Pathfinding: Record history of cost changes in pathfinder

libopenage/pathfinding/cost_field.cpp

@@ -14,7 +14,8 @@ namespace openage::path {
 CostField::CostField(size_t size) :
 	size{size},
 	valid_until{time::TIME_MIN},
-	cells(this->size * this->size, COST_MIN) {
+	cells(this->size * this->size, COST_MIN),
+	cell_cost_history() {
 	log::log(DBG << "Created cost field with size " << this->size << "x" << this->size);
 }
 
@@ -52,6 +53,7 @@ void CostField::set_costs(std::vector<cost_t> &&cells, const time::time_t &valid
 	                                       << "; expected: "
 	                                       << this->cells.size());
 
+	this->cell_cost_history.set_insert_range(valid_until, this->cells.begin(), this->cells.end());
 	this->cells = std::move(cells);
 	this->valid_until = valid_until;
 }

libopenage/pathfinding/cost_field.h

@@ -6,6 +6,7 @@
 #include <vector>
 #include <optional>
 
+#include "curve/container/array.h"
 #include "pathfinding/types.h"
 #include "time/time.h"
 
@@ -15,6 +16,8 @@ namespace coord {
 struct tile_delta;
 } // namespace coord
 
+const unsigned int CHUNK_SIZE = 100;
+
 namespace path {
 
 /**
@@ -88,6 +91,7 @@ class CostField {
 	 * @param valid_until Time at which the cost value expires.
 	 */
 	inline void set_cost(size_t idx, cost_t cost, const time::time_t &valid_until) {
+		this->cell_cost_history.set_insert(valid_until, idx, this->cells[idx]);
 		this->cells[idx] = cost;
 		this->valid_until = valid_until;
 	}
@@ -162,6 +166,12 @@ class CostField {
 	 * Cost stamp vector.
 	 */
 	std::vector<std::optional<cost_stamp_t>> cost_stamps;
+
+
+	/**
+	 * Array curve recording cell cost history,
+	 */
+	curve::Array<cost_t, CHUNK_SIZE> cell_cost_history;
 };
 
 } // namespace path