//=============================================================================
  // GfxStats.cpp by Frank Luna (C) 2005 All Rights Reserved.
  //=============================================================================
  
  include <d3dUtil.h>
  include <d3dApp.h>
  include <GfxStats.h>
  include <tchar.h>
  
  GfxStats::GfxStats()
  : mFont(0), mFPS(0.0f), mMilliSecPerFrame(0.0f), mNumTris(0), mNumVertices(0)
  {
          D3DXFONT_DESC fontDesc;
          fontDesc.Height          = 18;
      fontDesc.Width           = 0;
      fontDesc.Weight          = 0;
      fontDesc.MipLevels       = 1;
      fontDesc.Italic          = false;
      fontDesc.CharSet         = DEFAULT_CHARSET;
      fontDesc.OutputPrecision = OUT_DEFAULT_PRECIS;
      fontDesc.Quality         = DEFAULT_QUALITY;
      fontDesc.PitchAndFamily  = DEFAULT_PITCH | FF_DONTCARE;
      _tcscpy(fontDesc.FaceName, _T("Times New Roman"));
  
          HR(D3DXCreateFontIndirect(gd3dDevice, &fontDesc, &mFont));
  }
  
  GfxStats::~GfxStats()
  {
          ReleaseCOM(mFont);
  }
  
  void GfxStats::onLostDevice()
  {
          HR(mFont->OnLostDevice());
  }
  
  void GfxStats::onResetDevice()
  {
          HR(mFont->OnResetDevice());
  }
  
  void GfxStats::addVertices(DWORD n)
  {
          mNumVertices += n;
  }
  
  void GfxStats::subVertices(DWORD n)
  {
          mNumVertices -= n;
  }
  
  void GfxStats::addTriangles(DWORD n)
  {
          mNumTris += n;
  }
  
  void GfxStats::subTriangles(DWORD n)
  {
          mNumTris -= n;
  }
  
  void GfxStats::setTriCount(DWORD n)
  {
          mNumTris = n;
  }
  
  void GfxStats::setVertexCount(DWORD n)
  {
          mNumVertices = n;
  }
  
  void GfxStats::update(float dt)
  {
          // Make static so that their values persist accross function calls.
          static float numFrames   = 0.0f;
          static float timeElapsed = 0.0f;
  
          // Increment the frame count.
          numFrames += 1.0f;
  
          // Accumulate how much time has passed.
          timeElapsed += dt;
  
          // Has one second passed?--we compute the frame statistics once 
          // per second.  Note that the time between frames can vary so 
          // these stats are averages over a second.
          if( timeElapsed >= 1.0f )
          {
                  // Frames Per Second = numFrames / timeElapsed,
                  // but timeElapsed approx. equals 1.0, so 
                  // frames per second = numFrames.
  
                  mFPS = numFrames;
  
                  // Average time, in miliseconds, it took to render a single frame.
                  mMilliSecPerFrame = 1000.0f / mFPS;
  
                  // Reset time counter and frame count to prepare for computing
                  // the average stats over the next second.
                  timeElapsed = 0.0f;
                  numFrames   = 0.0f;
          }
  }
  
  void GfxStats::display()
  {
          // Make static so memory is not allocated every frame.
          static char buffer[256];
  
          sprintf(buffer, "Frames Per Second = %.2f\n"
                  "Milliseconds Per Frame = %.4f\n"
                  "Triangle Count = \%d\n"
                  "Vertex Count = \%d", mFPS, mMilliSecPerFrame, mNumTris, mNumVertices);
  
          RECT R = {5, 5, 0, 0};
          HR(mFont->DrawText(0, buffer, -1, &R, DT_NOCLIP, D3DCOLOR_XRGB(0,0,0)));
  }