Undo System: remove accumulate/store modes

This complicated handling of undo steps in a generic way
especially switching between undo systems that stored data to ones
that accumulated changes.

Now each undo system must treat it's steps as check-point,
internally it can apply/rewind changes.

This commit also fixes projection paint where the object mode wasn't
following the undo steps.

1 files changed, 61 insertions, 12 deletions

diff --git a/source/blender/editors/space_text/text_undo.c b/source/blender/editors/space_text/text_undo.c
index e945481a2bd..869c7d03af9 100644
--- a/source/blender/editors/space_text/text_undo.c
+++ b/source/blender/editors/space_text/text_undo.c
@@ -101,6 +101,8 @@ static bool text_undosys_step_encode(struct bContext *C, struct Main *UNUSED(bma
 		return false;
 	}
 
+	us_p->is_applied = true;
+
 	us->text_ref.ptr = text;
 
 	us->step.data_size = us->data.len;
@@ -108,25 +110,73 @@ static bool text_undosys_step_encode(struct bContext *C, struct Main *UNUSED(bma
 	return true;
 }
 
+
+static void text_undosys_step_decode_undo_impl(Text *text, TextUndoStep *us)
+{
+	BLI_assert(us->step.is_applied == true);
+	TextUndoBuf data = us->data;
+	while (data.pos > -1) {
+		txt_do_undo(text, &data);
+	}
+	BLI_assert(data.pos == -1);
+	us->step.is_applied = false;
+}
+
+static void text_undosys_step_decode_redo_impl(Text *text, TextUndoStep *us)
+{
+	BLI_assert(us->step.is_applied == false);
+	TextUndoBuf data = us->data;
+	data.pos = -1;
+	while (data.pos < us->data.pos) {
+		txt_do_redo(text, &data);
+	}
+	BLI_assert(data.pos == us->data.pos);
+	us->step.is_applied = true;
+}
+
+static void text_undosys_step_decode_undo(Text *text, TextUndoStep *us)
+{
+	TextUndoStep *us_iter = us;
+	while (us_iter->step.next && (us_iter->step.next->type == us_iter->step.type)) {
+		if (us_iter->step.next->is_applied == false) {
+			break;
+		}
+		us_iter = (TextUndoStep *)us_iter->step.next;
+	}
+	while (us_iter != us) {
+		text_undosys_step_decode_undo_impl(text, us_iter);
+		us_iter = (TextUndoStep *)us_iter->step.prev;
+	}
+}
+
+static void text_undosys_step_decode_redo(Text *text, TextUndoStep *us)
+{
+	TextUndoStep *us_iter = us;
+	while (us_iter->step.prev && (us_iter->step.prev->type == us_iter->step.type)) {
+		if (us_iter->step.prev->is_applied == true) {
+			break;
+		}
+		us_iter = (TextUndoStep *)us_iter->step.prev;
+	}
+	while (us_iter && (us_iter->step.is_applied == false)) {
+		text_undosys_step_decode_redo_impl(text, us_iter);
+		if (us_iter == us) {
+			break;
+		}
+		us_iter = (TextUndoStep *)us_iter->step.next;
+	}
+}
+
 static void text_undosys_step_decode(struct bContext *C, struct Main *UNUSED(bmain), UndoStep *us_p, int dir)
 {
 	TextUndoStep *us = (TextUndoStep *)us_p;
 	Text *text = us->text_ref.ptr;
 
 	if (dir < 0) {
-		TextUndoBuf data = us->data;
-		while (data.pos > -1) {
-			txt_do_undo(text, &data);
-		}
-		BLI_assert(data.pos == -1);
+		text_undosys_step_decode_undo(text, us);
 	}
 	else {
-		TextUndoBuf data = us->data;
-		data.pos = -1;
-		while (data.pos < us->data.pos) {
-			txt_do_redo(text, &data);
-		}
-		BLI_assert(data.pos == us->data.pos);
+		text_undosys_step_decode_redo(text, us);
 	}
 
 	SpaceText *st = CTX_wm_space_text(C);
@@ -166,7 +216,6 @@ void ED_text_undosys_type(UndoType *ut)
 
 	ut->step_foreach_ID_ref = text_undosys_foreach_ID_ref;
 
-	ut->mode = BKE_UNDOTYPE_MODE_ACCUMULATE;
 	ut->use_context = false;
 
 	ut->step_size = sizeof(TextUndoStep);