text: //
  // Copyright (c) 2008-2021 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.
  //
  
  #include <Urho3D/AngelScript/Script.h>
  #include <Urho3D/AngelScript/ScriptFile.h>
  #include <Urho3D/AngelScript/ScriptInstance.h>
  #include <Urho3D/Core/CoreEvents.h>
  #include <Urho3D/Engine/Engine.h>
  #include <Urho3D/Graphics/Camera.h>
  #include <Urho3D/Graphics/Graphics.h>
  #include <Urho3D/Graphics/Material.h>
  #include <Urho3D/Graphics/Model.h>
  #include <Urho3D/Graphics/Octree.h>
  #include <Urho3D/Graphics/Renderer.h>
  #include <Urho3D/Graphics/StaticModel.h>
  #include <Urho3D/Graphics/Zone.h>
  #include <Urho3D/Input/Input.h>
  #include <Urho3D/Resource/ResourceCache.h>
  #include <Urho3D/Scene/Scene.h>
  #include <Urho3D/UI/Font.h>
  #include <Urho3D/UI/Text.h>
  #include <Urho3D/UI/UI.h>
  
  #include "AngelScriptIntegration.h"
  
  #include <Urho3D/DebugNew.h>
  
  URHO3D_DEFINE_APPLICATION_MAIN(AngelScriptIntegration)
  
  AngelScriptIntegration::AngelScriptIntegration(Context* context) :
      Sample(context)
  {
      // Instantiate and register the AngelScript subsystem so that we can use the ScriptInstance component
      context_->RegisterSubsystem(new Script(context_));
  }
  
  void AngelScriptIntegration::Start()
  {
      // Execute base class startup
      Sample::Start();
  
      // Create the scene content
      CreateScene();
  
      // Create the UI content
      CreateInstructions();
  
      // Setup the viewport for displaying the scene
      SetupViewport();
  
      // Hook up to the frame update events
      SubscribeToEvents();
  
      // Set the mouse mode to use in the sample
      Sample::InitMouseMode(MM_RELATIVE);
  }
  
  void AngelScriptIntegration::CreateScene()
  {
      auto* cache = GetSubsystem<ResourceCache>();
  
      scene_ = new Scene(context_);
  
      // Create the Octree component to the scene so that drawable objects can be rendered. Use default volume
      // (-1000, -1000, -1000) to (1000, 1000, 1000)
      scene_->CreateComponent<Octree>();
  
      // Create a Zone component into a child scene node. The Zone controls ambient lighting and fog settings. Like the Octree,
      // it also defines its volume with a bounding box, but can be rotated (so it does not need to be aligned to the world X, Y
      // and Z axes.) Drawable objects "pick up" the zone they belong to and use it when rendering; several zones can exist
      Node* zoneNode = scene_->CreateChild("Zone");
      auto* zone = zoneNode->CreateComponent<Zone>();
      // Set same volume as the Octree, set a close bluish fog and some ambient light
      zone->SetBoundingBox(BoundingBox(-1000.0f, 1000.0f));
      zone->SetAmbientColor(Color(0.05f, 0.1f, 0.15f));
      zone->SetFogColor(Color(0.1f, 0.2f, 0.3f));
      zone->SetFogStart(10.0f);
      zone->SetFogEnd(100.0f);
  
      // Create randomly positioned and oriented box StaticModels in the scene
      const unsigned NUM_OBJECTS = 2000;
      for (unsigned i = 0; i < NUM_OBJECTS; ++i)
      {
          Node* boxNode = scene_->CreateChild("Box");
          boxNode->SetPosition(Vector3(Random(200.0f) - 100.0f, Random(200.0f) - 100.0f, Random(200.0f) - 100.0f));
          // Orient using random pitch, yaw and roll Euler angles
          boxNode->SetRotation(Quaternion(Random(360.0f), Random(360.0f), Random(360.0f)));
          auto* boxObject = boxNode->CreateComponent<StaticModel>();
          boxObject->SetModel(cache->GetResource<Model>("Models/Box.mdl"));
          boxObject->SetMaterial(cache->GetResource<Material>("Materials/Stone.xml"));
  
