preliminary support for undo

1 files changed, 12 insertions, 1 deletions

diff --git a/gramscii.h b/gramscii.h
index a08d211..73b9db7 100644
--- a/gramscii.h
+++ b/gramscii.h
@@ -44,6 +44,9 @@
 #define VIDEO_NRM 0
 #define VIDEO_REV 7 
 
+#define CUR 0x01
+#define LST 0x02
+
 /** types **/
 
 typedef struct{
@@ -59,6 +62,7 @@ typedef struct{
 	line_t *l;
 } lineset_t;
 
+
 /** MACROS **/
 
 #define MIN(x,y)  (x) < (y) ? (x) : (y)
@@ -73,6 +77,11 @@ typedef struct{
 
 lineset_t screen;
 lineset_t cutbuf;
+lineset_t *undo;
+
+int undo_sz;
+int undo_cur;
+int undo_lst;
 
 int WIDTH, HEIGHT;
 
@@ -155,6 +164,8 @@ void ensure_line_length(line_t *l, int len);
 void ensure_num_lines(lineset_t *ls, int n);
 void yank_region(int x1, int y1, int x2, int y2);
 void paste_region(int x1, int y1);
-
+void copy_lines_to_ring(int y1, int y2, int which);
+void undo_change();
+void redo_change();
 
 #endif