== Action Editor - Snap Current-Frame Marker to Keys ==

This little feature snaps the current frame marker to the average frame of all the selected keyframes. Use the hotkey Ctrl-Shift-S to use it.

source/blender/include/BIF_editaction.h

@@ -104,6 +104,7 @@ struct ListBase;
 /* Key operations */
 void transform_action_keys(int mode, int dummy);
 void duplicate_action_keys(void);
+void snap_cfra_action(void);
 void snap_action_keys(short mode);
 void mirror_action_keys(short mode);
 void insertkey_action(void);

source/blender/include/BSE_editipo.h

@@ -151,6 +151,7 @@ void transform_ipo(int mode);
 void actstrip_map_ipo_keys(struct Object *ob, struct Ipo *ipo, short restore, short only_keys);
 
 void sethandles_ipo_keys(struct Ipo *ipo, int code);
+void snap_cfra_ipo_keys(struct Ipo *ipo, short mode);
 void snap_ipo_keys(struct Ipo *ipo, short snaptype);
 void mirror_ipo_keys(struct Ipo *ipo, short mirror_mode);
 void setipotype_ipo(struct Ipo *ipo, int code);

source/blender/src/editaction.c

@@ -779,6 +779,45 @@ void duplicate_action_keys (void)
 	transform_action_keys('g', 0);
 }
 
+/* this function is responsible for snapping the current frame to selected data  */
+void snap_cfra_action() 
+{
+	ListBase act_data = {NULL, NULL};
+	bActListElem *ale;
+	int filter;
+	void *data;
+	short datatype;
+		
+	/* get data */
+	data= get_action_context(&datatype);
+	if (data == NULL) return;
+	
+	/* filter data */
+	filter= (ACTFILTER_VISIBLE | ACTFILTER_IPOKEYS);
+	actdata_filter(&act_data, filter, data, datatype);
+	
+	/* snap current frame to selected data */
+	snap_cfra_ipo_keys(NULL, -1);
+	
+	for (ale= act_data.first; ale; ale= ale->next) {
+		if (NLA_ACTION_SCALED && datatype==ACTCONT_ACTION) {
+			actstrip_map_ipo_keys(OBACT, ale->key_data, 0, 1); 
+			snap_cfra_ipo_keys(ale->key_data, 0);
+			actstrip_map_ipo_keys(OBACT, ale->key_data, 1, 1);
+		}
+		else 
+			snap_cfra_ipo_keys(ale->key_data, 0);
+	}
+	BLI_freelistN(&act_data);
+	
+	snap_cfra_ipo_keys(NULL, 1);
+	
+	BIF_undo_push("Snap Current Frame to Keys");
+	allqueue(REDRAWACTION, 0);
+	allqueue(REDRAWIPO, 0);
+	allqueue(REDRAWNLA, 0);
+}
+
 /* this function is responsible for snapping keyframes to frame-times */
 void snap_action_keys(short mode) 
 {
@@ -2793,7 +2832,12 @@ void winqreadactionspace(ScrArea *sa, void *spacedata, BWinEvent *evt)
 			
 		case SKEY: 
 			if (mval[0]>=ACTWIDTH) {
-				if (G.qual & LR_SHIFTKEY) {
+				if (G.qual == (LR_SHIFTKEY|LR_CTRLKEY)) {
+					if (data) {
+						snap_cfra_action();
+					}
+				}
+				else if (G.qual & LR_SHIFTKEY) {
 					if (data) {
 						if (G.saction->flag & SACTION_DRAWTIME)
 							val = pupmenu("Snap Keys To%t|Nearest Second%x4|Current Time%x2|Nearest Marker %x3");

