CCmpObstruction.cpp

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/* Copyright (C) 2013 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * 0 A.D. is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "precompiled.h"

#include "simulation2/system/Component.h"
#include "ICmpObstruction.h"

#include "ps/CLogger.h"
#include "simulation2/MessageTypes.h"
#include "simulation2/components/ICmpObstructionManager.h"
#include "simulation2/components/ICmpPosition.h"
#include "simulation2/serialization/SerializeTemplates.h"

#define MAX(x,y) x>y ? x : y
#define MIN(x,y) x>y ? y : x

/**
 * Obstruction implementation. This keeps the ICmpPathfinder's model of the world updated when the
 * entities move and die, with shapes derived from ICmpFootprint.
 */
class CCmpObstruction : public ICmpObstruction
{
public:
    static void ClassInit(CComponentManager& componentManager)
    {
        componentManager.SubscribeToMessageType(MT_PositionChanged);
        componentManager.SubscribeToMessageType(MT_Destroy);
    }

    DEFAULT_COMPONENT_ALLOCATOR(Obstruction)

    typedef ICmpObstructionManager::tag_t tag_t;
    typedef ICmpObstructionManager::flags_t flags_t;

    // Template state:

    enum {
        STATIC,
        UNIT,
        CLUSTER
    } m_Type;

    entity_pos_t m_Size0; // radius or width
    entity_pos_t m_Size1; // radius or depth
    flags_t m_TemplateFlags;

    typedef struct {
        entity_pos_t dx, dz;
        entity_angle_t da;  
        entity_pos_t size0, size1;
        flags_t flags;
    } Shape;

    std::vector<Shape> m_Shapes;

    // Dynamic state:

    /// Whether the obstruction is actively obstructing or just an inactive placeholder.
    bool m_Active;
    /// Whether the entity associated with this obstruction is currently moving. Only applicable for
    /// UNIT-type obstructions.
    bool m_Moving;
    /// Whether an obstruction's control group should be kept consistent and
    /// used to set control groups for entities that collide with it.
    bool m_ControlPersist;

    /**
     * Primary control group identifier. Indicates to which control group this entity's shape belongs.
     * Typically used in combination with obstruction test filters to have member shapes ignore each
     * other during obstruction tests. Defaults to the entity's ID. Must never be set to INVALID_ENTITY.
     */
    entity_id_t m_ControlGroup;

    /**
     * Optional secondary control group identifier. Similar to m_ControlGroup; if set to a valid value,
     * then this field identifies an additional, secondary control group to which this entity's shape
     * belongs. Set to INVALID_ENTITY to not assign any secondary group. Defaults to INVALID_ENTITY.
     * 
     * These are only necessary in case it is not sufficient for an entity to belong to only one control
     * group. Otherwise, they can be ignored.
     */
    entity_id_t m_ControlGroup2;

    /// Identifier of this entity's obstruction shape, as registered in the obstruction manager. Contains
    /// structure, but should be treated as opaque here.
    tag_t m_Tag;
    std::vector<tag_t> m_ClusterTags;

    /// Set of flags affecting the behaviour of this entity's obstruction shape.
    flags_t m_Flags;

