#include <Terrain/OgreTerrain.h>
#include <Terrain/OgreTerrainGroup.h>

#include "BaseApplication.h"

class TutorialApplication : public BaseApplication
{
public:
  TutorialApplication();
  virtual ~TutorialApplication();

protected:
  virtual void createScene();
  virtual void createFrameListener();
  virtual void destroyScene();
  virtual bool frameRenderingQueued(const Ogre::FrameEvent& fe);

private:
  void defineTerrain(long x, long y);
  void initBlendMaps(Ogre::Terrain* terrain);
  void configureTerrainDefaults(Ogre::Light* light);

  bool mTerrainsImported;
  Ogre::TerrainGroup* mTerrainGroup;
  Ogre::TerrainGlobalOptions* mTerrainGlobals;

  OgreBites::Label* mInfoLabel;

};

#endif // #ifndef __TutorialApplication_h_

#include "TutorialApplication.h"

TutorialApplication::TutorialApplication()
  : mTerrainGroup(0),
    mTerrainGlobals(0),
    mInfoLabel(0)
{
}

TutorialApplication::~TutorialApplication()
{
}

void TutorialApplication::createScene()
{
  mCamera->setPosition(Ogre::Vector3(1683, 50, 2116));
  mCamera->lookAt(Ogre::Vector3(1963, 50, 1660));
  mCamera->setNearClipDistance(.1);

  bool infiniteClip =
    mRoot->getRenderSystem()->getCapabilities()->hasCapability(
      Ogre::RSC_INFINITE_FAR_PLANE);

  if (infiniteClip)
    mCamera->setFarClipDistance(0);
  else
    mCamera->setFarClipDistance(50000);

  mSceneMgr->setAmbientLight(Ogre::ColourValue(.2, .2, .2));

  Ogre::Vector3 lightDir(.55, -.3, .75);
  lightDir.normalise();

  Ogre::Light* light = mSceneMgr->createLight("TestLight");
  light->setType(Ogre::Light::LT_DIRECTIONAL);
  light->setDirection(lightDir);
  light->setDiffuseColour(Ogre::ColourValue::White);
  light->setSpecularColour(Ogre::ColourValue(.4, .4, .4));

  // Fog
  Ogre::ColourValue fadeColour(.9, .9, .9);
  mWindow->getViewport(0)->setBackgroundColour(fadeColour);

  mSceneMgr->setFog(Ogre::FOG_EXP2, fadeColour, 0.002);

  // Terrain
  mTerrainGlobals = OGRE_NEW Ogre::TerrainGlobalOptions();

  mTerrainGroup = OGRE_NEW Ogre::TerrainGroup(
    mSceneMgr,
    Ogre::Terrain::ALIGN_X_Z,
    513, 12000.0);
  mTerrainGroup->setFilenameConvention(Ogre::String("terrain"), Ogre::String("dat"));
  mTerrainGroup->setOrigin(Ogre::Vector3::ZERO);

  configureTerrainDefaults(light);

  for (long x = 0; x <= 0; ++x)
    for (long y = 0; y <= 0; ++y)
      defineTerrain(x, y);

  mTerrainGroup->loadAllTerrains(true);

  if (mTerrainsImported)
  {
    Ogre::TerrainGroup::TerrainIterator ti = mTerrainGroup->getTerrainIterator();

    while (ti.hasMoreElements())
    {
      Ogre::Terrain* t = ti.getNext()->instance;
      initBlendMaps(t);
    }
  }

  mTerrainGroup->freeTemporaryResources();

  // Sky Techniques
  // mSceneMgr->setSkyBox(true, "Examples/SpaceSkyBox", 300, false);
  mSceneMgr->setSkyDome(true, "Examples/CloudySky", 5, 8);
  // Ogre::Plane plane;
  // plane.d = 1000;
  // plane.normal = Ogre::Vector3::NEGATIVE_UNIT_Y;

  // mSceneMgr->setSkyPlane(
  //   true, plane, "Examples/SpaceSkyPlane", 1500, 40, true, 1.5, 150, 150);

}

void TutorialApplication::createFrameListener()
{
  BaseApplication::createFrameListener();

  mInfoLabel = mTrayMgr->createLabel(OgreBites::TL_TOP, "TerrainInfo", "", 350);
}

void TutorialApplication::destroyScene()
{
  OGRE_DELETE mTerrainGroup;
  OGRE_DELETE mTerrainGlobals;
}

bool TutorialApplication::frameRenderingQueued(const Ogre::FrameEvent& fe)
{
  bool ret = BaseApplication::frameRenderingQueued(fe);

  if (mTerrainGroup->isDerivedDataUpdateInProgress())
  {
    mTrayMgr->moveWidgetToTray(mInfoLabel, OgreBites::TL_TOP, 0);
    mInfoLabel->show();

    if (mTerrainsImported)
      mInfoLabel->setCaption("Building terrain...");
    else
      mInfoLabel->setCaption("Updating textures...");
  }
  else
  {
    mTrayMgr->removeWidgetFromTray(mInfoLabel);
    mInfoLabel->hide();

    if (mTerrainsImported)
    {
      mTerrainGroup->saveAllTerrains(true);
      mTerrainsImported = false;
    }
  }

  return ret;
}

void getTerrainImage(bool flipX, bool flipY, Ogre::Image& img)
{
  img.load("terrain.png", Ogre::ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME);

  if (flipX)
    img.flipAroundY();
  if (flipY)
    img.flipAroundX();

