0001456: Rethink mod conversion - OpenMPT Issue Tracker

ID	Project	Category	View Status	Date Submitted	Last Update

0001456	OpenMPT	General	public	2021-05-06 17:07	2022-01-09 13:31

Reporter	Saga Musix	Assigned To
Priority	normal	Severity	minor	Reproducibility	have not tried
Status	new	Resolution	open
Target Version	OpenMPT 1.?? (long term goals)

Summary	0001456: Rethink mod conversion
Description	Currently, converting between various module formats can have surprising results, e.g. when invoking Undo. It's probably known to most users that this kind of conversion is almost always lossy, but the results can still be surprising. Alternative approaches should be explored, e.g. always creating a new CModDoc as a result of a format change. This way, the old module would stay open and editable, and the user can more easily compare what has changed. If a conversion is more lossy than the user expected, they can still easily go back to the previous state even if they forgot to save the file before conversion. Technically this approach would require some refactoring because many objects cannot simply be copied between different CSoundFiles.
Tags	No tags attached.

Has the bug occurred in previous versions?
Tested code revision (in case you know it)

manx 2021-05-06 17:13 administrator ~0004758	The logical step would be to implement a working copy-constructor for CSoundFile, and nothing else. Then, nothing of the existing conversion code would even need to be touched. Implementing a working copy-constructor basically implies having working copy-constructors for all sub-objects. I somewhat doubt any refactoring not strictly directed into this direction would be all that useful in the end.

Saga Musix 2021-11-02 20:28 administrator ~0004894	One important thing to keep in mind is that plugins cannot simply be "copied"; their state has to be serialized, a new instance has to be created and then the state needs to be unserialized again. As this is a non-const operation on the copied-from object, and a potentially expensive one, this should probably be rather implemented as a member function than as an actual copy constructor. Alternatively, the copy constructor wouldn't try copying over plugin state, and also not instantiate any of the copied-over plugins, and it would be the responsibility of the caller to do both.

Date Modified	Username	Field	Change
2021-05-06 17:07	Saga Musix	New Issue
2021-05-06 17:13	manx	Note Added: 0004758
2021-05-06 17:13	manx	Relationship added	related to 0001112
2021-05-06 17:14	manx	Target Version	=> OpenMPT 1.?? (long term goals)
2021-11-02 20:28	Saga Musix	Note Added: 0004894
2022-01-09 13:31	Saga Musix	Relationship added	related to 0001544

related to	0001112	acknowledged	manx	Properly report and handle out-of-memory
related to	0001544	resolved	Saga Musix	Sample sustain loop fields are greyed out for Digital Symphony modules.