    static std::string GetSchema()
    {
        return
            "<a:example/>"
            "<a:help>Causes this entity to obstruct the motion of other units.</a:help>"
            "<choice>"
                "<element name='Static'>"
                    "<attribute name='width'>"
                        "<ref name='positiveDecimal'/>"
                    "</attribute>"
                    "<attribute name='depth'>"
                        "<ref name='positiveDecimal'/>"
                    "</attribute>"
                "</element>"
                "<element name='Unit'>"
                    "<attribute name='radius'>"
                        "<ref name='positiveDecimal'/>"
                    "</attribute>"
                "</element>"
                "<element name='Obstructions'>"
                    "<zeroOrMore>"
                        "<element>"
                            "<anyName/>"
                            "<optional>"
                                "<attribute name='x'>"
                                    "<data type='decimal'/>"
                                "</attribute>"
                            "</optional>"
                            "<optional>"
                                "<attribute name='z'>"
                                    "<data type='decimal'/>"
                                "</attribute>"
                            "</optional>"
                            "<attribute name='width'>"
                                "<ref name='positiveDecimal'/>"
                            "</attribute>"
                            "<attribute name='depth'>"
                                "<ref name='positiveDecimal'/>"
                            "</attribute>"
                        "</element>"
                    "</zeroOrMore>"
                "</element>"
            "</choice>"
            "<element name='Active' a:help='If false, this entity will be ignored in collision tests by other units but can still perform its own collision tests'>"
                "<data type='boolean'/>"
            "</element>"
            "<element name='BlockMovement' a:help='Whether units should be allowed to walk through this entity'>"
                "<data type='boolean'/>"
            "</element>"
            "<element name='BlockPathfinding' a:help='Whether the long-distance pathfinder should avoid paths through this entity. This should only be set for large stationary obstructions'>"
                "<data type='boolean'/>"
            "</element>"
            "<element name='BlockFoundation' a:help='Whether players should be unable to place building foundations on top of this entity. If true, BlockConstruction should be true too'>"
                "<data type='boolean'/>"
            "</element>"
            "<element name='BlockConstruction' a:help='Whether players should be unable to begin constructing buildings placed on top of this entity'>"
                "<data type='boolean'/>"
            "</element>"
            "<element name='DisableBlockMovement' a:help='If true, BlockMovement will be overridden and treated as false. (This is a special case to handle foundations)'>"
                "<data type='boolean'/>"
            "</element>"
            "<element name='DisableBlockPathfinding' a:help='If true, BlockPathfinding will be overridden and treated as false. (This is a special case to handle foundations)'>"
                "<data type='boolean'/>"
            "</element>"
            "<optional>"
                "<element name='ControlPersist' a:help='If present, the control group of this entity will be given to entities that are colliding with it.'>"
                    "<empty/>"
                "</element>"
            "</optional>";
    }

    virtual void Init(const CParamNode& paramNode)
    {
        m_TemplateFlags = 0;
        if (paramNode.GetChild("BlockMovement").ToBool())
            m_TemplateFlags |= ICmpObstructionManager::FLAG_BLOCK_MOVEMENT;
        if (paramNode.GetChild("BlockPathfinding").ToBool())
            m_TemplateFlags |= ICmpObstructionManager::FLAG_BLOCK_PATHFINDING;
        if (paramNode.GetChild("BlockFoundation").ToBool())
            m_TemplateFlags |= ICmpObstructionManager::FLAG_BLOCK_FOUNDATION;
        if (paramNode.GetChild("BlockConstruction").ToBool())
            m_TemplateFlags |= ICmpObstructionManager::FLAG_BLOCK_CONSTRUCTION;

        m_Flags = m_TemplateFlags;
        if (paramNode.GetChild("DisableBlockMovement").ToBool())
            m_Flags &= (flags_t)(~ICmpObstructionManager::FLAG_BLOCK_MOVEMENT);
        if (paramNode.GetChild("DisableBlockPathfinding").ToBool())
            m_Flags &= (flags_t)(~ICmpObstructionManager::FLAG_BLOCK_PATHFINDING);

