/*

Open Asset Import Library (assimp)

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*/

/** @file  LWOAnimation.h

 *  @brief LWOAnimationResolver utility class

 *

 *  This is for all lightwave-related file format, not only LWO.

 *  LWS isthe main purpose.

*/

#ifndef AI_LWO_ANIMATION_INCLUDED

#define AI_LWO_ANIMATION_INCLUDED

//

#include <vector>

#include <list>

struct aiNodeAnim;

struct aiVectorKey;

namespace Assimp {

namespace LWO {

// ---------------------------------------------------------------------------

/** \brief List of recognized LWO envelopes

 */

enum EnvelopeType

{

    EnvelopeType_Position_X = 0x1,

    EnvelopeType_Position_Y = 0x2,

    EnvelopeType_Position_Z = 0x3,

    EnvelopeType_Rotation_Heading = 0x4,

    EnvelopeType_Rotation_Pitch = 0x5,

    EnvelopeType_Rotation_Bank = 0x6,

    EnvelopeType_Scaling_X = 0x7,

    EnvelopeType_Scaling_Y = 0x8,

    EnvelopeType_Scaling_Z = 0x9,

    // -- currently not yet handled

    EnvelopeType_Color_R = 0xa,

    EnvelopeType_Color_G = 0xb,

    EnvelopeType_Color_B = 0xc,

    EnvelopeType_Falloff_X = 0xd,

    EnvelopeType_Falloff_Y = 0xe,

    EnvelopeType_Falloff_Z = 0xf,

    EnvelopeType_Unknown

};

// ---------------------------------------------------------------------------

/** \brief List of recognized LWO interpolation modes

 */

enum InterpolationType

{

    IT_STEP, IT_LINE, IT_TCB, IT_HERM, IT_BEZI, IT_BEZ2

};

// ---------------------------------------------------------------------------

/** \brief List of recognized LWO pre or post range behaviours

 */

enum PrePostBehaviour

{

    PrePostBehaviour_Reset        = 0x0,

    PrePostBehaviour_Constant     = 0x1,

    PrePostBehaviour_Repeat       = 0x2,

    PrePostBehaviour_Oscillate    = 0x3,

    PrePostBehaviour_OffsetRepeat = 0x4,

    PrePostBehaviour_Linear       = 0x5

};

// ---------------------------------------------------------------------------

/** \brief Data structure for a LWO animation keyframe

 */

struct Key {

    Key() AI_NO_EXCEPT

    : time()

    , value()

    , inter(IT_LINE)

    , params() {

        // empty

    }

    //! Current time

    double time;

    //! Current value

    float value;

    //! How to interpolate this key with previous key?

    InterpolationType inter;

    //! Interpolation parameters

    float params[5];

    // for std::find()

    operator double () {

        return time;

    }

};

// ---------------------------------------------------------------------------

/** \brief Data structure for a LWO animation envelope

 */

struct Envelope {

    Envelope() AI_NO_EXCEPT

    : index()

    , type(EnvelopeType_Unknown)

    , pre(PrePostBehaviour_Constant)

    , post(PrePostBehaviour_Constant)

    , old_first(0)

    , old_last(0) {

        // empty

    }

    //! Index of this envelope

    unsigned int index;

    //! Type of envelope

    EnvelopeType type;

    //! Pre- and post-behavior

    PrePostBehaviour pre,post;

    //! Keyframes for this envelope

    std::vector<Key> keys;

    // temporary data for AnimResolver

    size_t old_first,old_last;

};

// ---------------------------------------------------------------------------

//! @def AI_LWO_ANIM_FLAG_SAMPLE_ANIMS

//! Flag for AnimResolver, subsamples the input data with the rate specified

//! by AnimResolver::SetSampleRate().

#define AI_LWO_ANIM_FLAG_SAMPLE_ANIMS 0x1

// ---------------------------------------------------------------------------

//! @def AI_LWO_ANIM_FLAG_START_AT_ZERO

//! Flag for AnimResolver, ensures that the animations starts at zero.

#define AI_LWO_ANIM_FLAG_START_AT_ZERO 0x2

// ---------------------------------------------------------------------------

/** @brief Utility class to build Assimp animations from LWO envelopes.

 *

 *  Used for both LWO and LWS (MOT also).

 */

class AnimResolver

{

public:

    // ------------------------------------------------------------------

    /** @brief Construct an AnimResolver from a given list of envelopes

     *  @param envelopes Input envelopes. May be empty.

     *  @param Output tick rate, per second

     *  @note The input envelopes are possibly modified.

     */

    AnimResolver(std::list<Envelope>& envelopes, double tick);

public:

    // ------------------------------------------------------------------

    /** @brief Extract the bind-pose transformation matrix.

