#ifndef TERRAIN_H
#define TERRAIN_H

#define MAP_WIDTH 300
#define MAP_HEIGHT 125
#define NUM_TRIANGLES_0 6
#define NUM_TRIANGLES_SUB 4
#define NUM_TRIANGLE_VERTICES 3
#define LOD_0_SIZE 1.0f
#define LOD_0_SIZE_Y 0.4328799197461722f
//#define LOD_0_S 0.75f

//#define NUM_POINTS_05f 10

//#define NUM_POINTS_WIDTH (NUM_POINTS_05f  * 3 * MAP_WIDTH*2)

//#define NUM_POINTS_HEIGHT (NUM_POINTS_05f * MAP_HEIGHT)

#define NUM_TRIANGLES  NUM_TRIANGLES_0*NUM_TRIANGLES_SUB * NUM_TRIANGLES_SUB

#define PI 3.14159265359f

#include <QVector2D>

struct TerrainPoint {
    unsigned char height;
    unsigned char type;
    unsigned char river;
};

// Returns the 6 edge midpoints in local tile coordinates (radius = 0.5)
inline QVector2D getHexEdgeMidpoint(int edge) {
    static const QVector2D midpoints[6] = {
        QVector2D(-0.375f,  0.21650635f), // Edge 0 (Top-Left)
        QVector2D( 0.0f,    0.43301270f), // Edge 1 (Top)
        QVector2D( 0.375f,  0.21650635f), // Edge 2 (Top-Right)
        QVector2D( 0.375f, -0.21650635f), // Edge 3 (Bottom-Right)
        QVector2D( 0.0f,   -0.43301270f), // Edge 4 (Bottom)
        QVector2D(-0.375f, -0.21650635f)  // Edge 5 (Bottom-Left)
    };
    return midpoints[(edge % 6 + 6) % 6];
}

// Returns the two corner endpoints in local tile coordinates for a given edge (radius = 0.5)
inline void getHexEdgeEndpoints(int edge, QVector2D &p1, QVector2D &p2) {
    static const QVector2D corners[6] = {
        QVector2D(-0.25f,  0.43301270f), // 0: Top-Left
        QVector2D( 0.25f,  0.43301270f), // 1: Top-Right
        QVector2D( 0.5f,   0.0f),         // 2: Right
        QVector2D( 0.25f, -0.43301270f), // 3: Bottom-Right
        QVector2D(-0.25f, -0.43301270f), // 4: Bottom-Left
        QVector2D(-0.5f,   0.0f)          // 5: Left
    };
    switch ((edge % 6 + 6) % 6) {
        case 0: p1 = corners[5]; p2 = corners[0]; break;
        case 1: p1 = corners[0]; p2 = corners[1]; break;
        case 2: p1 = corners[1]; p2 = corners[2]; break;
        case 3: p1 = corners[2]; p2 = corners[3]; break;
        case 4: p1 = corners[3]; p2 = corners[4]; break;
        case 5: p1 = corners[4]; p2 = corners[5]; break;
        default: p1 = corners[0]; p2 = corners[1]; break;
    }
}

// Returns the coordinates of the neighbor tile sharing the given edge
inline void getHexNeighbor(int x, int y, int edge, int &nx, int &ny) {
    bool even = (x % 2 == 0);
    switch ((edge % 6 + 6) % 6) {
        case 0: nx = x - 1; ny = even ? y : y + 1;     break;
        case 1: nx = x;     ny = y + 1;                break;
        case 2: nx = x + 1; ny = even ? y : y + 1;     break;
        case 3: nx = x + 1; ny = even ? y - 1 : y;     break;
        case 4: nx = x;     ny = y - 1;                break;
        case 5: nx = x - 1; ny = even ? y - 1 : y;     break;
        default: nx = x; ny = y; break;
    }
}

#endif // TERRAIN_H