--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/ode/inc/joint.h Tue Feb 02 01:00:49 2010 +0200
@@ -0,0 +1,338 @@
+/*************************************************************************
+ * *
+ * Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith. *
+ * All rights reserved. Email: russ@q12.org Web: www.q12.org *
+ * *
+ * This library is free software; you can redistribute it and/or *
+ * modify it under the terms of EITHER: *
+ * (1) The GNU Lesser General Public License as published by the Free *
+ * Software Foundation; either version 2.1 of the License, or (at *
+ * your option) any later version. The text of the GNU Lesser *
+ * General Public License is included with this library in the *
+ * file LICENSE.TXT. *
+ * (2) The BSD-style license that is included with this library in *
+ * the file LICENSE-BSD.TXT. *
+ * *
+ * This library is distributed in the hope that it will be useful, *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files *
+ * LICENSE.TXT and LICENSE-BSD.TXT for more details. *
+ * *
+ *************************************************************************/
+
+#ifndef _ODE_JOINT_H_
+#define _ODE_JOINT_H_
+
+
+#include "object.h"
+#include <ode/contact.h>
+#include "obstack.h"
+
+
+// joint flags
+enum {
+ // if this flag is set, the joint was allocated in a joint group
+ dJOINT_INGROUP = 1,
+
+ // if this flag is set, the joint was attached with arguments (0,body).
+ // our convention is to treat all attaches as (body,0), i.e. so node[0].body
+ // is always nonzero, so this flag records the fact that the arguments were
+ // swapped.
+ dJOINT_REVERSE = 2,
+
+ // if this flag is set, the joint can not have just one body attached to it,
+ // it must have either zero or two bodies attached.
+ dJOINT_TWOBODIES = 4
+};
+
+
+// there are two of these nodes in the joint, one for each connection to a
+// body. these are node of a linked list kept by each body of it's connecting
+// joints. but note that the body pointer in each node points to the body that
+// makes use of the *other* node, not this node. this trick makes it a bit
+// easier to traverse the body/joint graph.
+
+struct dxJointNode {
+ dxJoint *joint; // pointer to enclosing dxJoint object
+ dxBody *body; // *other* body this joint is connected to
+ dxJointNode *next; // next node in body's list of connected joints
+};
+
+
+struct dxJoint : public dObject {
+ // naming convention: the "first" body this is connected to is node[0].body,
+ // and the "second" body is node[1].body. if this joint is only connected
+ // to one body then the second body is 0.
+
+ // info returned by getInfo1 function. the constraint dimension is m (<=6).
+ // i.e. that is the total number of rows in the jacobian. `nub' is the
+ // number of unbounded variables (which have lo,hi = -/+ infinity).
+
+ struct Info1 {
+ int m,nub;
+ };
+
+ // info returned by getInfo2 function
+
+ struct Info2 {
+ // integrator parameters: frames per second (1/stepsize), default error
+ // reduction parameter (0..1).
+ dReal fps,erp;
+
+ // for the first and second body, pointers to two (linear and angular)
+ // n*3 jacobian sub matrices, stored by rows. these matrices will have
+ // been initialized to 0 on entry. if the second body is zero then the
+ // J2xx pointers may be 0.
+ dReal *J1l,*J1a,*J2l,*J2a;
+
+ // elements to jump from one row to the next in J's
+ int rowskip;
+
+ // right hand sides of the equation J*v = c + cfm * lambda. cfm is the
+ // "constraint force mixing" vector. c is set to zero on entry, cfm is
+ // set to a constant value (typically very small or zero) value on entry.
+ dReal *c,*cfm;
+
+ // lo and hi limits for variables (set to -/+ infinity on entry).
+ dReal *lo,*hi;
+
+ // findex vector for variables. see the LCP solver interface for a
+ // description of what this does. this is set to -1 on entry.
+ // note that the returned indexes are relative to the first index of
+ // the constraint.
+ int *findex;
+ };
+
+ // virtual function table: size of the joint structure, function pointers.
+ // we do it this way instead of using C++ virtual functions because
+ // sometimes we need to allocate joints ourself within a memory pool.
