Mercurial > hg > svcore
changeset 925:3efc20c59a94 tonioni
Add comment about meaning of start and end frame of selection
author | Chris Cannam |
---|---|
date | Mon, 16 Jun 2014 11:28:45 +0100 |
parents | 85879408f665 |
children | 5f021c13a4cc f960d67ce842 |
files | base/Selection.h |
diffstat | 1 files changed, 15 insertions(+), 0 deletions(-) [+] |
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--- a/base/Selection.h Mon Jun 16 09:28:12 2014 +0100 +++ b/base/Selection.h Mon Jun 16 11:28:45 2014 +0100 @@ -21,6 +21,21 @@ #include "XmlExportable.h" +/** + * A selection object simply represents a range in time, via start and + * end frame. + * + * The end frame is the index of the frame just *after* the end of the + * selection. For example a selection of length 10 frames starting at + * time 0 will have start frame 0 and end frame 10. This will be + * contiguous with (rather than overlapping with) a selection that + * starts at frame 10. + * + * Any selection with equal start and end frames is empty, + * representing "no selection". All empty selections are equal under + * the comparison operators. The default constructor makes an empty + * selection with start and end frames equal to zero. + */ class Selection { public: