== Clamp To Constraint ==

Now there's an option for the owner to follow the path of the target cyclically. Previously, if the owner moved past the extents of the side of the bounding-box used for the calculations, the object was placed on the curve at the nearest extent. 

This option is only really useful if the curve itself is cyclic, although you can still use it otherwise. To enable, just turn on the cyclic option. 

5 files changed, 71 insertions, 16 deletions

diff --git a/source/blender/blenkernel/intern/constraint.c b/source/blender/blenkernel/intern/constraint.c
index 4f79e6867b9..8445fe88797 100644
--- a/source/blender/blenkernel/intern/constraint.c
+++ b/source/blender/blenkernel/intern/constraint.c
@@ -2599,7 +2599,7 @@ static void evaluate_constraint (bConstraint *constraint, float ownermat[][4], f
 				
 				/* find best position on curve */
 				/* 1. determine which axis to sample on? */
-				if (data->flag==CLAMPTO_AUTO) {
+				if (data->flag == CLAMPTO_AUTO) {
 					float size[3];
 					VecSubf(size, curveMax, curveMin);
 					
@@ -2608,23 +2608,60 @@ static void evaluate_constraint (bConstraint *constraint, float ownermat[][4], f
 					 * frequently used.
 					 */
 					if ((size[2]>size[0]) && (size[2]>size[1]))
-						clamp_axis= CLAMPTO_Z;
+						clamp_axis= CLAMPTO_Z - 1;
 					else if ((size[1]>size[0]) && (size[1]>size[2]))
-						clamp_axis= CLAMPTO_Y;
+						clamp_axis= CLAMPTO_Y - 1;
 					else
-						clamp_axis = CLAMPTO_X;
+						clamp_axis = CLAMPTO_X - 1;
 				}
 				else 
-					clamp_axis= data->flag;
+					clamp_axis= data->flag - 1;
 					
-				/* 2. determine position relative to curve on a 0-1 scale */
-				if (clamp_axis > 0) clamp_axis--;
-				if (ownLoc[clamp_axis] <= curveMin[clamp_axis])
-					curvetime = 0.0;
-				else if (ownLoc[clamp_axis] >= curveMax[clamp_axis])
-					curvetime = 1.0;
-				else
-					curvetime = (ownLoc[clamp_axis] - curveMin[clamp_axis]) / (curveMax[clamp_axis] - curveMin[clamp_axis]);
+				/* 2. determine position relative to curve on a 0-1 scale based on bounding box */
+				if (data->flag2 & CLAMPTO_CYCLIC) {
+					/* cyclic, so offset within relative bounding box is used */
+					float len= (curveMax[clamp_axis] - curveMin[clamp_axis]);
+					float offset;
+					
+					/* find bounding-box range where target is located */
+					if (ownLoc[clamp_axis] < curveMin[clamp_axis]) {
+						/* bounding-box range is before */
+						offset= curveMin[clamp_axis];
+						
+						while (ownLoc[clamp_axis] < offset)
+							offset -= len;
+						
+						/* now, we calculate as per normal, except using offset instead of curveMin[clamp_axis] */
+						curvetime = (ownLoc[clamp_axis] - offset) / (len);
+					}
+					else if (ownLoc[clamp_axis] > curveMax[clamp_axis]) {
+						/* bounding-box range is after */
+						offset= curveMax[clamp_axis];
+						
+						while (ownLoc[clamp_axis] > offset) {
+							if ((offset + len) > ownLoc[clamp_axis])
+								break;
+							else
+								offset += len;
+						}
+						
+						/* now, we calculate as per normal, except using offset instead of curveMax[clamp_axis] */
+						curvetime = (ownLoc[clamp_axis] - offset) / (len);
+					}
+					else {
+						/* as the location falls within bounds, just calculate */
+						curvetime = (ownLoc[clamp_axis] - curveMin[clamp_axis]) / (len);
+					}
+				}
+				else {
+					/* no cyclic, so position is clamped to within the bounding box */
+					if (ownLoc[clamp_axis] <= curveMin[clamp_axis])
+						curvetime = 0.0;
+					else if (ownLoc[clamp_axis] >= curveMax[clamp_axis])
+						curvetime = 1.0;
+					else
+						curvetime = (ownLoc[clamp_axis] - curveMin[clamp_axis]) / (curveMax[clamp_axis] - curveMin[clamp_axis]);
+				}
 				