+
+ typedef void init_fn (dxJoint *joint);
+ typedef void getInfo1_fn (dxJoint *joint, Info1 *info);
+ typedef void getInfo2_fn (dxJoint *joint, Info2 *info);
+ struct Vtable {
+ int size;
+ init_fn *init;
+ getInfo1_fn *getInfo1;
+ getInfo2_fn *getInfo2;
+ int typenum; // a dJointTypeXXX type number
+ };
+
+ Vtable *vtable; // virtual function table
+ int flags; // dJOINT_xxx flags
+ dxJointNode node[2]; // connections to bodies. node[1].body can be 0
+ dJointFeedback *feedback; // optional feedback structure
+ dReal lambda[6]; // lambda generated by last step
+};
+
+
+// joint group. NOTE: any joints in the group that have their world destroyed
+// will have their world pointer set to 0.
+
+struct dxJointGroup : public dBase {
+ int num; // number of joints on the stack
+ dObStack stack; // a stack of (possibly differently sized) dxJoint
+}; // objects.
+
+
+// common limit and motor information for a single joint axis of movement
+struct dxJointLimitMotor {
+ dReal vel,fmax; // powered joint: velocity, max force
+ dReal lostop,histop; // joint limits, relative to initial position
+ dReal fudge_factor; // when powering away from joint limits
+ dReal normal_cfm; // cfm to use when not at a stop
+ dReal stop_erp,stop_cfm; // erp and cfm for when at joint limit
+ dReal bounce; // restitution factor
+ // variables used between getInfo1() and getInfo2()
+ int limit; // 0=free, 1=at lo limit, 2=at hi limit
+ dReal limit_err; // if at limit, amount over limit
+
+ void init (dxWorld *);
+ void set (int num, dReal value);
+ dReal get (int num);
+ int testRotationalLimit (dReal angle);
+ int addLimot (dxJoint *joint, dxJoint::Info2 *info, int row,
+ const dVector3 ax1, int rotational);
+};
+
+
+// ball and socket
+
+struct dxJointBall : public dxJoint {
+ dVector3 anchor1; // anchor w.r.t first body
+ dVector3 anchor2; // anchor w.r.t second body
+};
+extern struct dxJoint::Vtable __dball_vtable;
+
+
+// hinge
+
+struct dxJointHinge : public dxJoint {
+ dVector3 anchor1; // anchor w.r.t first body
+ dVector3 anchor2; // anchor w.r.t second body
+ dVector3 axis1; // axis w.r.t first body
+ dVector3 axis2; // axis w.r.t second body
+ dQuaternion qrel; // initial relative rotation body1 -> body2
+ dxJointLimitMotor limot; // limit and motor information
+};
+extern struct dxJoint::Vtable __dhinge_vtable;
+
+
+// universal
+
+struct dxJointUniversal : public dxJoint {
+ dVector3 anchor1; // anchor w.r.t first body
+ dVector3 anchor2; // anchor w.r.t second body
+ dVector3 axis1; // axis w.r.t first body
+ dVector3 axis2; // axis w.r.t second body
+ dQuaternion qrel1; // initial relative rotation body1 -> virtual cross piece
+ dQuaternion qrel2; // initial relative rotation virtual cross piece -> body2
+ dxJointLimitMotor limot1; // limit and motor information for axis1
+ dxJointLimitMotor limot2; // limit and motor information for axis2
+};
+extern struct dxJoint::Vtable __duniversal_vtable;
+
+
+/**
+ * The axisP must be perpendicular to axis2
+ * <PRE>
+ * +-------------+
+ * | x |
+ * +------------\+
+ * Prismatic articulation .. ..
+ * | .. ..
+ * \/ .. ..
+ * +--------------+ --| __.. .. anchor2
+ * | x | .....|.......(__) ..
+ * +--------------+ --| ^ <
+ * |----------------------->|
+ * Offset |--- Rotoide articulation
+ * </PRE>
+ */
+struct dxJointPR : public dxJoint {
+
+ dVector3 anchor2; ///< @brief Position of the rotoide articulation
+ ///< w.r.t second body.
+ ///< @note Position of body 2 in world frame +
+ ///< anchor2 in world frame give the position
+ ///< of the rotoide articulation
+ dVector3 axisR1; ///< axis of the rotoide articulation w.r.t first body.
+ ///< @note This is considered as axis1 from the parameter
+ ///< view.
