//! Finds the collision point of a line and lots of triangles, if there is one.
bool CSceneCollisionManager::getCollisionPoint(const core::line3d<f32>& ray,
	ITriangleSelector* selector, core::vector3df& outIntersection,
	core::triangle3df& outTriangle)
{
	if (!selector)
	{
		_IRR_IMPLEMENT_MANAGED_MARSHALLING_BUGFIX;
		return false;
	}

	s32 totalcnt = selector->getTriangleCount();
	Triangles.set_used(totalcnt);

	s32 cnt = 0;
	selector->getTriangles(Triangles.pointer(), totalcnt, cnt, ray);

	const core::vector3df linevect = ray.getVector().normalize();
	core::vector3df intersection;
	f32 nearest = 9999999999999.0f;
	bool found = false;
	const f32 raylength = ray.getLengthSQ();

	for (s32 i=0; i<cnt; ++i)
	{
		if (Triangles[i].getIntersectionWithLine(ray.start, linevect, intersection))
		{
			const f32 tmp = intersection.getDistanceFromSQ(ray.start);
			const f32 tmp2 = intersection.getDistanceFromSQ(ray.end);

			if (tmp < raylength && tmp2 < raylength && tmp < nearest)
			{
				nearest = tmp;
				outTriangle = Triangles[i];
				outIntersection = intersection;
				found = true;
			}
		}
	}

	_IRR_IMPLEMENT_MANAGED_MARSHALLING_BUGFIX;
	return found;
}
Beispiel #2
0
static bool testGetIntersectionWithLine(core::triangle3d<T>& triangle, const core::line3d<T>& ray)
{
	bool allExpected=true;
	const vector3d<T> linevect = ray.getVector().normalize();
	vector3d<T> intersection;
	for (u32 i=0; i<100; ++i)
	{
		if (!triangle.getIntersectionOfPlaneWithLine(ray.start, linevect, intersection))
		{
			allExpected=false;
			logTestString("triangle3d plane test %d failed\n", i);
		}
		if (!triangle.isPointInsideFast(intersection))
		{
			allExpected=false;
			logTestString("triangle3d fast point test %d failed\n", i);
		}
		if (!triangle.isPointInside(intersection))
		{
			allExpected=false;
			logTestString("triangle3d point test %d failed\n", i);
		        if (!isOnSameSide(intersection, triangle.pointA, triangle.pointB, triangle.pointC))
				logTestString("triangle3d side1 test %d failed\n", i);
			if (!isOnSameSide(intersection, triangle.pointB, triangle.pointA, triangle.pointC))
				logTestString("triangle3d side2 test %d failed\n", i);
			if (!isOnSameSide(intersection, triangle.pointC, triangle.pointA, triangle.pointB))
				logTestString("triangle3d side3 test %d failed\n", i);
		}

		if (!triangle.getIntersectionWithLine(ray.start, linevect, intersection))
		{
			allExpected=false;
			logTestString("triangle3d tri test %d failed\n", i);
		}

		triangle.pointB.Y += 1;
	}
	return allExpected;
}
PointedThing ClientEnvironment::getPointedThing(
	core::line3d<f32> shootline,
	bool liquids_pointable,
	bool look_for_object)
{
	PointedThing result;

	INodeDefManager *nodedef = m_map->getNodeDefManager();

	core::aabbox3d<s16> maximal_exceed = nodedef->getSelectionBoxIntUnion();
	// The code needs to search these nodes
	core::aabbox3d<s16> search_range(-maximal_exceed.MaxEdge,
		-maximal_exceed.MinEdge);
	// If a node is found, there might be a larger node behind.
	// To find it, we have to go further.
	s16 maximal_overcheck =
		std::max(abs(search_range.MinEdge.X), abs(search_range.MaxEdge.X))
			+ std::max(abs(search_range.MinEdge.Y), abs(search_range.MaxEdge.Y))
			+ std::max(abs(search_range.MinEdge.Z), abs(search_range.MaxEdge.Z));

	const v3f original_vector = shootline.getVector();
	const f32 original_length = original_vector.getLength();

	f32 min_distance = original_length;

	// First try to find an active object
	if (look_for_object) {
		ClientActiveObject *selected_object = getSelectedActiveObject(
			shootline, &result.intersection_point,
			&result.intersection_normal);

		if (selected_object != NULL) {
			min_distance =
				(result.intersection_point - shootline.start).getLength();

			result.type = POINTEDTHING_OBJECT;
			result.object_id = selected_object->getId();
		}
	}

	// Reduce shootline
	if (original_length > 0) {
		shootline.end = shootline.start
			+ shootline.getVector() / original_length * min_distance;
	}

	// Try to find a node that is closer than the selected active
	// object (if it exists).

	voxalgo::VoxelLineIterator iterator(shootline.start / BS,
		shootline.getVector() / BS);
	v3s16 oldnode = iterator.m_current_node_pos;
	// Indicates that a node was found.
	bool is_node_found = false;
	// If a node is found, it is possible that there's a node
	// behind it with a large nodebox, so continue the search.
	u16 node_foundcounter = 0;
	// If a node is found, this is the center of the
	// first nodebox the shootline meets.
	v3f found_boxcenter(0, 0, 0);
	// The untested nodes are in this range.
	core::aabbox3d<s16> new_nodes;
	while (true) {
		// Test the nodes around the current node in search_range.
		new_nodes = search_range;
		new_nodes.MinEdge += iterator.m_current_node_pos;
		new_nodes.MaxEdge += iterator.m_current_node_pos;

		// Only check new nodes
		v3s16 delta = iterator.m_current_node_pos - oldnode;
		if (delta.X > 0)
			new_nodes.MinEdge.X = new_nodes.MaxEdge.X;
		else if (delta.X < 0)
			new_nodes.MaxEdge.X = new_nodes.MinEdge.X;
		else if (delta.Y > 0)
			new_nodes.MinEdge.Y = new_nodes.MaxEdge.Y;
		else if (delta.Y < 0)
			new_nodes.MaxEdge.Y = new_nodes.MinEdge.Y;
		else if (delta.Z > 0)
			new_nodes.MinEdge.Z = new_nodes.MaxEdge.Z;
		else if (delta.Z < 0)
			new_nodes.MaxEdge.Z = new_nodes.MinEdge.Z;

		// For each untested node
		for (s16 x = new_nodes.MinEdge.X; x <= new_nodes.MaxEdge.X; x++) {
			for (s16 y = new_nodes.MinEdge.Y; y <= new_nodes.MaxEdge.Y; y++) {
				for (s16 z = new_nodes.MinEdge.Z; z <= new_nodes.MaxEdge.Z; z++) {
					MapNode n;
					v3s16 np(x, y, z);
					bool is_valid_position;

					n = m_map->getNodeNoEx(np, &is_valid_position);
					if (!(is_valid_position &&
						isPointableNode(n, nodedef, liquids_pointable))) {
						continue;
					}
					std::vector<aabb3f> boxes;
					n.getSelectionBoxes(nodedef, &boxes,
						n.getNeighbors(np, m_map));

					v3f npf = intToFloat(np, BS);
					for (std::vector<aabb3f>::const_iterator i = boxes.begin();
						i != boxes.end(); ++i) {
						aabb3f box = *i;
						box.MinEdge += npf;
						box.MaxEdge += npf;
						v3f intersection_point;
						v3s16 intersection_normal;
						if (!boxLineCollision(box, shootline.start, shootline.getVector(),
							&intersection_point, &intersection_normal)) {
							continue;
						}
						f32 distance = (intersection_point - shootline.start).getLength();
						if (distance >= min_distance) {
							continue;
						}
						result.type = POINTEDTHING_NODE;
						result.node_undersurface = np;
						result.intersection_point = intersection_point;
						result.intersection_normal = intersection_normal;
						found_boxcenter = box.getCenter();
						min_distance = distance;
						is_node_found = true;
					}
				}
			}
		}
		if (is_node_found) {
			node_foundcounter++;
			if (node_foundcounter > maximal_overcheck) {
				break;
			}
		}
		// Next node
		if (iterator.hasNext()) {
			oldnode = iterator.m_current_node_pos;
			iterator.next();
		} else {
			break;
		}
	}

	if (is_node_found) {
		// Set undersurface and abovesurface nodes
		f32 d = 0.002 * BS;
		v3f fake_intersection = result.intersection_point;
		// Move intersection towards its source block.
		if (fake_intersection.X < found_boxcenter.X)
			fake_intersection.X += d;
		else
			fake_intersection.X -= d;

		if (fake_intersection.Y < found_boxcenter.Y)
			fake_intersection.Y += d;
		else
			fake_intersection.Y -= d;

		if (fake_intersection.Z < found_boxcenter.Z)
			fake_intersection.Z += d;
		else
			fake_intersection.Z -= d;

		result.node_real_undersurface = floatToInt(fake_intersection, BS);
		result.node_abovesurface = result.node_real_undersurface
			+ result.intersection_normal;
	}
	return result;
}