gls_moving_eye.h

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/*! \file
  \brief  The disti::GlsMovingEye class.

  \par Copyright Information

  Copyright (c) 2017 by The DiSTI Corporation.<br>
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  <br>
  All rights reserved.<br>

  This Software contains proprietary trade secrets of DiSTI and may not be
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  NO WARRANTY. THE SOFTWARE IS PROVIDED "AS-IS," WITHOUT WARRANTY OF ANY KIND,
AND ANY USE OF THIS SOFTWARE PRODUCT IS AT YOUR OWN RISK. TO THE MAXIMUM EXTENT
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AND CONDITIONS, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
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  LIMITATION OF LIABILITY. TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW,
IN NO EVENT SHALL DISTI OR ITS SUPPLIERS BE LIABLE FOR ANY SPECIAL, INCIDENTAL,
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*/
#ifndef INCLUDED_GLS_MOVING_EYE_H
#define INCLUDED_GLS_MOVING_EYE_H

#include <cstddef>
#include <queue>

#ifdef __VXWORKS__
#    define va_list std::va_list
#endif

#include "gls_cpp_lang_support.h"
#include "gls_eyepoint.h"

/// Provides support for creating DLLs
#if( defined( GLSGEN_EXPORT_GLSMOVINGEYE ) || defined( GLSGEN_IMPORT_GLSMOVINGEYE ) || defined( GLS_EXPORT_GENERATED ) || defined( GLS_IMPORT_GENERATED ) ) \
    && defined( _MSC_VER )
#    if defined( GLSGEN_EXPORT_GLSMOVINGEYE ) || defined( GLS_EXPORT_GENERATED )
#        define GLSGEN_GLSMOVINGEYE_EXPORT __declspec( dllexport )
#    else
#        define GLSGEN_GLSMOVINGEYE_EXPORT __declspec( dllimport )
#    endif
#else
#    define GLSGEN_GLSMOVINGEYE_EXPORT
#endif
///////////////////////////////////////////////////////////////////////////////

#define LIB_BASE_NAME "gls_moving_eye"
#include "gls_auto_lib.h"
#undef LIB_BASE_NAME

namespace disti
{
// SetValue enumerations
enum
{
    GLS_MOVINGEYE_EMIT_EVENT = GLS_EYEPOINT_VIEW_VECTORS + 1,
    GLS_MOVINGEYE_LOOK_AT_OBJECT,
    GLS_MOVINGEYE_MAX_SPEED,
    GLS_MOVINGEYE_MOVEMENT,
    GLS_MOVINGEYE_ROUTE,
    GLS_MOVINGEYE_DISABLE_HISTORY
};

//------------------------------------------------------------------------
/** 
* Runtime implementation of a GlsMovingEye
*/
class GlsMovingEye : public GlsEyePoint
{
private:
    GlsMovingEye& operator=( const GlsMovingEye& ) DISTI_SPECIAL_MEM_FUN_DELETE;
    GlsMovingEye( const GlsMovingEye& ) DISTI_SPECIAL_MEM_FUN_DELETE;

public:
    DISTI_DEPRECATED( "This identifier is forbidden by the C++ standard. Use BaseClass instead." )
    typedef GlsEyePoint _BaseClass;
    typedef GlsEyePoint BaseClass;

    /// This specifies the type of route taken from one eyepoint to another.
    enum Movement_t
    {
        CONSTANT   = 0,
        SINUSOIDAL = 1
    };

    /// This specifies the type of route taken from one eyepoint to another.
    enum Route_t
    {
        DIRECT = 0,
        ARC    = 1
    };

    // Name of the event emitted when a move is completed
    static const char* MOVE_COMPLETE_EVENT_NAME;

    //------------------------------------------------------------------------
    /**
    * Create a new GlsMovingEye.
    */
    GLSGEN_GLSMOVINGEYE_EXPORT GlsMovingEye();

    GLSGEN_GLSMOVINGEYE_EXPORT GlsMovingEye( const GlsMovingEye& that, const bool generateNames );

    //------------------------------------------------------------------------
    /** 
    * GlsMovingEyeEditor destructor 
    */
    virtual GLSGEN_GLSMOVINGEYE_EXPORT ~GlsMovingEye();

    //------------------------------------------------------------------------
    /** 
    * Returns true if the we're at the beginning of the history of movements.
    */
    bool AtStartOfHistory() const
    {
        return _historyPos == 0;
    }

    //------------------------------------------------------------------------
    /** 
    * Returns true if the we're at the end of the history of movements.
    */
    bool AtEndOfHistory() const
    {
        return _historyPos == _moveHistory.size() - 1;
    }

    //------------------------------------------------------------------------
    /** 
    * Aborts any move currently in progress.
    */
    GLSGEN_GLSMOVINGEYE_EXPORT void AbortMove();

    virtual GLSGEN_GLSMOVINGEYE_EXPORT void SetAvailableAttributes( unsigned int value );

