Imported existing code

indra/llcharacter/lljointsolverrp3.h

@@ -0,0 +1,182 @@
+/** 
+ * @file lljointsolverrp3.h
+ * @brief Implementation of LLJointSolverRP3 class
+ *
+ * $LicenseInfo:firstyear=2001&license=viewergpl$
+ * 
+ * Copyright (c) 2001-2009, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at
+ * http://secondlifegrid.net/programs/open_source/licensing/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ */
+
+#ifndef LL_LLJOINTSOLVERRP3_H
+#define LL_LLJOINTSOLVERRP3_H
+
+//-----------------------------------------------------------------------------
+// Header Files
+//-----------------------------------------------------------------------------
+#include "lljoint.h"
+
+/* -some compilers don't like line continuation chars-
+//-----------------------------------------------------------------------------
+// class LLJointSolverRP3
+//
+// This class is a "poor man's" IK for simple 3 joint kinematic chains.
+// It is modeled after the 'ikRPSolver' in Maya.
+// This class takes 4 LLJoints:
+//   jointA
+//   jointB
+//   jointC
+//   jointGoal
+//
+// Such that jointA is the parent of jointB, jointB is the parent of jointC.
+// When invoked, this class modifies the rotations of jointA and jointB such
+// that the position of the jointC attempts to reach the position of jointGoal.
+//
+// At object initialization time, the distances between jointA - jointB and
+// jointB - jointC are cached.  During evaluation these bone lengths are
+// preserved.
+//
+//  A          A 
+//  |          |
+//  |          |
+//  B          B---CG     A---B---C...G
+//   \
+//    \
+//     CG
+//
+//
+// In addition a "poleVector" is specified that does two things:
+//
+// a) defines the plane in which the solution occurs, thus
+//    reducing an infinite number of solutions, down to 2.
+//
+// b) disambiguates the resulting two solutions as follows:
+//
+//  A             A            A--->poleVector
+//  |              \            \
+//  |               \            \
+//  B       vs.      B   ==>      B
+//   \               |            |
+//    \              |            |
+//     CG            CG           CG
+//
+// A "twist" setting allows the solution plane to be rotated about the
+// line between A and C.  A handy animation feature.
+//
+// For "smarter" results for non-coplanar limbs, specify the joints axis
+// of bend in the B's local frame (see setBAxis())
+//-----------------------------------------------------------------------------
+*/
+
+class LLJointSolverRP3
+{
+protected:
+	LLJoint		*mJointA;
+	LLJoint		*mJointB;
+	LLJoint		*mJointC;
+	LLJoint		*mJointGoal;
+
+	F32			mLengthAB;
+	F32			mLengthBC;
+
+	LLVector3	mPoleVector;
+	LLVector3	mBAxis;
+	BOOL		mbUseBAxis;
+
+	F32			mTwist;
+
+	BOOL		mFirstTime;
+	LLMatrix4	mSavedJointAMat;
+	LLMatrix4	mSavedInvPlaneMat;
+
+	LLQuaternion	mJointABaseRotation;
+	LLQuaternion	mJointBBaseRotation;
+
+public:
+	//-------------------------------------------------------------------------
+	// Constructor/Destructor
+	//-------------------------------------------------------------------------
+	LLJointSolverRP3();
+	virtual ~LLJointSolverRP3();
+
+	//-------------------------------------------------------------------------
+	// setupJoints()
+	// This must be called one time to setup the solver.
+	// This must be called AFTER the skeleton has been created, all parent/child
+	// relationships are established, and after the joints are placed in
+	// a valid configuration (as distances between them will be cached).
+	//-------------------------------------------------------------------------
+	void setupJoints(	LLJoint* jointA,
+						LLJoint* jointB,
+						LLJoint* jointC,
+						LLJoint* jointGoal );
+
+	//-------------------------------------------------------------------------
+	// getPoleVector()
+	// Returns the current pole vector.
+	//-------------------------------------------------------------------------
+	const LLVector3& getPoleVector();
+
+	//-------------------------------------------------------------------------
+	// setPoleVector()
+	// Sets the pole vector.
+	// The pole vector is defined relative to (in the space of) jointA's parent.
+	// The default pole vector is (1,0,0), and this is used if this function
+	// is never called.
+	// This vector is normalized when set.
+	//-------------------------------------------------------------------------
+	void setPoleVector( const LLVector3& poleVector );
+
+	//-------------------------------------------------------------------------
+	// setBAxis()
+	// Sets the joint's axis in B's local frame, and enable "smarter" solve(). 
+	// This allows for smarter IK when for twisted limbs.
+	//-------------------------------------------------------------------------
+	void setBAxis( const LLVector3& bAxis );
+
+	//-------------------------------------------------------------------------
+	// getTwist()
+	// Returns the current twist in radians.
+	//-------------------------------------------------------------------------
+	F32 getTwist();
+
+	//-------------------------------------------------------------------------
+	// setTwist()
+	// Sets the twist value.
+	// The default is 0.0.
+	//-------------------------------------------------------------------------
+	void setTwist( F32 twist );
+
+	//-------------------------------------------------------------------------
+	// solve()
+	// This is the "work" function.
+	// When called, the rotations of jointA and jointB will be modified
+	// such that jointC attempts to reach jointGoal.
+	//-------------------------------------------------------------------------
+	void solve();
+};
+
+#endif // LL_LLJOINTSOLVERRP3_H
+