/*************************************************************************
 *                          D bindings for ODE                           *
 *                                                                       *
 *       C header port by Daniel "q66" Kolesa <quaker66@gmail.com>       *
 *                                                                       *
 * Open Dynamics Engine, Copyright (C) 2001-2003 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.                     *
 *                                                                       *
 *************************************************************************/

module deimos.ode.collision;

private
{
    import deimos.ode.common;
    import deimos.ode.collision_space;
    import deimos.ode.contact;

    import deimos.ode.odeinit;
}

extern (C):
nothrow:


/**
 * @defgroup collide Collision Detection
 *
 * ODE has two main components: a dynamics simulation engine and a collision
 * detection engine. The collision engine is given information about the
 * shape of each body. At each time step it figures out which bodies touch
 * each other and passes the resulting contact point information to the user.
 * The user in turn creates contact joints between bodies.
 *
 * Using ODE's collision detection is optional - an alternative collision
 * detection system can be used as long as it can supply the right kinds of
 * contact information.
 */


/* ************************************************************************ */
/* general functions */

/**
 * @brief Destroy a geom, removing it from any space.
 *
 * Destroy a geom, removing it from any space it is in first. This one
 * function destroys a geom of any type, but to create a geom you must call
 * a creation function for that type.
 *
 * When a space is destroyed, if its cleanup mode is 1 (the default) then all
 * the geoms in that space are automatically destroyed as well.
 *
 * @param geom the geom to be destroyed.
 * @ingroup collide
 */
void dGeomDestroy(dGeomID geom);


/**
 * @brief Set the user-defined data pointer stored in the geom.
 *
 * @param geom the geom to hold the data
 * @param data the data pointer to be stored
 * @ingroup collide
 */
void dGeomSetData(dGeomID geom, void* data);


/**
 * @brief Get the user-defined data pointer stored in the geom.
 *
 * @param geom the geom containing the data
 * @ingroup collide
 */
void* dGeomGetData(dGeomID geom);


/**
 * @brief Set the body associated with a placeable geom.
 *
 * Setting a body on a geom automatically combines the position vector and
 * rotation matrix of the body and geom, so that setting the position or
 * orientation of one will set the value for both objects. Setting a body
 * ID of zero gives the geom its own position and rotation, independent
 * from any body. If the geom was previously connected to a body then its
 * new independent position/rotation is set to the current position/rotation
 * of the body.
 *
 * Calling these functions on a non-placeable geom results in a runtime
 * error in the debug build of ODE.
 *
 * @param geom the geom to connect
 * @param body the body to attach to the geom
 * @ingroup collide
 */
void dGeomSetBody(dGeomID geom, dBodyID gbody);


/**
 * @brief Get the body associated with a placeable geom.
 * @param geom the geom to query.
 * @sa dGeomSetBody
 * @ingroup collide
 */
dBodyID dGeomGetBody(dGeomID geom);


/**
 * @brief Set the position vector of a placeable geom.
 *
 * If the geom is attached to a body, the body's position will also be changed.
 * Calling this function on a non-placeable geom results in a runtime error in
 * the debug build of ODE.
 *
 * @param geom the geom to set.
 * @param x the new X coordinate.
 * @param y the new Y coordinate.
 * @param z the new Z coordinate.
 * @sa dBodySetPosition
 * @ingroup collide
 */
void dGeomSetPosition(dGeomID geom, dReal x, dReal y, dReal z);


/**
 * @brief Set the rotation matrix of a placeable geom.
 *
 * If the geom is attached to a body, the body's rotation will also be changed.
 * Calling this function on a non-placeable geom results in a runtime error in
 * the debug build of ODE.
 *
 * @param geom the geom to set.
 * @param R the new rotation matrix.
 * @sa dBodySetRotation
 * @ingroup collide
 */
void dGeomSetRotation(dGeomID geom, in dMatrix3 R);


/**
 * @brief Set the rotation of a placeable geom.
 *
 * If the geom is attached to a body, the body's rotation will also be changed.
 *
 * Calling this function on a non-placeable geom results in a runtime error in
 * the debug build of ODE.
 *
 * @param geom the geom to set.
 * @param Q the new rotation.
 * @sa dBodySetQuaternion
 * @ingroup collide
 */
void dGeomSetQuaternion(dGeomID geom, in dQuaternion Q);


/**
 * @brief Get the position vector of a placeable geom.
 *
 * If the geom is attached to a body, the body's position will be returned.
 *
 * Calling this function on a non-placeable geom results in a runtime error in
 * the debug build of ODE.
 *
 * @param geom the geom to query.
 * @returns A pointer to the geom's position vector.
 * @remarks The returned value is a pointer to the geom's internal
 *          data structure. It is valid until any changes are made
 *          to the geom.
 * @sa dBodyGetPosition
 * @ingroup collide
 */
const(dReal)* dGeomGetPosition(dGeomID geom);


/**
 * @brief Copy the position of a geom into a vector.
 * @ingroup collide
 * @param geom  the geom to query
 * @param pos   a copy of the geom position
 * @sa dGeomGetPosition
 */
void dGeomCopyPosition(dGeomID geom, dVector3 pos);


/**
 * @brief Get the rotation matrix of a placeable geom.
 *
 * If the geom is attached to a body, the body's rotation will be returned.
 *
 * Calling this function on a non-placeable geom results in a runtime error in
 * the debug build of ODE.
 *
 * @param geom the geom to query.
 * @returns A pointer to the geom's rotation matrix.
 * @remarks The returned value is a pointer to the geom's internal
 *          data structure. It is valid until any changes are made
 *          to the geom.
 * @sa dBodyGetRotation
 * @ingroup collide
 */
const(dReal)* dGeomGetRotation(dGeomID geom);


/**
 * @brief Get the rotation matrix of a placeable geom.
 *
 * If the geom is attached to a body, the body's rotation will be returned.
 *
 * Calling this function on a non-placeable geom results in a runtime error in
 * the debug build of ODE.
 *
 * @param geom   the geom to query.
 * @param R      a copy of the geom rotation
 * @sa dGeomGetRotation
 * @ingroup collide
 */
void dGeomCopyRotation(dGeomID geom, dMatrix3 R);


