Initialize.

The features can either be SeqFeature objects, or tuples of values: start (int), end (int), strand (+1, -1, O or None), label (string), ReportLab color (string or object), and optional ReportLab fill color.

Note we require 0 <= start <= end <= bp_length, and within the vertical space allocated to this segmenet lines will be places according to the start/end coordinates (starting from the top).

Positive stand features are drawn on the right, negative on the left, otherwise all the way across.

We recommend using consisent units for all the segment’s scale values (e.g. their length in base pairs).

When providing features as SeqFeature objects, the default color is used, unless the feature’s qualifiers include an Artemis colour string (functionality also in GenomeDiagram). The caption also follows the GenomeDiagram approach and takes the first qualifier from the list or tuple specified in name_qualifiers.

Note additional attribute label_sep_percent controls the percentage of area that the chromosome segment takes up, by default half of the chr_percent attribute (half of 25%, thus 12.5%)

Draw any annotated features on the chromosome segment.

Assumes _draw_segment already called to fill out the basic shape, and assmes that uses the same boundaries.