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Maze generation: Difference between revisions

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Maze generation (view source)

Revision as of 12:48, 13 July 2016

116 bytes removed ,  7 years ago
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-- Fisher-Yates shuffle from http://santos.nfshost.com/shuffling.html
function shuffle(t)
for i = 1, #t - 1 do
local r = math.random(i, #t)
t[i], t[r] = t[r], t[i]
end
end
 
-- builds a width-by-height grid of falsestrues
function initialize_grid(w, h)
local a = {}
for i = 1, h do
table.insert(a, {})
for j = 1, w do
table.insert(a[i], falsetrue)
end
end
return a
end
 
-- average of a and b
function avg(a, b)
return (a + b) / 2
end
 
 
dirs = {
{x = x0, y = y-2}, -- north▼
{x = x+2, y = y0}, -- east▼
{x = x-2, y = y0}, -- west▼
{x = x0, y = y+2}, -- south▼
}
 
function make_maze(w, h)
w = w or 16
h = h or 8
 
local map = initialize_grid(w*2+1, h*2+1)
 
function walk(x, y)
map[y][x] = truefalse
 
local d = { 1, 2, 3, 4 }
shuffle(d)▼
▲ {x = x, y = y-2}, -- north
for i, dirdirnum in ipairs(d) do▼
▲ {x = x+2, y = y}, -- east
local xx = x + dirs[dirnum].x
▲ {x = x-2, y = y}, -- west
local yy = y + dirs[dirnum].y
▲ {x = x, y = y+2}, -- south
if map[yy] ==and nilmap[yy][xx] then▼
}
map[avg(y, yy)][avg(x, xx)] = truefalse▼
▲ shuffle(d)
walk(xx, yy)▼
▲ for i, dir in ipairs(d) do
end
local xx = dir.x
end▼
local yy = dir.y
end▼
▲ if map[yy] == nil then
-- out of bounds north or south
elseif map[yy][xx] == nil then
-- out of bounds east or west
elseif map[yy][xx] then
-- already visited
else
if xx == x then
▲ map[avg(y, yy)][x] = true
else -- by elimination, yy == y
map[y][avg(x, xx)] = true
▲ end
▲ walk(xx, yy)
end
▲ end
end
 
walk(math.random(1, w)*2, math.random(1, h)*2)
 
local s = {}
for i = 1, h*2+1 do
for j = 1, w*2+1 do
if map[i][j] then
table.insert(s, ' #')
else
table.insert(s, '# ')
end
end
table.insert(s, '\n')
end
return table.concat(s)
end
 
Johnicholas
16

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