/**
 * @brief Get the rotation quaternion of a placeable geom.
 *
 * If the geom is attached to a body, the body's quaternion will be returned.
 *
 * Calling this function on a non-placeable geom results in a runtime error in
 * the debug build of ODE.
 *
 * @param geom the geom to query.
 * @param result a copy of the rotation quaternion.
 * @sa dBodyGetQuaternion
 * @ingroup collide
 */
void dGeomGetQuaternion(dGeomID geom, dQuaternion result);


/**
 * @brief Return the axis-aligned bounding box.
 *
 * Return in aabb an axis aligned bounding box that surrounds the given geom.
 * The aabb array has elements (minx, maxx, miny, maxy, minz, maxz). If the
 * geom is a space, a bounding box that surrounds all contained geoms is
 * returned.
 *
 * This function may return a pre-computed cached bounding box, if it can
 * determine that the geom has not moved since the last time the bounding
 * box was computed.
 *
 * @param geom the geom to query
 * @param aabb the returned bounding box
 * @ingroup collide
 */
void dGeomGetAABB(dGeomID geom, ref dReal[6] aabb);


/**
 * @brief Determing if a geom is a space.
 * @param geom the geom to query
 * @returns Non-zero if the geom is a space, zero otherwise.
 * @ingroup collide
 */
int dGeomIsSpace(dGeomID geom);


/**
 * @brief Query for the space containing a particular geom.
 * @param geom the geom to query
 * @returns The space that contains the geom, or NULL if the geom is
 *          not contained by a space.
 * @ingroup collide
 */
dSpaceID dGeomGetSpace(dGeomID);


/**
 * @brief Given a geom, this returns its class.
 *
 * The ODE classes are:
 *  @li dSphereClass
 *  @li dBoxClass
 *  @li dCylinderClass
 *  @li dPlaneClass
 *  @li dRayClass
 *  @li dConvexClass
 *  @li dGeomTransformClass
 *  @li dTriMeshClass
 *  @li dSimpleSpaceClass
 *  @li dHashSpaceClass
 *  @li dQuadTreeSpaceClass
 *  @li dFirstUserClass
 *  @li dLastUserClass
 *
 * User-defined class will return their own number.
 *
 * @param geom the geom to query
 * @returns The geom class ID.
 * @ingroup collide
 */
int dGeomGetClass(dGeomID geom);


/**
 * @brief Set the "category" bitfield for the given geom.
 *
 * The category bitfield is used by spaces to govern which geoms will
 * interact with each other. The bitfield is guaranteed to be at least
 * 32 bits wide. The default category values for newly created geoms
 * have all bits set.
 *
 * @param geom the geom to set
 * @param bits the new bitfield value
 * @ingroup collide
 */
void dGeomSetCategoryBits(dGeomID geom, c_ulong bits);


/**
 * @brief Set the "collide" bitfield for the given geom.
 *
 * The collide bitfield is used by spaces to govern which geoms will
 * interact with each other. The bitfield is guaranteed to be at least
 * 32 bits wide. The default category values for newly created geoms
 * have all bits set.
 *
 * @param geom the geom to set
 * @param bits the new bitfield value
 * @ingroup collide
 */
void dGeomSetCollideBits(dGeomID geom, c_ulong bits);


/**
 * @brief Get the "category" bitfield for the given geom.
 *
 * @param geom the geom to set
 * @param bits the new bitfield value
 * @sa dGeomSetCategoryBits
 * @ingroup collide
 */
c_ulong dGeomGetCategoryBits(dGeomID);


/**
 * @brief Get the "collide" bitfield for the given geom.
 *
 * @param geom the geom to set
 * @param bits the new bitfield value
 * @sa dGeomSetCollideBits
 * @ingroup collide
 */
c_ulong dGeomGetCollideBits(dGeomID);


/**
 * @brief Enable a geom.
 *
 * Disabled geoms are completely ignored by dSpaceCollide and dSpaceCollide2,
 * although they can still be members of a space. New geoms are created in
 * the enabled state.
 *
 * @param geom   the geom to enable
 * @sa dGeomDisable
 * @sa dGeomIsEnabled
 * @ingroup collide
 */
void dGeomEnable(dGeomID geom);


/**
 * @brief Disable a geom.
 *
 * Disabled geoms are completely ignored by dSpaceCollide and dSpaceCollide2,
 * although they can still be members of a space. New geoms are created in
 * the enabled state.
 *
 * @param geom   the geom to disable
 * @sa dGeomDisable
 * @sa dGeomIsEnabled
 * @ingroup collide
 */
void dGeomDisable(dGeomID geom);


/**
 * @brief Check to see if a geom is enabled.
 *
 * Disabled geoms are completely ignored by dSpaceCollide and dSpaceCollide2,
 * although they can still be members of a space. New geoms are created in
 * the enabled state.
 *
 * @param geom   the geom to query
 * @returns Non-zero if the geom is enabled, zero otherwise.
 * @sa dGeomDisable
 * @sa dGeomIsEnabled
 * @ingroup collide
 */
int dGeomIsEnabled(dGeomID geom);

enum
{
    dGeomCommonControlClass = 0,
    dGeomColliderControlClass = 1
}

enum
{
    dGeomCommonAnyControlCode = 0,

    dGeomColliderSetMergeSphereContactsControlCode = 1,
    dGeomColliderGetMergeSphereContactsControlCode = 2
}

enum
{
    dGeomColliderMergeContactsValue__Default = 0, // Used with Set... to restore default value
    dGeomColliderMergeContactsValue_None = 1,
    dGeomColliderMergeContactsValue_Normals = 2,
    dGeomColliderMergeContactsValue_Full = 3
}

/**
 * @brief Execute low level control operation for geometry.
 *
 * The variable the dataSize points to must be initialized before the call.
 * If the size does not match the one expected for the control class/code function
 * changes it to the size expected and returns failure. This implies the function 
 * can be called with NULL data and zero size to test if control class/code is supported
 * and obtain required data size for it.
 *
 * dGeomCommonAnyControlCode applies to any control class and returns success if 
 * at least one control code is available for the given class with given geom.
 *
 * Currently there are the folliwing control classes supported:
 *  @li dGeomColliderControlClass
 *
 * For dGeomColliderControlClass there are the following codes available:
 *  @li dGeomColliderSetMergeSphereContactsControlCode (arg of type int, dGeomColliderMergeContactsValue_*)
 *  @li dGeomColliderGetMergeSphereContactsControlCode (arg of type int, dGeomColliderMergeContactsValue_*)
 *
 * @param geom   the geom to control
 * @param controlClass   the control class
 * @param controlCode   the control code for the class
 * @param dataValue   the control argument pointer
 * @param dataSize   the control argument size provided or expected
 * @returns Boolean execution status
 * @ingroup collide
 */
int dGeomLowLevelControl(dGeomID geom, int controlClass, int controlCode, void* dataValue, int* dataSize);


