Drawn map is described by a list of points, which define polylines to draw and format of each polyline.

Point is defined as
|| Big-endian int16 || Big-endian int16 || Byte ||
|| *X* coordinate || *Y* coordinate || *flags* ||

where *flags* are:
|| 8th bit || 7th bit || 6th-1st bits ||
|| if set, this is a first point of polyline || if set, polyline is erasing || *width*(thickness) of line ||

where *width* defines `(width * 10) + 6` pixels width line to draw

Second and further points of polyline have 8th bit of *flags* unset, the content of others doesn't matter.

Single-point polyline defines a circle (well, that's kinda obvious).