//=============================================================================
  // ShadowMapDemo.cpp by Frank Luna (C) 2005 All Rights Reserved.
  //
  // Demonstrates shadow mapping.
  //
  // 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>
  include <DrawableTex2D.h>
  
  struct SpotLight
  {
          D3DXCOLOR ambient;
          D3DXCOLOR diffuse;
          D3DXCOLOR spec;
          D3DXVECTOR3 posW;
          D3DXVECTOR3 dirW;  
          float  spotPower;
  };
  
  class ShadowMapDemo : public D3DApp
  {
  public:
          ShadowMapDemo(HINSTANCE hInstance, std::string winCaption, D3DDEVTYPE devType, DWORD requestedVP);
          ~ShadowMapDemo();
  
          bool checkDeviceCaps();
          void onLostDevice();
          void onResetDevice();
          void updateScene(float dt);
          void drawScene();
          void drawShadowMap();
          void buildFX();
  private:
          GfxStats* mGfxStats;
           
          Sky* mSky;
          ID3DXMesh* mSceneMesh;
          D3DXMATRIX mSceneWorld;
          std::vector<Mtrl> mSceneMtrls;
          std::vector<IDirect3DTexture9*> mSceneTextures;
  
          ID3DXMesh* mCarMesh;
          D3DXMATRIX mCarWorld;
          std::vector<Mtrl> mCarMtrls;
          std::vector<IDirect3DTexture9*> mCarTextures;
  
          IDirect3DTexture9* mWhiteTex;
          DrawableTex2D* mShadowMap;
  
          D3DXMATRIX mLightVP;
  
          ID3DXEffect* mFX;
          D3DXHANDLE   mhBuildShadowMapTech;
          D3DXHANDLE   mhLightWVP;
  
          D3DXHANDLE   mhTech;
          D3DXHANDLE   mhWVP;
          D3DXHANDLE   mhWorldInvTrans;
          D3DXHANDLE   mhEyePosW;
          D3DXHANDLE   mhWorld;
          D3DXHANDLE   mhTex;
          D3DXHANDLE   mhShadowMap;
          D3DXHANDLE   mhMtrl;
          D3DXHANDLE   mhLight;
   
          SpotLight 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;
  
          ShadowMapDemo app(hInstance, "Shadow Map Demo", D3DDEVTYPE_HAL, D3DCREATE_HARDWARE_VERTEXPROCESSING);
          gd3dApp = &app;
  
          DirectInput di(DISCL_NONEXCLUSIVE|DISCL_FOREGROUND, DISCL_NONEXCLUSIVE|DISCL_FOREGROUND);
          gDInput = &di;
  
      return gd3dApp->run();
  }
  
  ShadowMapDemo::ShadowMapDemo(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);
   
          LoadXFile(<BasicColumnScene.x>, &mSceneMesh, mSceneMtrls, mSceneTextures);
          D3DXMatrixIdentity(&mSceneWorld);
  
          LoadXFile(<car.x>, &mCarMesh, mCarMtrls, mCarTextures);
          D3DXMATRIX S, T;
          D3DXMatrixScaling(&S, 1.5f, 1.5f, 1.5f);
          D3DXMatrixTranslation(&T, 6.0f, 3.5f, -3.0f);
          mCarWorld = S*T;
  
          HR(D3DXCreateTextureFromFile(gd3dDevice, "whitetex.dds", &mWhiteTex));
  
          // Set some light properties; other properties are set in update function,
          // where they are animated.
          mLight.ambient   = D3DXCOLOR(0.5f, 0.5f, 0.5f, 1.0f);
          mLight.diffuse   = D3DXCOLOR(1.0f, 1.0f, 1.0f, 1.0f);
          mLight.spec      = D3DXCOLOR(0.5f, 0.5f, 0.5f, 1.0f);
          mLight.spotPower = 32.0f;
  
          // Create shadow map.
          D3DVIEWPORT9 vp = {0, 0, 512, 512, 0.0f, 1.0f};
          mShadowMap = new DrawableTex2D(512, 512, 1, D3DFMT_R32F, true, D3DFMT_D24X8, vp, false);
  
          // Initialize camera.
          gCamera->pos().y = 20.0f;
          gCamera->pos().z = -100.0f;
          gCamera->setSpeed(50.0f);
  
          mGfxStats->addVertices(mSceneMesh->GetNumVertices());
          mGfxStats->addTriangles(mSceneMesh->GetNumFaces());
  
          mGfxStats->addVertices(mCarMesh->GetNumVertices());
          mGfxStats->addTriangles(mCarMesh->GetNumFaces());
  
          mGfxStats->addVertices(mSky->getNumVertices());
          mGfxStats->addTriangles(mSky->getNumTriangles());
  
          buildFX();
  
          onResetDevice();
  }
  
  ShadowMapDemo::~ShadowMapDemo()
  {
          delete mGfxStats;
          delete mSky;
          ReleaseCOM(mFX);
          ReleaseCOM(mWhiteTex);
          delete mShadowMap;
  