/**
 * @brief Get world position of a relative point on geom.
 *
 * Calling this function on a non-placeable geom results in the same point being
 * returned.
 *
 * @ingroup collide
 * @param result will contain the result.
 */
void dGeomGetRelPointPos(dGeomID geom, dReal px, dReal py, dReal pz, dVector3 result);

/**
 * @brief takes a point in global coordinates and returns
 * the point's position in geom-relative coordinates.
 *
 * Calling this function on a non-placeable geom results in the same point being
 * returned.
 *
 * @remarks
 * This is the inverse of dGeomGetRelPointPos()
 * @ingroup collide
 * @param result will contain the result.
 */
void dGeomGetPosRelPoint(dGeomID geom, dReal px, dReal py, dReal pz, dVector3 result);

/**
 * @brief Convert from geom-local to world coordinates.
 *
 * Calling this function on a non-placeable geom results in the same vector being
 * returned.
 *
 * @ingroup collide
 * @param result will contain the result.
 */
void dGeomVectorToWorld(dGeomID geom, dReal px, dReal py, dReal pz, dVector3 result);

/**
 * @brief Convert from world to geom-local coordinates.
 *
 * Calling this function on a non-placeable geom results in the same vector being
 * returned.
 *
 * @ingroup collide
 * @param result will contain the result.
 */
void dGeomVectorFromWorld(dGeomID geom, dReal px, dReal py, dReal pz, dVector3 result);


/* ************************************************************************ */
/* geom offset from body */

/**
 * @brief Set the local offset position of a geom from its body.
 *
 * Sets the geom's positional offset in local coordinates.
 * After this call, the geom will be at a new position determined from the
 * body's position and the offset.
 * The geom must be attached to a body.
 * If the geom did not have an offset, it is automatically created.
 *
 * @param geom the geom to set.
 * @param x the new X coordinate.
 * @param y the new Y coordinate.
 * @param z the new Z coordinate.
 * @ingroup collide
 */
void dGeomSetOffsetPosition(dGeomID geom, dReal x, dReal y, dReal z);


/**
 * @brief Set the local offset rotation matrix of a geom from its body.
 *
 * Sets the geom's rotational offset in local coordinates.
 * After this call, the geom will be at a new position determined from the
 * body's position and the offset.
 * The geom must be attached to a body.
 * If the geom did not have an offset, it is automatically created.
 *
 * @param geom the geom to set.
 * @param R the new rotation matrix.
 * @ingroup collide
 */
void dGeomSetOffsetRotation(dGeomID geom, in dMatrix3 R);


/**
 * @brief Set the local offset rotation of a geom from its body.
 *
 * Sets the geom's rotational offset in local coordinates.
 * After this call, the geom will be at a new position determined from the
 * body's position and the offset.
 * The geom must be attached to a body.
 * If the geom did not have an offset, it is automatically created.
 *
 * @param geom the geom to set.
 * @param Q the new rotation.
 * @ingroup collide
 */
void dGeomSetOffsetQuaternion(dGeomID geom, in dQuaternion Q);


/**
 * @brief Set the offset position of a geom from its body.
 *
 * Sets the geom's positional offset to move it to the new world
 * coordinates.
 * After this call, the geom will be at the world position passed in,
 * and the offset will be the difference from the current body position.
 * The geom must be attached to a body.
 * If the geom did not have an offset, it is automatically created.
 *
 * @param geom the geom to set.
 * @param x the new X coordinate.
 * @param y the new Y coordinate.
 * @param z the new Z coordinate.
 * @ingroup collide
 */
void dGeomSetOffsetWorldPosition(dGeomID geom, dReal x, dReal y, dReal z);


/**
 * @brief Set the offset rotation of a geom from its body.
 *
 * Sets the geom's rotational offset to orient it to the new world
 * rotation matrix.
 * After this call, the geom will be at the world orientation passed in,
 * and the offset will be the difference from the current body orientation.
 * The geom must be attached to a body.
 * If the geom did not have an offset, it is automatically created.
 *
 * @param geom the geom to set.
 * @param R the new rotation matrix.
 * @ingroup collide
 */
void dGeomSetOffsetWorldRotation(dGeomID geom, in dMatrix3 R);


/**
 * @brief Set the offset rotation of a geom from its body.
 *
 * Sets the geom's rotational offset to orient it to the new world
 * rotation matrix.
 * After this call, the geom will be at the world orientation passed in,
 * and the offset will be the difference from the current body orientation.
 * The geom must be attached to a body.
 * If the geom did not have an offset, it is automatically created.
 *
 * @param geom the geom to set.
 * @param Q the new rotation.
 * @ingroup collide
 */
void dGeomSetOffsetWorldQuaternion(dGeomID geom, in dQuaternion);


/**
 * @brief Clear any offset from the geom.
 *
 * If the geom has an offset, it is eliminated and the geom is
 * repositioned at the body's position.  If the geom has no offset,
 * this function does nothing.
 * This is more efficient than calling dGeomSetOffsetPosition(zero)
 * and dGeomSetOffsetRotation(identiy), because this function actually
 * eliminates the offset, rather than leaving it as the identity transform.
 *
 * @param geom the geom to have its offset destroyed.
 * @ingroup collide
 */
void dGeomClearOffset(dGeomID geom);


/**
 * @brief Check to see whether the geom has an offset.
 *
 * This function will return non-zero if the offset has been created.
 * Note that there is a difference between a geom with no offset,
 * and a geom with an offset that is the identity transform.
 * In the latter case, although the observed behaviour is identical,
 * there is a unnecessary computation involved because the geom will
 * be applying the transform whenever it needs to recalculate its world
 * position.
 *
 * @param geom the geom to query.
 * @returns Non-zero if the geom has an offset, zero otherwise.
 * @ingroup collide
 */
int dGeomIsOffset(dGeomID geom);


