poz

--this is an experiment
--will hold movement help functions
--and change in position caused by movement


-- directions
f="f" -- forward
b="b" -- back
u="u" -- up
d="d" -- down
tr="r" -- turn right
tl="l" -- turn left
r="r" -- right, not used yet
l="l" -- left, not used yet
n="n" -- north (the direction that has been set to north, not the in game north)
s="s" -- south
w="w" -- west
e="e" -- east

sr="sr" -- strafe right, not yet implemented
sl="sl" -- strafe left, not yet implemented


-- position data names
x="x" -- forward, back
y="y" -- up, down
z="z" -- right, left (not turn)
dir="dir" -- direction the turtle is facing, n, e, s, w

-- lookup table for: function rev(dir)
revT={
f=b,
b=f,
u=d,
d=u,
r=l,
l=r,
n=s,
s=n,
w=e,
e=w,
}
-- returns the reverse/inverted direction
function rev(dir)
 return revT[dir]
end --function


-- functions to update pos in horizontal movement
horzT={
  n=function(posT,length)
    posT[x]=posT[x]+length
  end,
  e=function(posT,length)
    posT[z]=posT[z]+length
  end,
  s=function(posT,length)
    posT[x]=posT[x]-length
  end,
  w=function(posT,length)
    posT[z]=posT[z]-length
  end,
}

getUpdateFuncT={
f=function(dir)
    return horzT[dir]
end,
b=function(dir)
    return horzT[rev(dir)]
end,
tr=function(dir)

end
}

-- lookup tables to quickly get the
-- turtle function for a given direction
detectT={
f=turtle.detect,
u=turtle.detectUp,
d=turtle.detectDown,
}
compareT={
f=turtle.compare,
u=turtle.compareUp,
d=turtle.compareDown,
}
digT={
f=turtle.dig,
u=turtle.digUp,
d=turtle.digDown,
}
goT={
f=turtle.forward,
b=turtle.back,
u=turtle.up,
d=turtle.down,
tr=turtle.turnRight,
tl=turtle.turnLeft,
}

turnT={
tr=turtle.turnRight,
tl=turtle.turnLeft,
}



go2T={
f=function(pos,length)
    -- go forward the given length
    local dist=0
    while dist < length and turtle.forward() do
        dist=dist+1
    end
    -- update the position
    horzT[pos["dir"]](pos,dist)
    -- return the completed length
    return dist
end



b=function(length,pos)
    -- go back the given length
    local dist=0
    while dist < length and turtle.back() do
        dist=dist+1
    end
    -- update the position
    horzT[pos[dr]](pos,-dist)
    -- return the completed length
    return dist
end


}


function testGoHelp()

    go=turtle.forward
    update=getUpdateFuncT[f](pos[dr])
end



function helpGo(go, update, length,pos)
    local dist=0
    while dist < length and go() do
        dist = dist + 1
    end
    update(pos,dist)
    return dist
end

function getNewPoz(x,y,z,dir)
if x==nil then x=0 end
if y==nil then y=0 end
if z==nil then z=0 end
if rot==nil then dir="n" end
local pos={
["x"]=x,
["y"]=y,
["z"]=z,
[dr]=dir,
}
end

-- may change the direction the turtle is facing
go(dir,length,pos)
    if length < 0 then
        return go(rev(dir),-length,pos)
    end
    --length must be positive here
    gof=goT[dir]
    if gof == nil then
        --turn to right direction


        dir=f
        gof=goT[dir]
    end
    local dist=0
    while dist<length and gof() do

    end
end

-- lookup table for knowing the tuen value
-- when facing direction and want to face other direction
faceT={
n={n=0,e=1,s=2,w=-1},
e={n=-1,e=0,s=1,w=2},
w={n=1,e=2,s=-1,w=0},
s={n=2,e=-1,s=0,w=1},
}

--warning: does not update pos
rotate(length)
    if length==0 then
        return true
    end
    local turning
    if length>0 then
        turning=turtle.turnRight
    else
        turning=turle.turnLeft
    end
    local repeats=0
    while repeats<length do
        turning()
        repeats=repeats+1
    end
    return true
end


-- turns the turtle so it's facing in the given newDir
face(newDir, pos)
    local oldDir=pos["dir"]
    rotate(faceT[oldDir][newDir])
    pos["dir"]=newDir
    return true
end