unable to go to next case', 2)
end
break
end
end
return outline
end
end
do
local function sqr(x)
return x * x
end
local function dist2(v, w)
return sqr(v[1] - w[1]) + sqr(v[2] - w[2])
end
local function disttosegmentvertd(p, v, w)
local l2 = dist2(v, w)
if (l2 == 0) then return dist2(p, v) end
local t = ((p[1] - v[1]) * (w[1] - v[1]) + (p[2] - v[2]) * (w[2] - v[2])) / l2
t = math.max(0, math.min(1, t))
return dist2(p, {
v[1] + t * (w[1] - v[1]),
v[2] + t * (w[2] - v[2])
})
end
local function disttosegment(p, v, w)
return math.sqrt(disttosegmentvertd(p, v, w))
end
function DouglasPeucker(points, epsilon)
local dmax = 0
local index = 0
local len = #points
for i = 2, (len - 1) do
d = disttosegment(points[i], points[1], points[len])
if d > dmax then
index = i
dmax = d
end
end
local result
if dmax > epsilon then
local pointstoindex = {}
for i = 1, index do
pointstoindex[#pointstoindex + 1] = points[i]
end
local result1 = DouglasPeucker(pointstoindex, epsilon)
local pointsfromindex = {}
for i = index, len do
pointsfromindex[#pointsfromindex + 1] = points[i]
end
result1[#result1] = nil
local result2 = DouglasPeucker(pointsfromindex, epsilon)
result = {}
for i = 1, #result1 do
result[#result + 1] = result1[i]
end
for i = 1, #result2 do
result[#result + 1] = result2[i]
end
else
result = {points[1], points[len]}
end
return result
end
end
local areas = {}
do
local scannedcases = {}
for x = 0, map 'width' * 2 - 1 do
for y = 0, map 'height'* 2 - 1 do
if not (scannedcases[x + 1] and scannedcases[x + 1][y + 1]) then
local case = cases[x + 1][y + 1]
if case ~= 0 and case ~= 15 then
local fromx, fromy = GetFromWhere(x, y)
local outline = MarchingSquares(x, y, fromx, fromy, fromx, fromy)
for _, vert in ipairs(outline) do
local x, y = unpack(vert)
scannedcases[x + 1] = scannedcases[x + 1] or {}
scannedcases[x + 1][y + 1] = true
end
for i = 1, #outline do
local vert = outline[i]
vert[1], vert[2] = vert[1] * 16 + 8, vert[2] * 16 + 8
end
local hole
if case == 1 or
case == 11 then
hole = {-1, 1}
elseif case == 2 or
case == 7 then
hole = {1, 1}
elseif case == 3 then
hole = {0, 1}
elseif case == 4 or
case == 14 then
hole = {1, -1}
elseif case == 6 then
hole = {1, 0}
elseif case == 8 or
case == 13 then
hole = {-1, -1}
elseif case == 9 then
hole = {-1, 0}
elseif case == 12 then
hole = {0, -1}
end
areas[#areas + 1] = {
hole = {x * 16 + (hole[1] or 0) * 16 + 8, y * 16 + (hole[2] or 0) * 16 + 8},
outline = DouglasPeucker(outline, 0)
}
end
end
end
end
print('Areas: ' .. #areas)
for index, area in ipairs(areas) do
local from, to = area.outline[1], area.outline[#area.outline]
print('Area #' .. index .. ' has ' .. #area.outline .. ' tiles: from ' .. from[1] .. ', ' .. from[2] .. ' to ' .. to[1] .. ', ' .. to[2] .. (area.hole and ' with hole on ' .. area.hole[1] .. ', ' .. area.hole[2] or ''))
end
end
do
local file, err = io.open(mappath .. '.poly', 'w+')
if file then
local totalverts, curverts = 0
for i = 1, #areas do
totalverts = totalverts + #areas[i].outline
end
file:write(('%d %d %d %d\n'):format(totalverts, 2, 0, 0))
curverts = 0
for i = 1, #areas do
for index, vert in ipairs(areas[i].outline) do
index = curverts + index
file:write(('%d %f %f\n'):format(index, vert[1], vert[2]))
end
curverts = curverts + #areas[i].outline
end
file:write(('%d %d\n'):format(totalverts, 0))
curverts = 0
for i = 1, #areas do
for index, vert in ipairs(areas[i].outline) do
index = curverts + index
file:write(('%d %d %d\n'):format(index, index == curverts + 1 and curverts + #areas[i].outline or index - 1, index))
end
curverts = curverts + #areas[i].outline
end
local holes = {}
for i = 1, #areas do
local hole = areas[i].hole
if hole then
holes[#holes + 1] = hole
end
end
file:write(('%d\n'):format(#holes))
for index, hole in ipairs(holes) do
file:write(('%d %f %f\n'):format(index, hole[1], hole[2]))
end
file:close()
else
error(err, 2)
end
end
end