//=============================================================================
  // EnvMapDemo.cpp by Frank Luna (C) 2005 All Rights Reserved.
  //
  // Demonstrates how to texture a sky sphere with an environment map
  //   and how to simulate reflections on arbitrary objects with an
  //   environment map.
  //
  // Controls: Use mouse to look and 'W', 'S', 'A', and 'D' keys to move.
  //=============================================================================
  
  include <d3dApp.h>
  include <DirectInput.h>
  include <crtdbg.h>
  include <GfxStats.h>
  include <list>
  include <Camera.h>
  include <Sky.h>
  include <Vertex.h>
  
  class EnvMapDemo : public D3DApp
  {
  public:
          EnvMapDemo(HINSTANCE hInstance, std::string winCaption, D3DDEVTYPE devType, DWORD requestedVP);
          ~EnvMapDemo();
  
          bool checkDeviceCaps();
          void onLostDevice();
          void onResetDevice();
          void updateScene(float dt);
          void drawScene();
          
          void buildFX();
  private:
          GfxStats* mGfxStats;
           
          Sky* mSky;
          ID3DXMesh* mSceneMesh;
          D3DXMATRIX mSceneWorld;
          std::vector<Mtrl> mSceneMtrls;
          std::vector<IDirect3DTexture9*> mSceneTextures;
  
          IDirect3DTexture9* mWhiteTex;
  
          ID3DXEffect* mFX;
          D3DXHANDLE   mhTech;
          D3DXHANDLE   mhWVP;
          D3DXHANDLE   mhWorldInvTrans;
          D3DXHANDLE   mhEyePosW;
          D3DXHANDLE   mhWorld;
          D3DXHANDLE   mhTex;
          D3DXHANDLE   mhMtrl;
          D3DXHANDLE   mhLight;
          D3DXHANDLE   mhEnvMap;
  
          DirLight mLight;
  };
  
  int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE prevInstance,
                                     PSTR cmdLine, int showCmd)
  {
          // Enable run-time memory check for debug builds.
          #if defined(DEBUG) | defined(_DEBUG)
                  _CrtSetDbgFlag( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF );
          #endif
  
          // Construct camera before application, since the application uses the camera.
          Camera camera;
          gCamera = &camera;
  
          EnvMapDemo app(hInstance, "Environment Map Demo", D3DDEVTYPE_HAL, D3DCREATE_HARDWARE_VERTEXPROCESSING);
          gd3dApp = &app;
  
          DirectInput di(DISCL_NONEXCLUSIVE|DISCL_FOREGROUND, DISCL_NONEXCLUSIVE|DISCL_FOREGROUND);
          gDInput = &di;
  
      return gd3dApp->run();
  }
  
  EnvMapDemo::EnvMapDemo(HINSTANCE hInstance, std::string winCaption, D3DDEVTYPE devType, DWORD requestedVP)
  : D3DApp(hInstance, winCaption, devType, requestedVP)
  {
          if(!checkDeviceCaps())
          {
                  MessageBox(0, "checkDeviceCaps() Failed", 0, 0);
                  PostQuitMessage(0);
          }
  
          InitAllVertexDeclarations();
  
          mGfxStats = new GfxStats();
          mSky = new Sky("grassenvmap1024.dds", 10000.0f);
   
          mLight.dirW    = D3DXVECTOR3(0.0f, 1.0f, 2.0f);
          D3DXVec3Normalize(&mLight.dirW, &mLight.dirW);
          mLight.ambient = D3DXCOLOR(0.5f, 0.5f, 0.5f, 1.0f);
          mLight.diffuse = D3DXCOLOR(0.8f, 0.8f, 0.8f, 1.0f);
          mLight.spec    = D3DXCOLOR(0.8f, 0.8f, 0.8f, 1.0f);
  
          LoadXFile(<skullocc.x>, &mSceneMesh, mSceneMtrls, mSceneTextures);
          D3DXMatrixIdentity(&mSceneWorld);
  
          HR(D3DXCreateTextureFromFile(gd3dDevice, "whitetex.dds", &mWhiteTex));
  
          // Initialize camera.
          gCamera->pos().y = 3.0f;
          gCamera->pos().z = -10.0f;
          gCamera->setSpeed(5.0f);
  
          mGfxStats->addVertices(mSceneMesh->GetNumVertices());
          mGfxStats->addTriangles(mSceneMesh->GetNumFaces());
  
          mGfxStats->addVertices(mSky->getNumVertices());
          mGfxStats->addTriangles(mSky->getNumTriangles());
  
          buildFX();
  
          onResetDevice();
  }
  
  EnvMapDemo::~EnvMapDemo()
  {
          delete mGfxStats;
          delete mSky;
   
          ReleaseCOM(mFX);
  
          ReleaseCOM(mSceneMesh);
          for(UINT i = 0; i < mSceneTextures.size(); ++i)
                  ReleaseCOM(mSceneTextures[i]);
  