}

void TutorialApplication::defineTerrain(long x, long y)
{
  Ogre::String filename = mTerrainGroup->generateFilename(x, y);

  bool exists =
    Ogre::ResourceGroupManager::getSingleton().resourceExists(
      mTerrainGroup->getResourceGroup(),
      filename);

  if (exists)
    mTerrainGroup->defineTerrain(x, y);
  else
  {
    Ogre::Image img;
    getTerrainImage(x % 2 != 0, y % 2 != 0, img);
    mTerrainGroup->defineTerrain(x, y, &img);

    mTerrainsImported = true;
  }
}

void TutorialApplication::initBlendMaps(Ogre::Terrain* terrain)
{
  Ogre::Real minHeight0 = 70;
  Ogre::Real fadeDist0 = 40;
  Ogre::Real minHeight1 = 70;
  Ogre::Real fadeDist1 = 15;

  Ogre::TerrainLayerBlendMap* blendMap0 = terrain->getLayerBlendMap(1);
  Ogre::TerrainLayerBlendMap* blendMap1 = terrain->getLayerBlendMap(2);

  float* pBlend0 = blendMap0->getBlendPointer();
  float* pBlend1 = blendMap1->getBlendPointer();

  for (Ogre::uint16 y = 0; y < terrain->getLayerBlendMapSize(); ++y)
  {
    for (Ogre::uint16 x = 0; x < terrain->getLayerBlendMapSize(); ++x)
    {
      Ogre::Real tx, ty;

      blendMap0->convertImageToTerrainSpace(x, y, &tx, &ty);
      Ogre::Real height = terrain->getHeightAtTerrainPosition(tx, ty);
      Ogre::Real val = (height - minHeight0) / fadeDist0;
      val = Ogre::Math::Clamp(val, (Ogre::Real)0, (Ogre::Real)1);
      *pBlend0++ = val;

      val = (height - minHeight1) / fadeDist1;
      val = Ogre::Math::Clamp(val, (Ogre::Real)0, (Ogre::Real)1);
      *pBlend1++ = val;
    }
  }

  blendMap0->dirty();
  blendMap1->dirty();
  blendMap0->update();
  blendMap1->update();

}

void TutorialApplication::configureTerrainDefaults(Ogre::Light* light)
{
  mTerrainGlobals->setMaxPixelError(8);
  mTerrainGlobals->setCompositeMapDistance(3000);

  mTerrainGlobals->setLightMapDirection(light->getDerivedDirection());
  mTerrainGlobals->setCompositeMapAmbient(mSceneMgr->getAmbientLight());
  mTerrainGlobals->setCompositeMapDiffuse(light->getDiffuseColour());

  Ogre::Terrain::ImportData& importData = mTerrainGroup->getDefaultImportSettings();
  importData.terrainSize = 513;
  importData.worldSize = 12000.0;
  importData.inputScale = 600;
  importData.minBatchSize = 33;
  importData.maxBatchSize = 65;

  importData.layerList.resize(3);
  importData.layerList[0].worldSize = 100;
  importData.layerList[0].textureNames.push_back(
    "dirt_grayrocky_diffusespecular.dds");
  importData.layerList[0].textureNames.push_back(
    "dirt_grayrocky_normalheight.dds");
  importData.layerList[1].worldSize = 30;
  importData.layerList[1].textureNames.push_back(
    "grass_green-01_diffusespecular.dds");
  importData.layerList[1].textureNames.push_back(
    "grass_green-01_normalheight.dds");
  importData.layerList[2].worldSize = 200;
  importData.layerList[2].textureNames.push_back(
    "growth_weirdfungus-03_diffusespecular.dds");
  importData.layerList[2].textureNames.push_back(
    "growth_weirdfungus-03_normalheight.dds");

}


#if Ogre_PLATFORM == OGRE_PLATFORM_WIN32
#define WIN32_LEAN_AND_MEAN
#include "windows.h"
#endif

#ifdef __cplusplus
extern "C" {
#endif

#if OGRE_PLATFORM == OGRE_PLATFORM_WIN32
  INT WINAPI WinMain( HINSTANCE hInst, HINSTANCE, LPSTR strCmdLine, INT )
#else
  int main(int argc, char *argv[])
#endif
  {
    // Create application object
    TutorialApplication app;

    try {
      app.go();
    } catch( Ogre::Exception& e ) {
#if OGRE_PLATFORM == OGRE_PLATFORM_WIN32
      MessageBox( NULL, e.getFullDescription().c_str(), "An exception has occured!", MB_OK | MB_ICONERROR | MB_TASKMODAL);
#else
      std::cerr << "An exception has occured: " <<
	e.getFullDescription().c_str() << std::endl;
#endif
    }

    return 0;
  }

#ifdef __cplusplus
}
#endif