Merge pull request #1725 from dmwever/Add-Cost-Field-Dirty-Flag

Add dirty flag and integrate

Author: heinezen

.mailmap

@@ -20,4 +20,5 @@ Tobias Feldballe <tobias@osandweb.dk> <tobi.fp@gmail.com>
 Tobias Feldballe <tobias@osandweb.dk> <tf@jumpstory.com>
 Jonas Borchelt <jonas.borchelt@connected.link>
 Derek Frogget <fro22003@byui.edu> <114030121+derekfrogget@users.noreply.github.com>
-Nikhil Ghosh <nghosh606@gmail.com>
+Nikhil Ghosh <nghosh606@gmail.com>
+David Wever <dmwever@crimson.ua.edu> <56411717+dmwever@users.noreply.github.com>

copying.md

@@ -158,6 +158,7 @@ _the openage authors_ are:
 | Jeremiah Morgan             | jere8184                    | jeremiahmorgan dawt bham à outlook dawt com       |
 | Tobias Alam                 | alamt22                     | tobiasal à umich dawt edu                         |
 | Alex Zhuohao He             | ZzzhHe                      | zhuohao dawt he à outlook dawt com                |
+| David Wever                 | dmwever                     | dmwever à crimson dawt ua dawt edu                |
 
 If you're a first-time committer, add yourself to the above list. This is not
 just for legal reasons, but also to keep an overview of all those nicknames.

libopenage/gamestate/map.cpp

@@ -49,7 +49,7 @@ Map::Map(const std::shared_ptr<GameState> &state,
 
 				auto sector = grid->get_sector(chunk_idx);
 				auto cost_field = sector->get_cost_field();
-				cost_field->set_cost(tile_idx, path_cost.second);
+				cost_field->set_cost(tile_idx, path_cost.second, time::TIME_ZERO);
 			}
 		}
 	}

libopenage/gamestate/system/move.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023-2024 the openage authors. See copying.md for legal info.
+// Copyright 2023-2025 the openage authors. See copying.md for legal info.
 
 #include "move.h"
 
@@ -37,7 +37,8 @@ namespace openage::gamestate::system {
 std::vector<coord::phys3> find_path(const std::shared_ptr<path::Pathfinder> &pathfinder,
                                     path::grid_id_t grid_id,
                                     const coord::phys3 &start,
-                                    const coord::phys3 &end) {
+                                    const coord::phys3 &end,
+                                    const time::time_t &start_time) {
 	auto start_tile = start.to_tile();
 	auto end_tile = end.to_tile();
 
@@ -46,6 +47,7 @@ std::vector<coord::phys3> find_path(const std::shared_ptr<path::Pathfinder> &pat
 		grid_id,
 		start_tile,
 		end_tile,
+		start_time,
 	};
 	auto tile_path = pathfinder->get_path(request);
 
@@ -122,7 +124,7 @@ const time::time_t Move::move_default(const std::shared_ptr<gamestate::GameEntit
 	auto map = state->get_map();
 	auto pathfinder = map->get_pathfinder();
 	auto grid_id = map->get_grid_id(move_path_grid->get_name());
-	auto waypoints = find_path(pathfinder, grid_id, current_pos, destination);
+	auto waypoints = find_path(pathfinder, grid_id, current_pos, destination, start_time);
 
 	// use waypoints for movement
 	double total_time = 0;

libopenage/pathfinding/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_sources(libopenage
     cost_field.cpp
 	definitions.cpp
+	field_cache.cpp
     flow_field.cpp
 	grid.cpp
 	integration_field.cpp

libopenage/pathfinding/cost_field.cpp

@@ -1,4 +1,4 @@
-// Copyright 2024-2024 the openage authors. See copying.md for legal info.
+// Copyright 2024-2025 the openage authors. See copying.md for legal info.
 
