Editmesh Undo:

User Info:
	Pressing UKey in mesh edit mode now undoes only last step.  Undo can save
	upto 64 steps of undo info.  This is configurable under User Prefs->
	Edit Methods.  The default is 32.  High numbers of undo steps use a
	lot of memory, since each step stores a copy of the mesh.

	Shift-U redoes the last undone step (Undoes the undo.)

	Alt-U brings up a menu of possible steps that can be undone.  Selecting
	an item on the list undoes that item plus all items before it on the list.
	The top selection "Undo All" is identical to the old Ukey.  It undoes
	all editing since entering Editmode, even if all regular undo steps are
	used up.

	Undo info is only saved for one object at a time.  You can leave and re-
	enter editmode for the same object, and all undo steps for that object are
	preserved.  Undo info for an object is lost once a different object is
	edited.

Coder Info:
	In order for undo to work, a checkpoint save has to be made.  This is
	done with a call to undo_push_mesh("name of step").  This should be done
	after the last quick abort for a function (typ. the
	"if (G.obedit==0) return;", or similar).  the undo_push_mesh() does alter some
	flags, so don't try to be too tricky and call undo_push_mesh() too late.
	The step name is what shows up in the undo_menu.  The name "U" is reserved.

1 files changed, 20 insertions, 1 deletions

diff --git a/source/blender/blenkernel/BKE_global.h b/source/blender/blenkernel/BKE_global.h
index 2f75dd8be16..698982f5396 100644
--- a/source/blender/blenkernel/BKE_global.h
+++ b/source/blender/blenkernel/BKE_global.h
@@ -62,6 +62,17 @@ struct Object;
 struct bSoundListener;
 struct BMF_Font;
 
+#define UNDO_MAX	64
+#define UNDO_EDIT_MAX 	64
+
+typedef struct UndoBufferEdit {
+
+	void *datablock;
+	char name[64];
+
+} UndoBufferEdit;
+
+
 typedef struct Global {
 
     /* active pointers */
@@ -143,7 +154,15 @@ typedef struct Global {
     short special1, special2;
 
     int flags;
-    
+
+    /* editmode undo - written by intrr, ported by Det. Thorn  */
+    struct UndoBufferEdit undo_edit[UNDO_EDIT_MAX+1];/* need one more for undoing first undo */
+    int undo_edit_level;			/* index of last undo buffer created */
+    int undo_edit_highest;			/* index of highest undo buffer in use */
+    void *undo_last_data;			/* pointer to last datablock edited */
+    void (*undo_clear)(void);		/* pointer to function to free the undo data */
+
+        
 } Global;
 
 /* **************** GLOBAL ********************* */