    //------------------------------------------------------------------------
    /* See base class */
    virtual GLSGEN_GLSMOVINGEYE_EXPORT void Calculate( double time );

    //------------------------------------------------------------------------
    /* See base class */
    virtual GLSGEN_GLSMOVINGEYE_EXPORT
        DisplayObject*
        CloneObject( bool generateNames = false );

    //------------------------------------------------------------------------
    /* See base class */
    virtual GLSGEN_GLSMOVINGEYE_EXPORT void CopyProperties( DisplayObject* src );

    //------------------------------------------------------------------------
    /** 
    * Creates a new, blank GlsMovingEye object.
    * \return DisplayObject type pointer to the new GlsMovingEye.
    */
    static GLSGEN_GLSMOVINGEYE_EXPORT DisplayObject* CreateInstance();

    //------------------------------------------------------------------------
    /* See base class */
    virtual GLSGEN_GLSMOVINGEYE_EXPORT void Draw();

    //------------------------------------------------------------------------
    /** 
    * Returns whether or not an event is emitted upon completion of a
    * commanded movement. 
    */
    bool EmitEvent() const { return _emitEvent; }

    //------------------------------------------------------------------------
    /** 
    * Sets whether or not an event is emitted upon completion of a
    * commanded movement. 
    */
    void EmitEvent( bool emitEvent );

    //------------------------------------------------------------------------
    /** 
    * Returns whether or not an the move history is disabled. 
    */
    bool DisableMoveHistory() const { return _disableMoveHistory; }

    //------------------------------------------------------------------------
    /** 
    * Sets whether or not the move history is disabled. 
    */
    void DisableMoveHistory( bool his );

    //------------------------------------------------------------------------
    /* See base class */
    virtual GLSGEN_GLSMOVINGEYE_EXPORT void GenerateInstanceName();

#ifndef GLES
    //------------------------------------------------------------------------
    /* See base class */
    virtual GLSGEN_GLSMOVINGEYE_EXPORT
        InterfaceListType*
        GetCppInterfaceDescription(
            InterfaceListType* addToThisList = 0 );

    //------------------------------------------------------------------------
    /* See base class */
    virtual GLSGEN_GLSMOVINGEYE_EXPORT void GetCppInterfaceDescriptionFree( InterfaceListType* array );
#endif
    //------------------------------------------------------------------------
    /** 
    * \return The name of the object that the eyepoint should be always
    * looking at.
    * Lifetime is guaranteed to coincide with the GlsMovingEye's lifetime
    * or until LookAtObject is changed.
    */
    const std::string& LookAtObject() const { return _lookAtObject; }

    //------------------------------------------------------------------------
    /** 
    * Sets the name of the object that the eyepoint should be always
    * looking at. 
    */
    void LookAtObject( const std::string& name );

    //------------------------------------------------------------------------
    /** 
    * Returns the maximum speed in logical units/second which will
    * be used to achive the transition between eyepoints.  
    */
    float MaxSpeed() const { return _maxSpeed; }

    //------------------------------------------------------------------------
    /** 
    * Sets the maximum speed in logical units/second which will
    * be used to achive the transition between eyepoints.  
    */
    void MaxSpeed( float speed );

    //------------------------------------------------------------------------
    /** 
    * Returns the type of movement algorithm to use when moving to another 
    * eyepoint.
    */
    Movement_t Movement() const { return _movement; }

    //------------------------------------------------------------------------
    /** 
    * Sets the type of movement algorithm to use when moving to another 
    * eyepoint.
    */
    void Movement( Movement_t movementType );

    //------------------------------------------------------------------------
    /** 
    * Moves this eyepoint to the previously set eyepoint. If a move is 
    * already in progress, it will be immediately stopped, and this move 
    * will start.
    */
    GLSGEN_GLSMOVINGEYE_EXPORT void MoveBack();

    //------------------------------------------------------------------------
    /** 
    * Moves this eyepoint to the eyepoint which was last achieved from a 
    * MoveBack(). If a move is already in progress, it will be immediately
    * stopped, and this move will start.
    */
    GLSGEN_GLSMOVINGEYE_EXPORT void MoveForward();

    //------------------------------------------------------------------------
    /** 
    * Causes this eye to move from its current state to the state specified 
    * by the targetEye.  It will take moveTime to get there.  If a move is 
    * already in progress, it will be immediately stopped, and this move
    * will start.
    */
    GLSGEN_GLSMOVINGEYE_EXPORT
    void MoveToEye( GlsEyePoint* eye, float moveTime = 2.0f );

