mentlerd - BowTurtles

os.loadAPI("ocs/apis/sensor")

SHOOT_AT = {
    [ "Creeper" ]   = true,
    [ "Skeleton" ]  = true,
    [ "Spider"]     = true,
}

local function isTarget( data )
    return SHOOT_AT[ data.Name ]
end

TRESHOLD = 45
PITCH_OFF = { 0, 90, 180, -90 }

local bow  = peripheral.wrap( "left" )
local prox = sensor.wrap("right")

local dir = 0

while true do
    local targets = prox.getTargets()

    local voteLeft = 0
    local voteRight = 0

    local hadTarget = false
    local shot = false

    for key, data in pairs(targets) do
        if ( isTarget(data) ) then

            local off = data.Position
            local aux = prox.getTargetDetails( key )

            if ( aux and aux.IsAlive ) then
                local x = off.X
                local z = off.Z

                local y = off.Y + 1

                local len = math.sqrt( x * x + z * z )

                local pitch = math.deg( -math.atan2( x/len, z/len ) ) - PITCH_OFF[dir +1]
                local yaw   = math.deg( math.atan( y/len ) )

                if ( pitch < -180 ) then
                    pitch = pitch + 360
                end

                if ( math.abs( yaw ) < TRESHOLD ) then
                    hadTarget = true

                    if ( pitch < -TRESHOLD ) then
                        voteLeft = voteLeft +1
                    elseif ( pitch > TRESHOLD ) then
                        voteRight = voteRight +1
                    else
                        bow.shoot( 1, pitch, yaw )
                        sleep( 0.5 )

                        shot = true
                        break
                    end
                end

            end
        end
    end

    if ( hadTarget ) then
        if ( not shot ) then
            if ( voteRight > voteLeft ) then
                dir = (dir +1) % 4
                turtle.turnRight()
            else
                dir = (dir +3) % 4
                turtle.turnLeft()
            end
        end
    else
        sleep( 5 )
    end

end