物理引擎系统-ode

#ifdef _MSC_VER
#pragma warning(disable:4291)  // for VC++, no complaints about "no matching operator delete found"
#endif

// this source file is mostly concerned with the data structures, not the
// numerics.

#include "objects.h"
#include
#include "joint.h"
#include
#include
#include "step.h"
#include
#include

// misc defines
#define ALLOCA dALLOCA16

//****************************************************************************
// utility

static inline void initObject (dObject *obj, dxWorld *w)
{
  obj->world = w;
  obj->next = 0;
  obj->tome = 0;
  obj->userdata = 0;
  obj->tag = 0;
}

// add an object `obj' to the list who's head pointer is pointed to by `first'.

static inline void addObjectToList (dObject *obj, dObject **first)
{
  obj->next = *first;
  obj->tome = first;
  if (*first) (*first)->tome = &obj->next;
  (*first) = obj;
}

// remove the object from the linked list

static inline void removeObjectFromList (dObject *obj)
{
  if (obj->next) obj->next->tome = obj->tome;
  *(obj->tome) = obj->next;
  // safeguard
  obj->next = 0;
  obj->tome = 0;
}

// remove the joint from neighbour lists of all connected bodies

static void removeJointReferencesFromAttachedBodies (dxJoint *j)
{
  for (int i=0; i<2; i++) {
    dxBody *body = j->node[i].body;
    if (body) {
      dxJointNode *n = body->firstjoint;
      dxJointNode *last = 0;
      while (n) {
    if (n->joint == j) {
      if (last) last->next = n->next;
      else body->firstjoint = n->next;
      break;
    }
    last = n;
    n = n->next;
      }
    }
  }
  j->node[0].body = 0;
  j->node[0].next = 0;
  j->node[1].body = 0;
  j->node[1].next = 0;
}