    //------------------------------------------------------------------------
    /** 
    * Causes the eye to move from its current state to each eyepoint in the
    * specified group ending with the last eye in the group.  If a move is 
    * already in progress, it will be immediately stopped, and this move 
    * will start.
    */
    GLSGEN_GLSMOVINGEYE_EXPORT
    void MoveToEye( Group* eyeGroup, float moveTime = 2.0f );

    //------------------------------------------------------------------------
    /** 
    * Causes the specified eye to be added to the end of the list of eyes 
    * which should be moved through.
    */
    GLSGEN_GLSMOVINGEYE_EXPORT
    void MoveToEyeAdd( GlsEyePoint* eye, float moveTime = 2.0f );

    //------------------------------------------------------------------------
    /** 
    * Causes the specified eyes to be added to the end of the list of eyes 
    * which should be moved through.
    */
    GLSGEN_GLSMOVINGEYE_EXPORT
    void MoveToEyeAdd( Group* eyeGroup, float moveTime = 2.0f );

    //------------------------------------------------------------------------
    /** 
    * Causes this eye to move to the specified location in the scene without
    * modifying the view direction or any other eye specific information.  
    */
    GLSGEN_GLSMOVINGEYE_EXPORT
    void MoveToLocation( const Vector& location, float moveTime = 2.0f );

    //------------------------------------------------------------------------
    /** 
    * Moves the eyepoint in view-relative coordinates by the specified amount,
    * over the specified time.  The units are in relative screen coordinates:
    * X and Y are pixels, Z is 0->1.  See WindowToLogical() or 
    * LogicalToWindow().
    */
    GLSGEN_GLSMOVINGEYE_EXPORT void MoveRelative(
        const Vector& moveAmount,
        const Vector& rotation );

    //------------------------------------------------------------------------
    /** 
    * Returns the type of route to use when moving to another eyepoint.
    */
    Route_t Route() const { return _route; }

    //------------------------------------------------------------------------
    /** 
    * Sets the type of route to use when moving to another eyepoint.
    */
    void Route( Route_t routeType );

    //------------------------------------------------------------------------
    /* See base class */
    GLSGEN_GLSMOVINGEYE_EXPORT virtual void SetValue( int spec, va_list& args );

protected:
#ifdef GLES
    /** Set a single attribute from the GLO file.
     * \param data The attribute to set and its associated data.
     */
    GLSGEN_GLSMOVINGEYE_EXPORT virtual void SetFromGloData( GlsGloFileAttribute& data );
#endif

    /// Type to store eyepoint state information.
    struct EyeState_t
    {
        Vector            location;
        bool              orthographic;
        double            FOV;
        double            otherFOV;
        bool              fovIsHorizontal;
        double            orthoSize;
        double            otherOrthoSize;
        double            farClip;
        double            nearClip;
        FovConstraintType horizontalConstraint;
        FovConstraintType verticalConstraint;
        Vector            viewVectors[ 3 ];

        /** Default constructor */
        EyeState_t();

        /** Initialize EyeState_t using targetEye parameters.
          * \param movingEye The GlsMovingEye that the state information is for (needed for coordinate conversions)
          * \param targetEye The GlsEyePoint to move to
          */
        EyeState_t( GlsMovingEye* movingEye, GlsEyePoint* targetEye );

        inline Vector Direction()
        {
            /*  Copied from GlsEyePoint::Direction() */
            return viewVectors[ 2 ];
        }
    };

    /// Type to store eyepoint movement parameters.
    struct MoveParms_t : public EyeState_t
    {
        bool        addToHistory;
        double      time;
        std::string qualifiedEyeName;

        MoveParms_t(
            bool          storeHistory,
            double        moveTime,
            GlsMovingEye* movingEye,
            GlsEyePoint*  targetEye );
    };

    /// Whether or not to emit an event when the move has completed.
    bool _emitEvent;

    /// This is true when a move is occurring and the route segment being
    /// moved along is the very first one in the queue.  This is used during
    /// sinusoidal movement to smoothly speed up when starting.
    bool _firstSegment;

    /// Current position into the history list
    std::size_t _historyPos;

    /// Flag to keep track of when the object gets initialized.
    bool _initialized;

    /// Automatically adjust the view direction to point at the specified
    /// targetObject.  This is inactivated when the string is blank.
    /// While this is active, the move methods will not control the view
    /// direction.  They can still control the position and other eye
    /// information.
    std::string _lookAtObject;

    /// The last up vector provided by the user or the move code.
    /// Used by the 'look at' algorithm to orient the eyepoint
    Vector _lookAtReferenceUpVector;

    /// The last up vector calculated by the lookAt algorithm.
    Vector _lookAtCalculatedUpVector;

    /// Stores a history of visited eyepoints for moving back and forth.
    std::vector<MoveParms_t> _moveHistory;

    bool _disableMoveHistory;