/**
 * @brief Get the offset position vector of a geom.
 *
 * Returns the positional offset of the geom in local coordinates.
 * If the geom has no offset, this function returns the zero vector.
 *
 * @param geom the geom to query.
 * @returns A pointer to the geom's offset vector.
 * @remarks The returned value is a pointer to the geom's internal
 *          data structure. It is valid until any changes are made
 *          to the geom.
 * @ingroup collide
 */
const(dReal)* dGeomGetOffsetPosition(dGeomID geom);


/**
 * @brief Copy the offset position vector of a geom.
 *
 * Returns the positional offset of the geom in local coordinates.
 * If the geom has no offset, this function returns the zero vector.
 *
 * @param geom   the geom to query.
 * @param pos    returns the offset position
 * @ingroup collide
 */
void dGeomCopyOffsetPosition(dGeomID geom, dVector3 pos);


/**
 * @brief Get the offset rotation matrix of a geom.
 *
 * Returns the rotational offset of the geom in local coordinates.
 * If the geom has no offset, this function returns the identity
 * matrix.
 *
 * @param geom the geom to query.
 * @returns A pointer to the geom's offset rotation matrix.
 * @remarks The returned value is a pointer to the geom's internal
 *          data structure. It is valid until any changes are made
 *          to the geom.
 * @ingroup collide
 */
const(dReal)* dGeomGetOffsetRotation(dGeomID geom);


/**
 * @brief Copy the offset rotation matrix of a geom.
 *
 * Returns the rotational offset of the geom in local coordinates.
 * If the geom has no offset, this function returns the identity
 * matrix.
 *
 * @param geom   the geom to query.
 * @param R      returns the rotation matrix.
 * @ingroup collide
 */
void dGeomCopyOffsetRotation(dGeomID geom, dMatrix3 R);


/**
 * @brief Get the offset rotation quaternion of a geom.
 *
 * Returns the rotation offset of the geom as a quaternion.
 * If the geom has no offset, the identity quaternion is returned.
 *
 * @param geom the geom to query.
 * @param result a copy of the rotation quaternion.
 * @ingroup collide
 */
void dGeomGetOffsetQuaternion(dGeomID geom, dQuaternion result);


/* ************************************************************************ */
/* collision detection */

/*
 *    Just generate any contacts (disables any contact refining).
 */
enum CONTACTS_UNIMPORTANT = 0x80000000;

/**
 *
 * @brief Given two geoms o1 and o2 that potentially intersect,
 * generate contact information for them.
 *
 * Internally, this just calls the correct class-specific collision
 * functions for o1 and o2.
 *
 * @param o1 The first geom to test.
 * @param o2 The second geom to test.
 *
 * @param flags The flags specify how contacts should be generated if
 * the geoms touch. The lower 16 bits of flags is an integer that
 * specifies the maximum number of contact points to generate. You must
 * ask for at least one contact. 
 * Additionally, following bits may be set:
 * CONTACTS_UNIMPORTANT -- just generate any contacts (skip contact refining).
 * All other bits in flags must be set to zero. In the future the other bits 
 * may be used to select from different contact generation strategies.
 *
 * @param contact Points to an array of dContactGeom structures. The array
 * must be able to hold at least the maximum number of contacts. These
 * dContactGeom structures may be embedded within larger structures in the
 * array -- the skip parameter is the byte offset from one dContactGeom to
 * the next in the array. If skip is sizeof(dContactGeom) then contact
 * points to a normal (C-style) array. It is an error for skip to be smaller
 * than sizeof(dContactGeom).
 *
 * @returns If the geoms intersect, this function returns the number of contact
 * points generated (and updates the contact array), otherwise it returns 0
 * (and the contact array is not touched).
 *
 * @remarks If a space is passed as o1 or o2 then this function will collide
 * all objects contained in o1 with all objects contained in o2, and return
 * the resulting contact points. This method for colliding spaces with geoms
 * (or spaces with spaces) provides no user control over the individual
 * collisions. To get that control, use dSpaceCollide or dSpaceCollide2 instead.
 *
 * @remarks If o1 and o2 are the same geom then this function will do nothing
 * and return 0. Technically speaking an object intersects with itself, but it
 * is not useful to find contact points in this case.
 *
 * @remarks This function does not care if o1 and o2 are in the same space or not
 * (or indeed if they are in any space at all).
 *
 * @ingroup collide
 */
int dCollide(dGeomID o1, dGeomID o2, int flags, dContactGeom* contact, int skip);

/**
 * @brief Determines which pairs of geoms in a space may potentially intersect,
 * and calls the callback function for each candidate pair.
 *
 * @param space The space to test.
 *
 * @param data Passed from dSpaceCollide directly to the callback
 * function. Its meaning is user defined. The o1 and o2 arguments are the
 * geoms that may be near each other.
 *
 * @param callback A callback function is of type @ref dNearCallback.
 *
 * @remarks Other spaces that are contained within the colliding space are
 * not treated specially, i.e. they are not recursed into. The callback
 * function may be passed these contained spaces as one or both geom
 * arguments.
 *
 * @remarks dSpaceCollide() is guaranteed to pass all intersecting geom
 * pairs to the callback function, but may also pass close but
 * non-intersecting pairs. The number of these calls depends on the
 * internal algorithms used by the space. Thus you should not expect
 * that dCollide will return contacts for every pair passed to the
 * callback.
 *
 * @sa dSpaceCollide2
 * @ingroup collide
 */
void dSpaceCollide(dSpaceID space, void* data, dNearCallback* callback);


