-ARDOUR::OverlapType
-ARDOUR::coverage (framepos_t sa, framepos_t ea,
- framepos_t sb, framepos_t eb)
-{
- /* OverlapType returned reflects how the second (B)
- range overlaps the first (A).
-
- The diagrams show various relative placements
- of A and B for each OverlapType.
-
- Notes:
- Internal: the start points cannot coincide
- External: the start and end points can coincide
- Start: end points can coincide
- End: start points can coincide
-
- XXX Logically, Internal should disallow end
- point equality.
- */
-
- /*
- |--------------------| A
- |------| B
- |-----------------| B
-
-
- "B is internal to A"
-
- */
-
- if ((sb > sa) && (eb <= ea)) {
- return OverlapInternal;
- }
-
- /*
- |--------------------| A
- ----| B
- -----------------------| B
- --| B
-
- "B overlaps the start of A"
-
- */
-
- if ((eb >= sa) && (eb <= ea)) {
- return OverlapStart;
- }
- /*
- |---------------------| A
- |----------------- B
- |----------------------- B
- |- B
-
- "B overlaps the end of A"
-
- */
- if ((sb > sa) && (sb <= ea)) {
- return OverlapEnd;
- }
- /*
- |--------------------| A
- -------------------------- B
- |----------------------- B
- ----------------------| B
- |--------------------| B
-
-
- "B overlaps all of A"
- */
- if ((sa >= sb) && (sa <= eb) && (ea <= eb)) {
- return OverlapExternal;
- }
-
- return OverlapNone;
-}
-