DeferredShading.cpp

/******************************************************************************
Copyright (c) W.J. van der Laan

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#include "DeferredShading.h"

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

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

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

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

#include "MLight.h"
#include "LightMaterialGenerator.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();
	}
}