        if (paramNode.GetChild("Unit").IsOk())
        {
            m_Type = UNIT;
            m_Size0 = m_Size1 = paramNode.GetChild("Unit").GetChild("@radius").ToFixed();
        }
        else if (paramNode.GetChild("Static").IsOk())
        {
            m_Type = STATIC;
            m_Size0 = paramNode.GetChild("Static").GetChild("@width").ToFixed();
            m_Size1 = paramNode.GetChild("Static").GetChild("@depth").ToFixed();
        }
        else
        {
            m_Type = CLUSTER;
            CFixedVector2D max = CFixedVector2D(fixed::FromInt(0), fixed::FromInt(0));
            CFixedVector2D min = CFixedVector2D(fixed::FromInt(0), fixed::FromInt(0));
            const CParamNode::ChildrenMap& clusterMap = paramNode.GetChild("Obstructions").GetChildren();
            for(CParamNode::ChildrenMap::const_iterator it = clusterMap.begin(); it != clusterMap.end(); ++it)
            {
                Shape b;
                b.size0 = it->second.GetChild("@width").ToFixed();
                b.size1 = it->second.GetChild("@depth").ToFixed();
                b.dx = it->second.GetChild("@x").ToFixed();
                b.dz = it->second.GetChild("@z").ToFixed();
                b.da = entity_angle_t::FromInt(0);
                b.flags = m_Flags;
                m_Shapes.push_back(b);
                max.X = MAX(max.X, b.dx + b.size0/2);
                max.Y = MAX(max.Y, b.dz + b.size1/2);
                min.X = MIN(min.X, b.dx - b.size0/2);
                min.Y = MIN(min.Y, b.dz - b.size1/2);
            }
            m_Size0 = fixed::FromInt(2).Multiply(MAX(max.X, -min.X));
            m_Size1 = fixed::FromInt(2).Multiply(MAX(max.Y, -min.Y));
        }

        m_Active = paramNode.GetChild("Active").ToBool();
        m_ControlPersist = paramNode.GetChild("ControlPersist").IsOk();

        m_Tag = tag_t();
        if (m_Type == CLUSTER)
            m_ClusterTags.clear();
        m_Moving = false;
        m_ControlGroup = GetEntityId();
        m_ControlGroup2 = INVALID_ENTITY;
    }

    virtual void Deinit()
    {
    }

    struct SerializeTag
    {
        template<typename S>
        void operator()(S& serialize, const char* UNUSED(name), tag_t& value)
        {
            serialize.NumberU32_Unbounded("tag", value.n);
        }
    };

    template<typename S>
    void SerializeCommon(S& serialize)
    {
        serialize.Bool("active", m_Active);
        serialize.Bool("moving", m_Moving);
        serialize.NumberU32_Unbounded("control group", m_ControlGroup);
        serialize.NumberU32_Unbounded("control group 2", m_ControlGroup2);
        serialize.NumberU32_Unbounded("tag", m_Tag.n);
        serialize.NumberU8_Unbounded("flags", m_Flags);
        if (m_Type == CLUSTER)
            SerializeVector<SerializeTag>()(serialize, "cluster tags", m_ClusterTags);
    }

    virtual void Serialize(ISerializer& serialize)
    {
        SerializeCommon(serialize);
    }

    virtual void Deserialize(const CParamNode& paramNode, IDeserializer& deserialize)
    {
        Init(paramNode);

        SerializeCommon(deserialize);
    }

    virtual void HandleMessage(const CMessage& msg, bool UNUSED(global))
    {
        switch (msg.GetType())
        {
        case MT_PositionChanged:
        {
            if (!m_Active)
                break;

            const CMessagePositionChanged& data = static_cast<const CMessagePositionChanged&> (msg);

            if (!data.inWorld && !m_Tag.valid())
                break; // nothing needs to change

