/*
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

   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, or (at your option)
   any later version.

   ### File Specific:
   main-programmer: bottac@ee.ethz.ch

   review: patrick boenzli, patrick@orxonox.ethz.ch
*/


#include "vertex_array_model.h"
#include "p_node.h"


#define HM_TEX_RATE      32
#define HM_TILE_SIZE     64

//!< define the LOD level distances. later this could be dynamicaly adjusted
#define HM_LOD_LOW_RES     5000         //!< low resolution unless farther away than LOW_RES
#define HM_LOD_HIGH_RES    1000


class SDL_Surface;
class Vector;
class Material;
class PNode;
class Texture;
class HeightMap;


//!< one part of the height map
class Tile : public PNode
{
  public:
    Tile(int i1, int j1, int i2, int j2, HeightMap* hm) ;
    virtual ~Tile();

    int getRes();
    int setHighRes(bool b);

    void draw();
    inline void drawHighRes() const { highResModel->draw(); }
    inline void drawLowRes() const { lowResModel->draw(); }


  private:
    void load(int i1, int j1, int i2, int i2, VertexArrayModel* model, int Res);


  public:
    float x;
    float z;


  private:
    VertexArrayModel*                          highResModel;                      //!< heigh resolution model of the tile
    VertexArrayModel*                          lowResModel;                       //!< low resolution model of the tile

    HeightMap*                                 heightMapReference;                //!< reference to the heightmap this tile belongs to
    int                                        highRes;                           //!<
    int                                        lowRes;                            //!<
};


//!< the height map representation itself
class HeightMap : public VertexArrayModel
{
  friend class Tile;

  public:
    HeightMap(const std::string& heightMapName);
    HeightMap(const std::string& heightMapName, const std::string& colorMapName);
    virtual ~HeightMap();

    void setAbsCoor(Vector V);
    float getHeight(float x, float y);
    float getNormal(float x, float y);

    void load();
    void load(int Mode);
    void load(const std::string&, int Mode);
    void scale( Vector V);

    void draw() const;


  private:
    void init(const std::string& heightMapName);

    void generateNormalVectorField();
    void drawRect(int xBottomLeft, int yBottomLeft, int xTopRight, int yTopRight );
    void fixBoarder(int xBottomLeft, int yBottomLeft, int xTopRight, int yTopRight);

    /** helper function absolute value @param val value*/
    inline int abs(int val) { return (val<0)?-val:val; }
    /** returns the max of two numbers @param x value 1 @param y value 2*/
    inline int max(int x, int y) { return (x>y)? x:y; }
    /** returns the min of two numbers @param x value 1 @param y value 2*/
    inline int min(int x, int y) { return (x<y)? x: y; }


  private:
    SDL_Surface*                          heightMap;                          //!< image of the height map
    SDL_Surface*                          colorMap;                           //!< image of the color map
    unsigned char*                        heights;
    unsigned char*                        colors;

    Vector**                              normalVectorField;
    Tile***                               tiles;
    Vector                                camCoords;
    Vector                                offsetCoords;
    Material*                             tmp_mat;
    Material*                             red_mat;
    Texture*                              texture;
    const PNode*                          camera;

    float                                 scaleX ;
    float                                 scaleY ;
    float                                 scaleZ ;
    float                                 shiftX ; // to be removed
    float                                 shiftY ; // to be removed
    float                                 shiftZ ; // to be removed
    float                                 offsetX;
    float                                 offsetY;
    float                                 offsetZ;
    int                                   cmScaleX;
    int                                   cmScaleY;
    bool                                  hasColourMap;
};