dijkstra.cpp

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#include <dlux_plugins/dijkstra.h>
#include <nav_grid/coordinate_conversion.h>
#include <nav_core2/exceptions.h>
#include <dlux_global_planner/kernel_function.h>
#include <pluginlib/class_list_macros.h>
#include <queue>
 
PLUGINLIB_EXPORT_CLASS(dlux_plugins::Dijkstra, dlux_global_planner::PotentialCalculator)
 
namespace dlux_plugins
{
unsigned int Dijkstra::updatePotentials(dlux_global_planner::PotentialGrid& potential_grid,
                                        const geometry_msgs::Pose2D& start, const geometry_msgs::Pose2D& goal)
{
  const nav_grid::NavGridInfo& info = potential_grid.getInfo();
  queue_ = std::queue<nav_grid::Index>();
  potential_grid.reset();
 
  nav_grid::Index goal_i;
  worldToGridBounded(info, goal.x, goal.y, goal_i.x, goal_i.y);
  queue_.push(goal_i);
  potential_grid.setValue(goal_i, 0.0);
 
  nav_grid::Index start_i;
  worldToGridBounded(info, start.x, start.y, start_i.x, start_i.y);
  unsigned int c = 0;
 
  while (!queue_.empty())
  {
    nav_grid::Index i = queue_.front();
    queue_.pop();
    c++;
 
    if (i == start_i) return c;
 
    if (i.x > 0)
      add(potential_grid, nav_grid::Index(i.x - 1, i.y));
    if (i.y > 0)
      add(potential_grid, nav_grid::Index(i.x, i.y - 1));
 
    if (i.x < info.width - 1)
      add(potential_grid, nav_grid::Index(i.x + 1, i.y));
    if (i.y < info.height - 1)
      add(potential_grid, nav_grid::Index(i.x, i.y + 1));
  }
 
  throw nav_core2::NoGlobalPathException();
}
 
void Dijkstra::add(dlux_global_planner::PotentialGrid& potential_grid, nav_grid::Index next_index)
{
  if (potential_grid(next_index.x, next_index.y) < dlux_global_planner::HIGH_POTENTIAL)
    return;
 
  float cost = cost_interpreter_->getCost(next_index.x, next_index.y);
  if (cost_interpreter_->isLethal(cost))
    return;
  potential_grid.setValue(next_index,
                          dlux_global_planner::calculateKernel(potential_grid, cost, next_index.x, next_index.y));
  queue_.push(next_index);
}
 
}  // namespace dlux_plugins