Three functionalities in one commit, but there's overlap so I can't

separate it...

1) Curve/Surface editmode undo
Uses same syntax as mesh undo, so simple to integrate. Edit-curve data is
also quite simpler, so no need for any hack at all.
It re-uses the undo system from next point, which is nice short & clean
local code

2) Framework for global undo
The undo calls themselves are commented out. In a next commit I want to
enable it for a couple of main features, for further feedback.
The speed goes surprisingly well, especially with this new version that
'pushes' undo after a command, ensuring interactivity isnt frustrated

3) framework for texture based icons in Blender
Not activated code, but tested here. Part of 2.3 UI project.

btw: Johnny Matthews will assist in (and complete) the undo project

1 files changed, 125 insertions, 1 deletions

diff --git a/source/blender/src/usiblender.c b/source/blender/src/usiblender.c
index 244dcc738fd..ff5b334e480 100644
--- a/source/blender/src/usiblender.c
+++ b/source/blender/src/usiblender.c
@@ -107,6 +107,7 @@
 
 #include "BDR_drawobject.h"
 #include "BDR_editobject.h"
+#include "BDR_editcurve.h"
 #include "BDR_vpaint.h"
 
 #include "BPY_extern.h"
@@ -126,7 +127,10 @@
 void BIF_read_file(char *name)
 {
 	extern short winqueue_break; /* editscreen.c */
+	void BIF_reset_undo(void);
+	void BIF_write_undo(char *);	
 
+	BIF_reset_undo();
 
 	//here?
 	//sound_end_all_sounds();
@@ -145,6 +149,7 @@ void BIF_read_file(char *name)
 
 	winqueue_break= 1;	/* leave queues everywhere */
 
+	BIF_write_undo("original");	/* save current state */
 }
 
 int BIF_read_homefile(void)
@@ -461,6 +466,123 @@ static void delete_autosave(void)
 
 /***/
 
+#define MAXUNDONAME	64
+typedef struct UndoElem {
+	struct UndoElem *next, *prev;
+	char str[FILE_MAXDIR+FILE_MAXFILE];
+	char name[MAXUNDONAME];
+} UndoElem;
+
+#define MAXUNDO	 32
+static ListBase undobase={NULL, NULL};
+static UndoElem *curundo= NULL;
+
+static void get_undosave_location(char buf[FILE_MAXDIR+FILE_MAXFILE], int num)
+{
+	char numstr[32];
+	
+	sprintf(numstr, "%d.blend", num);
+	BLI_make_file_string("/", buf, U.tempdir, numstr);
+
+}
+
+static int read_undosave(char *tstr)
+{
+	char scestr[FILE_MAXDIR+FILE_MAXFILE];
+	int success;
+	
+	strcpy(scestr, G.sce);	/* temporal store */
+	
+	success= BKE_read_file(tstr, NULL);
+	strcpy(G.sce, scestr);
+
+	return success;
+}
+
+/* name can be a dynamic string */
+void BIF_write_undo(char *name)
+{
+	static int counter= 0;
+	int nr;
+	char *err, tstr[FILE_MAXDIR+FILE_MAXFILE];
+	UndoElem *uel;
+	
+	/* calculate current filename */
+	
+	counter++;
+	counter= counter % MAXUNDO;	
+	get_undosave_location(tstr, counter);
+	
+	if(BLO_write_file(tstr, G.fileflags, &err)) {
+
+		/* remove all undos after (also when curundo==NULL) */
+		while(undobase.last != curundo) {
+			uel= undobase.last;
+			BLI_remlink(&undobase, uel);
+			MEM_freeN(uel);
+		}
+		
+		/* make new */
+		curundo= uel= MEM_mallocN(sizeof(UndoElem), "undo file");
+		strcpy(uel->str, tstr);
+		strncpy(uel->name, name, MAXUNDONAME-1);
+		BLI_addtail(&undobase, uel);
+		
+		/* and limit amount to the maximum */
+		nr= 0;
+		uel= undobase.last;
+		while(uel) {
+			nr++;
+			if(nr==MAXUNDO) break;
+			uel= uel->prev;
+		}
+		if(uel) {
+			while(undobase.first!=uel) {
+				UndoElem *first= undobase.first;
+				BLI_remlink(&undobase, first);
+				MEM_freeN(first);
+			}
+		}
+	}
+	
+}
+
+/* 1= an undo, -1 is a redo. we have to make sure 'curundo' remains at current situation */
+void BIF_undo_step(int step)
+{
+	
+	if(step==1) {
+		/* curundo should never be NULL, after restart or load file it should call undo_save */
+		if(curundo==NULL || curundo->prev==NULL) error("No undo available");
+		else {
+			printf("undo %s\n", curundo->name);
+			curundo= curundo->prev;
+			read_undosave(curundo->str);
+		}
+	}
+	else {
+		
+		/* curundo has to remain current situation! */
+		
+		if(curundo==NULL || curundo->next==NULL) error("No redo available");
+		else {
+			read_undosave(curundo->next->str);
+			curundo= curundo->next;
+			printf("redo %s\n", curundo->name);
+		}
+	}
+}
+
+void BIF_reset_undo(void)
+{
+	
+	BLI_freelistN(&undobase);
+	curundo= NULL;
+}
+
+
+/***/
+
 static void initbuttons(void)
 {
 	uiDefFont(UI_HELVB, 
@@ -576,7 +698,9 @@ void exit_usiblender(void)
 #endif
 
 	if (G.undo_clear) G.undo_clear();
-
+	undo_clear_curve();
+	BIF_reset_undo();
+	
 	BLI_freelistN(&U.themes);
 	
 	if(totblock!=0) {