            CmpPtr<ICmpObstructionManager> cmpObstructionManager(GetSystemEntity());
            if (!cmpObstructionManager)
                break; // error

            if (data.inWorld && m_Tag.valid())
            {
                cmpObstructionManager->MoveShape(m_Tag, data.x, data.z, data.a);

                if(m_Type == CLUSTER)
                {
                    for (size_t i = 0; i < m_Shapes.size(); ++i)
                    {
                        Shape& b = m_Shapes[i];
                        fixed s, c;
                        sincos_approx(data.a, s, c);
                        cmpObstructionManager->MoveShape(m_ClusterTags[i], data.x + b.dx.Multiply(c) + b.dz.Multiply(s), data.z + b.dz.Multiply(c) - b.dx.Multiply(s), data.a + b.da);
                    }
                }
            }
            else if (data.inWorld && !m_Tag.valid())
            {
                // Need to create a new pathfinder shape:
                if (m_Type == STATIC)
                    m_Tag = cmpObstructionManager->AddStaticShape(GetEntityId(),
                        data.x, data.z, data.a, m_Size0, m_Size1, m_Flags, m_ControlGroup, m_ControlGroup2);
                else if (m_Type == UNIT)
                    m_Tag = cmpObstructionManager->AddUnitShape(GetEntityId(),
                        data.x, data.z, m_Size0, (flags_t)(m_Flags | (m_Moving ? ICmpObstructionManager::FLAG_MOVING : 0)), m_ControlGroup);
                else
                    AddClusterShapes(data.x, data.x, data.a);
            }
            else if (!data.inWorld && m_Tag.valid())
            {
                cmpObstructionManager->RemoveShape(m_Tag);
                m_Tag = tag_t();
                if(m_Type == CLUSTER)
                    RemoveClusterShapes();
            }
            break;
        }
        case MT_Destroy:
        {
            if (m_Tag.valid())
            {
                CmpPtr<ICmpObstructionManager> cmpObstructionManager(GetSystemEntity());
                if (!cmpObstructionManager)
                    break; // error

                cmpObstructionManager->RemoveShape(m_Tag);
                m_Tag = tag_t();
                if(m_Type == CLUSTER)
                    RemoveClusterShapes();
            }
            break;
        }
        }
    }

    virtual void SetActive(bool active)
    {
        if (active && !m_Active)
        {
            m_Active = true;

            // Construct the obstruction shape

            CmpPtr<ICmpObstructionManager> cmpObstructionManager(GetSystemEntity());
            if (!cmpObstructionManager)
                return; // error

            CmpPtr<ICmpPosition> cmpPosition(GetEntityHandle());
            if (!cmpPosition)
                return; // error

            if (!cmpPosition->IsInWorld())
                return; // don't need an obstruction

            // TODO: code duplication from message handlers
            CFixedVector2D pos = cmpPosition->GetPosition2D();
            if (m_Type == STATIC)
                m_Tag = cmpObstructionManager->AddStaticShape(GetEntityId(),
                    pos.X, pos.Y, cmpPosition->GetRotation().Y, m_Size0, m_Size1, m_Flags, m_ControlGroup, m_ControlGroup2);
            else if (m_Type == UNIT)
                m_Tag = cmpObstructionManager->AddUnitShape(GetEntityId(),
                    pos.X, pos.Y, m_Size0, (flags_t)(m_Flags | (m_Moving ? ICmpObstructionManager::FLAG_MOVING : 0)), m_ControlGroup);
            else 
                AddClusterShapes(pos.X, pos.Y, cmpPosition->GetRotation().Y);
        }
        else if (!active && m_Active)
        {
            m_Active = false;

            // Delete the obstruction shape

            // TODO: code duplication from message handlers
            if (m_Tag.valid())
            {
                CmpPtr<ICmpObstructionManager> cmpObstructionManager(GetSystemEntity());
                if (!cmpObstructionManager)
                    return; // error

                cmpObstructionManager->RemoveShape(m_Tag);
                m_Tag = tag_t();
                if (m_Type == CLUSTER)
                    RemoveClusterShapes();
            }
        }
        // else we didn't change the active status
    }

    virtual void SetDisableBlockMovementPathfinding(bool movementDisabled, bool pathfindingDisabled, int32_t shape)
    {
        flags_t *flags = NULL;
        if (shape == -1)
            flags = &m_Flags;
        else if (m_Type == CLUSTER && shape < (int32_t)m_Shapes.size())
            flags = &m_Shapes[shape].flags;
        else
            return; // error