          ReleaseCOM(mSceneMesh);
          for(UINT i = 0; i < mSceneTextures.size(); ++i)
                  ReleaseCOM(mSceneTextures[i]);
  
          ReleaseCOM(mCarMesh);
          for(UINT i = 0; i < mCarTextures.size(); ++i)
                  ReleaseCOM(mCarTextures[i]);
  
          DestroyAllVertexDeclarations();
  }
  
  bool ShadowMapDemo::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;
  
          // Check render target support.  The adapter format can be either the display mode format
          // for windowed mode, or D3DFMT_X8R8G8B8 for fullscreen mode, so we need to test against
          // both.  We use D3DFMT_R32F as the render texture format and D3DFMT_D24X8 as the 
          // render texture depth format.
          D3DDISPLAYMODE mode;
          md3dObject->GetAdapterDisplayMode(D3DADAPTER_DEFAULT, &mode);
  
          // Windowed.
          if(FAILED(md3dObject->CheckDeviceFormat(D3DADAPTER_DEFAULT, mDevType, mode.Format, 
                  D3DUSAGE_RENDERTARGET, D3DRTYPE_TEXTURE, D3DFMT_R32F)))
                  return false;
          if(FAILED(md3dObject->CheckDepthStencilMatch(D3DADAPTER_DEFAULT, mDevType, mode.Format,
                  D3DFMT_R32F, D3DFMT_D24X8)))
                  return false;
  
          // Fullscreen.
          if(FAILED(md3dObject->CheckDeviceFormat(D3DADAPTER_DEFAULT, mDevType, D3DFMT_X8R8G8B8, 
                  D3DUSAGE_RENDERTARGET, D3DRTYPE_TEXTURE, D3DFMT_R32F)))
                  return false;
          if(FAILED(md3dObject->CheckDepthStencilMatch(D3DADAPTER_DEFAULT, mDevType, D3DFMT_X8R8G8B8,
                  D3DFMT_R32F, D3DFMT_D24X8)))
                  return false;
  
          return true;
  }
  
  void ShadowMapDemo::onLostDevice()
  {
          mGfxStats->onLostDevice();
          mSky->onLostDevice();
          mShadowMap->onLostDevice();
          HR(mFX->OnLostDevice());
  }
  
  void ShadowMapDemo::onResetDevice()
  {
          mGfxStats->onResetDevice();
          mSky->onResetDevice();
          mShadowMap->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 ShadowMapDemo::updateScene(float dt)
  {
          mGfxStats->update(dt);
  
          gDInput->poll();
  
          gCamera->update(dt, 0, 0);
  
          // Animate spot light by rotating it on y-axis with respect to time.
          D3DXMATRIX lightView;
          D3DXVECTOR3 lightPosW(125.0f, 50.0f, 0.0f);
          D3DXVECTOR3 lightTargetW(0.0f, 0.0f, 0.0f);
          D3DXVECTOR3 lightUpW(0.0f, 1.0f, 0.0f);
  
          static float t = 0.0f;
          t += dt;
          if( t >= 2.0f*D3DX_PI )
                  t = 0.0f;
          D3DXMATRIX Ry;
          D3DXMatrixRotationY(&Ry, t);
          D3DXVec3TransformCoord(&lightPosW, &lightPosW, &Ry);
  
          D3DXMatrixLookAtLH(&lightView, &lightPosW, &lightTargetW, &lightUpW);
          
          D3DXMATRIX lightLens;
          float lightFOV = D3DX_PI*0.25f;
          D3DXMatrixPerspectiveFovLH(&lightLens, lightFOV, 1.0f, 1.0f, 200.0f);
  
          mLightVP = lightView*lightLens;
  
          // Setup a spotlight corresponding to the projector.
          D3DXVECTOR3 lightDirW = lightTargetW - lightPosW;
          D3DXVec3Normalize(&lightDirW, &lightDirW);
          mLight.posW      = lightPosW;
          mLight.dirW      = lightDirW;
  }
  
  void ShadowMapDemo::drawScene()
  {
          drawShadowMap();
  
          HR(gd3dDevice->BeginScene());
  
          mSky->draw();
  
          HR(mFX->SetTechnique(mhTech));
          
          HR(mFX->SetValue(mhLight, &mLight, sizeof(SpotLight)));
          HR(mFX->SetValue(mhEyePosW, &gCamera->pos(), sizeof(D3DXVECTOR3)));
          HR(mFX->SetTexture(mhShadowMap, mShadowMap->d3dTex()));
  