/**
 * @brief Determines which geoms from one space may potentially intersect with 
 * geoms from another space, and calls the callback function for each candidate 
 * pair. 
 *
 * @param space1 The first space to test.
 *
 * @param space2 The second space to test.
 *
 * @param data Passed from dSpaceCollide directly to the callback
 * function. Its meaning is user defined. The o1 and o2 arguments are the
 * geoms that may be near each other.
 *
 * @param callback A callback function is of type @ref dNearCallback.
 *
 * @remarks This function can also test a single non-space geom against a 
 * space. This function is useful when there is a collision hierarchy, i.e. 
 * when there are spaces that contain other spaces.
 *
 * @remarks Other spaces that are contained within the colliding space are
 * not treated specially, i.e. they are not recursed into. The callback
 * function may be passed these contained spaces as one or both geom
 * arguments.
 *
 * @remarks Sublevel value of space affects how the spaces are iterated.
 * Both spaces are recursed only if their sublevels match. Otherwise, only
 * the space with greater sublevel is recursed and the one with lesser sublevel
 * is used as a geom itself.
 *
 * @remarks dSpaceCollide2() is guaranteed to pass all intersecting geom
 * pairs to the callback function, but may also pass close but
 * non-intersecting pairs. The number of these calls depends on the
 * internal algorithms used by the space. Thus you should not expect
 * that dCollide will return contacts for every pair passed to the
 * callback.
 *
 * @sa dSpaceCollide
 * @sa dSpaceSetSublevel
 * @ingroup collide
 */
void dSpaceCollide2(dGeomID space1, dGeomID space2, void* data, dNearCallback* callback);


/* ************************************************************************ */
/* standard classes */

/* the maximum number of user classes that are supported */
enum dMaxUserClasses = 4;

/* class numbers - each geometry object needs a unique number */
enum
{
    dSphereClass = 0,
    dBoxClass,
    dCapsuleClass,
    dCylinderClass,
    dPlaneClass,
    dRayClass,
    dConvexClass,
    dGeomTransformClass,
    dTriMeshClass,
    dHeightFieldClass,

    dFirstSpaceClass,
    dSimpleSpaceClass = dFirstSpaceClass,
    dHashSpaceClass,
    dSweepAndPruneSpaceClass, // SAP
    dQuadTreeClass,
    dLastSpaceClass = dQuadTreeClass,

    dFirstUserClass,
    dLastUserClass = dFirstUserClass + dMaxUserClasses - 1,
    dGeomNumClasses
}


/**
 * @defgroup collide_sphere Sphere Class
 * @ingroup collide
 */

/**
 * @brief Create a sphere geom of the given radius, and return its ID. 
 *
 * @param space   a space to contain the new geom. May be null.
 * @param radius  the radius of the sphere.
 *
 * @returns A new sphere geom.
 *
 * @remarks The point of reference for a sphere is its center.
 *
 * @sa dGeomDestroy
 * @sa dGeomSphereSetRadius
 * @ingroup collide_sphere
 */
dGeomID dCreateSphere(dSpaceID space, dReal radius);


/**
 * @brief Set the radius of a sphere geom.
 *
 * @param sphere  the sphere to set.
 * @param radius  the new radius.
 *
 * @sa dGeomSphereGetRadius
 * @ingroup collide_sphere
 */
void dGeomSphereSetRadius(dGeomID sphere, dReal radius);


/**
 * @brief Retrieves the radius of a sphere geom.
 *
 * @param sphere  the sphere to query.
 *
 * @sa dGeomSphereSetRadius
 * @ingroup collide_sphere
 */
dReal dGeomSphereGetRadius(dGeomID sphere);


/**
 * @brief Calculate the depth of the a given point within a sphere.
 *
 * @param sphere  the sphere to query.
 * @param x       the X coordinate of the point.
 * @param y       the Y coordinate of the point.
 * @param z       the Z coordinate of the point.
 *
 * @returns The depth of the point. Points inside the sphere will have a 
 * positive depth, points outside it will have a negative depth, and points
 * on the surface will have a depth of zero.
 *
 * @ingroup collide_sphere
 */
dReal dGeomSpherePointDepth(dGeomID sphere, dReal x, dReal y, dReal z);


//--> Convex Functions
dGeomID dCreateConvex(
    dSpaceID space, dReal* _planes, uint _planecount, dReal* _points,
    uint _pointcount, uint* _polygons
);

void dGeomSetConvex(
    dGeomID g, dReal* _planes, uint _count, dReal* _points,
    uint _pointcount, uint* _polygons
);
//<-- Convex Functions

/**
 * @defgroup collide_box Box Class
 * @ingroup collide
 */

/**
 * @brief Create a box geom with the provided side lengths.
 *
 * @param space   a space to contain the new geom. May be null.
 * @param lx      the length of the box along the X axis
 * @param ly      the length of the box along the Y axis
 * @param lz      the length of the box along the Z axis
 *
 * @returns A new box geom.
 *
 * @remarks The point of reference for a box is its center.
 *
 * @sa dGeomDestroy
 * @sa dGeomBoxSetLengths
 * @ingroup collide_box
 */
dGeomID dCreateBox(dSpaceID space, dReal lx, dReal ly, dReal lz);


/**
 * @brief Set the side lengths of the given box.
 *
 * @param box  the box to set
 * @param lx      the length of the box along the X axis
 * @param ly      the length of the box along the Y axis
 * @param lz      the length of the box along the Z axis
 *
 * @sa dGeomBoxGetLengths
 * @ingroup collide_box
 */
void dGeomBoxSetLengths(dGeomID box, dReal lx, dReal ly, dReal lz);


/**
 * @brief Get the side lengths of a box.
 *
 * @param box     the box to query
 * @param result  the returned side lengths
 *
 * @sa dGeomBoxSetLengths
 * @ingroup collide_box
 */
void dGeomBoxGetLengths(dGeomID box, dVector3 result);


/**
 * @brief Return the depth of a point in a box.
 * 
 * @param box  the box to query
 * @param x    the X coordinate of the point to test.
 * @param y    the Y coordinate of the point to test.
 * @param z    the Z coordinate of the point to test.
 *
 * @returns The depth of the point. Points inside the box will have a 
 * positive depth, points outside it will have a negative depth, and points
 * on the surface will have a depth of zero.
 */
dReal dGeomBoxPointDepth(dGeomID box, dReal x, dReal y, dReal z);


dGeomID dCreatePlane(dSpaceID space, dReal a, dReal b, dReal c, dReal d);
void dGeomPlaneSetParams(dGeomID plane, dReal a, dReal b, dReal c, dReal d);
void dGeomPlaneGetParams(dGeomID plane, dVector4 result);
dReal dGeomPlanePointDepth(dGeomID plane, dReal x, dReal y, dReal z);

dGeomID dCreateCapsule (dSpaceID space, dReal radius, dReal length);
void dGeomCapsuleSetParams (dGeomID ccylinder, dReal radius, dReal length);
void dGeomCapsuleGetParams (dGeomID ccylinder, dReal* radius, dReal* length);
dReal dGeomCapsulePointDepth (dGeomID ccylinder, dReal x, dReal y, dReal z);