+ dVector3 axisR2; ///< axis of the rotoide articulation w.r.t second body.
+ ///< @note This is considered also as axis1 from the
+ ///< parameter view
+ dVector3 axisP1; ///< axis for the prismatic articulation w.r.t first body.
+ ///< @note This is considered as axis2 in from the parameter
+ ///< view
+ dQuaternion qrel; ///< initial relative rotation body1 -> body2.
+ dVector3 offset; ///< @brief vector between the body1 and the rotoide
+ ///< articulation.
+ ///<
+ ///< Going from the first to the second in the frame
+ ///< of body1.
+ ///< That should be aligned with body1 center along axisP
+ ///< This is calculated whe the axis are set.
+ dxJointLimitMotor limotR; ///< limit and motor information for the rotoide articulation.
+ dxJointLimitMotor limotP; ///< limit and motor information for the prismatic articulation.
+};
+extern struct dxJoint::Vtable __dPR_vtable;
+
+
+
+// slider. if body2 is 0 then qrel is the absolute rotation of body1 and
+// offset is the position of body1 center along axis1.
+
+struct dxJointSlider : public dxJoint {
+ dVector3 axis1; // axis w.r.t first body
+ dQuaternion qrel; // initial relative rotation body1 -> body2
+ dVector3 offset; // point relative to body2 that should be
+ // aligned with body1 center along axis1
+ dxJointLimitMotor limot; // limit and motor information
+};
+extern struct dxJoint::Vtable __dslider_vtable;
+
+
+// contact
+
+struct dxJointContact : public dxJoint {
+ int the_m; // number of rows computed by getInfo1
+ dContact contact;
+};
+extern struct dxJoint::Vtable __dcontact_vtable;
+
+
+// hinge 2
+
+struct dxJointHinge2 : public dxJoint {
+ dVector3 anchor1; // anchor w.r.t first body
+ dVector3 anchor2; // anchor w.r.t second body
+ dVector3 axis1; // axis 1 w.r.t first body
+ dVector3 axis2; // axis 2 w.r.t second body
+ dReal c0,s0; // cos,sin of desired angle between axis 1,2
+ dVector3 v1,v2; // angle ref vectors embedded in first body
+ dxJointLimitMotor limot1; // limit+motor info for axis 1
+ dxJointLimitMotor limot2; // limit+motor info for axis 2
+ dReal susp_erp,susp_cfm; // suspension parameters (erp,cfm)
+};
+extern struct dxJoint::Vtable __dhinge2_vtable;
+
+
+// angular motor
+
+struct dxJointAMotor : public dxJoint {
+ int num; // number of axes (0..3)
+ int mode; // a dAMotorXXX constant
+ int rel[3]; // what the axes are relative to (global,b1,b2)
+ dVector3 axis[3]; // three axes
+ dxJointLimitMotor limot[3]; // limit+motor info for axes
+ dReal angle[3]; // user-supplied angles for axes
+ // these vectors are used for calculating euler angles
+ dVector3 reference1; // original axis[2], relative to body 1
+ dVector3 reference2; // original axis[0], relative to body 2
+};
+extern struct dxJoint::Vtable __damotor_vtable;
+
+
+struct dxJointLMotor : public dxJoint {
+ int num;
+ int rel[3];
+ dVector3 axis[3];
+ dxJointLimitMotor limot[3];
+};
+
+extern struct dxJoint::Vtable __dlmotor_vtable;
+
+
+// 2d joint, constrains to z == 0
+
+struct dxJointPlane2D : public dxJoint
+{
+ int row_motor_x;
+ int row_motor_y;
+ int row_motor_angle;
+ dxJointLimitMotor motor_x;
+ dxJointLimitMotor motor_y;
+ dxJointLimitMotor motor_angle;
+};
+
+extern struct dxJoint::Vtable __dplane2d_vtable;
+
+
+// fixed
+
+struct dxJointFixed : public dxJoint {
+ dQuaternion qrel; // initial relative rotation body1 -> body2
+ dVector3 offset; // relative offset between the bodies
+};
+extern struct dxJoint::Vtable __dfixed_vtable;
+
+
+// null joint, for testing only
+
+struct dxJointNull : public dxJoint {
+};
+extern struct dxJoint::Vtable __dnull_vtable;
+
+
+#endif