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MdtBclContactParams.h

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#ifndef _MDTBCLCONTACTPARAMS_H
#define _MDTBCLCONTACTPARAMS_H
/*
  Copyright 2000 MathEngine

  $Name: t-release-0-0-5-msvcrt $

  $Id: MdtBclContactParams.h,v 1.3 2000/07/20 15:45:18 gilesc Exp $
*/

/** @file
 * Constraint Library Contact Parameters.
 *
 * Definitions of the MdtBclContactParam struct used by MdtBcl Contact.
 * This includes friction, restitution, softness, slip, surface velocity etc.
 */


/**
 * MdtBcl Contact friction type enum.
 */
typedef enum
{
    /**
     * Frictionless contact.
     */
    MdtContactTypeFrictionZero,

    /**
     * Friction only along primary direction.
     */
    MdtContactTypeFriction1D,

    /**
     * Friction in both directions.
     */
    MdtContactTypeFriction2D,

    /**
     * Invalid contact type.
     */
    MdtContactTypeUnknown = -1
}
MdtContactType;



/**
 * MdtBcl Contact options enum.
 *
 * Contact options such as friction (slipperiness) and restitution
 * (bounciness).  Any bitwise combination of these options is valid for use
 * in 'MdtBclContact.direction'.
 *
 * @see MdtBclContact
 * @see MdtBclContactParams
 */
typedef enum
{
    /**
     * Use primary direction vector.
     *
     * Use \a MdtBclContact.direction vector for primary direction
     * (otherwise use auto).
     */
    MdtBclContactOptionUseDirection = 0x00001,

    /**
     * Use restitution at the contact.
     *
     * The restitution factor is specified in \a
     * MdtBclContactParams.restitution.
     */
    MdtBclContactOptionBounce = 0x00002,

    /**
     * Use a simple soft contact model..
     *
     * The softness factor is specified in \a MdtBclContactParams.softness.
     * This factor corresponds to 1/(h.k) in an undamped spring model,
     * where h is the timestep and k is the spring stiffness factor.
     */
    MdtBclContactOptionSoft = 0x00004,

    /**
     * Use a simple adhesive contact model.
     *
     * The maximum adhesive force is specified in \a
     * MdtBclContactParams.max_adhesive_force.
     */
    MdtBclContactOptionAdhesive = 0x00008,

    /**
     * Use a first order slip in the primary direction.
     *
     * The slip velocity is specified in \a MdtBclContactParams.slip1.
     */
    MdtBclContactOptionSlip1 = 0x00010,

    /**
     * Use a first order slip in the secondary direction.
     *
     * The slip velocity is specified in \a MdtBclContactParams.slip2.
     */
    MdtBclContactOptionSlip2 = 0x00020,

    /**
     * Use a surface velocity in the primary direction (like a conveyor belt
     * motion).
     *
     * The slide velocity is specified in \a MdtBclContactParams.slide1.
     */
    MdtBclContactOptionSlide1 = 0x00040,

    /**
     * Use a surface velocity in the secondary direction.
     *
     * The secondary slide velocity is specified in \a
     * MdtBclContactParams.slide1.
     */
    MdtBclContactOptionSlide2 = 0x00080
}
MdtBclContactOption;

/**
 * MdtBcl Friction model enum.
 *
 * Friction model to use along primary or secondary direction.
 */
typedef enum
{
    /**
     * Box-type friction model.
     */
    MdtFrictionModelBox,

    /**
     * Invalid friction model.
     */
    MdtFrictionModelUnknown = -1
}
MdtFrictionModel;

/**
 * MdtBcl Contact constraint parameters struct.
 *
 * If contact type is 1D friction - motion along secondary direction is
 * frictionless, and model2, slip2, slide2 and friction2 are ignored.
 *
 * @see MdtBclContactOption
 */
typedef struct
{
    /**
     * Contact type (zero, 1D or 2D friction).
     */
    MdtContactType type;        /* 0x00 */

    /** @var model1
     * Friction model to use along primary direction.
     */
    /** @var model2
     * Friction model to use along secondary direction.
     */
    MdtFrictionModel model1;
    MdtFrictionModel model2;

    /**
     * Bitwise combination of MdtBclContactOption's.
     *
     * @see MdtBclContactOption.
     */
    int options;

    /** @var restitution
     * Restitution parameter.
     */
    /** @var velThreshold
     * Minimum velocity for restitution.
     */
    /** @var softness
     * Contact softness parameter (soft mode).
     */
    /** @var max_adhesive_force
     * Contact maximum adhesive force parameter (adhesive mode).
     */
    MeReal restitution;          /* 0x10 */
    MeReal velThreshold;
    MeReal softness;
    MeReal max_adhesive_force;

    /** @var friction1
     * Max friction force in primary direction.
     */
    /** @var slip1
     * First order slip in primary direction.
     */
    /** @var friction2
     * Max friction force in secondary direction.
     */
    /** @var slip2
     * First order slip in primary direction.
     */
    MeReal friction1;           /* 0x20 */
    MeReal slip1;
    MeReal friction2;
    MeReal slip2;

    /** @var slide1
     * Surface velocity in primary direction.
     */
    /** @var slide2
     * Surface velocity in secondary direction.
     */
    MeReal slide1;              /* 0x30 */
    MeReal slide2;

    /**
     * Padding - not used.
     */
    int pad[2];
}
MdtBclContactParams;

#endif

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