DeferredShading.cpp

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#include "DeferredShading.h"

#include "OgreConfigFile.h"
#include "OgreException.h"
#include "OgreStringConverter.h"

#include "OgreHardwarePixelBuffer.h"
#include "OgreMaterialManager.h"
#include "OgreRenderSystem.h"
#include "OgreRoot.h"

#include "OgreEntity.h"
#include "OgreRoot.h"
#include "OgreSubEntity.h"

#include "OgreCompositionPass.h"
#include "OgreCompositionTargetPass.h"
#include "OgreCompositionTechnique.h"
#include "OgreCompositor.h"
#include "OgreCompositorChain.h"
#include "OgreCompositorInstance.h"
#include "OgreCompositorManager.h"

#include "LightMaterialGenerator.h"
#include "MLight.h"

#include "AmbientLight.h"

#include "OgreHighLevelGpuProgram.h"
#include "OgreHighLevelGpuProgramManager.h"

#include "OgreLogManager.h"

using namespace Ogre;

DeferredShadingSystem::DeferredShadingSystem(Viewport *vp, SceneManager *sm,
                                             Camera *cam)
    : mSceneMgr(sm), mViewport(vp), mCamera(cam), mLightMaterialGenerator(0) {
  for (int i = 0; i < DSM_COUNT; ++i)
    mInstance[i] = 0;

  createResources();
  createAmbientLight();

  mActive = true;
  mCurrentMode = DSM_COUNT;
  setMode(DSM_SHOWLIT);

  mLightMaterialsDirty = true;
}

DeferredShadingSystem::~DeferredShadingSystem() {
  // Delete mini lights
  for (std::set<MLight *>::iterator i = mLights.begin(); i != mLights.end();
       ++i) {
    delete (*i);
  }
  // Delete the ambient light
  delete mAmbientLight;

  if (mCurrentMode == DSM_SHOWLIT && mInstance[mCurrentMode]->getEnabled()) {
    RenderTarget *renderTarget =
        mInstance[mCurrentMode]->getRenderTarget("mrt_output");
    assert(renderTarget);

    LogManager::getSingleton().logMessage("Removing Listener from:");
    LogManager::getSingleton().logMessage(renderTarget->getName());

    renderTarget->removeListener(this);
  }

  CompositorChain *chain =
      CompositorManager::getSingleton().getCompositorChain(mViewport);
  for (int i = 0; i < DSM_COUNT; ++i)
    chain->_removeInstance(mInstance[i]);

  delete mLightMaterialGenerator;
}

void DeferredShadingSystem::setMode(DSMode mode) {
  assert(0 <= mode && mode < DSM_COUNT);

  // prevent duplicate setups
  if (mCurrentMode == mode && mInstance[mode]->getEnabled() == mActive)
    return;

  // if the mode is getting disabled
  // -> we need to remove self as listener only if it was enabled to begin with
  // This should happen before the setEnabled(false) is called
  if (mCurrentMode == DSM_SHOWLIT && mInstance[mCurrentMode]->getEnabled()) {
    RenderTarget *renderTarget =
        mInstance[mCurrentMode]->getRenderTarget("mrt_output");
    assert(renderTarget);

    LogManager::getSingleton().logMessage("Removing Listener from:");
    LogManager::getSingleton().logMessage(renderTarget->getName());

    // remove the listener prior to the texture getting possibly reclaimed
    renderTarget->removeListener(this);
  }

  for (int i = 0; i < DSM_COUNT; ++i) {
    if (i == mode) {
      mInstance[i]->setEnabled(mActive);
    } else {
      mInstance[i]->setEnabled(false);
    }
  }
  mCurrentMode = mode;

  // if some mode got enabled,
  // set self as listener so that the light materials can be set up if dirty.
  // This should happen after the setEnabled(true) is called
  if (mCurrentMode == DSM_SHOWLIT && mInstance[mCurrentMode]->getEnabled()) {
    RenderTarget *renderTarget =
        mInstance[mCurrentMode]->getRenderTarget("mrt_output");
    assert(renderTarget);

    LogManager::getSingleton().logMessage("Adding Listener to:");
    LogManager::getSingleton().logMessage(renderTarget->getName());
    renderTarget->addListener(this);

    // Additionally, mark the light materials as always dirty
    mLightMaterialsDirty = true;
    mDirtyLightList.clear();
    mDirtyLightList = mLights;

    // set up the ambient light here
    setUpAmbientLightMaterial();
  }
}

void DeferredShadingSystem::setActive(bool active) {
  if (mActive != active) {
    mActive = active;
    // mCurrentMode could have changed with a prior call to setMode, so iterate
    // all
    setMode(mCurrentMode);
  }
}

DeferredShadingSystem::DSMode DeferredShadingSystem::getMode(void) const {
  return mCurrentMode;
}

