godot/tests/test_astar.h
Rémi Verschelde b5334d14f7
Update copyright statements to 2021
Happy new year to the wonderful Godot community!

2020 has been a tough year for most of us personally, but a good year for
Godot development nonetheless with a huge amount of work done towards Godot
4.0 and great improvements backported to the long-lived 3.2 branch.

We've had close to 400 contributors to engine code this year, authoring near
7,000 commit! (And that's only for the `master` branch and for the engine code,
there's a lot more when counting docs, demos and other first-party repos.)

Here's to a great year 2021 for all Godot users 🎆
2021-01-01 20:19:21 +01:00

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/*************************************************************************/
/* test_astar.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#ifndef TEST_ASTAR_H
#define TEST_ASTAR_H
#include "core/math/a_star.h"
#include "core/math/math_funcs.h"
#include "core/os/os.h"
#include <math.h>
#include <stdio.h>
#include "tests/test_macros.h"
namespace TestAStar {
class ABCX : public AStar {
public:
enum {
A,
B,
C,
X,
};
ABCX() {
add_point(A, Vector3(0, 0, 0));
add_point(B, Vector3(1, 0, 0));
add_point(C, Vector3(0, 1, 0));
add_point(X, Vector3(0, 0, 1));
connect_points(A, B);
connect_points(A, C);
connect_points(B, C);
connect_points(X, A);
}
// Disable heuristic completely.
float _compute_cost(int p_from, int p_to) {
if (p_from == A && p_to == C) {
return 1000;
}
return 100;
}
};
TEST_CASE("[AStar] ABC path") {
ABCX abcx;
Vector<int> path = abcx.get_id_path(ABCX::A, ABCX::C);
REQUIRE(path.size() == 3);
CHECK(path[0] == ABCX::A);
CHECK(path[1] == ABCX::B);
CHECK(path[2] == ABCX::C);
}
TEST_CASE("[AStar] ABCX path") {
ABCX abcx;
Vector<int> path = abcx.get_id_path(ABCX::X, ABCX::C);
REQUIRE(path.size() == 4);
CHECK(path[0] == ABCX::X);
CHECK(path[1] == ABCX::A);
CHECK(path[2] == ABCX::B);
CHECK(path[3] == ABCX::C);
}
TEST_CASE("[AStar] Add/Remove") {
AStar a;
// Manual tests.
a.add_point(1, Vector3(0, 0, 0));
a.add_point(2, Vector3(0, 1, 0));
a.add_point(3, Vector3(1, 1, 0));
a.add_point(4, Vector3(2, 0, 0));
a.connect_points(1, 2, true);
a.connect_points(1, 3, true);
a.connect_points(1, 4, false);
CHECK(a.are_points_connected(2, 1));
CHECK(a.are_points_connected(4, 1));
CHECK(a.are_points_connected(2, 1, false));
CHECK_FALSE(a.are_points_connected(4, 1, false));
a.disconnect_points(1, 2, true);
CHECK(a.get_point_connections(1).size() == 2); // 3, 4
CHECK(a.get_point_connections(2).size() == 0);
a.disconnect_points(4, 1, false);
CHECK(a.get_point_connections(1).size() == 2); // 3, 4
CHECK(a.get_point_connections(4).size() == 0);
a.disconnect_points(4, 1, true);
CHECK(a.get_point_connections(1).size() == 1); // 3
CHECK(a.get_point_connections(4).size() == 0);
a.connect_points(2, 3, false);
CHECK(a.get_point_connections(2).size() == 1); // 3
CHECK(a.get_point_connections(3).size() == 1); // 1
a.connect_points(2, 3, true);
CHECK(a.get_point_connections(2).size() == 1); // 3
CHECK(a.get_point_connections(3).size() == 2); // 1, 2
a.disconnect_points(2, 3, false);
CHECK(a.get_point_connections(2).size() == 0);
CHECK(a.get_point_connections(3).size() == 2); // 1, 2
a.connect_points(4, 3, true);
CHECK(a.get_point_connections(3).size() == 3); // 1, 2, 4
CHECK(a.get_point_connections(4).size() == 1); // 3
a.disconnect_points(3, 4, false);
CHECK(a.get_point_connections(3).size() == 2); // 1, 2
CHECK(a.get_point_connections(4).size() == 1); // 3
a.remove_point(3);
CHECK(a.get_point_connections(1).size() == 0);
CHECK(a.get_point_connections(2).size() == 0);
CHECK(a.get_point_connections(4).size() == 0);
a.add_point(0, Vector3(0, -1, 0));
a.add_point(3, Vector3(2, 1, 0));
// 0: (0, -1)
// 1: (0, 0)
// 2: (0, 1)
// 3: (2, 1)
// 4: (2, 0)
// Tests for get_closest_position_in_segment.
a.connect_points(2, 3);
CHECK(a.get_closest_position_in_segment(Vector3(0.5, 0.5, 0)) == Vector3(0.5, 1, 0));
a.connect_points(3, 4);
a.connect_points(0, 3);
a.connect_points(1, 4);
a.disconnect_points(1, 4, false);
a.disconnect_points(4, 3, false);
a.disconnect_points(3, 4, false);
// Remaining edges: <2, 3>, <0, 3>, <1, 4> (directed).
CHECK(a.get_closest_position_in_segment(Vector3(2, 0.5, 0)) == Vector3(1.75, 0.75, 0));
CHECK(a.get_closest_position_in_segment(Vector3(-1, 0.2, 0)) == Vector3(0, 0, 0));
