From 47416c725c9790c17abddfbcd96c080e28e76abb Mon Sep 17 00:00:00 2001
From: Campbell Barton <ideasman42@gmail.com>
Date: Mon, 7 Dec 2009 19:59:04 +0000
Subject: [PATCH] driver type 'Sum'

---
 source/blender/blenkernel/intern/fcurve.c   | 14 +++++++++-----
 source/blender/makesdna/DNA_anim_types.h    |  2 ++
 source/blender/makesrna/intern/rna_fcurve.c |  1 +
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/source/blender/blenkernel/intern/fcurve.c b/source/blender/blenkernel/intern/fcurve.c
index 0623a5cbe5e..b3a6b773cf3 100644
--- a/source/blender/blenkernel/intern/fcurve.c
+++ b/source/blender/blenkernel/intern/fcurve.c
@@ -910,6 +910,7 @@ static float evaluate_driver (ChannelDriver *driver, float evaltime)
 	// TODO: the flags for individual targets need to be used too for more fine-grained support...
 	switch (driver->type) {
 		case DRIVER_TYPE_AVERAGE: /* average values of driver targets */
+		case DRIVER_TYPE_SUM: /* sum values of driver targets */
 		{
 			/* check how many targets there are first (i.e. just one?) */
 			if (driver->targets.first == driver->targets.last) {
@@ -921,19 +922,22 @@ static float evaluate_driver (ChannelDriver *driver, float evaltime)
 				/* more than one target, so average the values of the targets */
 				int tot = 0;
 				float value = 0.0f;
-				
+
 				/* loop through targets, adding (hopefully we don't get any overflow!) */
 				for (dtar= driver->targets.first; dtar; dtar=dtar->next) {
-					value += driver_get_target_value(driver, dtar); 
+					value += driver_get_target_value(driver, dtar);
 					tot++;
 				}
-				
+
 				/* return the average of these */
-				return (value / (float)tot);
+				if(driver->type == DRIVER_TYPE_AVERAGE)
+					return (value / (float)tot);
+				else
+					return value;
+
 			}
 		}
 			break;
-		
 		case DRIVER_TYPE_PYTHON: /* expression */
 		{
 #ifndef DISABLE_PYTHON
diff --git a/source/blender/makesdna/DNA_anim_types.h b/source/blender/makesdna/DNA_anim_types.h
index c6330861fd2..09f77d98f4b 100644
--- a/source/blender/makesdna/DNA_anim_types.h
+++ b/source/blender/makesdna/DNA_anim_types.h
@@ -309,6 +309,8 @@ typedef enum eDriver_Types {
 	DRIVER_TYPE_PYTHON,
 		/* rotational difference (must use rotation channels only) */
 	DRIVER_TYPE_ROTDIFF,
+		/* sum of all values */
+	DRIVER_TYPE_SUM,
 } eDriver_Types;
 
 /* driver flags */
diff --git a/source/blender/makesrna/intern/rna_fcurve.c b/source/blender/makesrna/intern/rna_fcurve.c
index fbf4a8b41c5..bf8b74d08ee 100644
--- a/source/blender/makesrna/intern/rna_fcurve.c
+++ b/source/blender/makesrna/intern/rna_fcurve.c
@@ -789,6 +789,7 @@ static void rna_def_channeldriver(BlenderRNA *brna)
 	
 	static EnumPropertyItem prop_type_items[] = {
 		{DRIVER_TYPE_AVERAGE, "AVERAGE", 0, "Averaged Value", ""},
+		{DRIVER_TYPE_SUM, "SUM", 0, "Sum Values", ""},
 		{DRIVER_TYPE_PYTHON, "SCRIPTED", 0, "Scripted Expression", ""},
 		{DRIVER_TYPE_ROTDIFF, "ROTDIFF", 0, "Rotational Difference", ""},
 		{0, NULL, 0, NULL, NULL}};