sbox-public/engine/Tests/Sandbox.Test.Integration/Navigation/Navigation.cs

using Sandbox;
using Sandbox.Navigation;
using Sandbox.Navigation.Generation;
namespace NavigationTests;

[TestClass]
public class MeshBuildingTest
{
	private static readonly Config testConfig = Config.CreateValidatedConfig(
		new Vector2Int( 0, 0 ),
		BBox.FromPositionAndSize( 0, 400 ),
		4.0f,
		2.0f,
		64.0f,
		16.0f,
		18.0f,
		40.0f
	);

	[TestMethod]
	public void Generator_FromPhysicsShape_Simple()
	{
		// A physics world to generate the navmesh from
		var world = new PhysicsWorld();
		var body = new PhysicsBody( world );
		var shape = body.AddBoxShape( BBox.FromPositionAndSize( 0, 200 ), Rotation.Identity );


		// generate the navmesh using CNavMeshHeightFieldGenerator
		{
			using HeightFieldGenerator hfGenerator = new();
			hfGenerator.Init( testConfig );

			hfGenerator.AddGeometryFromPhysicsShape( shape );
			Assert.AreEqual( 8, hfGenerator.inputGeoVerticesCount );
			Assert.AreEqual( 36, hfGenerator.inputGeoIndicesCount );

			using var heightField = hfGenerator.Generate();

			Assert.IsTrue( heightField != default );

			using NavMeshGenerator nmGenerator = new();
			nmGenerator.Init( testConfig, heightField );

			using var meshData = nmGenerator.Generate();

			Assert.IsNotNull( meshData );

			world.Delete();
		}
	}

	[TestMethod]
	public async Task Generator_GenerateTile_HighLevel()
	{
		using var navMesh = new NavMesh();
		var world = new PhysicsWorld();

		var boxSize = BBox.FromPositionAndSize( 0, 100 );
		var body = new PhysicsBody( world );
		body.AddBoxShape( boxSize, Rotation.Identity );

		navMesh.IsEnabled = true;
		navMesh.Init();

		// The tile grid is centered on the world origin, so tile (0,0) is the far corner
		// of the 512x512 grid - use the tile that actually contains our box geometry.
		var testTilePosition = navMesh.WorldPositionToTilePosition( Vector3.Zero );
		var testTileWorldPosition = navMesh.TilePositionToWorldPosition( testTilePosition );

		var generateTask = navMesh.GenerateTile( world, testTileWorldPosition );
		await generateTask;

		world.Delete();

		boxSize = boxSize.Grow( 5 );

		// An empty tile would make the loop below pass without asserting anything
		var polyCount = navMesh.GetPolyCount( testTilePosition );
		Assert.IsTrue( polyCount > 0, "Generated tile should contain at least one poly" );

		for ( int i = 0; i < polyCount; i++ )
		{
			foreach ( var vert in navMesh.GetPolyVerts( testTilePosition, i ) )
			{
				Assert.IsTrue( boxSize.Contains( vert ) );
			}
		}
	}

	[TestMethod]
	public async Task Query_RandomPoint()
	{
		var navMesh = new NavMesh();
		var world = new PhysicsWorld();

		var boxSize = BBox.FromPositionAndSize( 0, 500 );
		var body = new PhysicsBody( world );
		body.AddBoxShape( boxSize, Rotation.Identity );

		var generatedTask = navMesh.Generate( world );
		var generated = await generatedTask;
		Assert.IsTrue( generated );

		world.Delete();

		var p = navMesh.GetRandomPoint();
		Assert.IsTrue( p.HasValue );

		navMesh.Dispose();
	}

	[TestMethod]
	public async Task Query_ClosestPoint()
	{
		var navMesh = new NavMesh();
		var world = new PhysicsWorld();

		var boxSize = BBox.FromPositionAndSize( 0, 200 );
		var body = new PhysicsBody( world );
		body.AddBoxShape( boxSize, Rotation.Identity );

		var generatedTask = navMesh.Generate( world );
		var generated = await generatedTask;
		Assert.IsTrue( generated );

		world.Delete();

		var p = navMesh.GetClosestPoint( new Vector3( 100, 100, 100 ) );
		Assert.IsTrue( p.HasValue );