 #include "cost_field.h"
 
@@ -13,6 +13,7 @@ namespace openage::path {
 
 CostField::CostField(size_t size) :
 	size{size},
+	valid_until{time::TIME_MIN},
 	cells(this->size * this->size, COST_MIN) {
 	log::log(DBG << "Created cost field with size " << this->size << "x" << this->size);
 }
@@ -33,29 +34,34 @@ cost_t CostField::get_cost(size_t idx) const {
 	return this->cells.at(idx);
 }
 
-void CostField::set_cost(const coord::tile_delta &pos, cost_t cost) {
-	this->cells[pos.ne + pos.se * this->size] = cost;
+void CostField::set_cost(const coord::tile_delta &pos, cost_t cost, const time::time_t &valid_until) {
+	this->set_cost(pos.ne + pos.se * this->size, cost, valid_until);
 }
 
-void CostField::set_cost(size_t x, size_t y, cost_t cost) {
-	this->cells[x + y * this->size] = cost;
-}
-
-void CostField::set_cost(size_t idx, cost_t cost) {
-	this->cells[idx] = cost;
+void CostField::set_cost(size_t x, size_t y, cost_t cost, const time::time_t &valid_until) {
+	this->set_cost(x + y * this->size, cost, valid_until);
 }
 
 const std::vector<cost_t> &CostField::get_costs() const {
 	return this->cells;
 }
 
-void CostField::set_costs(std::vector<cost_t> &&cells) {
+void CostField::set_costs(std::vector<cost_t> &&cells, const time::time_t &valid_until) {
 	ENSURE(cells.size() == this->cells.size(),
 	       "cells vector has wrong size: " << cells.size()
 	                                       << "; expected: "
 	                                       << this->cells.size());
 
 	this->cells = std::move(cells);
+	this->valid_until = valid_until;
+}
+
+bool CostField::is_dirty(const time::time_t &time) const {
+	return time >= this->valid_until;
+}
+
+void CostField::clear_dirty() {
+	this->valid_until = time::TIME_MAX;
 }
 
 } // namespace openage::path

libopenage/pathfinding/cost_field.h

@@ -1,11 +1,12 @@
-// Copyright 2024-2024 the openage authors. See copying.md for legal info.
+// Copyright 2024-2025 the openage authors. See copying.md for legal info.
 
 #pragma once
 
 #include <cstddef>
 #include <vector>
 
 #include "pathfinding/types.h"
+#include "time/time.h"
 
 
 namespace openage {
@@ -64,25 +65,31 @@ class CostField {
 	 *
 	 * @param pos Coordinates of the cell (relative to field origin).
 	 * @param cost Cost to set.
+	 * @param valid_until Time at which the cost value expires.
 	 */
-	void set_cost(const coord::tile_delta &pos, cost_t cost);
+	void set_cost(const coord::tile_delta &pos, cost_t cost, const time::time_t &valid_until);
 
 	/**
 	 * Set the cost at a specified position.
 	 *
 	 * @param x X-coordinate of the cell.
 	 * @param y Y-coordinate of the cell.
 	 * @param cost Cost to set.
+	 * @param valid_until Time at which the cost value expires.
 	 */
-	void set_cost(size_t x, size_t y, cost_t cost);
+	void set_cost(size_t x, size_t y, cost_t cost, const time::time_t &valid_until);
 
 	/**
 	 * Set the cost at a specified position.
 	 *
 	 * @param idx Index of the cell.
 	 * @param cost Cost to set.
+	 * @param valid_until Time at which the cost value expires.
 	 */
-	void set_cost(size_t idx, cost_t cost);
+	inline void set_cost(size_t idx, cost_t cost, const time::time_t &valid_until) {
+		this->cells[idx] = cost;
+		this->valid_until = valid_until;
+	}
 
 	/**
 	 * Get the cost field values.
@@ -95,15 +102,35 @@ class CostField {
 	 * Set the cost field values.
 	 *
 	 * @param cells Cost field values.
+	 * @param valid_until Time at which the cost value expires.
 	 */
-	void set_costs(std::vector<cost_t> &&cells);
+	void set_costs(std::vector<cost_t> &&cells, const time::time_t &changed);
+
+	/**
+	 * Check if the cost field is dirty at the specified time.
+	 *
+	 * @param time Time of access to the cost field.
+	 *
+	 * @return Whether the cost field is dirty.
+	 */
+	bool is_dirty(const time::time_t &time) const;
+
+	/**
+	 * Clear the dirty flag.
+	 */
+	void clear_dirty();
 
 private:
 	/**
 	 * Side length of the field.
 	 */
 	size_t size;
 
