text: //
  // Copyright (c) 2008-2020 the Urho3D project.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a copy
  // of this software and associated documentation files (the "Software"), to deal
  // in the Software without restriction, including without limitation the rights
  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  // copies of the Software, and to permit persons to whom the Software is
  // furnished to do so, subject to the following conditions:
  //
  // The above copyright notice and this permission notice shall be included in
  // all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  // THE SOFTWARE.
  //
  
  #pragma once
  
  #include <EASTL/hash_set.h>
  #include "Sample.h"
  
  namespace Urho3D
  {
  
  class Drawable;
  class Node;
  class Scene;
  class DynamicNavigationMesh;
  
  }
  
  /// CrowdNavigation example.
  /// This sample demonstrates:
  ///     - Generating a dynamic navigation mesh into the scene
  ///     - Performing path queries to the navigation mesh
  ///     - Adding and removing obstacles/agents at runtime
  ///     - Raycasting drawable components
  ///     - Crowd movement management
  ///     - Accessing crowd agents with the crowd manager
  ///     - Using off-mesh connections to make boxes climbable
  ///     - Using agents to simulate moving obstacles
  class CrowdNavigation : public Sample
  {
      URHO3D_OBJECT(CrowdNavigation, Sample);
  
  public:
      /// Construct.
      explicit CrowdNavigation(Context* context);
  
      /// Setup after engine initialization and before running the main loop.
      void Start() override;
  
  protected:
      /// Return XML patch instructions for screen joystick layout for a specific sample app, if any.
      ea::string GetScreenJoystickPatchString() const override { return
          "<patch>"
          "    <add sel=\"/element\">"
          "        <element type=\"Button\">"
          "            <attribute name=\"Name\" value=\"Button3\" />"
          "            <attribute name=\"Position\" value=\"-120 -120\" />"
          "            <attribute name=\"Size\" value=\"96 96\" />"
          "            <attribute name=\"Horiz Alignment\" value=\"Right\" />"
          "            <attribute name=\"Vert Alignment\" value=\"Bottom\" />"
          "            <attribute name=\"Texture\" value=\"Texture2D;Textures/TouchInput.png\" />"
          "            <attribute name=\"Image Rect\" value=\"96 0 192 96\" />"
          "            <attribute name=\"Hover Image Offset\" value=\"0 0\" />"
          "            <attribute name=\"Pressed Image Offset\" value=\"0 0\" />"
          "            <element type=\"Text\">"
          "                <attribute name=\"Name\" value=\"Label\" />"
          "                <attribute name=\"Horiz Alignment\" value=\"Center\" />"
          "                <attribute name=\"Vert Alignment\" value=\"Center\" />"
          "                <attribute name=\"Color\" value=\"0 0 0 1\" />"
          "                <attribute name=\"Text\" value=\"Spawn\" />"
          "            </element>"
          "            <element type=\"Text\">"
          "                <attribute name=\"Name\" value=\"KeyBinding\" />"
          "                <attribute name=\"Text\" value=\"LSHIFT\" />"
          "            </element>"
          "            <element type=\"Text\">"
          "                <attribute name=\"Name\" value=\"MouseButtonBinding\" />"
          "                <attribute name=\"Text\" value=\"LEFT\" />"
          "            </element>"
          "        </element>"
          "        <element type=\"Button\">"
          "            <attribute name=\"Name\" value=\"Button4\" />"
          "            <attribute name=\"Position\" value=\"-120 -12\" />"
          "            <attribute name=\"Size\" value=\"96 96\" />"
          "            <attribute name=\"Horiz Alignment\" value=\"Right\" />"
          "            <attribute name=\"Vert Alignment\" value=\"Bottom\" />"
          "            <attribute name=\"Texture\" value=\"Texture2D;Textures/TouchInput.png\" />"
          "            <attribute name=\"Image Rect\" value=\"96 0 192 96\" />"
          "            <attribute name=\"Hover Image Offset\" value=\"0 0\" />"
          "            <attribute name=\"Pressed Image Offset\" value=\"0 0\" />"
          "            <element type=\"Text\">"
          "                <attribute name=\"Name\" value=\"Label\" />"
          "                <attribute name=\"Horiz Alignment\" value=\"Center\" />"
          "                <attribute name=\"Vert Alignment\" value=\"Center\" />"
          "                <attribute name=\"Color\" value=\"0 0 0 1\" />"
          "                <attribute name=\"Text\" value=\"Obstacles\" />"
          "            </element>"
          "            <element type=\"Text\">"
          "                <attribute name=\"Name\" value=\"MouseButtonBinding\" />"
          "                <attribute name=\"Text\" value=\"MIDDLE\" />"
          "            </element>"
          "        </element>"
          "    </add>"
          "    <remove sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]/attribute[@name='Is Visible']\" />"
          "    <replace sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]/element[./attribute[@name='Name' and @value='Label']]/attribute[@name='Text']/@value\">Set</replace>"
          "    <add sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]\">"
          "        <element type=\"Text\">"
          "            <attribute name=\"Name\" value=\"MouseButtonBinding\" />"
          "            <attribute name=\"Text\" value=\"LEFT\" />"
          "        </element>"
          "    </add>"
          "    <remove sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]/attribute[@name='Is Visible']\" />"
          "    <replace sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]/element[./attribute[@name='Name' and @value='Label']]/attribute[@name='Text']/@value\">Debug</replace>"
          "    <add sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]\">"
          "        <element type=\"Text\">"
          "            <attribute name=\"Name\" value=\"KeyBinding\" />"
          "            <attribute name=\"Text\" value=\"SPACE\" />"
          "        </element>"
          "    </add>"
          "</patch>";
      }
  
