expander.h

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 * Author: Eitan Marder-Eppstein
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#ifndef _EXPANDER_H
#define _EXPANDER_H
#include <global_planner/potential_calculator.h>
#include <global_planner/planner_core.h>

namespace global_planner {

class Expander {
    public:
        Expander(PotentialCalculator* p_calc, int nx, int ny) :
                unknown_(true), lethal_cost_(253), neutral_cost_(50), factor_(3.0), p_calc_(p_calc) {
            setSize(nx, ny);
        }
        virtual bool calculatePotentials(unsigned char* costs, double start_x, double start_y, double end_x, double end_y,
                                        int cycles, float* potential) = 0;

        virtual void setSize(int nx, int ny) {
            nx_ = nx;
            ny_ = ny;
            ns_ = nx * ny;
        } 
        void setLethalCost(unsigned char lethal_cost) {
            lethal_cost_ = lethal_cost;
        }
        void setNeutralCost(unsigned char neutral_cost) {
            neutral_cost_ = neutral_cost;
        }
        void setFactor(float factor) {
            factor_ = factor;
        }
        void setHasUnknown(bool unknown) {
            unknown_ = unknown;
        }

        void clearEndpoint(unsigned char* costs, float* potential, int gx, int gy, int s){
            int startCell = toIndex(gx, gy);
            for(int i=-s;i<=s;i++){
            for(int j=-s;j<=s;j++){
                int n = startCell+i+nx_*j;
                if(potential[n]<POT_HIGH)
                    continue;
                float c = costs[n]+neutral_cost_;
                float pot = p_calc_->calculatePotential(potential, c, n);
                potential[n] = pot;
            }
            }
        }

    protected:
        inline int toIndex(int x, int y) {
            return x + nx_ * y;
        }

        int nx_, ny_, ns_; 
        bool unknown_;
        unsigned char lethal_cost_, neutral_cost_;
        int cells_visited_;
        float factor_;
        PotentialCalculator* p_calc_;

};

} //end namespace global_planner
#endif