CHECK(a.get_closest_position_in_segment(Vector3(3, 2, 0)) == Vector3(2, 1, 0));
Math::seed(0);
// Random tests for connectivity checks
for (int i = 0; i < 20000; i++) {
int u = Math::rand() % 5;
int v = Math::rand() % 4;
if (u == v) {
v = 4;
}
if (Math::rand() % 2 == 1) {
// Add a (possibly existing) directed edge and confirm connectivity.
a.connect_points(u, v, false);
CHECK(a.are_points_connected(u, v, false));
} else {
// Remove a (possibly nonexistent) directed edge and confirm disconnectivity.
a.disconnect_points(u, v, false);
CHECK_FALSE(a.are_points_connected(u, v, false));
}
}
// Random tests for point removal.
for (int i = 0; i < 20000; i++) {
a.clear();
for (int j = 0; j < 5; j++) {
a.add_point(j, Vector3(0, 0, 0));
}
// Add or remove random edges.
for (int j = 0; j < 10; j++) {
int u = Math::rand() % 5;
int v = Math::rand() % 4;
if (u == v) {
v = 4;
}
if (Math::rand() % 2 == 1) {
a.connect_points(u, v, false);
} else {
a.disconnect_points(u, v, false);
}
}
// Remove point 0.
a.remove_point(0);
// White box: this will check all edges remaining in the segments set.
for (int j = 1; j < 5; j++) {
CHECK_FALSE(a.are_points_connected(0, j, true));
}
}
// It's been great work, cheers. \(^ ^)/
}
TEST_CASE("[Stress][AStar] Find paths") {
// Random stress tests with Floyd-Warshall.
const int N = 30;
Math::seed(0);
for (int test = 0; test < 1000; test++) {
AStar a;
Vector3 p[N];
bool adj[N][N] = { { false } };
// Assign initial coordinates.
for (int u = 0; u < N; u++) {
p[u].x = Math::rand() % 100;
p[u].y = Math::rand() % 100;
p[u].z = Math::rand() % 100;
a.add_point(u, p[u]);
}
// Generate a random sequence of operations.
for (int i = 0; i < 1000; i++) {
// Pick two different vertices.
int u, v;
u = Math::rand() % N;
v = Math::rand() % (N - 1);
if (u == v) {
v = N - 1;
}
// Pick a random operation.
int op = Math::rand();
switch (op % 9) {
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
// Add edge (u, v); possibly bidirectional.
a.connect_points(u, v, op % 2);
adj[u][v] = true;
if (op % 2) {
adj[v][u] = true;
}
break;
case 6:
case 7:
// Remove edge (u, v); possibly bidirectional.
a.disconnect_points(u, v, op % 2);
adj[u][v] = false;
if (op % 2) {
adj[v][u] = false;
}
break;
case 8:
// Remove point u and add it back; clears adjacent edges and changes coordinates.
a.remove_point(u);
p[u].x = Math::rand() % 100;
p[u].y = Math::rand() % 100;
p[u].z = Math::rand() % 100;
a.add_point(u, p[u]);
for (v = 0; v < N; v++) {
adj[u][v] = adj[v][u] = false;
}
break;
}
}
// Floyd-Warshall.
float d[N][N];
for (int u = 0; u < N; u++) {
for (int v = 0; v < N; v++) {
d[u][v] = (u == v || adj[u][v]) ? p[u].distance_to(p[v]) : INFINITY;
}
}
for (int w = 0; w < N; w++) {
for (int u = 0; u < N; u++) {
for (int v = 0; v < N; v++) {
if (d[u][v] > d[u][w] + d[w][v]) {
d[u][v] = d[u][w] + d[w][v];
}
}
}
}
// Display statistics.
int count = 0;
for (int u = 0; u < N; u++) {
for (int v = 0; v < N; v++) {
if (adj[u][v]) {
count++;
}
}
}
print_verbose(vformat("Test #%4d: %3d edges, ", test + 1, count));
count = 0;
for (int u = 0; u < N; u++) {
for (int v = 0; v < N; v++) {
if (!Math::is_inf(d[u][v])) {
count++;
}
}
}
print_verbose(vformat("%3d/%d pairs of reachable points\n", count - N, N * (N - 1)));
// Check A*'s output.
bool match = true;
for (int u = 0; u < N; u++) {
for (int v = 0; v < N; v++) {
if (u != v) {
Vector<int> route = a.get_id_path(u, v);
if (!Math::is_inf(d[u][v])) {
// Reachable.
if (route.size() == 0) {
print_verbose(vformat("From %d to %d: A* did not find a path\n", u, v));
match = false;
goto exit;
}
float astar_dist = 0;
for (int i = 1; i < route.size(); i++) {
if (!adj[route[i - 1]][route[i]]) {
print_verbose(vformat("From %d to %d: edge (%d, %d) does not exist\n",
u, v, route[i - 1], route[i]));
match = false;
goto exit;
}
astar_dist += p[route[i - 1]].distance_to(p[route[i]]);
}
if (!Math::is_equal_approx(astar_dist, d[u][v])) {
print_verbose(vformat("From %d to %d: Floyd-Warshall gives %.6f, A* gives %.6f\n",
u, v, d[u][v], astar_dist));
match = false;
goto exit;
}
} else {
// Unreachable.
if (route.size() > 0) {
print_verbose(vformat("From %d to %d: A* somehow found a nonexistent path\n", u, v));
match = false;
goto exit;
}
}
}
}
}
exit:
CHECK_MESSAGE(match, "Found all paths.");
}
}
} // namespace TestAStar
#endif // TEST_ASTAR_H