// For now we want to have a backwards compatible C-API, note: C++ API is not.
alias dCreateCapsule dCreateCCylinder;
alias dGeomCapsuleSetParams dGeomCCylinderSetParams;
alias dGeomCapsuleGetParams dGeomCCylinderGetParams;
alias dGeomCapsulePointDepth dGeomCCylinderPointDepth;
alias dCapsuleClass dCCylinderClass;

dGeomID dCreateCylinder(dSpaceID space, dReal radius, dReal length);
void dGeomCylinderSetParams(dGeomID cylinder, dReal radius, dReal length);
void dGeomCylinderGetParams(dGeomID cylinder, dReal* radius, dReal* length);

dGeomID dCreateRay(dSpaceID space, dReal length);
void dGeomRaySetLength(dGeomID ray, dReal length);
dReal dGeomRayGetLength(dGeomID ray);
void dGeomRaySet(dGeomID ray, dReal px, dReal py, dReal pz, dReal dx, dReal dy, dReal dz);
void dGeomRayGet(dGeomID ray, dVector3 start, dVector3 dir);

/*
 * Set/get ray flags that influence ray collision detection.
 * These flags are currently only noticed by the trimesh collider, because
 * they can make a major differences there.
 */
void dGeomRaySetParams(dGeomID g, int FirstContact, int BackfaceCull);
void dGeomRayGetParams(dGeomID g, int* FirstContact, int* BackfaceCull);
void dGeomRaySetClosestHit(dGeomID g, int closestHit);
int dGeomRayGetClosestHit(dGeomID g);

public import deimos.ode.collision_trimesh;

dGeomID dCreateGeomTransform(dSpaceID space);
void dGeomTransformSetGeom(dGeomID g, dGeomID obj);
dGeomID dGeomTransformGetGeom(dGeomID g);
void dGeomTransformSetCleanup(dGeomID g, int mode);
int dGeomTransformGetCleanup(dGeomID g);
void dGeomTransformSetInfo(dGeomID g, int mode);
int dGeomTransformGetInfo(dGeomID g);

/* ************************************************************************ */
/* heightfield functions */

// Data storage for heightfield data.
struct dxHeightfieldData;
alias dxHeightfieldData* dHeightfieldDataID;

/**
 * @brief Callback prototype
 *
 * Used by the callback heightfield data type to sample a height for a
 * given cell position.
 *
 * @param p_user_data User data specified when creating the dHeightfieldDataID
 * @param x The index of a sample in the local x axis. It is a value
 * in the range zero to ( nWidthSamples - 1 ).
 * @param x The index of a sample in the local z axis. It is a value
 * in the range zero to ( nDepthSamples - 1 ).
 *
 * @return The sample height which is then scaled and offset using the
 * values specified when the heightfield data was created.
 *
 * @ingroup collide
 */
alias dReal function(void* p_user_data, int x, int z) dHeightfieldGetHeight;

/**
 * @brief Creates a heightfield geom.
 *
 * Uses the information in the given dHeightfieldDataID to construct
 * a geom representing a heightfield in a collision space.
 *
 * @param space The space to add the geom to.
 * @param data The dHeightfieldDataID created by dGeomHeightfieldDataCreate and
 * setup by dGeomHeightfieldDataBuildCallback, dGeomHeightfieldDataBuildByte,
 * dGeomHeightfieldDataBuildShort or dGeomHeightfieldDataBuildFloat.
 * @param bPlaceable If non-zero this geom can be transformed in the world using the
 * usual functions such as dGeomSetPosition and dGeomSetRotation. If the geom is
 * not set as placeable, then it uses a fixed orientation where the global y axis
 * represents the dynamic 'height' of the heightfield.
 *
 * @return A geom id to reference this geom in other calls.
 *
 * @ingroup collide
 */
dGeomID dCreateHeightfield(dSpaceID space, dHeightfieldDataID data, int bPlaceable);

/**
 * @brief Creates a new empty dHeightfieldDataID.
 *
 * Allocates a new dHeightfieldDataID and returns it. You must call
 * dGeomHeightfieldDataDestroy to destroy it after the geom has been removed.
 * The dHeightfieldDataID value is used when specifying a data format type.
 *
 * @return A dHeightfieldDataID for use with dGeomHeightfieldDataBuildCallback,
 * dGeomHeightfieldDataBuildByte, dGeomHeightfieldDataBuildShort or
 * dGeomHeightfieldDataBuildFloat.
 * @ingroup collide
 */
dHeightfieldDataID dGeomHeightfieldDataCreate();

/**
 * @brief Destroys a dHeightfieldDataID.
 *
 * Deallocates a given dHeightfieldDataID and all managed resources.
 *
 * @param d A dHeightfieldDataID created by dGeomHeightfieldDataCreate
 * @ingroup collide
 */
void dGeomHeightfieldDataDestroy(dHeightfieldDataID d);

/**
 * @brief Configures a dHeightfieldDataID to use a callback to
 * retrieve height data.
 *
 * Before a dHeightfieldDataID can be used by a geom it must be
 * configured to specify the format of the height data.
 * This call specifies that the heightfield data is computed by
 * the user and it should use the given callback when determining
 * the height of a given element of it's shape.
 *
 * @param d A new dHeightfieldDataID created by dGeomHeightfieldDataCreate
 *
 * @param width Specifies the total 'width' of the heightfield along
 * the geom's local x axis.
 * @param depth Specifies the total 'depth' of the heightfield along
 * the geom's local z axis.
 *
 * @param widthSamples Specifies the number of vertices to sample
 * along the width of the heightfield. Each vertex has a corresponding
 * height value which forms the overall shape.
 * Naturally this value must be at least two or more.
 * @param depthSamples Specifies the number of vertices to sample
 * along the depth of the heightfield.
 *
 * @param scale A uniform scale applied to all raw height data.
 * @param offset An offset applied to the scaled height data.
 *
 * @param thickness A value subtracted from the lowest height
 * value which in effect adds an additional cuboid to the base of the
 * heightfield. This is used to prevent geoms from looping under the
 * desired terrain and not registering as a collision. Note that the
 * thickness is not affected by the scale or offset parameters.
 *
 * @param bWrap If non-zero the heightfield will infinitely tile in both
 * directions along the local x and z axes. If zero the heightfield is
 * bounded from zero to width in the local x axis, and zero to depth in
 * the local z axis.
 *
 * @ingroup collide
 */
void dGeomHeightfieldDataBuildCallback(
    dHeightfieldDataID d, void* pUserData, dHeightfieldGetHeight pCallback,
    dReal width, dReal depth, int widthSamples, int depthSamples, dReal scale,
    dReal offset, dReal thickness, int bWrap
);

