feat: hash Coordinate2D

Author: dxrcy

include/mcpp/coordinate.h

@@ -176,6 +176,15 @@ struct Coordinate2D {
    */
   Coordinate2D operator-(const Coordinate2D& obj) const;
 
+  /**
+   * @brief Implements hash algorithm for Coordinate2D object using non-negative
+   * mapping and weighted coordinate values.
+   *
+   * @param obj The Coordinate2D object to hash.
+   * @return Hash of Coordinate2D object.
+   */
+  std::size_t operator()(const Coordinate2D& obj) const;
+
   /**
    * @brief Outputs the Coordinate2D object to an ostream.
    *

src/coordinate.cpp

@@ -79,6 +79,16 @@ Coordinate2D Coordinate2D::operator-(const Coordinate2D& obj) const {
     return result;
 }
 
+std::size_t Coordinate2D::operator()(const mcpp::Coordinate2D& obj) const {
+  int lower = -3e7, upper = 3e7;
+  size_t base = upper - lower + 1;
+
+  size_t nx = obj.x - lower;
+  size_t nz = obj.z - lower;
+
+  return nx * base + nz;
+}
+
 std::string to_string(const Coordinate2D& coord) {
     using std::to_string;
     return "(" + to_string(coord.x) + "," + to_string(coord.z) + ")";