          ReleaseCOM(mWhiteTex);
  
          DestroyAllVertexDeclarations();
  }
  
  bool EnvMapDemo::checkDeviceCaps()
  {
          D3DCAPS9 caps;
          HR(gd3dDevice->GetDeviceCaps(&caps));
  
          // Check for vertex shader version 2.0 support.
          if( caps.VertexShaderVersion < D3DVS_VERSION(2, 0) )
                  return false;
  
          // Check for pixel shader version 2.0 support.
          if( caps.PixelShaderVersion < D3DPS_VERSION(2, 0) )
                  return false;
  
          return true;
  }
  
  void EnvMapDemo::onLostDevice()
  {
          mGfxStats->onLostDevice();
          mSky->onLostDevice();
          HR(mFX->OnLostDevice());
  }
  
  void EnvMapDemo::onResetDevice()
  {
          mGfxStats->onResetDevice();
          mSky->onResetDevice();
          HR(mFX->OnResetDevice());
  
          // The aspect ratio depends on the backbuffer dimensions, which can 
          // possibly change after a reset.  So rebuild the projection matrix.
          float w = (float)md3dPP.BackBufferWidth;
          float h = (float)md3dPP.BackBufferHeight;
          gCamera->setLens(D3DX_PI * 0.25f, w/h, 1.0f, 2000.0f);
  }
  
  void EnvMapDemo::updateScene(float dt)
  {
          mGfxStats->update(dt);
  
          gDInput->poll();
  
          gCamera->update(dt, 0, 0);
  }
  
  void EnvMapDemo::drawScene()
  {
          HR(gd3dDevice->BeginScene());
  
          // Draw sky first--this also replaces our gd3dDevice->Clear call.
          mSky->draw();
  
          HR(mFX->SetValue(mhLight, &mLight, sizeof(DirLight)));
          HR(mFX->SetMatrix(mhWVP, &(mSceneWorld*gCamera->viewProj())));
          HR(mFX->SetValue(mhEyePosW, &gCamera->pos(), sizeof(D3DXVECTOR3)));
          
          UINT numPasses = 0;
          HR(mFX->Begin(&numPasses, 0));
          HR(mFX->BeginPass(0));
  
          for(UINT j = 0; j < mSceneMtrls.size(); ++j)
          {
                  HR(mFX->SetValue(mhMtrl, &mSceneMtrls[j], sizeof(Mtrl)));
          
                  // If there is a texture, then use.
                  if(mSceneTextures[j] != 0)
                  {
                          HR(mFX->SetTexture(mhTex, mSceneTextures[j]));
                  }
  
                  // But if not, then set a pure white texture.  When the texture color
                  // is multiplied by the color from lighting, it is like multiplying by
                  // 1 and won't change the color from lighting.
                  else
                  {
                          HR(mFX->SetTexture(mhTex, mWhiteTex));
                  }
          
                  HR(mFX->CommitChanges());
                  HR(mSceneMesh->DrawSubset(j));
          }
          HR(mFX->EndPass());
          HR(mFX->End());
   
          mGfxStats->display();
  
          HR(gd3dDevice->EndScene());
  
          // Present the backbuffer.
          HR(gd3dDevice->Present(0, 0, 0, 0));
  }
  
  void EnvMapDemo::buildFX()
  {
          // Create the FX from a .fx file.
          ID3DXBuffer* errors = 0;
          HR(D3DXCreateEffectFromFile(gd3dDevice, "EnvMap.fx", 
                  0, 0, D3DXSHADER_DEBUG, 0, &mFX, &errors));
          if( errors )
                  MessageBox(0, (char*)errors->GetBufferPointer(), 0, 0);
  
          // Obtain handles.
          mhTech            = mFX->GetTechniqueByName("EnvMapTech");
          mhWVP             = mFX->GetParameterByName(0, "gWVP");
          mhWorldInvTrans   = mFX->GetParameterByName(0, "gWorldInvTrans");
          mhMtrl            = mFX->GetParameterByName(0, "gMtrl");
          mhLight           = mFX->GetParameterByName(0, "gLight");
          mhEyePosW         = mFX->GetParameterByName(0, "gEyePosW");
          mhWorld           = mFX->GetParameterByName(0, "gWorld");
          mhTex             = mFX->GetParameterByName(0, "gTex");
          mhEnvMap          = mFX->GetParameterByName(0, "gEnvMap");
  
          // Set parameters that do not vary:
  
          // World is the identity, so inverse-transpose also identity.
          HR(mFX->SetMatrix(mhWorldInvTrans, &mSceneWorld));
          HR(mFX->SetMatrix(mhWorld, &mSceneWorld));
  
          HR(mFX->SetTexture(mhEnvMap, mSky->getEnvMap()));
          HR(mFX->SetTechnique(mhTech));
  }