njin_nav.h

#pragma once
#include "_math.h"
#include "_tilemap.h"
#include "_types.h"
#include <utility>
#include <vector>
 
namespace njin {
struct context;


struct nav_grid {
  vec2 origin{};            
  vec2 cell_size{16.0f, 16.0f}; 
  i32 width = 0;            
  i32 height = 0;           
  std::vector<u8> cost;
};

nav_grid nav_grid_make(vec2 origin, vec2 cell_size, i32 width, i32 height, u8 cost = 1);

nav_grid nav_grid_from_world(const context &ctx, rect area, vec2 cell_size, u32 mask = 0xFFFFFFFFu);

cell nav_cell_at(const nav_grid &grid, vec2 pos);

vec2 nav_cell_center(const nav_grid &grid, cell c);

u8 nav_cost(const nav_grid &grid, cell c);

void nav_set_cost(nav_grid &grid, cell c, u8 cost);

void nav_set_area(nav_grid &grid, rect area, u8 cost = 0);

struct nav_path_opts {
  bool diagonal = true;
  bool cut_corners = false;
  bool smooth = true;
  bool partial = true;
  i32 max_nodes = 20000;
  f32 greed = 1.0f;
};

bool nav_find_path(const nav_grid &grid, vec2 from, vec2 to, std::vector<vec2> &out,
                   const nav_path_opts &opts = {});

bool nav_line_clear(const nav_grid &grid, vec2 a, vec2 b);

struct nav_agent {
  std::vector<vec2> path; 
  i32 next = 0;           
  f32 reach = 3.0f;       

  void set(std::vector<vec2> p) {
    path = std::move(p);
    next = 0;
  }

  bool done() const { return next >= (i32)path.size(); }
};

vec2 nav_steer(nav_agent &agent, vec2 pos);
} // namespace njin