    /// This specifies the maximum speed in logical units / second which will
    /// be used to achive the transition.  If the requested transition cannot
    /// occur within the requested move time without exceeding the max speed,
    /// the move time will be longer than requested.  In other words, this
    /// limit has priority over any requested moveTime.  A MaxSpeed value of
    /// < 0.0 means the speed limit is disabled.
    float _maxSpeed;

    /// Type of movement algorithm to use when moving to another eyepoint.
    Movement_t _movement;

    /// Contains movement parameters for each move that should be performed.
    /// The last one contains the final eyepoint to stop at.
    std::queue<MoveParms_t> _moveQ;

    /// Type of route to take when moving to another eyepoint.
    Route_t _route;

    /// Stores this eyepoint's current state at the start of a move and is
    /// used in calculating movement during each execution frame.
    EyeState_t _start;

    /// Latest known simulation time.
    double _simTime;

    /// Simulation time that a move starts.
    double _startTime;

    /// This specifies the up direction and is used when interpolating
    /// movement to keep the view oriented 'correctly'.
    Vector _upVector;

    /// This specifies a buffer area around _upVector and -_upVector which
    /// the moving eye will try to avoid.  Setting this to non-zero avoids
    /// flipping problems when orientation passes through _upVector or -_upVector
    /// during moves.
    float _bufferAngle;

    //------------------------------------------------------------------------
    /** 
    * Calculates the direction to the named object.
    */
    //------------------------------------------------------------------------
    Vector DirectionToObj( const std::string& qualifiedObjName ) const;

    //------------------------------------------------------------------------
    /** 
    * Extracts all eyepoint objects from the group hierarchy.  The group
    * can contain other groups and object types.
    */
    //------------------------------------------------------------------------
    void ExtractEyepoints( Group* group, std::vector<GlsEyePoint*>& eyes );

    //------------------------------------------------------------------------
    /** 
    * Called when the destination eyepoint is reached to perform actions
    * necessary to complete the movement.
    */
    //------------------------------------------------------------------------
    void FinishMoving();

    //------------------------------------------------------------------------
    /** 
    * Initializes the movement history with the initial state of the eyepoint.
    */
    //------------------------------------------------------------------------
    void Initialize();

    //------------------------------------------------------------------------
    /** 
    * Returns an adjusted move time based on the maximum speed setting. If the
    * speed of moving over distance in desiredTime is greater than the 
    * maximum speed setting, the move time will be lengthened.
    * 
    * \param distance: distance in logical units that will be moved.
    * \param desiredTime: time in which we wish to cover the specified 
    *                     distance.
    */
    //------------------------------------------------------------------------
    float MoveTime( float distance, float desiredTime ) const;

    //------------------------------------------------------------------------
    /** 
    * Calculates the distance over the entire route if moving between all
    * eyepoints in the list.
    */
    //------------------------------------------------------------------------
    float RouteDistance( std::vector<GlsEyePoint*>& eyes ) const;

    //------------------------------------------------------------------------
    /** 
    * Queues the move using the passed in movement parameters and sets up
    * the start time and starting state of the move.
    */
    //------------------------------------------------------------------------
    void StartMoving( const MoveParms_t& moveParms );

    /// The editor class needs to access this class' privates. :)
    friend class GlsMovingEyeEditor;
};

//----------------------------------------------------------------------------
inline std::ostream& operator<<( std::ostream& outstr, GlsMovingEye::Movement_t m )
{
    switch( m )
    {
    case GlsMovingEye::CONSTANT:
        outstr << "CONSTANT";
        break;
    case GlsMovingEye::SINUSOIDAL:
        outstr << "SINUSOIDAL";
        break;
    default:
        outstr << "BAD_MOVEMENT";
    };

    return outstr;
}

//----------------------------------------------------------------------------
inline std::istream& operator>>( std::istream& instr, GlsMovingEye::Movement_t& m )
{
    std::string str;
    instr >> str;
    if( str == "CONSTANT" )
    {
        m = GlsMovingEye::CONSTANT;
    }
    else if( str == "SINUSOIDAL" )
    {
        m = GlsMovingEye::SINUSOIDAL;
    }
    return instr;
}

//----------------------------------------------------------------------------
inline std::ostream& operator<<( std::ostream& outstr, GlsMovingEye::Route_t r )
{
    switch( r )
    {
    case GlsMovingEye::DIRECT:
        outstr << "DIRECT";
        break;
    case GlsMovingEye::ARC:
        outstr << "ARC";
        break;
    default:
        outstr << "BAD_ROUTE";
    };

    return outstr;
}

//----------------------------------------------------------------------------
inline std::istream& operator>>( std::istream& instr, GlsMovingEye::Route_t& r )
{
    std::string str;
    instr >> str;
    if( str == "DIRECT" )
    {
        r = GlsMovingEye::DIRECT;
    }
    else if( str == "ARC" )
    {
        r = GlsMovingEye::ARC;
    }
    return instr;
}

} // namespace disti
#endif