     *  @param out Receives bind-pose transformation matrix

     */

    void ExtractBindPose(aiMatrix4x4& out);

    // ------------------------------------------------------------------

    /** @brief Extract a node animation channel

     *  @param out Receives a pointer to a newly allocated node anim.

     *    If there's just one keyframe defined, *out is set to nullptr and

     *    no animation channel is computed.

     *  @param flags Any combination of the AI_LWO_ANIM_FLAG_XXX flags.

     */

    void ExtractAnimChannel(aiNodeAnim** out, unsigned int flags = 0);

    // ------------------------------------------------------------------

    /** @brief Set the sampling rate for ExtractAnimChannel().

     *

     *  Non-linear interpolations are subsampled with this rate (keys

     *  per second). Closer sampling positions, if existent, are kept.

     *  The sampling rate defaults to 0, if this value is not changed and

     *  AI_LWO_ANIM_FLAG_SAMPLE_ANIMS is specified for ExtractAnimChannel(),

     *  the class finds a suitable sample rate by itself.

     */

    void SetSampleRate(double sr) {

        sample_rate = sr;

    }

    // ------------------------------------------------------------------

    /** @brief Getter for SetSampleRate()

     */

    double GetSampleRate() const {

        return sample_rate;

    }

    // ------------------------------------------------------------------

    /** @brief Set the animation time range

     *

     *  @param first Time where the animation starts, in ticks

     *  @param last  Time where the animation ends, in ticks

     */

    void SetAnimationRange(double _first, double _last) {

        first = _first;

        last  = _last;

        ClearAnimRangeSetup();

        UpdateAnimRangeSetup();

    }

protected:

    // ------------------------------------------------------------------

    /** @brief Build linearly subsampled keys from 3 single envelopes

     *  @param out Receives output keys

     *  @param envl_x X-component envelope

     *  @param envl_y Y-component envelope

     *  @param envl_z Z-component envelope

     *  @param flags Any combination of the AI_LWO_ANIM_FLAG_XXX flags.

     *  @note Up to two input envelopes may be nullptr

     */

    void GetKeys(std::vector<aiVectorKey>& out,

        LWO::Envelope* envl_x,

        LWO::Envelope* envl_y,

        LWO::Envelope* envl_z,

        unsigned int flags);

    // ------------------------------------------------------------------

    /** @brief Resolve a single animation key by applying the right

     *  interpolation to it.

     *  @param cur Current key

     *  @param envl Envelope working on

     *  @param time time to be interpolated

     *  @param fill Receives the interpolated output value.

     */

    void DoInterpolation(std::vector<LWO::Key>::const_iterator cur,

        LWO::Envelope* envl,double time, float& fill);

    // ------------------------------------------------------------------

    /** @brief Almost the same, except we won't handle pre/post

     *  conditions here.

     *  @see DoInterpolation

     */

    void DoInterpolation2(std::vector<LWO::Key>::const_iterator beg,

        std::vector<LWO::Key>::const_iterator end,double time, float& fill);

    // ------------------------------------------------------------------

    /** @brief Interpolate 2 tracks if one is given

     *

     *  @param out Receives extra output keys

     *  @param key_out Primary output key

     *  @param time Time to interpolate for

     */

    void InterpolateTrack(std::vector<aiVectorKey>& out,

        aiVectorKey& key_out,double time);

    // ------------------------------------------------------------------

    /** @brief Subsample an animation track by a given sampling rate

     *

     *  @param out Receives output keys. Last key at input defines the

     *    time where subsampling starts.

     *  @param time Time to end subsampling at

     *  @param sample_delta Time delta between two samples

     */

    void SubsampleAnimTrack(std::vector<aiVectorKey>& out,

        double time,double sample_delta);

    // ------------------------------------------------------------------

    /** @brief Delete all keys which we inserted to match anim setup

     */

    void ClearAnimRangeSetup();

    // ------------------------------------------------------------------

    /** @brief Insert extra keys to match LWO's pre and post behaviours

     *  in a given time range [first...last]

     */

    void UpdateAnimRangeSetup();

private:

    std::list<Envelope>& envelopes;

    double sample_rate;

    LWO::Envelope* trans_x, *trans_y, *trans_z;

    LWO::Envelope* rotat_x, *rotat_y, *rotat_z;

    LWO::Envelope* scale_x, *scale_y, *scale_z;

    double first, last;

    bool need_to_setup;

    // temporary storage

    LWO::Envelope* envl_x, * envl_y, * envl_z;

    std::vector<LWO::Key>::const_iterator cur_x,cur_y,cur_z;

    bool end_x, end_y, end_z;

    unsigned int flags;

    double sample_delta;

};

} // end namespace LWO

} // end namespace Assimp

#endif // !! AI_LWO_ANIMATION_INCLUDED