          // Add our custom Rotator script object (using the ScriptInstance C++ component to instantiate / store it) which will
          // rotate the scene node each frame, when the scene sends its update event
          auto* instance = boxNode->CreateComponent<ScriptInstance>();
          instance->CreateObject(cache->GetResource<ScriptFile>("Scripts/Utilities/Rotator.as"), "Rotator");
          // Call the script object's "SetRotationSpeed" function. Function arguments need to be passed in a VariantVector
          VariantVector parameters;
          parameters.Push(Vector3(10.0f, 20.0f, 30.0f));
          instance->Execute("void SetRotationSpeed(const Vector3&in)", parameters);
      }
  
      // Create the camera. Let the starting position be at the world origin. As the fog limits maximum visible distance, we can
      // bring the far clip plane closer for more effective culling of distant objects
      cameraNode_ = scene_->CreateChild("Camera");
      auto* camera = cameraNode_->CreateComponent<Camera>();
      camera->SetFarClip(100.0f);
  
      // Create a point light to the camera scene node
      auto* light = cameraNode_->CreateComponent<Light>();
      light->SetLightType(LIGHT_POINT);
      light->SetRange(30.0f);
  }
  
  void AngelScriptIntegration::CreateInstructions()
  {
      auto* cache = GetSubsystem<ResourceCache>();
      auto* ui = GetSubsystem<UI>();
  
      // Construct new Text object, set string to display and font to use
      auto* instructionText = ui->GetRoot()->CreateChild<Text>();
      instructionText->SetText("Use WASD keys and mouse/touch to move");
      instructionText->SetFont(cache->GetResource<Font>("Fonts/Anonymous Pro.ttf"), 15);
  
      // Position the text relative to the screen center
      instructionText->SetHorizontalAlignment(HA_CENTER);
      instructionText->SetVerticalAlignment(VA_CENTER);
      instructionText->SetPosition(0, ui->GetRoot()->GetHeight() / 4);
  }
  
  void AngelScriptIntegration::SetupViewport()
  {
      auto* renderer = GetSubsystem<Renderer>();
  
      // Set up a viewport to the Renderer subsystem so that the 3D scene can be seen
      SharedPtr<Viewport> viewport(new Viewport(context_, scene_, cameraNode_->GetComponent<Camera>()));
      renderer->SetViewport(0, viewport);
  }
  
  void AngelScriptIntegration::SubscribeToEvents()
  {
      // Subscribe HandleUpdate() function for processing update events
      SubscribeToEvent(E_UPDATE, URHO3D_HANDLER(AngelScriptIntegration, HandleUpdate));
  }
  
  void AngelScriptIntegration::MoveCamera(float timeStep)
  {
      // Do not move if the UI has a focused element (the console)
      if (GetSubsystem<UI>()->GetFocusElement())
          return;
  
      auto* input = GetSubsystem<Input>();
  
      // Movement speed as world units per second
      const float MOVE_SPEED = 20.0f;
      // Mouse sensitivity as degrees per pixel
      const float MOUSE_SENSITIVITY = 0.1f;
  
      // Use this frame's mouse motion to adjust camera node yaw and pitch. Clamp the pitch between -90 and 90 degrees
      IntVector2 mouseMove = input->GetMouseMove();
      yaw_ += MOUSE_SENSITIVITY * mouseMove.x_;
      pitch_ += MOUSE_SENSITIVITY * mouseMove.y_;
      pitch_ = Clamp(pitch_, -90.0f, 90.0f);
  
      // Construct new orientation for the camera scene node from yaw and pitch. Roll is fixed to zero
      cameraNode_->SetRotation(Quaternion(pitch_, yaw_, 0.0f));
  
      // Read WASD keys and move the camera scene node to the corresponding direction if they are pressed
      if (input->GetKeyDown(KEY_W))
          cameraNode_->Translate(Vector3::FORWARD * MOVE_SPEED * timeStep);
      if (input->GetKeyDown(KEY_S))
          cameraNode_->Translate(Vector3::BACK * MOVE_SPEED * timeStep);
      if (input->GetKeyDown(KEY_A))
          cameraNode_->Translate(Vector3::LEFT * MOVE_SPEED * timeStep);
      if (input->GetKeyDown(KEY_D))
          cameraNode_->Translate(Vector3::RIGHT * MOVE_SPEED * timeStep);
  }
  
  void AngelScriptIntegration::HandleUpdate(StringHash eventType, VariantMap& eventData)
  {
      using namespace Update;
  
      // Take the frame time step, which is stored as a float
      float timeStep = eventData[P_TIMESTEP].GetFloat();
  
      // Move the camera, scale movement with time step
      MoveCamera(timeStep);
  }
  