        // Remove the blocking / pathfinding flags or
        // Add the blocking / pathfinding flags if the template had enabled them
        if (movementDisabled)
            *flags &= (flags_t)(~ICmpObstructionManager::FLAG_BLOCK_MOVEMENT);
        else
            *flags |= (flags_t)(m_TemplateFlags & ICmpObstructionManager::FLAG_BLOCK_MOVEMENT);
        if (pathfindingDisabled)
            *flags &= (flags_t)(~ICmpObstructionManager::FLAG_BLOCK_PATHFINDING);
        else
            *flags |= (flags_t)(m_TemplateFlags & ICmpObstructionManager::FLAG_BLOCK_PATHFINDING);

        // Reset the shape with the new flags (kind of inefficiently - we
        // should have a ICmpObstructionManager::SetFlags function or something)
        if (m_Active)
        {
            SetActive(false);
            SetActive(true);
        }
    }

    virtual bool GetBlockMovementFlag()
    {
        return (m_TemplateFlags & ICmpObstructionManager::FLAG_BLOCK_MOVEMENT) != 0;
    }

    virtual ICmpObstructionManager::tag_t GetObstruction()
    {
        return m_Tag;
    }

    virtual bool GetObstructionSquare(ICmpObstructionManager::ObstructionSquare& out)
    {
        CmpPtr<ICmpPosition> cmpPosition(GetEntityHandle());
        if (!cmpPosition)
            return false; // error

        CmpPtr<ICmpObstructionManager> cmpObstructionManager(GetSystemEntity());
        if (!cmpObstructionManager)
            return false; // error

        if (!cmpPosition->IsInWorld())
            return false; // no obstruction square

        CFixedVector2D pos = cmpPosition->GetPosition2D();
        if (m_Type == STATIC)
            out = cmpObstructionManager->GetStaticShapeObstruction(pos.X, pos.Y, cmpPosition->GetRotation().Y, m_Size0, m_Size1);
        else if (m_Type == UNIT)
            out = cmpObstructionManager->GetUnitShapeObstruction(pos.X, pos.Y, m_Size0);
        else
            out = cmpObstructionManager->GetStaticShapeObstruction(pos.X, pos.Y, cmpPosition->GetRotation().Y, m_Size0, m_Size1);
        return true;
    }

    virtual entity_pos_t GetUnitRadius()
    {
        if (m_Type == UNIT)
            return m_Size0;
        else
            return entity_pos_t::Zero();
    }

    virtual bool IsControlPersistent()
    {
        return m_ControlPersist;
    }
    
    virtual EFoundationCheck CheckFoundation(std::string className)
    {
        return  CheckFoundation(className, false);
    }

    virtual EFoundationCheck CheckFoundation(std::string className, bool onlyCenterPoint)
    {
        CmpPtr<ICmpPosition> cmpPosition(GetEntityHandle());
        if (!cmpPosition)
            return FOUNDATION_CHECK_FAIL_ERROR; // error

        if (!cmpPosition->IsInWorld())
            return FOUNDATION_CHECK_FAIL_NO_OBSTRUCTION; // no obstruction

        CFixedVector2D pos = cmpPosition->GetPosition2D();

        CmpPtr<ICmpPathfinder> cmpPathfinder(GetSystemEntity());
        if (!cmpPathfinder)
            return FOUNDATION_CHECK_FAIL_ERROR; // error

        // required precondition to use SkipControlGroupsRequireFlagObstructionFilter
        if (m_ControlGroup == INVALID_ENTITY)
        {
            LOGERROR(L"[CmpObstruction] Cannot test for foundation obstructions; primary control group must be valid");
            return FOUNDATION_CHECK_FAIL_ERROR;
        }

        // Get passability class
        ICmpPathfinder::pass_class_t passClass = cmpPathfinder->GetPassabilityClass(className);