  private:
      /// Construct the scene content.
      void CreateScene();
      /// Construct user interface elements.
      void CreateUI();
      /// Set up a viewport for displaying the scene.
      void SetupViewport();
      /// Subscribe to application-wide logic update and post-render update events.
      void SubscribeToEvents();
      /// Read input and moves the camera.
      void MoveCamera(float timeStep);
      /// Set crowd agents target or spawn another jack.
      void SetPathPoint(bool spawning);
      /// Add new obstacle or remove existing obstacle/agent.
      void AddOrRemoveObject();
      /// Create a "Jack" object at position.
      void SpawnJack(const Vector3& pos, Node* jackGroup);
      /// Create a mushroom object at position.
      void CreateMushroom(const Vector3& pos);
      /// Create an off-mesh connection for each box to make it climbable.
      void CreateBoxOffMeshConnections(DynamicNavigationMesh* navMesh, Node* boxGroup);
      /// Create some movable barrels as crowd agents.
      void CreateMovingBarrels(DynamicNavigationMesh* navMesh);
      /// Utility function to raycast to the cursor position. Return true if hit.
      bool Raycast(float maxDistance, Vector3& hitPos, Drawable*& hitDrawable);
      /// Toggle navigation mesh streaming.
      void ToggleStreaming(bool enabled);
      /// Update navigation mesh streaming.
      void UpdateStreaming();
      /// Save navigation data for streaming.
      void SaveNavigationData();
      /// Handle the logic update event.
      void HandleUpdate(StringHash eventType, VariantMap& eventData);
      /// Handle the post-render update event.
      void HandlePostRenderUpdate(StringHash eventType, VariantMap& eventData);
      /// Handle problems with crowd agent placement.
      void HandleCrowdAgentFailure(StringHash eventType, VariantMap& eventData);
      /// Handle crowd agent reposition.
      void HandleCrowdAgentReposition(StringHash eventType, VariantMap& eventData);
      /// Handle crowd agent formation.
      void HandleCrowdAgentFormation(StringHash eventType, VariantMap& eventData);
  
      /// Flag for using navigation mesh streaming.
      bool useStreaming_{};
      /// Streaming distance.
      int streamingDistance_{2};
      /// Tile data.
      ea::unordered_map<IntVector2, ea::vector<unsigned char> > tileData_;
      /// Added tiles.
      ea::hash_set<IntVector2> addedTiles_;
      /// Flag for drawing debug geometry.
      bool drawDebug_{};
      /// Instruction text UI-element.
      Text* instructionText_{};
  };
  