hgeDataGrid.h

//
// Opal SDK 1.0 
// Copyright(C) 2009, Paul Blower
//
// hgePolygonGrid
// Stores polygons on a 2d landscape into a grid and provides optimized
// lookup & render functions
//

#ifndef HGEDATAGRID__
#define HGEDATAGRID__

#include <hge.h> // FOR DEBUG
#include <vector>
#include <hgevector.h>
#include <hgerect.h>

#include "hgeShape.h"
#include "hgePolygon.h"
#include "hgeEntity.h"
#include "hgeIntersect.h"

// Collide types
enum hgePolygonMapCollide
{
    COLLIDE_STATIC  = 1,    // Collide with static polygons
    COLLIDE_DYNAMIC = 2,    // Collide with dynamic entitys
    COLLIDE_ALL     = 3,    // ^^ Above, Combined
    COLLIDE_VISIBLE = 4,    // Only visible polygons (faster)
    COLLIDE_MULTI   = 8     // Return multiple collisions
};

// hgePolygonCellData Class

struct hgePolygonCellData
{
    hgePolygon *polygon;    // polygon pointer
    byte layer;             // layer of polygon (0,1,2)
    int sublayer;           // sublayer of polygon (array position) - sorting by this guarantees correct render order
    bool rflag;             // rflag - used for fast lookups to avoid repeat searching lists

    hgePolygonCellData(hgePolygon *m_Polygon, byte m_Layer, int m_Sublayer)
    {
        polygon = m_Polygon;
        layer = m_Layer;
        sublayer = m_Sublayer;
        rflag = 0;
    }
};

// hgePolygonCell Class

struct hgePolygonCell
{
    hgeRect rect;                       // region this cell covers
    std::vector<hgePolygonCellData*> objects;   // polygons owned by region
};

// hgePolygonGrid Class

class hgePolygonGrid
{
private:

    //debug
    HGE *hge;

    hgeRect area;           // actual area of datagrid (V1, V2)
    hgeVector cell_size;    // actual cell size        (Gx, Gy)

    int gs_x;      // grid width in cells     (Sx)
    int gs_y;      // grid height in cells    (Sy)
    int gs_count;  // total cell count        (S)

    // previous visible cells, stored so we only re-list visible when cells change
    int prev_x1;
    int prev_y1;
    int prev_x2;
    int prev_y2;

    // The linear array of polygonCellData
    std::vector<hgePolygonCellData*> polys;

    // The 2D grid array of polygons
    std::vector<hgePolygonCell *> cells;

    // Linear array of visible polygons
    std::vector<hgePolygonCellData *> visible;

    // Pointer to the maps viewport rect
    hgeRect *viewport;

public:

    // Area of the map, cell size, viewport pointer
    hgePolygonGrid(hgeRect m_Area, hgeRect *m_Viewport, hgeVector m_CellSize = hgeVector(800, 600));

    ~hgePolygonGrid();

    // Prepares the visible list of polygons for this frame
    void Prepare();

    // Renders the grid
    void Render(int m_Layer = -1);

    void Update(float dt);

    // Optimized collision point testing
    hgePolygon *TestPoint(hgeVector point, std::string class_filter = "", int layer_filter = -1);

    // Test 
    hgeIntersect Test(hgeShape *shape, hgeVector offset = hgeVector(0,0), hgePolygon **return_poly = NULL, int test_type = COLLIDE_STATIC, std::string class_filter = "",  int layer_filter = -1);

    // TestEx - Includes rotation
    hgeIntersect TestEx(hgeEntityEx *polygon, hgeVector offset = hgeVector(0,0), float rot = 0, hgePolygon **return_poly = NULL, int test_type = COLLIDE_STATIC, std::string class_filter = "",  int layer_filter = -1);

    // AddPolygon is designed to work from map->Load. It relies on the polygons being added in visible order.
    void AddPolygon(hgePolygon *m_Poly, byte m_Layer);
};

#endif

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