        // Ignore collisions within the same control group, or with other non-foundation-blocking shapes.
        // Note that, since the control group for each entity defaults to the entity's ID, this is typically 
        // equivalent to only ignoring the entity's own shape and other non-foundation-blocking shapes.
        SkipControlGroupsRequireFlagObstructionFilter filter(m_ControlGroup, m_ControlGroup2,
            ICmpObstructionManager::FLAG_BLOCK_FOUNDATION);

        if (m_Type == UNIT)
            return cmpPathfinder->CheckUnitPlacement(filter, pos.X, pos.Y, m_Size0, passClass, onlyCenterPoint);
        else
            return cmpPathfinder->CheckBuildingPlacement(filter, pos.X, pos.Y, cmpPosition->GetRotation().Y, m_Size0, m_Size1, GetEntityId(), passClass, onlyCenterPoint);
    }

    virtual bool CheckDuplicateFoundation()
    {
        CmpPtr<ICmpPosition> cmpPosition(GetEntityHandle());
        if (!cmpPosition)
            return false; // error

        if (!cmpPosition->IsInWorld())
            return false; // no obstruction

        CFixedVector2D pos = cmpPosition->GetPosition2D();

        CmpPtr<ICmpObstructionManager> cmpObstructionManager(GetSystemEntity());
        if (!cmpObstructionManager)
            return false; // error

        // required precondition to use SkipControlGroupsRequireFlagObstructionFilter
        if (m_ControlGroup == INVALID_ENTITY)
        {
            LOGERROR(L"[CmpObstruction] Cannot test for foundation obstructions; primary control group must be valid");
            return false;
        }

        // Ignore collisions with entities unless they block foundations and match both control groups.
        SkipTagRequireControlGroupsAndFlagObstructionFilter filter(m_Tag, m_ControlGroup, m_ControlGroup2,
            ICmpObstructionManager::FLAG_BLOCK_FOUNDATION);

        if (m_Type == UNIT)
            return !cmpObstructionManager->TestUnitShape(filter, pos.X, pos.Y, m_Size0, NULL);
        else
            return !cmpObstructionManager->TestStaticShape(filter, pos.X, pos.Y, cmpPosition->GetRotation().Y, m_Size0, m_Size1, NULL );
    } 

    virtual std::vector<entity_id_t> GetEntityCollisions(bool checkStructures, bool checkUnits)
    {
        std::vector<entity_id_t> ret;

        CmpPtr<ICmpPosition> cmpPosition(GetEntityHandle());
        if (!cmpPosition)
            return ret; // error

        if (!cmpPosition->IsInWorld())
            return ret; // no obstruction

        CFixedVector2D pos = cmpPosition->GetPosition2D();

        CmpPtr<ICmpObstructionManager> cmpObstructionManager(GetSystemEntity());
        if (!cmpObstructionManager)
            return ret; // error

        // required precondition to use SkipControlGroupsRequireFlagObstructionFilter
        if (m_ControlGroup == INVALID_ENTITY)
        {
            LOGERROR(L"[CmpObstruction] Cannot test for unit or structure obstructions; primary control group must be valid");
            return ret;
        }

        flags_t flags = 0;
        bool invertMatch = false;

        // There are four 'block' flags: construction, foundation, movement,
        // and pathfinding. Structures have all of these flags, while units
        // block only movement and construction.

