Undo: unified undo system w/ linear history

- Use a single undo history for all operations.
- UndoType's are registered and poll the context to check if they
  should be used when performing an undo push.
- Mode switching is used to ensure the state is correct before
  undo data is restored.
- Some undo types accumulate changes (image & text editing)
  others store the state multiple times (with de-duplication).
  This is supported by checking UndoStack.mode `ACCUMULATE` / `STORE`.
- Each undo step stores ID datablocks they use with utilities to help
  manage restoring correct ID's.
  Needed since global undo is now mixed with other modes undo.
- Currently performs each undo step when going up/down history
  Previously this wasn't done, making history fail in some cases.
  This can be optimized to skip some combinations of undo steps.

grease-pencil is an exception which has not been updated
since it integrates undo into the draw-session.

See D3113

1 files changed, 15 insertions, 7 deletions

diff --git a/source/blender/editors/sculpt_paint/paint_curve.c b/source/blender/editors/sculpt_paint/paint_curve.c
index 8d9812f41d9..120514762f4 100644
--- a/source/blender/editors/sculpt_paint/paint_curve.c
+++ b/source/blender/editors/sculpt_paint/paint_curve.c
@@ -40,6 +40,7 @@
 #include "BKE_paint.h"
 
 #include "ED_view3d.h"
+#include "ED_paint.h"
 
 #include "WM_api.h"
 #include "WM_types.h"
@@ -203,7 +204,7 @@ static void paintcurve_point_add(bContext *C,  wmOperator *op, const int loc[2])
 		br->paint_curve = pc = BKE_paint_curve_add(bmain, "PaintCurve");
 	}
 
-	ED_paintcurve_undo_push(C, op, pc);
+	ED_paintcurve_undo_push_begin(op->type->name);
 
 	pcp = MEM_mallocN((pc->tot_points + 1) * sizeof(PaintCurvePoint), "PaintCurvePoint");
 	add_index = pc->add_index;
@@ -241,6 +242,8 @@ static void paintcurve_point_add(bContext *C,  wmOperator *op, const int loc[2])
 		pcp[add_index].bez.h1 = HD_ALIGN;
 	}
 
+	ED_paintcurve_undo_push_end();
+
 	WM_paint_cursor_tag_redraw(window, ar);
 }
 
@@ -302,7 +305,7 @@ static int paintcurve_delete_point_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	ED_paintcurve_undo_push(C, op, pc);
+	ED_paintcurve_undo_push_begin(op->type->name);
 
 #define DELETE_TAG 2
 
@@ -342,6 +345,8 @@ static int paintcurve_delete_point_exec(bContext *C, wmOperator *op)
 
 #undef DELETE_TAG
 
+	ED_paintcurve_undo_push_end();
+
 	WM_paint_cursor_tag_redraw(window, ar);
 
 	return OPERATOR_FINISHED;
@@ -379,7 +384,7 @@ static bool paintcurve_point_select(bContext *C, wmOperator *op, const int loc[2
 	if (!pc)
 		return false;
 
-	ED_paintcurve_undo_push(C, op, pc);
+	ED_paintcurve_undo_push_begin(op->type->name);
 
 	if (toggle) {
 		PaintCurvePoint *pcp;
@@ -444,10 +449,14 @@ static bool paintcurve_point_select(bContext *C, wmOperator *op, const int loc[2
 			}
 		}
 
-		if (!pcp)
+		if (!pcp) {
+			ED_paintcurve_undo_push_end();
 			return false;
+		}
 	}
 
+	ED_paintcurve_undo_push_end();
+
 	WM_paint_cursor_tag_redraw(window, ar);
 
 	return true;
@@ -562,9 +571,6 @@ static int paintcurve_slide_invoke(bContext *C, wmOperator *op, const wmEvent *e
 		psd->align = align;
 		op->customdata = psd;
 
-		if (do_select)
-			ED_paintcurve_undo_push(C, op, pc);
-
 		/* first, clear all selection from points */
 		for (i = 0; i < pc->tot_points; i++)
 			pc->points[i].bez.f1 = pc->points[i].bez.f3 = pc->points[i].bez.f2 = 0;
@@ -587,6 +593,8 @@ static int paintcurve_slide_modal(bContext *C, wmOperator *op, const wmEvent *ev
 
 	if (event->type == psd->event && event->val == KM_RELEASE) {
 		MEM_freeN(psd);
+		ED_paintcurve_undo_push_begin(op->type->name);
+		ED_paintcurve_undo_push_end();
 		return OPERATOR_FINISHED;
 	}