 				/* 3. position on curve */
 				if(where_on_path(data->tar, curvetime, vec, dir) ) {
diff --git a/source/blender/makesdna/DNA_constraint_types.h b/source/blender/makesdna/DNA_constraint_types.h
index 9a0d5a095e5..fcde95371ac 100644
--- a/source/blender/makesdna/DNA_constraint_types.h
+++ b/source/blender/makesdna/DNA_constraint_types.h
@@ -205,7 +205,7 @@ typedef struct bRigidBodyJointConstraint {
 typedef struct bClampToConstraint {
 	Object 		*tar;			/* 'target' must be a curve */
 	int			flag;			/* which axis/plane to compare owner's location on  */
-	int			pad;
+	int			flag2;			/* for legacy reasons, this is flag2. used for any extra settings */
 } bClampToConstraint;
 
 /* Child Of Constraint */
@@ -373,6 +373,9 @@ typedef struct bSizeLimitConstraint {
 #define	CLAMPTO_Y		2
 #define CLAMPTO_Z		3
 
+/* ClampTo Constraint ->flag2 */
+#define CLAMPTO_CYCLIC	1
+
 /* bKinematicConstraint->flag */
 #define CONSTRAINT_IK_TIP		1
 #define CONSTRAINT_IK_ROT		2
diff --git a/source/blender/python/api2_2x/Constraint.c b/source/blender/python/api2_2x/Constraint.c
index 0e235082c61..4dddd274a0e 100644
--- a/source/blender/python/api2_2x/Constraint.c
+++ b/source/blender/python/api2_2x/Constraint.c
@@ -125,6 +125,8 @@ enum constraint_constants {
 	EXPP_CONSTR_LIMYROT = LIMIT_YROT,
 	EXPP_CONSTR_LIMZROT = LIMIT_ZROT,
 	
+	EXPP_CONSTR_CLAMPCYCLIC,
+	
 	EXPP_CONSTR_XMIN,
 	EXPP_CONSTR_XMAX,
 	EXPP_CONSTR_YMIN,
@@ -887,6 +889,8 @@ static PyObject *clampto_getter( BPy_Constraint * self, int type )
 		return Object_CreatePyObject( con->tar );
 	case EXPP_CONSTR_CLAMP:
 		return PyInt_FromLong( (long)con->flag );
+	case EXPP_CONSTR_CLAMPCYCLIC:
+		return PyBool_FromLong( (long)(con->flag2 & CLAMPTO_CYCLIC) );
 	default:
 		return EXPP_ReturnPyObjError( PyExc_KeyError, "key not found" );
 	}
@@ -908,6 +912,8 @@ static int clampto_setter( BPy_Constraint *self, int type, PyObject *value )
 	case EXPP_CONSTR_CLAMP:
 		return EXPP_setIValueRange( value, &con->flag,
 				CLAMPTO_AUTO, CLAMPTO_Z, 'i' );
+	case EXPP_CONSTR_CLAMPCYCLIC:
+		return EXPP_setBitfield( value, &con->flag2, CLAMPTO_CYCLIC, 'i' );
 	default:
 		return EXPP_ReturnIntError( PyExc_KeyError, "key not found" );
 	}
@@ -2418,6 +2424,8 @@ static PyObject *M_Constraint_SettingsDict( void )
 				PyInt_FromLong( CLAMPTO_Y ) );
 		PyConstant_Insert( d, "CLAMPZ",
 				PyInt_FromLong( CLAMPTO_Z ) );
+		PyConstant_Insert( d, "CLAMPCYCLIC",
+				PyInt_FromLong( EXPP_CONSTR_CLAMPCYCLIC ));
 