        // The 'block construction' flag is common to both units and structures.
        if (checkStructures && checkUnits)
            flags = ICmpObstructionManager::FLAG_BLOCK_CONSTRUCTION;
        // The 'block foundation' flag is exclusive to structures.
        else if (checkStructures)
            flags = ICmpObstructionManager::FLAG_BLOCK_FOUNDATION;
        else if (checkUnits)
        {
            // As structures block a superset of what units do, matching units
            // but not structures means excluding entities that contain any of
            // the structure-specific flags (foundation and pathfinding).
            invertMatch = true;
            flags = ICmpObstructionManager::FLAG_BLOCK_FOUNDATION | ICmpObstructionManager::FLAG_BLOCK_PATHFINDING;
        }

        // Ignore collisions within the same control group, or with other shapes that don't match the filter.
        // Note that, since the control group for each entity defaults to the entity's ID, this is typically 
        // equivalent to only ignoring the entity's own shape and other shapes that don't match the filter.
        SkipControlGroupsRequireFlagObstructionFilter filter(invertMatch,
                m_ControlGroup, m_ControlGroup2, flags);

        if (m_Type == STATIC)
            cmpObstructionManager->TestStaticShape(filter, pos.X, pos.Y, cmpPosition->GetRotation().Y, m_Size0, m_Size1, &ret);
        else if (m_Type == UNIT)
            cmpObstructionManager->TestUnitShape(filter, pos.X, pos.Y, m_Size0, &ret);
        else
            cmpObstructionManager->TestStaticShape(filter, pos.X, pos.Y, cmpPosition->GetRotation().Y, m_Size0, m_Size1, &ret);
    
        return ret;
    }

    virtual void SetMovingFlag(bool enabled)
    {
        m_Moving = enabled;

        if (m_Tag.valid() && m_Type == UNIT)
        {
            CmpPtr<ICmpObstructionManager> cmpObstructionManager(GetSystemEntity());
            if (cmpObstructionManager)
                cmpObstructionManager->SetUnitMovingFlag(m_Tag, m_Moving);
        }
    }

    virtual void SetControlGroup(entity_id_t group)
    {
        m_ControlGroup = group;
        UpdateControlGroups();
    }

    virtual void SetControlGroup2(entity_id_t group2)
    {
        m_ControlGroup2 = group2;
        UpdateControlGroups();
    }

    virtual entity_id_t GetControlGroup() 
    {
        return m_ControlGroup;
    }

    virtual entity_id_t GetControlGroup2() 
    {
        return m_ControlGroup2;
    }

    void UpdateControlGroups()
    {
        if (m_Tag.valid())
        {
            CmpPtr<ICmpObstructionManager> cmpObstructionManager(GetSystemEntity());
            if (cmpObstructionManager)
            {
                if (m_Type == UNIT)
                {
                    cmpObstructionManager->SetUnitControlGroup(m_Tag, m_ControlGroup);
                }
                else if (m_Type == STATIC)
                {
                    cmpObstructionManager->SetStaticControlGroup(m_Tag, m_ControlGroup, m_ControlGroup2);
                }
                else
                {
                    cmpObstructionManager->SetStaticControlGroup(m_Tag, m_ControlGroup, m_ControlGroup2);
                    for (size_t i = 0; i < m_ClusterTags.size(); ++i)
                    {
                        cmpObstructionManager->SetStaticControlGroup(m_ClusterTags[i], m_ControlGroup, m_ControlGroup2);
                    }
                }
            }
        }
    }

    void ResolveFoundationCollisions()
    {
        if (m_Type == UNIT)
            return;

        CmpPtr<ICmpObstructionManager> cmpObstructionManager(GetSystemEntity());
        if (!cmpObstructionManager)
            return;

        CmpPtr<ICmpPosition> cmpPosition(GetEntityHandle());
        if (!cmpPosition)
            return; // error

        if (!cmpPosition->IsInWorld())
            return; // no obstruction

        CFixedVector2D pos = cmpPosition->GetPosition2D();

