/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2015 Mario Luzeiro <mrluzeiro@ua.pt>
 * Copyright (C) 1992-2015 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */

/**
 * @file  ccamera.h
 * @brief Define an abstract camera
 */

#ifndef CCAMERA_H
#define CCAMERA_H

#include "plugins/3dapi/xv3d_types.h"
#include "3d_rendering/3d_render_raytracing/ray.h"
#include <wx/gdicmn.h>                                                          // for wxSize
#include <vector>

enum PROJECTION_TYPE
{
    PROJECTION_ORTHO,
    PROJECTION_PERSPECTIVE
};

/**
 * Frustum structure
 * Frustum is a implementation based on a tutorial by
 * http://www.lighthouse3d.com/tutorials/view-frustum-culling/
 */
struct FRUSTUM
{
    SFVEC3F nc;
    SFVEC3F fc;
    SFVEC3F ntl; ///< Near Top Left
    SFVEC3F ntr; ///< Near Top Right
    SFVEC3F nbl; ///< Near Bottom Left
    SFVEC3F nbr; ///< Near Bottom Right
    SFVEC3F ftl; ///< Far Top Left
    SFVEC3F ftr; ///< Far Top Right
    SFVEC3F fbl; ///< Far Bottom Left
    SFVEC3F fbr; ///< Far Bottom Right
    float nearD, farD, ratio, angle, tang;
    float nw, nh, fw, fh;
};

/**
 *  Class CCAMERA
 *  is a virtual class used to derive CCAMERA objects from.
 *
 *  It must be derived to other classes to implement a real camera object.
 */
class CCAMERA
{

 public:

    /**
     * @brief CCAMERA initialize a camera
     * @param aRangeScale: it will be expected that the board will have a -aRangeScale/2 to +aRangeScale/2
     * it will initialize the initial Z position with aRangeScale
     */
    CCAMERA( float aRangeScale );


    /**
     *  Function GetRotationMatrix
     *  Get the rotation matrix to be applied in a transformation camera
     *  @return the rotation matrix of the camera
     */
    const glm::mat4 &GetRotationMatrix() const;

    const glm::mat4 &GetViewMatrix() const;
    const glm::mat4 &GetViewMatrix_Inv() const;

    const glm::mat4 &GetProjectionMatrix() const;
    const glm::mat4 &GetProjectionMatrixInv() const;

    const SFVEC3F &GetRight()    const { return m_right; }
    const SFVEC3F &GetUp()       const { return m_up; }
    const SFVEC3F &GetDir()      const { return m_dir; }
    const SFVEC3F &GetPos()      const { return m_pos; }
    const SFVEC2F &GetFocalLen() const { return m_focalLen; }
    float GetNear() const { return m_frustum.nearD; }
    float GetFar() const { return m_frustum.farD; }

    virtual void SetBoardLookAtPos( const SFVEC3F &aBoardPos ) = 0;

    /**
     *  Calculate a new mouse drag position
     */
    virtual void Drag( const wxPoint &aNewMousePosition )  = 0;

    virtual void Pan( const wxPoint &aNewMousePosition )  = 0;

    virtual void Pan( const SFVEC3F &aDeltaOffsetInc )  = 0;


    /**
     *  Reset the camera to initial state
     */
    virtual void Reset()  = 0;


    /**
     *  It updates the current mouse position without make any new recalculations on camera.
     */
    void SetCurMousePosition( const wxPoint &aPosition );

    void SetProjection( PROJECTION_TYPE aProjectionType );

    void SetCurWindowSize( const wxSize &aSize );

    void ZoomReset();

    void ZoomIn( float aFactor );

    void ZoomOut( float aFactor );

    float ZoomGet() const ;

    /**
     *  Function ParametersChanged
     *  @return true if some of the parameters in camera was changed, it will reset the flag
     */
    bool ParametersChanged();

    void MakeRay( const SFVEC2I &aWindowPos, SFVEC3F &aOutOrigin, SFVEC3F &aOutDirection ) const;

    void GLdebug_Lines();

    void GLdebug_Planes();

    void GLdebug_Vectors();

 protected:

    void rebuildProjection();
    void updateFrustum();
    void updateViewMatrix();

    /**
     * @brief m_range_scale - the nominal range expected to be used in the camera.
     * It will be used to initialize the Z position
     */
    float m_range_scale;

    /**
     *  3D zoom value (Min 0.0 ... Max 1.0)
     */
    float m_zoom;

    /**
     *  The window size that this camera is working.
     */
    wxSize m_windowSize;

    /**
     *  The last mouse position in the screen
     */
    wxPoint m_lastPosition;

    glm::mat4 m_rotationMatrix;
    glm::mat4 m_viewMatrix;
    glm::mat4 m_viewMatrix_inverse;
    glm::mat4 m_projectionMatrix;
    glm::mat4 m_projectionMatrix_inv;
    PROJECTION_TYPE m_projectionType;

    FRUSTUM m_frustum;

    SFVEC3F m_right;
    SFVEC3F m_up;
    SFVEC3F m_dir;
    SFVEC3F m_pos;

    SFVEC2F m_focalLen;

    SFVEC3F m_camera_pos_init;
    SFVEC3F m_camera_pos;

    SFVEC3F m_boardLookAt_pos;

    /**
     *  Precalc values array used to calc ray for each pixel (constant for the same window size)
     */
    std::vector< float > m_scr_nX;
    std::vector< float > m_scr_nY;

    /**
     *  Precalc values array used to calc ray for each pixel, for X and Y axis of each new camera position
     */
    std::vector< SFVEC3F > m_right_nX;
    std::vector< SFVEC3F > m_up_nY;


    /**
     *  Set to true if any of the parameters in the camera was changed
     */
    bool m_parametersChanged;

    /**
     *  Trace mask used to enable or disable the trace output of this class.
     *  The debug output can be turned on by setting the WXTRACE environment variable to
     *  "KI_TRACE_CCAMERA".  See the wxWidgets documentation on wxLogTrace for
     *  more information.
     */
    static const wxChar *m_logTrace;
};

#endif // CCAMERA_H