		navMesh.Dispose();
	}


	[TestMethod]
	public async Task Query_ClosestEdge()
	{
		var navMesh = new NavMesh();
		var world = new PhysicsWorld();

		var boxSize = BBox.FromPositionAndSize( 0, 500 );
		var body = new PhysicsBody( world );
		body.AddBoxShape( boxSize, Rotation.Identity );

		var generatedTask = navMesh.Generate( world );
		var generated = await generatedTask;
		Assert.IsTrue( generated );

		world.Delete();

		var p = navMesh.GetClosestEdge( new Vector3( 100, 100, 100 ) );
		Assert.IsTrue( p.HasValue );

		navMesh.Dispose();
	}

	[TestMethod]
	public async Task Query_Path()
	{
		var navMesh = new NavMesh();
		var world = new PhysicsWorld();

		var boxSize = BBox.FromPositionAndSize( 0, 500 );
		var body = new PhysicsBody( world );
		body.AddBoxShape( boxSize, Rotation.Identity );

		var generatedTask = navMesh.Generate( world );
		var generated = await generatedTask;
		Assert.IsTrue( generated );

		world.Delete();


		var pathResult = navMesh.CalculatePath( new CalculatePathRequest { Start = new Vector3( 200, 200, 250 ), Target = new Vector3( -200, -200, 250 ) } );
		Assert.IsTrue( pathResult.IsValid() );
		Assert.AreNotEqual( 0, pathResult.Points.Count );

		navMesh.Dispose();
	}

	[TestMethod]
	public async Task Bake_Roundtrip_PreservesNavMesh()
	{
		// Generate a navmesh
		var sourceNavMesh = new NavMesh();
		var world = new PhysicsWorld();

		var boxSize = BBox.FromPositionAndSize( 0, 500 );
		var body = new PhysicsBody( world );
		body.AddBoxShape( boxSize, Rotation.Identity );

		var generated = await sourceNavMesh.Generate( world );
		Assert.IsTrue( generated, "Failed to generate source navmesh" );

		// Capture some data from source for comparison
		var sourceRandomPoint = sourceNavMesh.GetRandomPoint();
		Assert.IsTrue( sourceRandomPoint.HasValue, "Source navmesh should have valid points" );

		// Bake the heightfield data to bytes (in-memory, no file I/O)
		var bakedData = await sourceNavMesh.BakeDataToBytes();
		Assert.IsNotNull( bakedData, "Baked data should not be null" );
		Assert.IsTrue( bakedData.Length > 0, "Baked data should have content" );

		// Drop the source geometry NOW: regenerating against the live world would fall
		// back to collecting world geometry, hiding a completely broken bake/load path.
		// With an empty world, a working mesh can only come from the baked heightfields.
		world.Delete();
		var emptyWorld = new PhysicsWorld();

		// Create new navmesh and load from baked data directly
		var loadedNavMesh = new NavMesh();
		loadedNavMesh.IsEnabled = true;
		loadedNavMesh.Init();
		await loadedNavMesh.LoadFromBakedData( bakedData );

		// Generate() derives Bounds from the world - with the empty world that's a zero-size
		// box and no tile would be processed. Pin the source's generation bounds instead.
		loadedNavMesh.CustomBounds = true;
		loadedNavMesh.Bounds = sourceNavMesh.Bounds;

		// Regenerate the navmesh from the loaded heightfield data
		var loadedGenerated = await loadedNavMesh.Generate( emptyWorld );
		Assert.IsTrue( loadedGenerated, "Failed to generate navmesh from loaded baked data" );

		// Verify the loaded navmesh is functional
		var loadedRandomPoint = loadedNavMesh.GetRandomPoint();
		Assert.IsTrue( loadedRandomPoint.HasValue, "Loaded navmesh should have valid points" );

		// Test path finding on loaded navmesh
		var pathResult = loadedNavMesh.CalculatePath( new CalculatePathRequest
		{
			Start = new Vector3( 200, 200, 250 ),
			Target = new Vector3( -200, -200, 250 )
		} );
		Assert.IsTrue( pathResult.IsValid(), "Path should be valid on loaded navmesh" );
		Assert.AreNotEqual( 0, pathResult.Points.Count, "Path should have points" );

		emptyWorld.Delete();

		sourceNavMesh.Dispose();
		loadedNavMesh.Dispose();
	}
}