+	/**
+	 * Time the cost field expires.
+	 */
+	time::time_t valid_until;
+
 	/**
 	 * Cost field values.
 	 */

libopenage/pathfinding/demo/demo_0.cpp

@@ -1,4 +1,4 @@
-// Copyright 2024-2024 the openage authors. See copying.md for legal info.
+// Copyright 2024-2025 the openage authors. See copying.md for legal info.
 
 #include "demo_0.h"
 
@@ -33,15 +33,17 @@ void path_demo_0(const util::Path &path) {
 
 	// Cost field with some obstacles
 	auto cost_field = std::make_shared<CostField>(field_length);
-	cost_field->set_cost(coord::tile_delta{0, 0}, COST_IMPASSABLE);
-	cost_field->set_cost(coord::tile_delta{1, 0}, 254);
-	cost_field->set_cost(coord::tile_delta{4, 3}, 128);
-	cost_field->set_cost(coord::tile_delta{5, 3}, 128);
-	cost_field->set_cost(coord::tile_delta{6, 3}, 128);
-	cost_field->set_cost(coord::tile_delta{4, 4}, 128);
-	cost_field->set_cost(coord::tile_delta{5, 4}, 128);
-	cost_field->set_cost(coord::tile_delta{6, 4}, 128);
-	cost_field->set_cost(coord::tile_delta{1, 7}, COST_IMPASSABLE);
+
+	const time::time_t time = time::TIME_ZERO;
+	cost_field->set_cost(coord::tile_delta{0, 0}, COST_IMPASSABLE, time);
+	cost_field->set_cost(coord::tile_delta{1, 0}, 254, time);
+	cost_field->set_cost(coord::tile_delta{4, 3}, 128, time);
+	cost_field->set_cost(coord::tile_delta{5, 3}, 128, time);
+	cost_field->set_cost(coord::tile_delta{6, 3}, 128, time);
+	cost_field->set_cost(coord::tile_delta{4, 4}, 128, time);
+	cost_field->set_cost(coord::tile_delta{5, 4}, 128, time);
+	cost_field->set_cost(coord::tile_delta{6, 4}, 128, time);
+	cost_field->set_cost(coord::tile_delta{1, 7}, COST_IMPASSABLE, time);
 	log::log(INFO << "Created cost field");
 
 	// Create an integration field from the cost field

libopenage/pathfinding/demo/demo_1.cpp

@@ -1,4 +1,4 @@
-// Copyright 2024-2024 the openage authors. See copying.md for legal info.
+// Copyright 2024-2025 the openage authors. See copying.md for legal info.
 
 #include "demo_1.h"
 
@@ -30,29 +30,42 @@ void path_demo_1(const util::Path &path) {
 	// Initialize the cost field for each sector.
 	for (auto &sector : grid->get_sectors()) {
 		auto cost_field = sector->get_cost_field();
-		std::vector<cost_t> sector_cost = sectors_cost.at(sector->get_id());
-		cost_field->set_costs(std::move(sector_cost));
+
+		// Read the data from the preconfigured table
+		std::vector<cost_t> sector_cost = SECTORS_COST.at(sector->get_id());
+
+		// Set the cost field for the sector
+		cost_field->set_costs(std::move(sector_cost), time::TIME_MAX);
 	}
 