        // Ignore collisions within the same control group, or with other non-foundation-blocking shapes.
        // Note that, since the control group for each entity defaults to the entity's ID, this is typically 
        // equivalent to only ignoring the entity's own shape and other non-foundation-blocking shapes.
        SkipControlGroupsRequireFlagObstructionFilter filter(m_ControlGroup, m_ControlGroup2,
            ICmpObstructionManager::FLAG_BLOCK_FOUNDATION);

        std::vector<entity_id_t> collisions;
        if (cmpObstructionManager->TestStaticShape(filter, pos.X, pos.Y, cmpPosition->GetRotation().Y, m_Size0, m_Size1, &collisions))
        {
            std::vector<entity_id_t> persistentEnts, normalEnts;

            if (m_ControlPersist)
                persistentEnts.push_back(m_ControlGroup);
            else
                normalEnts.push_back(GetEntityId());

            for (std::vector<entity_id_t>::iterator it = collisions.begin(); it != collisions.end(); ++it)
            {
                entity_id_t ent = *it;
                if (ent == INVALID_ENTITY)
                    continue;

                CmpPtr<ICmpObstruction> cmpObstruction(GetSimContext(), ent);
                if (!cmpObstruction->IsControlPersistent())
                    normalEnts.push_back(ent);
                else
                    persistentEnts.push_back(cmpObstruction->GetControlGroup());
            }

            // The collision can't be resolved without usable persistent control groups.
            if (persistentEnts.empty())
                return;

            // Attempt to replace colliding entities' control groups with a persistent one.
            for (std::vector<entity_id_t>::iterator it = normalEnts.begin(); it != normalEnts.end(); ++it)
            {
                entity_id_t ent = *it;

                CmpPtr<ICmpObstruction> cmpObstruction(GetSimContext(), ent);
                for (std::vector<entity_id_t>::iterator it = persistentEnts.begin(); it != persistentEnts.end(); ++it)
                {
                    entity_id_t persistent = *it;
                    entity_id_t group = cmpObstruction->GetControlGroup();

                    // Only clobber 'default' control groups.
                    if (group == ent)
                        cmpObstruction->SetControlGroup(persistent);
                    else if (cmpObstruction->GetControlGroup2() == INVALID_ENTITY && group != persistent)
                        cmpObstruction->SetControlGroup2(persistent);
                }
            }
        }
    }
protected:

    inline void AddClusterShapes(entity_pos_t x, entity_pos_t z, entity_angle_t a)
    {
        CmpPtr<ICmpObstructionManager> cmpObstructionManager(GetSystemEntity());
        if (!cmpObstructionManager)
            return; // error

        flags_t flags = m_Flags;
        // Disable block movement and block pathfinding for the obstruction shape
        flags &= (flags_t)(~ICmpObstructionManager::FLAG_BLOCK_MOVEMENT);
        flags &= (flags_t)(~ICmpObstructionManager::FLAG_BLOCK_PATHFINDING);
        
        m_Tag = cmpObstructionManager->AddStaticShape(GetEntityId(),
            x, z, a, m_Size0, m_Size1, flags, m_ControlGroup, m_ControlGroup2);

        fixed s, c;
        sincos_approx(a, s, c);

        for (size_t i = 0; i < m_Shapes.size(); ++i)
        {
            Shape& b = m_Shapes[i];
            tag_t tag = cmpObstructionManager->AddStaticShape(GetEntityId(),
                x + b.dx.Multiply(c) + b.dz.Multiply(s), z + b.dz.Multiply(c) - b.dx.Multiply(s), a + b.da, b.size0, b.size1, b.flags, m_ControlGroup, m_ControlGroup2);
            m_ClusterTags.push_back(tag);   
        }
    }

    inline void RemoveClusterShapes()
    {
        CmpPtr<ICmpObstructionManager> cmpObstructionManager(GetSystemEntity());
        if (!cmpObstructionManager)
            return; // error

        for (size_t i = 0; i < m_ClusterTags.size(); ++i)
        {
            if (m_ClusterTags[i].valid())
            {
                cmpObstructionManager->RemoveShape(m_ClusterTags[i]);
            }
        }
        m_ClusterTags.clear();
    }

};

REGISTER_COMPONENT_TYPE(Obstruction)