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local sys = require "system"
print [[
This example will draw a snake like spiral on the screen. Showing ANSI escape
codes for moving the cursor around.
]]
-- backup term settings with auto-restore on exit
sys.autotermrestore()
-- setup Windows console to handle ANSI processing
sys.setconsoleflags(io.stdout, sys.getconsoleflags(io.stdout) + sys.COF_VIRTUAL_TERMINAL_PROCESSING)
-- start drawing the spiral.
-- start from current pos, then right, then up, then left, then down, and again.
local x, y = 1, 1 -- current position
local dx, dy = 1, 0 -- direction after each step
local wx, wy = 30, 30 -- width and height of the room
local mx, my = 1, 1 -- margin
-- commands to move the cursor
local move_left = "\27[1D"
local move_right = "\27[1C"
local move_up = "\27[1A"
local move_down = "\27[1B"
-- create room: 30 empty lines
print(("\n"):rep(wy))
local move = move_right
while wx > 0 and wy > 0 do
sys.sleep(0.01) -- slow down the drawing a little
io.write("*" .. move_left .. move )
io.flush()
x = x + dx
y = y + dy
if x > wx and move == move_right then
-- end of move right
dx = 0
dy = 1
move = move_up
wy = wy - 1
my = my + 1
elseif y > wy and move == move_up then
-- end of move up
dx = -1
dy = 0
move = move_left
wx = wx - 1
mx = mx + 1
elseif x < mx and move == move_left then
-- end of move left
dx = 0
dy = -1
move = move_down
wy = wy - 1
my = my + 1
elseif y < my and move == move_down then
-- end of move down
dx = 1
dy = 0
move = move_right
wx = wx - 1
mx = mx + 1
end
end
io.write(move_down:rep(15))
print("\nDone!")
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