source: ps/trunk/source/simulation2/components/CCmpPathfinder_Common.h@ 24142

/* Copyright (C) 2020 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/>.
 */

#ifndef INCLUDED_CCMPPATHFINDER_COMMON
#define INCLUDED_CCMPPATHFINDER_COMMON

/**
 * @file
 * Declares CCmpPathfinder. Its implementation is mainly done in CCmpPathfinder.cpp,
 * but the short-range (vertex) pathfinding is done in CCmpPathfinder_Vertex.cpp.
 * This file provides common code needed for both files.
 *
 * The long-range pathfinding is done by a LongPathfinder object.
 */

#include "simulation2/system/Component.h"

#include "ICmpPathfinder.h"

#include "graphics/Overlay.h"
#include "graphics/Terrain.h"
#include "maths/MathUtil.h"
#include "ps/CLogger.h"
#include "renderer/TerrainOverlay.h"
#include "simulation2/components/ICmpObstructionManager.h"
#include "simulation2/helpers/Grid.h"


class HierarchicalPathfinder;
class LongPathfinder;
class VertexPathfinder;

class SceneCollector;
class AtlasOverlay;

#ifdef NDEBUG
#define PATHFIND_DEBUG 0
#else
#define PATHFIND_DEBUG 1
#endif

/**
 * Implementation of ICmpPathfinder
 */
class CCmpPathfinder final : public ICmpPathfinder
{
protected:

    class PathfinderWorker
    {
        friend CCmpPathfinder;
    public:
        PathfinderWorker();

        // Process path requests, checking if we should stop before each new one.
        void Work(const CCmpPathfinder& pathfinder);

    private:
        // Insert requests in m_[Long/Short]Requests depending on from.
        // This could be removed when we may use if-constexpr in CCmpPathfinder::PushRequestsToWorkers
        template<typename T>
        void PushRequests(std::vector<T>& from, ssize_t amount);

        // Stores our results, the main thread will fetch this.
        std::vector<PathResult> m_Results;

        std::vector<LongPathRequest> m_LongRequests;
        std::vector<ShortPathRequest> m_ShortRequests;
    };

    // Allow the workers to access our private variables
    friend class PathfinderWorker;

public:
    static void ClassInit(CComponentManager& componentManager)
    {
        componentManager.SubscribeToMessageType(MT_Deserialized);
        componentManager.SubscribeToMessageType(MT_RenderSubmit); // for debug overlays
        componentManager.SubscribeToMessageType(MT_TerrainChanged);
        componentManager.SubscribeToMessageType(MT_WaterChanged);
        componentManager.SubscribeToMessageType(MT_ObstructionMapShapeChanged);
    }

    ~CCmpPathfinder();

    DEFAULT_COMPONENT_ALLOCATOR(Pathfinder)

    // Template state:

    std::map<std::string, pass_class_t> m_PassClassMasks;
    std::vector<PathfinderPassability> m_PassClasses;

    // Dynamic state:

    std::vector<LongPathRequest> m_LongPathRequests;
    std::vector<ShortPathRequest> m_ShortPathRequests;
    u32 m_NextAsyncTicket; // Unique IDs for asynchronous path requests.
    u16 m_MaxSameTurnMoves; // Compute only this many paths when useMax is true in StartProcessingMoves.

    // Lazily-constructed dynamic state (not serialized):

    u16 m_MapSize; // tiles per side
    Grid<NavcellData>* m_Grid; // terrain/passability information
    Grid<NavcellData>* m_TerrainOnlyGrid; // same as m_Grid, but only with terrain, to avoid some recomputations

    // Keep clever updates in memory to avoid memory fragmentation from the grid.
    // This should be used only in UpdateGrid(), there is no guarantee the data is properly initialized anywhere else.
    GridUpdateInformation m_DirtinessInformation;
    // The data from clever updates is stored for the AI manager
    GridUpdateInformation m_AIPathfinderDirtinessInformation;
    bool m_TerrainDirty;

    std::unique_ptr<VertexPathfinder> m_VertexPathfinder;
    std::unique_ptr<HierarchicalPathfinder> m_PathfinderHier;
    std::unique_ptr<LongPathfinder> m_LongPathfinder;

    // Workers process pathing requests.
    std::vector<PathfinderWorker> m_Workers;

    AtlasOverlay* m_AtlasOverlay;

    static std::string GetSchema()
    {
        return "<a:component type='system'/><empty/>";
    }

    virtual void Init(const CParamNode& paramNode);

    virtual void Deinit();

    template<typename S>
    void SerializeCommon(S& serialize);

    virtual void Serialize(ISerializer& serialize);