 		PyConstant_Insert( d, "TARGET",
 				PyInt_FromLong( EXPP_CONSTR_TARGET ) );
diff --git a/source/blender/python/api2_2x/doc/Constraint.py b/source/blender/python/api2_2x/doc/Constraint.py
index bb81d2cba7a..4c1981c5238 100644
--- a/source/blender/python/api2_2x/doc/Constraint.py
+++ b/source/blender/python/api2_2x/doc/Constraint.py
@@ -86,6 +86,7 @@ Or to print all the constraints attached to each bone in a pose::
 		- LOCK (int): values are LOCKX, LOCKY, LOCKZ
 	- Used by Clamp To (CLAMPTO) constraint:
 		- CLAMP (int): values are CLAMPAUTO, CLAMPX, CLAMPY, CLAMPZ
+		- CLAMPCYCLIC (bool)
 	- Used by Floor (FLOOR) constraint:
 		- MINMAX (int): values are MINX, MINY, MINZ, MAXX, MAXY, MAXZ
 		- OFFSET (float): clamped to [-100.0,100.0]
diff --git a/source/blender/src/buttons_object.c b/source/blender/src/buttons_object.c
index 033a7dc18cc..cd3246fcd8d 100644
--- a/source/blender/src/buttons_object.c
+++ b/source/blender/src/buttons_object.c
@@ -1409,11 +1409,11 @@ static void draw_constraint (uiBlock *block, ListBase *list, bConstraint *con, s
 			{
 				bClampToConstraint *data = con->data;
 				
-				height = 66;
+				height = 90;
 				uiDefBut(block, ROUNDBOX, B_DIFF, "", *xco-10, *yco-height, width+40,height-1, NULL, 5.0, 0.0, 12, rb_col, ""); 
 				
 				uiDefBut(block, LABEL, B_CONSTRAINT_TEST, "Target:", *xco+65, *yco-24, 50, 18, NULL, 0.0, 0.0, 0.0, 0.0, ""); 
-
+				
 				/* Draw target parameters */
 				uiDefIDPoinBut(block, test_obpoin_but, ID_OB, B_CONSTRAINT_CHANGETARGET, "OB:", *xco+120, *yco-24, 135, 18, &data->tar, "Target Object"); 
 				
@@ -1425,6 +1425,12 @@ static void draw_constraint (uiBlock *block, ListBase *list, bConstraint *con, s
 				uiDefButI(block, ROW, B_CONSTRAINT_TEST, "Y", *xco+182, *yco-64, 32, 18, &data->flag, 12.0, CLAMPTO_Y, 0, 0, "Main axis of movement is y-axis");
 				uiDefButI(block, ROW, B_CONSTRAINT_TEST, "Z", *xco+214, *yco-64, 32, 18, &data->flag, 12.0, CLAMPTO_Z, 0, 0, "Main axis of movement is z-axis");
 				uiBlockEndAlign(block);
+				
+				/* Extra Options Controlling Behaviour */
+				uiBlockBeginAlign(block);
+				uiDefBut(block, LABEL, B_CONSTRAINT_TEST, "Options:", *xco, *yco-86, 90, 18, NULL, 0.0, 0.0, 0.0, 0.0, ""); 
+				uiDefButBitI(block, TOG, CLAMPTO_CYCLIC, B_CONSTRAINT_TEST, "Cyclic", *xco+((width/2)), *yco-86,60,19, &data->flag2, 0, 0, 0, 0, "Treat curve as cyclic curve (no clamping to curve bounding box)");
+				uiBlockEndAlign(block);
 			}
 			break;
 		case CONSTRAINT_TYPE_TRANSFORM: