C++ CCamera::BuildCameraRay方法代码示例

std::vector<entity_id_t> EntitySelection::PickEntitiesAtPoint(CSimulation2& simulation, const CCamera& camera, int screenX, int screenY, player_id_t player, bool allowEditorSelectables)
{
	CVector3D origin, dir;
	camera.BuildCameraRay(screenX, screenY, origin, dir);

	CmpPtr<ICmpRangeManager> cmpRangeManager(simulation, SYSTEM_ENTITY);
	ENSURE(cmpRangeManager);

	std::vector<std::pair<float, entity_id_t> > hits; // (dist^2, entity) pairs

	const CSimulation2::InterfaceListUnordered& ents = simulation.GetEntitiesWithInterfaceUnordered(IID_Selectable);
	for (CSimulation2::InterfaceListUnordered::const_iterator it = ents.begin(); it != ents.end(); ++it)
	{
		entity_id_t ent = it->first;

		// Check if this entity is only selectable in Atlas
		if (!allowEditorSelectables && static_cast<ICmpSelectable*>(it->second)->IsEditorOnly())
			continue;

		// Ignore entities hidden by LOS (or otherwise hidden, e.g. when not IsInWorld)
		if (cmpRangeManager->GetLosVisibility(ent, player) == ICmpRangeManager::VIS_HIDDEN)
			continue;

		CmpPtr<ICmpVisual> cmpVisual(simulation.GetSimContext(), ent);
		if (!cmpVisual)
			continue;

		CVector3D center;
		float tmin, tmax;

		CBoundingBoxOriented selectionBox = cmpVisual->GetSelectionBox();
		if (selectionBox.IsEmpty())
		{
			if (!allowEditorSelectables)
				continue;

			// Fall back to using old AABB selection method for decals
			//	see: http://trac.wildfiregames.com/ticket/1032
			CBoundingBoxAligned aABBox = cmpVisual->GetBounds();
			if (aABBox.IsEmpty())
				continue;

			if (!aABBox.RayIntersect(origin, dir, tmin, tmax))
				continue;

			aABBox.GetCentre(center);
		}
		else
		{
			if (!selectionBox.RayIntersect(origin, dir, tmin, tmax))
				continue;

			center = selectionBox.m_Center;
		}

		// Find the perpendicular distance from the object's centre to the picker ray

		float dist2;
		CVector3D closest = origin + dir * (center - origin).Dot(dir);
		dist2 = (closest - center).LengthSquared();

		hits.push_back(std::make_pair(dist2, ent));
	}

	// Sort hits by distance
	std::sort(hits.begin(), hits.end()); // lexicographic comparison

	// Extract the entity IDs
	std::vector<entity_id_t> hitEnts;
	hitEnts.reserve(hits.size());
	for (size_t i = 0; i < hits.size(); ++i)
		hitEnts.push_back(hits[i].second);
	return hitEnts;
}

std::vector<entity_id_t> EntitySelection::PickEntitiesAtPoint(CSimulation2& simulation, const CCamera& camera, int screenX, int screenY, player_id_t player, bool allowEditorSelectables, int range)
{
	PROFILE2("PickEntitiesAtPoint");
	CVector3D origin, dir;
	camera.BuildCameraRay(screenX, screenY, origin, dir);

	CmpPtr<ICmpRangeManager> cmpRangeManager(simulation, SYSTEM_ENTITY);
	ENSURE(cmpRangeManager);

	/* We try to approximate where the mouse is hovering by drawing a ray from
	 * the center of the camera and through the mouse then taking the position
	 * at which the ray intersects the terrain.                               */
	// TODO: Do this smarter without being slow.
	CVector3D pos3d = camera.GetWorldCoordinates(screenX, screenY, true);
	// Change the position to 2D by removing the terrain height.
	CFixedVector2D pos(fixed::FromFloat(pos3d.X), fixed::FromFloat(pos3d.Z));

	// Get a rough group of entities using our approximated origin.
	SpatialQueryArray ents;
	cmpRangeManager->GetSubdivision()->GetNear(ents, pos, entity_pos_t::FromInt(range));

	// Filter for relevent entities and calculate precise distances.
	std::vector<std::pair<float, entity_id_t> > hits; // (dist^2, entity) pairs
	for (int i = 0; i < ents.size(); ++i)
	{
		CmpPtr<ICmpSelectable> cmpSelectable(simulation, ents[i]);
		if (!cmpSelectable)
			continue;

		CEntityHandle handle = cmpSelectable->GetEntityHandle();

		// Check if this entity is only selectable in Atlas
		if (!allowEditorSelectables && cmpSelectable->IsEditorOnly())
			continue;

		// Ignore entities hidden by LOS (or otherwise hidden, e.g. when not IsInWorld)
		if (cmpRangeManager->GetLosVisibility(handle, player) == ICmpRangeManager::VIS_HIDDEN)
			continue;

		CmpPtr<ICmpVisual> cmpVisual(handle);
		if (!cmpVisual)
			continue;

		CVector3D center;
		float tmin, tmax;

		CBoundingBoxOriented selectionBox = cmpVisual->GetSelectionBox();
		if (selectionBox.IsEmpty())
		{
			if (!allowEditorSelectables)
				continue;

			// Fall back to using old AABB selection method for decals
			//	see: http://trac.wildfiregames.com/ticket/1032
			CBoundingBoxAligned aABBox = cmpVisual->GetBounds();
			if (aABBox.IsEmpty())
				continue;

			if (!aABBox.RayIntersect(origin, dir, tmin, tmax))
				continue;

			aABBox.GetCentre(center);
		}
		else
		{
			if (!selectionBox.RayIntersect(origin, dir, tmin, tmax))
				continue;

			center = selectionBox.m_Center;
		}

		// Find the perpendicular distance from the object's centre to the picker ray
		float dist2;
		CVector3D closest = origin + dir * (center - origin).Dot(dir);
		dist2 = (closest - center).LengthSquared();

		hits.push_back(std::make_pair(dist2, ents[i]));
	}

	// Sort hits by distance
	std::sort(hits.begin(), hits.end()); // lexicographic comparison

	// Extract the entity IDs
	std::vector<entity_id_t> hitEnts;
	hitEnts.reserve(hits.size());
	for (size_t i = 0; i < hits.size(); ++i)
		hitEnts.push_back(hits[i].second);
	return hitEnts;
}