There is a Java enum LineType containing types you can annotate a line with.
/** Before a type is determined */
UNKNOWN,
/** Not completely straight */
STRAIGHT, //only a start and an end point
/** only on one side of a line between the start and end point */
CURVE_ARCH,
/** On both sides of a line between the start and end point
* this is the rest category for lines */
WAVE,
/** Means that this is an arch and that it is concave compared to 1 or both
* neighbor points, meaning they are on the same side of the line as the
* arch */
CONCAVE_ARCH,
/** This line contains an inflection point, meaning the end points have
* different signed direction changes */
INFLECTION_POINT,
/** For multi lines, if 2 lines are added together */
STRAIGHT_MULTI_LINE,