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

    virtual void HandleMessage(const CMessage& msg, bool global);

    virtual pass_class_t GetPassabilityClass(const std::string& name) const;

    virtual void GetPassabilityClasses(std::map<std::string, pass_class_t>& passClasses) const;
    virtual void GetPassabilityClasses(
        std::map<std::string, pass_class_t>& nonPathfindingPassClasses,
        std::map<std::string, pass_class_t>& pathfindingPassClasses) const;

    const PathfinderPassability* GetPassabilityFromMask(pass_class_t passClass) const;

    virtual entity_pos_t GetClearance(pass_class_t passClass) const
    {
        const PathfinderPassability* passability = GetPassabilityFromMask(passClass);
        if (!passability)
            return fixed::Zero();

        return passability->m_Clearance;
    }

    virtual entity_pos_t GetMaximumClearance() const
    {
        entity_pos_t max = fixed::Zero();

        for (const PathfinderPassability& passability : m_PassClasses)
            if (passability.m_Clearance > max)
                max = passability.m_Clearance;

        return max + Pathfinding::CLEARANCE_EXTENSION_RADIUS;
    }

    virtual const Grid<NavcellData>& GetPassabilityGrid();

    virtual const GridUpdateInformation& GetAIPathfinderDirtinessInformation() const
    {
        return m_AIPathfinderDirtinessInformation;
    }

    virtual void FlushAIPathfinderDirtinessInformation()
    {
        m_AIPathfinderDirtinessInformation.Clean();
    }

    virtual Grid<u16> ComputeShoreGrid(bool expandOnWater = false);

    virtual void ComputePathImmediate(entity_pos_t x0, entity_pos_t z0, const PathGoal& goal, pass_class_t passClass, WaypointPath& ret) const;

    virtual u32 ComputePathAsync(entity_pos_t x0, entity_pos_t z0, const PathGoal& goal, pass_class_t passClass, entity_id_t notify);

    virtual WaypointPath ComputeShortPathImmediate(const ShortPathRequest& request) const;

    virtual u32 ComputeShortPathAsync(entity_pos_t x0, entity_pos_t z0, entity_pos_t clearance, entity_pos_t range, const PathGoal& goal, pass_class_t passClass, bool avoidMovingUnits, entity_id_t controller, entity_id_t notify);

    virtual bool IsGoalReachable(entity_pos_t x0, entity_pos_t z0, const PathGoal& goal, pass_class_t passClass);

    virtual void SetDebugPath(entity_pos_t x0, entity_pos_t z0, const PathGoal& goal, pass_class_t passClass);

    virtual void SetDebugOverlay(bool enabled);

    virtual void SetHierDebugOverlay(bool enabled);

    virtual void GetDebugData(u32& steps, double& time, Grid<u8>& grid) const;

    virtual void SetAtlasOverlay(bool enable, pass_class_t passClass = 0);

    virtual bool CheckMovement(const IObstructionTestFilter& filter, entity_pos_t x0, entity_pos_t z0, entity_pos_t x1, entity_pos_t z1, entity_pos_t r, pass_class_t passClass) const;

    virtual ICmpObstruction::EFoundationCheck CheckUnitPlacement(const IObstructionTestFilter& filter, entity_pos_t x, entity_pos_t z, entity_pos_t r, pass_class_t passClass, bool onlyCenterPoint) const;

    virtual ICmpObstruction::EFoundationCheck CheckBuildingPlacement(const IObstructionTestFilter& filter, entity_pos_t x, entity_pos_t z, entity_pos_t a, entity_pos_t w, entity_pos_t h, entity_id_t id, pass_class_t passClass) const;

    virtual ICmpObstruction::EFoundationCheck CheckBuildingPlacement(const IObstructionTestFilter& filter, entity_pos_t x, entity_pos_t z, entity_pos_t a, entity_pos_t w, entity_pos_t h, entity_id_t id, pass_class_t passClass, bool onlyCenterPoint) const;

    virtual void FetchAsyncResultsAndSendMessages();

    virtual void StartProcessingMoves(bool useMax);

    template <typename T>
    std::vector<T> GetMovesToProcess(std::vector<T>& requests, bool useMax = false, size_t maxMoves = 0);

    template <typename T>
    void PushRequestsToWorkers(std::vector<T>& from);

    /**
     * Regenerates the grid based on the current obstruction list, if necessary
     */
    virtual void UpdateGrid();

    /**
     * Updates the terrain-only grid without updating the dirtiness informations.
     * Useful for fast passability updates in Atlas.
     */
    void MinimalTerrainUpdate(int itile0, int jtile0, int itile1, int jtile1);

    /**
     * Regenerates the terrain-only grid.
     * Atlas doesn't need to have passability cells expanded.
     */
    void TerrainUpdateHelper(bool expandPassability = true, int itile0 = -1, int jtile0 = -1, int itile1 = -1, int jtile1 = -1);

    void RenderSubmit(SceneCollector& collector);
};

class AtlasOverlay : public TerrainTextureOverlay
{
public:
    const CCmpPathfinder* m_Pathfinder;
    pass_class_t m_PassClass;

    AtlasOverlay(const CCmpPathfinder* pathfinder, pass_class_t passClass) :
        TerrainTextureOverlay(Pathfinding::NAVCELLS_PER_TILE), m_Pathfinder(pathfinder), m_PassClass(passClass)
    {
    }

    virtual void BuildTextureRGBA(u8* data, size_t w, size_t h)
    {
        // Render navcell passability, based on the terrain-only grid
        u8* p = data;
        for (size_t j = 0; j < h; ++j)
        {
            for (size_t i = 0; i < w; ++i)
            {
                SColor4ub color(0, 0, 0, 0);
                if (!IS_PASSABLE(m_Pathfinder->m_TerrainOnlyGrid->get((int)i, (int)j), m_PassClass))
                    color = SColor4ub(255, 0, 0, 127);

                *p++ = color.R;
                *p++ = color.G;
                *p++ = color.B;
                *p++ = color.A;
            }
        }
    }
};

#endif // INCLUDED_CCMPPATHFINDER_COMMON