== Clamp-To Constraint (was Patch #4818) ==

This (new) constraint limits the location of an object/bone to the range of locations
on a given curve. It works by comparing the location of the owner on one axis, to
the extents of the curve's bounding-box on the same axis, to find the location on
the curve.

Usage Notes:
* 'Ob:' field must point to a valid curve object
* This curve should have 'Path' turned on in order for this constraint to work. You
don't really need to do this as it will be taken care of by the code.
* 'Auto' toggle automically determines which axis should be used for the distance estimations/calculations. It is the default option, but may not work that well for
some cases.
* X/Y/Z toggles can be used to select the axis to use for these calculations. Try
to choose the axis along which the curve stretches out for most.

Python Notes:
Python API access for this constraint is not included in this commit. Will be coming
soon.

1 files changed, 13 insertions, 0 deletions

diff --git a/source/blender/makesdna/DNA_constraint_types.h b/source/blender/makesdna/DNA_constraint_types.h
index 6cf1403b803..bb4065605e7 100644
--- a/source/blender/makesdna/DNA_constraint_types.h
+++ b/source/blender/makesdna/DNA_constraint_types.h
@@ -216,6 +216,13 @@ typedef struct bRigidBodyJointConstraint{
 	short		pad2;
 } bRigidBodyJointConstraint;
 
+/* ClampTo Constraint */
+typedef struct bClampToConstraint {
+	Object 		*tar;			/* 'target' must be a curve */
+	int			flag;			/* which plane to find object on */
+	int			pad;
+} bClampToConstraint;
+
 /* bConstraint.type */
 #define CONSTRAINT_TYPE_NULL		0
 #define CONSTRAINT_TYPE_CHILDOF		1	/* Unimplemented */
@@ -235,6 +242,7 @@ typedef struct bRigidBodyJointConstraint{
 #define CONSTRAINT_TYPE_STRETCHTO	15  /* claiming this to be mine :) is in tuhopuu bjornmose */ 
 #define CONSTRAINT_TYPE_MINMAX      16  /* floor constraint */
 #define CONSTRAINT_TYPE_RIGIDBODYJOINT 17 /* rigidbody constraint */
+#define CONSTRAINT_TYPE_CLAMPTO		18  /* clampto constraint */		
 
 /* bConstraint.flag */
 		/* expand for UI */
@@ -310,6 +318,11 @@ typedef struct bRigidBodyJointConstraint{
 #define PLANE_Y		0x01
 #define PLANE_Z		0x02
 
+#define CLAMPTO_AUTO	0
+#define CLAMPTO_X		1
+#define	CLAMPTO_Y		2
+#define CLAMPTO_Z		3
+
 /* bKinematicConstraint->flag */
 #define CONSTRAINT_IK_TIP		1
 #define CONSTRAINT_IK_ROT		2