source/blender/src/editipo_mods.c

@@ -723,6 +723,53 @@ void mirror_ipo_keys(Ipo *ipo, short mirror_type)
 	}
 }
 
+/* This function is called to calculate the average location of the
+ * selected keyframes, and place the current frame at that location.
+ *
+ * It must be called like so:
+ *	snap_cfra_ipo_keys(NULL, -1); // initialise the static vars first
+ *	for (ipo...) snap_cfra_ipo_keys(ipo, 0); // sum up keyframe times
+ *	snap_cfra_ipo_keys(NULL, 1); // set current frame after taking average
+ */
+void snap_cfra_ipo_keys(Ipo *ipo, short mode)
+{
+	static int cfra;
+	static int tot;
+	
+	IpoCurve *icu;
+	BezTriple *bezt;
+	int a;
+	
+	
+	if (mode == -1) {
+		/* initialise a new snap-operation */
+		cfra= 0;
+		tot= 0;
+	}
+	else if (mode == 1) {
+		/* set current frame - using average frame */
+		if (tot != 0)
+			CFRA = cfra / tot;
+	}
+	else {
+		/* loop through keys in ipo, summing the frame
+		 * numbers of those that are selected 
+		 */
+		if (ipo == NULL) 
+			return;
+		
+		for (icu= ipo->curve.first; icu; icu= icu->next) {
+			for (a=0, bezt=icu->bezt; a < icu->totvert; a++, bezt++) {
+				if (BEZSELECTED(bezt)) {
+					cfra += bezt->vec[1][0];
+					tot++;
+				}
+			}
+		}
+	}	
+}
+
+
 /* currently only used by some action editor tools, but may soon get used by ipo editor */
 /* restore = whether to map points back to ipo-time 
  * only_keys = whether to only adjust the location of the center point of beztriples

source/blender/src/header_action.c

@@ -158,6 +158,7 @@ enum {
 	ACTMENU_KEY_SNAP_CURFRAME,
 	ACTMENU_KEY_SNAP_NEARMARK,
 	ACTMENU_KEY_SNAP_NEARTIME,
+	ACTMENU_KEY_SNAP_CFRA2KEY,
 };
 
 enum {
@@ -872,6 +873,10 @@ static void do_action_keymenu_snapmenu(void *arg, int event)
 		case ACTMENU_KEY_SNAP_NEARTIME:
 			snap_action_keys(event);
 			break;
+			
+		case ACTMENU_KEY_SNAP_CFRA2KEY:
+			snap_cfra_action();
+			break;
 	}
 
 	scrarea_queue_winredraw(curarea);
@@ -888,27 +893,35 @@ static uiBlock *action_keymenu_snapmenu(void *arg_unused)
 
 	if (G.saction->flag & SACTION_DRAWTIME) {
 		uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, 
-						 "Nearest Second|Shift S, 1", 0, yco-=20, 
+						 "Key -> Nearest Second|Shift S, 1", 0, yco-=20, 
 						 menuwidth, 19, NULL, 0.0, 0.0, 0, 
 						 ACTMENU_KEY_SNAP_NEARTIME, "");
 		uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, 
-						 "Current Time|Shift S, 2", 0, yco-=20, 
+						 "Key -> Current Time|Shift S, 2", 0, yco-=20, 
 						 menuwidth, 19, NULL, 0.0, 0.0, 0, 
 						 ACTMENU_KEY_SNAP_CURFRAME, "");
 
 	}
 	else {
 		uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, 
-						 "Nearest Frame|Shift S, 1", 0, yco-=20, 
+						 "Key -> Nearest Frame|Shift S, 1", 0, yco-=20, 
 						 menuwidth, 19, NULL, 0.0, 0.0, 0, 
 						 ACTMENU_KEY_SNAP_NEARFRAME, "");
 		uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, 
-						 "Current Frame|Shift S, 2", 0, yco-=20, 
+						 "Key -> Current Frame|Shift S, 2", 0, yco-=20, 
 						 menuwidth, 19, NULL, 0.0, 0.0, 0, 
 						 ACTMENU_KEY_SNAP_CURFRAME, "");
 	}
 	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, 
-					 "Nearest Marker|Shift S, 3", 0, yco-=20, 
+					 "Key -> Nearest Marker|Shift S, 3", 0, yco-=20, 
+					 menuwidth, 19, NULL, 0.0, 0.0, 0, 
+					 ACTMENU_KEY_SNAP_NEARMARK, "");
+					 
+	uiDefBut(block, SEPR, 0, "", 0, yco-=6, 
+			 menuwidth, 6, NULL, 0.0, 0.0, 0, 0, "");
+			 
+	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, 
+					 "Current Frame -> Key|Ctrl Shift S", 0, yco-=20, 
 					 menuwidth, 19, NULL, 0.0, 0.0, 0, 
 					 ACTMENU_KEY_SNAP_NEARMARK, "");