NAME

Math::NumSeq::PlanePathTurn -- turn sequence from PlanePath module

SYNOPSIS

 use Math::NumSeq::PlanePathTurn;
 my $seq = Math::NumSeq::PlanePathTurn->new (planepath => 'DragonCurve',
                                                   turn_type => 'Left');
 my ($i, $value) = $seq->next;

DESCRIPTION

This is a tie-in to present turns from a Math::PlanePath module in the form of a NumSeq sequence.

The turn_type choices are

    "Left"     1=left 0=right or straight
    "LSR"      1=left 0=straight -1=right

In each case the value at i is turn which occurs at N=i, ie. between the segments N=i-1 to N=i to N=i+1

            i+1
             |
             |
    i-1 ---- i    turn at i

For multiple "arms" the turn follows that particular arm so it's i-arms, i, i+arms. i values start n_start()+arms_count() so i-arms is the first N on the path. For example a single arm path beginning N=0 has its first turn at i=1.

FUNCTIONS

See "FUNCTIONS" in Math::NumSeq for behaviour common to all sequence classes.

$seq = Math::NumSeq::PlanePathTurn->new (key=>value,...)

Create and return a new sequence object. The options are

    planepath          string, name of a PlanePath module
    planepath_object   PlanePath object
    turn_type          string, as described above

planepath can be just the module part such as "SquareSpiral" or a full class name "Math::PlanePath::SquareSpiral".

$value = $seq->ith($i)

Return the turn at N=$i in the PlanePath.

$bool = $seq->pred($value)

Return true if $value occurs as a turn. Often this is merely the possible turn values 1,0,-1, etc, but some spiral paths for example only go left or straight in which case only 1 and 0 occur and pred() reflects that.

$i = $seq->i_start()

Return the first index $i in the sequence. This is the position rewind() returns to.

This is $path->n_start() - $path->arms_count() from the PlanePath object.

SEE ALSO

Math::NumSeq, Math::NumSeq::PlanePathCoord, Math::NumSeq::PlanePathDelta, Math::NumSeq::PlanePathN