-	// Initialize portals between sectors.
+	// Initialize portals between sectors
 	util::Vector2s grid_size = grid->get_size();
 	portal_id_t portal_id = 0;
 	for (size_t y = 0; y < grid_size[1]; y++) {
 		for (size_t x = 0; x < grid_size[0]; x++) {
+			// For each sector on the grid, we will seatch for portals to the east and south
+			// sectors and connect them
+
 			auto sector = grid->get_sector(x, y);
 
 			if (x < grid_size[0] - 1) {
+				// Check the sector to the east
 				auto neighbor = grid->get_sector(x + 1, y);
 				auto portals = sector->find_portals(neighbor, PortalDirection::EAST_WEST, portal_id);
+
+				// Add the portals to the sector and the neighbor
 				for (auto &portal : portals) {
 					sector->add_portal(portal);
 					neighbor->add_portal(portal);
 				}
 				portal_id += portals.size();
 			}
 			if (y < grid_size[1] - 1) {
+				// Check the sector to the south
 				auto neighbor = grid->get_sector(x, y + 1);
 				auto portals = sector->find_portals(neighbor, PortalDirection::NORTH_SOUTH, portal_id);
+
+				// Add the portals to the sector and the neighbor
 				for (auto &portal : portals) {
 					sector->add_portal(portal);
 					neighbor->add_portal(portal);
@@ -62,7 +75,8 @@ void path_demo_1(const util::Path &path) {
 		}
 	}
 
-	// Connect portals inside sectors.
+	// Connect portals that can mutually reach each other
+	// within the same sector
 	for (auto sector : grid->get_sectors()) {
 		sector->connect_exits();
 
@@ -81,19 +95,25 @@ void path_demo_1(const util::Path &path) {
 	auto pathfinder = std::make_shared<path::Pathfinder>();
 	pathfinder->add_grid(grid);
 
+	// Add a timer to measure the pathfinding speed
 	util::Timer timer;
 
-	// Create a path request and get the path
+	// Create a path request from one end of the grid to the other
 	coord::tile start{2, 26};
 	coord::tile target{36, 2};
-
 	PathRequest path_request{
 		grid->get_id(),
 		start,
 		target,
+		time::TIME_ZERO,
 	};
+
+	// Initialize the portal nodes of the grid
+	// This is used for the A* pathfinding search at the beginning
 	grid->init_portal_nodes();
+
 	timer.start();
+	// Let the pathfinder search for a path
 	Path path_result = pathfinder->get_path(path_request);
 	timer.stop();
 
@@ -109,8 +129,11 @@ void path_demo_1(const util::Path &path) {
 	auto render_manager = std::make_shared<RenderManager1>(qtapp, window, path, grid);
 	log::log(INFO << "Created render manager for pathfinding demo");
 
+	// Callbacks for mouse button events
+	// Used to set the start and target cells for pathfinding
 	window->add_mouse_button_callback([&](const QMouseEvent &ev) {
 		if (ev.type() == QEvent::MouseButtonRelease) {
+			// From the mouse position, calculate the position/cell on the grid
 			auto cell_count_x = grid->get_size()[0] * grid->get_sector_size();
 			auto cell_count_y = grid->get_size()[1] * grid->get_sector_size();
 			auto window_size = window->get_size();
@@ -127,6 +150,7 @@ void path_demo_1(const util::Path &path) {
 					grid->get_id(),
 					start,
 					target,
+					time::TIME_ZERO,
 				};
 
 				timer.reset();
@@ -147,6 +171,7 @@ void path_demo_1(const util::Path &path) {
 					grid->get_id(),
 					start,
 					target,
+					time::TIME_ZERO,
 				};
 
 				timer.reset();

libopenage/pathfinding/demo/demo_1.h

@@ -1,4 +1,4 @@
-// Copyright 2024-2024 the openage authors. See copying.md for legal info.
+// Copyright 2024-2025 the openage authors. See copying.md for legal info.
 
 #pragma once
 
@@ -182,7 +182,7 @@ class RenderManager1 {
 
 // Cost for the sectors in the grid
 // taken from Figure 23.1 in "Crowd Pathfinding and Steering Using Flow Field Tiles"
-const std::vector<std::vector<cost_t>> sectors_cost = {
+const std::vector<std::vector<cost_t>> SECTORS_COST = {
 	{
 		// clang-format off
           1,   1,   1,   1,   1,   1,   1,   1,   1,   1,