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 *
 * Software License Agreement (BSD License)
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 * Author: Eitan Marder-Eppstein
 *         David V. Lu!!
 *********************************************************************/
#ifndef _DIJKSTRA_H
#define _DIJKSTRA_H

#define PRIORITYBUFSIZE 10000
#include <math.h>
#include <stdint.h>
#include <string.h>
#include <stdio.h>

#include <wp_global_planner/planner_core.h>
#include <wp_global_planner/expander.h>

// inserting onto the priority blocks
#define push_cur(n)  { if (n>=0 && n<ns_ && !pending_[n] && getCost(costs, n)<lethal_cost_ && currentEnd_<PRIORITYBUFSIZE){ currentBuffer_[currentEnd_++]=n; pending_[n]=true; }}
#define push_next(n) { if (n>=0 && n<ns_ && !pending_[n] && getCost(costs, n)<lethal_cost_ &&    nextEnd_<PRIORITYBUFSIZE){    nextBuffer_[   nextEnd_++]=n; pending_[n]=true; }}
#define push_over(n) { if (n>=0 && n<ns_ && !pending_[n] && getCost(costs, n)<lethal_cost_ &&    overEnd_<PRIORITYBUFSIZE){    overBuffer_[   overEnd_++]=n; pending_[n]=true; }}

namespace wp_global_planner {
class DijkstraExpansion : public Expander {
    public:
        DijkstraExpansion(PotentialCalculator* p_calc, int nx, int ny);
        ~DijkstraExpansion();
        bool calculatePotentials(unsigned char* costs, double start_x, double start_y, double end_x, double end_y, int cycles,
                                float* potential);

        /**
         * @brief  Sets or resets the size of the map
         * @param nx The x size of the map
         * @param ny The y size of the map
         */
        void setSize(int nx, int ny); /**< sets or resets the size of the map */

        void setNeutralCost(unsigned char neutral_cost) {
            neutral_cost_ = neutral_cost;
            priorityIncrement_ = 2 * neutral_cost_;
        }

        void setPreciseStart(bool precise){ precise_ = precise; }
    private:

        /**
         * @brief  Updates the cell at index n
         * @param costs The costmap
         * @param potential The potential array in which we are calculating
         * @param n The index to update
         */
        void updateCell(unsigned char* costs, float* potential, int n); /** updates the cell at index n */

        float getCost(unsigned char* costs, int n) {
            float c = costs[n];
            if (c < lethal_cost_ - 1 || (unknown_ && c==255)) {
                c = c * factor_ + neutral_cost_;
                if (c >= lethal_cost_)
                    c = lethal_cost_ - 1;
                return c;
            }
            return lethal_cost_;
        }

        /** block priority buffers */
        int *buffer1_, *buffer2_, *buffer3_; /**< storage buffers for priority blocks */
        int *currentBuffer_, *nextBuffer_, *overBuffer_; /**< priority buffer block ptrs */
        int currentEnd_, nextEnd_, overEnd_; /**< end points of arrays */
        bool *pending_; /**< pending_ cells during propagation */
        bool precise_;

        /** block priority thresholds */
        float threshold_; /**< current threshold */
        float priorityIncrement_; /**< priority threshold increment */

};
} //end namespace wp_global_planner
#endif