MLight *DeferredShadingSystem::createMLight() {
  MLight *rv = new MLight(mLightMaterialGenerator);
  mLights.insert(rv);

  if (mCurrentMode == DSM_SHOWLIT) {
    mDirtyLightList.insert(rv);
    mLightMaterialsDirty = true;
  }

  return rv;
}

void DeferredShadingSystem::destroyMLight(MLight *m) {
  mLights.erase(m);
  delete m;
}

void DeferredShadingSystem::destroyAllMLights() {
  LightList::iterator i;
  for (i = mLights.begin(); i != mLights.end(); i++) {
    MLight *m = *i;
    mLights.erase(m);
    delete m;
  }
}

void DeferredShadingSystem::createResources(void) {
  CompositorManager &compMan = CompositorManager::getSingleton();

  // Create lights material generator
  if (Root::getSingleton().getRenderSystem()->getName() ==
      "OpenGL Rendering Subsystem")
    mLightMaterialGenerator = new LightMaterialGenerator("glsl");
  else
    mLightMaterialGenerator = new LightMaterialGenerator("hlsl");

  // Create filters
  mInstance[DSM_SHOWLIT] =
      compMan.addCompositor(mViewport, "DeferredShading/ShowLit");
  mInstance[DSM_SHOWNORMALS] =
      compMan.addCompositor(mViewport, "DeferredShading/ShowNormals");
  mInstance[DSM_SHOWDSP] =
      compMan.addCompositor(mViewport, "DeferredShading/ShowDepthSpecular");
  mInstance[DSM_SHOWCOLOUR] =
      compMan.addCompositor(mViewport, "DeferredShading/ShowColour");
}

void DeferredShadingSystem::setupLightMaterials(void) {
  assert(mLightMaterialsDirty && mCurrentMode == DSM_SHOWLIT &&
         mInstance[mCurrentMode]->getEnabled() == true);

  CompositorInstance *ci = mInstance[mCurrentMode];

  String mrt0 = ci->getTextureInstanceName("mrt_output", 0);
  String mrt1 = ci->getTextureInstanceName("mrt_output", 1);

  for (LightList::iterator it = mDirtyLightList.begin();
       it != mDirtyLightList.end(); ++it) {
    MLight *light = *it;
    setupMaterial(light->getMaterial(), mrt0, mrt1);
  }

  mLightMaterialsDirty = false;
}

void DeferredShadingSystem::setupMaterial(const MaterialPtr &mat,
                                          const String &texName0,
                                          const String &texName1) {
  for (unsigned short i = 0; i < mat->getNumTechniques(); ++i) {
    Pass *pass = mat->getTechnique(i)->getPass(0);
    pass->getTextureUnitState(0)->setTextureName(texName0);
    pass->getTextureUnitState(1)->setTextureName(texName1);
  }
}

void DeferredShadingSystem::createAmbientLight(void) {
  mAmbientLight = new AmbientLight;
  mSceneMgr->getRootSceneNode()->attachObject(mAmbientLight);
}

void DeferredShadingSystem::setUpAmbientLightMaterial(void) {
  assert(mAmbientLight && mCurrentMode == DSM_SHOWLIT &&
         mInstance[mCurrentMode]->getEnabled() == true);

  String mrt0 =
      mInstance[mCurrentMode]->getTextureInstanceName("mrt_output", 0);
  String mrt1 =
      mInstance[mCurrentMode]->getTextureInstanceName("mrt_output", 1);
  setupMaterial(mAmbientLight->getMaterial(), mrt0, mrt1);
}

void DeferredShadingSystem::logCurrentMode(void) {
  if (mActive == false) {
    LogManager::getSingleton().logMessage("No Compositor Enabled!");
    return;
  }

  CompositorInstance *ci = mInstance[mCurrentMode];
  assert(ci->getEnabled() == true);

  LogManager::getSingleton().logMessage("Current Mode: ");
  LogManager::getSingleton().logMessage(ci->getCompositor()->getName());

  if (mCurrentMode == DSM_SHOWLIT) {
    LogManager::getSingleton().logMessage("Current mrt outputs are:");
    LogManager::getSingleton().logMessage(
        ci->getTextureInstanceName("mrt_output", 0));
    LogManager::getSingleton().logMessage(
        ci->getTextureInstanceName("mrt_output", 1));
  }
}

void DeferredShadingSystem::preRenderTargetUpdate(
    const RenderTargetEvent &evt) {
  if (mLightMaterialsDirty) {
    assert(
        mCurrentMode == DSM_SHOWLIT && mInstance[mCurrentMode]->getEnabled() &&
        (evt.source == mInstance[mCurrentMode]->getRenderTarget("mrt_output")));
    setupLightMaterials();
  }
}