/**
 * @brief Configures a dHeightfieldDataID to use height data in byte format.
 *
 * Before a dHeightfieldDataID can be used by a geom it must be
 * configured to specify the format of the height data.
 * This call specifies that the heightfield data is stored as a rectangular
 * array of bytes (8 bit unsigned) representing the height at each sample point.
 *
 * @param d A new dHeightfieldDataID created by dGeomHeightfieldDataCreate
 *
 * @param pHeightData A pointer to the height data.
 * @param bCopyHeightData When non-zero the height data is copied to an
 * internal store. When zero the height data is accessed by reference and
 * so must persist throughout the lifetime of the heightfield.
 *
 * @param width Specifies the total 'width' of the heightfield along
 * the geom's local x axis.
 * @param depth Specifies the total 'depth' of the heightfield along
 * the geom's local z axis.
 *
 * @param widthSamples Specifies the number of vertices to sample
 * along the width of the heightfield. Each vertex has a corresponding
 * height value which forms the overall shape.
 * Naturally this value must be at least two or more.
 * @param depthSamples Specifies the number of vertices to sample
 * along the depth of the heightfield.
 *
 * @param scale A uniform scale applied to all raw height data.
 * @param offset An offset applied to the scaled height data.
 *
 * @param thickness A value subtracted from the lowest height
 * value which in effect adds an additional cuboid to the base of the
 * heightfield. This is used to prevent geoms from looping under the
 * desired terrain and not registering as a collision. Note that the
 * thickness is not affected by the scale or offset parameters.
 *
 * @param bWrap If non-zero the heightfield will infinitely tile in both
 * directions along the local x and z axes. If zero the heightfield is
 * bounded from zero to width in the local x axis, and zero to depth in
 * the local z axis.
 *
 * @ingroup collide
 */
void dGeomHeightfieldDataBuildByte(
    dHeightfieldDataID d, in ubyte* pHeightData, int bCopyHeightData,
    dReal width, dReal depth, int widthSamples, int depthSamples, dReal scale,
    dReal offset, dReal thickness, int bWrap
);

/**
 * @brief Configures a dHeightfieldDataID to use height data in short format.
 *
 * Before a dHeightfieldDataID can be used by a geom it must be
 * configured to specify the format of the height data.
 * This call specifies that the heightfield data is stored as a rectangular
 * array of shorts (16 bit signed) representing the height at each sample point.
 *
 * @param d A new dHeightfieldDataID created by dGeomHeightfieldDataCreate
 *
 * @param pHeightData A pointer to the height data.
 * @param bCopyHeightData When non-zero the height data is copied to an
 * internal store. When zero the height data is accessed by reference and
 * so must persist throughout the lifetime of the heightfield.
 *
 * @param width Specifies the total 'width' of the heightfield along
 * the geom's local x axis.
 * @param depth Specifies the total 'depth' of the heightfield along
 * the geom's local z axis.
 *
 * @param widthSamples Specifies the number of vertices to sample
 * along the width of the heightfield. Each vertex has a corresponding
 * height value which forms the overall shape.
 * Naturally this value must be at least two or more.
 * @param depthSamples Specifies the number of vertices to sample
 * along the depth of the heightfield.
 *
 * @param scale A uniform scale applied to all raw height data.
 * @param offset An offset applied to the scaled height data.
 *
 * @param thickness A value subtracted from the lowest height
 * value which in effect adds an additional cuboid to the base of the
 * heightfield. This is used to prevent geoms from looping under the
 * desired terrain and not registering as a collision. Note that the
 * thickness is not affected by the scale or offset parameters.
 *
 * @param bWrap If non-zero the heightfield will infinitely tile in both
 * directions along the local x and z axes. If zero the heightfield is
 * bounded from zero to width in the local x axis, and zero to depth in
 * the local z axis.
 *
 * @ingroup collide
 */
void dGeomHeightfieldDataBuildShort(
    dHeightfieldDataID d, in short* pHeightData, int bCopyHeightData,
    dReal width, dReal depth, int widthSamples, int depthSamples, dReal scale,
    dReal offset, dReal thickness, int bWrap
);

/**
 * @brief Configures a dHeightfieldDataID to use height data in 
 * single precision floating point format.
 *
 * Before a dHeightfieldDataID can be used by a geom it must be
 * configured to specify the format of the height data.
 * This call specifies that the heightfield data is stored as a rectangular
 * array of single precision floats representing the height at each
 * sample point.
 *
 * @param d A new dHeightfieldDataID created by dGeomHeightfieldDataCreate
 *
 * @param pHeightData A pointer to the height data.
 * @param bCopyHeightData When non-zero the height data is copied to an
 * internal store. When zero the height data is accessed by reference and
 * so must persist throughout the lifetime of the heightfield.
 *
 * @param width Specifies the total 'width' of the heightfield along
 * the geom's local x axis.
 * @param depth Specifies the total 'depth' of the heightfield along
 * the geom's local z axis.
 *
 * @param widthSamples Specifies the number of vertices to sample
 * along the width of the heightfield. Each vertex has a corresponding
 * height value which forms the overall shape.
 * Naturally this value must be at least two or more.
 * @param depthSamples Specifies the number of vertices to sample
 * along the depth of the heightfield.
 *
 * @param scale A uniform scale applied to all raw height data.
 * @param offset An offset applied to the scaled height data.
 *
 * @param thickness A value subtracted from the lowest height
 * value which in effect adds an additional cuboid to the base of the
 * heightfield. This is used to prevent geoms from looping under the
 * desired terrain and not registering as a collision. Note that the
 * thickness is not affected by the scale or offset parameters.
 *
 * @param bWrap If non-zero the heightfield will infinitely tile in both
 * directions along the local x and z axes. If zero the heightfield is
 * bounded from zero to width in the local x axis, and zero to depth in
 * the local z axis.
 *
 * @ingroup collide
 */
void dGeomHeightfieldDataBuildSingle(
    dHeightfieldDataID d, in float* pHeightData, int bCopyHeightData,
    dReal width, dReal depth, int widthSamples, int depthSamples, dReal scale,
    dReal offset, dReal thickness, int bWrap
);

