diff options
author | Joseph Eagar <joeedh@gmail.com> | 2022-08-16 01:16:27 +0300 |
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committer | Joseph Eagar <joeedh@gmail.com> | 2022-08-16 01:16:27 +0300 |
commit | c5feb4e6fe27f013cc17b841729fb6c5097b4848 (patch) | |
tree | 95060e743a03596131ad0c8ebf14dfb7e462f3a4 /source/blender/editors/sculpt_paint/sculpt_undo.c | |
parent | 3f9299e45d39051f341fcc2d6415defcc01eca93 (diff) |
Sculpt: Write documentation in sculpt_undo.c
Diffstat (limited to 'source/blender/editors/sculpt_paint/sculpt_undo.c')
-rw-r--r-- | source/blender/editors/sculpt_paint/sculpt_undo.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/source/blender/editors/sculpt_paint/sculpt_undo.c b/source/blender/editors/sculpt_paint/sculpt_undo.c index 62b4b119c05..8370d8fa501 100644 --- a/source/blender/editors/sculpt_paint/sculpt_undo.c +++ b/source/blender/editors/sculpt_paint/sculpt_undo.c @@ -4,6 +4,29 @@ /** \file * \ingroup edsculpt * Implements the Sculpt Mode tools. + * + * Usage Guide + * =========== + * + * The sculpt undo system is a delta-based system. Each undo step stores + * the difference with the prior one. + * + * To use the sculpt undo system, you must call SCULPT_undo_push_begin + * inside an operator exec or invoke callback (ED_sculpt_undo_geometry_begin + * may be called if you wish to save a non-delta copy of the entire mesh). + * This will initialize the sculpt undo stack and set up an undo step. + * + * At the end of the operator you should call SCULPT_undo_push_end. + * + * SCULPT_undo_push_end and ED_sculpt_undo_geometry_begin both take a + * wmOperatorType as an argument. There are _ex versions that allow a custom + * name; try to avoid using them. These can break the redo panel since it requires + * the undo push have the same name as the calling operator. + * + * Note: Sculpt undo steps are not appended to the global undo stack until + * the operator finishes. We use BKE_undosys_step_push_init_with_type to build + * a tentative undo step with is appended later when the operator ends. + * Operators must have the OPTYPE_UNDO flag set for this to work properly. */ #include <stddef.h> @@ -1142,8 +1165,7 @@ static SculptUndoNode *sculpt_undo_alloc_node(Object *ob, PBVHNode *node, Sculpt unode->co = MEM_callocN(alloc_size, "SculptUndoNode.co"); usculpt->undo_size += alloc_size; - /* FIXME: Should explain why this is allocated here, to be freed in - * `SCULPT_undo_push_end_ex()`? */ + /* Needed for original data lookup. */ alloc_size = sizeof(*unode->no) * (size_t)allvert; unode->no = MEM_callocN(alloc_size, "SculptUndoNode.no"); usculpt->undo_size += alloc_size; |