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LULC.h

//
// Classes/structures to represent the data in a LULC file
//
// Copyright (c) 2001 Virtual Terrain Project
// Free for all uses, see license.txt for details.
//

#ifndef LULCH
#define LULCH

#include <stdio.h>
#include "MathTypes.h"

#define LULC_ERR_FILE   1
#define LULC_ERR_READ   2
#define LULC_ERR_HEADER 3

typedef struct 
{
    short x;
    short y;
} Coord;

typedef struct
{
    short first_coord;
    short last_coord;
    short PL;
    short PR;
    int PAL;
    int PAR;
    int Length;         // in coordinate units
    short StartNode;
    short FinishNode;
} LULCArc;

class LULCPoly
{
public:
    LULCPoly();
    ~LULCPoly();

    short first_arc;
    short last_arc;
    int Attribute;
    int PerimeterLength;
    short NumIslands;
    short SurroundingPoly;

    // Vertices extracted by following and decoding the Arc data
    int m_iCoords;
    DPoint2 *m_p;   // in lat-lon

    // store extents, in local coordinates, for speed in testing
    double xmin, zmin, xmax, zmax;
};

class LULCSection
{
public:
    ~LULCSection();

    int m_iNumArcs;
    int m_iNumCoords;
    int m_iNumPolys;
    int m_iLengthOfFAP;
    int m_iNumNodes;

    LULCArc *m_pArc;
    Coord *m_pCoord;
    LULCPoly *m_pPoly;
    short *m_pFAP;
};

class vtLULCFile 
{
public:
    // constructor - pass it the name of a LULC (GIRAS) file
    vtLULCFile(const char *fname);

    // destructor
    ~vtLULCFile();

    // attempt to determine the mapping from local to latlon
    void SetupMapping();

    // read a section (there are usually 4 sections)
    void ReadSection(LULCSection *pSection, FILE *fp);

    // read a single record from the file
    int GetRecord(FILE *fp, char *buf);

    // convert from local coordinates to latlon
    void LocalToLatlon(Coord &local, DPoint2 &latlon);

    // processing LULC
    void ProcessLULCPolys();
    void ProcessLULCPoly(LULCSection *pSection, LULCPoly *pPoly);
    int FindAttribute(double utm_x, double utm_y);

    // return error type if it didn't load successfully
    int m_iError;
    // if an error occured, return it as an English message
    const char *GetErrorMessage();

    // extent of control points, in local coordinates
    Coord m_cMin, m_cMax;

    // local coordinates of control points
    Coord m_cCorners[6];

    // latitude and longitude of control points
    DPoint2 m_Corners[6];

    // access
    int NumSections() { return m_iNumSections; };
    LULCSection *GetSection(int i) { return m_pSection+i; };

    // used for making a list of these files
    vtLULCFile *m_pNext;

private:
    int     m_iNumSections;
    LULCSection *m_pSection;
    DMatrix3 m_transform;
//  DMatrix3 m_forwards;
};

#endif // LULCH

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