          UINT numPasses = 0;
          HR(mFX->Begin(&numPasses, 0));
          HR(mFX->BeginPass(0));
  
          // Draw Scene mesh.
          HR(mFX->SetMatrix(mhLightWVP, &(mSceneWorld*mLightVP)));
          HR(mFX->SetMatrix(mhWVP, &(mSceneWorld*gCamera->viewProj())));
          HR(mFX->SetMatrix(mhWorld, &mSceneWorld));        
          for(UINT j = 0; j < mSceneMtrls.size(); ++j)
          {
                  HR(mFX->SetValue(mhMtrl, &mSceneMtrls[j], sizeof(Mtrl)));
          
                  if(mSceneTextures[j] != 0)
                  {
                          HR(mFX->SetTexture(mhTex, mSceneTextures[j]));
                  }
                  else
                  {
                          HR(mFX->SetTexture(mhTex, mWhiteTex));
                  }
          
                  HR(mFX->CommitChanges());
                  HR(mSceneMesh->DrawSubset(j));
          }
  
          // Draw car mesh.
          HR(mFX->SetMatrix(mhLightWVP, &(mCarWorld*mLightVP)));
          HR(mFX->SetMatrix(mhWVP, &(mCarWorld*gCamera->viewProj())));
          HR(mFX->SetMatrix(mhWorld, &mCarWorld));        
          for(UINT j = 0; j < mCarMtrls.size(); ++j)
          {
                  HR(mFX->SetValue(mhMtrl, &mCarMtrls[j], sizeof(Mtrl)));
          
                  if(mCarTextures[j] != 0)
                  {
                          HR(mFX->SetTexture(mhTex, mCarTextures[j]));
                  }
                  else
                  {
                          HR(mFX->SetTexture(mhTex, mWhiteTex));
                  }
          
                  HR(mFX->CommitChanges());
                  HR(mCarMesh->DrawSubset(j));
          }
  
          HR(mFX->EndPass());
          HR(mFX->End());
   
          mGfxStats->display();
  
          HR(gd3dDevice->EndScene());
  
          // Present the backbuffer.
          HR(gd3dDevice->Present(0, 0, 0, 0));
  }
  
  void ShadowMapDemo::drawShadowMap()
  {
          mShadowMap->beginScene();
          HR(gd3dDevice->Clear(0, 0, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0x00000000, 1.0f, 0));
   
          HR(mFX->SetTechnique(mhBuildShadowMapTech));
          
          UINT numPasses = 0;
          HR(mFX->Begin(&numPasses, 0));
          HR(mFX->BeginPass(0));
  
          // Draw scene mesh.
          HR(mFX->SetMatrix(mhLightWVP, &(mSceneWorld*mLightVP)));
          HR(mFX->CommitChanges());
          for(UINT j = 0; j < mSceneMtrls.size(); ++j)
          {
                  for(UINT j = 0; j < mSceneMtrls.size(); ++j)
                  {
                          HR(mSceneMesh->DrawSubset(j));
                  }
          }
  
          // Draw car mesh.
          HR(mFX->SetMatrix(mhLightWVP, &(mCarWorld*mLightVP)));
          HR(mFX->CommitChanges());
          for(UINT j = 0; j < mCarMtrls.size(); ++j)
          {
                  for(UINT j = 0; j < mCarMtrls.size(); ++j)
                  {
                          HR(mCarMesh->DrawSubset(j));
                  }
          }
  
          HR(mFX->EndPass());
          HR(mFX->End());
  
          mShadowMap->endScene();
  }
  
  void ShadowMapDemo::buildFX()
  {
           // Create the FX from a .fx file.
          ID3DXBuffer* errors = 0;
          HR(D3DXCreateEffectFromFile(gd3dDevice, "LightShadow.fx", 
                  0, 0, D3DXSHADER_DEBUG, 0, &mFX, &errors));
          if( errors )
                  MessageBox(0, (char*)errors->GetBufferPointer(), 0, 0);
  
          // Obtain handles.
          mhTech               = mFX->GetTechniqueByName("LightShadowTech");
          mhBuildShadowMapTech = mFX->GetTechniqueByName("BuildShadowMapTech");
          mhLightWVP           = mFX->GetParameterByName(0, "gLightWVP");
          mhWVP                = mFX->GetParameterByName(0, "gWVP");
          mhWorld              = mFX->GetParameterByName(0, "gWorld");
          mhMtrl               = mFX->GetParameterByName(0, "gMtrl");
          mhLight              = mFX->GetParameterByName(0, "gLight");
          mhEyePosW            = mFX->GetParameterByName(0, "gEyePosW");
          mhTex                = mFX->GetParameterByName(0, "gTex");
          mhShadowMap          = mFX->GetParameterByName(0, "gShadowMap");
  }