/**
 * @brief Configures a dHeightfieldDataID to use height data in 
 * double precision floating point format.
 *
 * Before a dHeightfieldDataID can be used by a geom it must be
 * configured to specify the format of the height data.
 * This call specifies that the heightfield data is stored as a rectangular
 * array of double precision floats representing the height at each
 * sample point.
 *
 * @param d A new dHeightfieldDataID created by dGeomHeightfieldDataCreate
 *
 * @param pHeightData A pointer to the height data.
 * @param bCopyHeightData When non-zero the height data is copied to an
 * internal store. When zero the height data is accessed by reference and
 * so must persist throughout the lifetime of the heightfield.
 *
 * @param width Specifies the total 'width' of the heightfield along
 * the geom's local x axis.
 * @param depth Specifies the total 'depth' of the heightfield along
 * the geom's local z axis.
 *
 * @param widthSamples Specifies the number of vertices to sample
 * along the width of the heightfield. Each vertex has a corresponding
 * height value which forms the overall shape.
 * Naturally this value must be at least two or more.
 * @param depthSamples Specifies the number of vertices to sample
 * along the depth of the heightfield.
 *
 * @param scale A uniform scale applied to all raw height data.
 * @param offset An offset applied to the scaled height data.
 *
 * @param thickness A value subtracted from the lowest height
 * value which in effect adds an additional cuboid to the base of the
 * heightfield. This is used to prevent geoms from looping under the
 * desired terrain and not registering as a collision. Note that the
 * thickness is not affected by the scale or offset parameters.
 *
 * @param bWrap If non-zero the heightfield will infinitely tile in both
 * directions along the local x and z axes. If zero the heightfield is
 * bounded from zero to width in the local x axis, and zero to depth in
 * the local z axis.
 *
 * @ingroup collide
 */
void dGeomHeightfieldDataBuildDouble(
    dHeightfieldDataID d, in double* pHeightData, int bCopyHeightData,
    dReal width, dReal depth, int widthSamples, int depthSamples, dReal scale,
    dReal offset, dReal thickness, int bWrap
);

/**
 * @brief Manually set the minimum and maximum height bounds.
 *
 * This call allows you to set explicit min / max values after initial
 * creation typically for callback heightfields which default to +/- infinity,
 * or those whose data has changed. This must be set prior to binding with a
 * geom, as the the AABB is not recomputed after it's first generation.
 *
 * @remarks The minimum and maximum values are used to compute the AABB
 * for the heightfield which is used for early rejection of collisions.
 * A close fit will yield a more efficient collision check.
 *
 * @param d A dHeightfieldDataID created by dGeomHeightfieldDataCreate
 * @param min_height The new minimum height value. Scale, offset and thickness is then applied.
 * @param max_height The new maximum height value. Scale and offset is then applied.
 * @ingroup collide
 */
void dGeomHeightfieldDataSetBounds(dHeightfieldDataID d, dReal minHeight, dReal maxHeight);


/**
 * @brief Assigns a dHeightfieldDataID to a heightfield geom.
 *
 * Associates the given dHeightfieldDataID with a heightfield geom.
 * This is done without affecting the GEOM_PLACEABLE flag.
 *
 * @param g A geom created by dCreateHeightfield
 * @param d A dHeightfieldDataID created by dGeomHeightfieldDataCreate
 * @ingroup collide
 */
void dGeomHeightfieldSetHeightfieldData(dGeomID g, dHeightfieldDataID d);


/**
 * @brief Gets the dHeightfieldDataID bound to a heightfield geom.
 *
 * Returns the dHeightfieldDataID associated with a heightfield geom.
 *
 * @param g A geom created by dCreateHeightfield
 * @return The dHeightfieldDataID which may be NULL if none was assigned.
 * @ingroup collide
 */
dHeightfieldDataID dGeomHeightfieldGetHeightfieldData(dGeomID g);



/* ************************************************************************ */
/* utility functions */

void dClosestLineSegmentPoints(
    in dVector3 a1, in dVector3 a2,
    in dVector3 b1, in dVector3 b2,
    dVector3 cp1, dVector3 cp2
);

int dBoxTouchesBox(
    in dVector3 _p1, in dMatrix3 R1, in dVector3 side1, in dVector3 _p2,
    in dMatrix3 R2, in dVector3 side2
);

// The meaning of flags parameter is the same as in dCollide()
int dBoxBox(
    in dVector3 p1, in dMatrix3 R1, in dVector3 side1, in dVector3 p2,
    in dMatrix3 R2, in dVector3 side2, dVector3 normal, dReal* depth,
    int* return_code, int flags, dContactGeom* contact, int skip
);

void dInfiniteAABB(dGeomID geom, ref dReal[6] aabb);


/* ************************************************************************ */
/* custom classes */

alias void function(dGeomID, ref dReal[6] aabb) dGetAABBFn;
alias int function(
    dGeomID o1, dGeomID o2, int flags, dContactGeom* contact, int skip
) dColliderFn;
alias dColliderFn function(int num) dGetColliderFnFn;
alias void function(dGeomID o) dGeomDtorFn;
alias int function(dGeomID o1, dGeomID o2, ref dReal[6] aabb) dAABBTestFn;

struct dGeomClass
{
    int bytes;
    dGetColliderFnFn collider;
    dGetAABBFn aabb;
    dAABBTestFn aabb_test;
    dGeomDtorFn dtor;
}

int dCreateGeomClass(in dGeomClass* classptr);
void* dGeomGetClassData(dGeomID);
dGeomID dCreateGeom(int classnum);

/**
 * @brief Sets a custom collider function for two geom classes. 
 *
 * @param i The first geom class handled by this collider
 * @param j The second geom class handled by this collider
 * @param fn The collider function to use to determine collisions.
 * @ingroup collide
 */
void dSetColliderOverride (int i, int j, dColliderFn* fn);