/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2006 Torus Knot Software Ltd
Also see acknowledgements in Readme.html

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.

You may alternatively use this source under the terms of a specific version of
the OGRE Unrestricted License provided you have obtained such a license from
Torus Knot Software Ltd.
-----------------------------------------------------------------------------
*/
#include "OgreStableHeaders.h"
// RenderSystem implementation
// Note that most of this class is abstract since
//  we cannot know how to implement the behaviour without
//  being aware of the 3D API. However there are a few
//  simple functions which can have a base implementation

#include "OgreRenderSystem.h"

#include "OgreRoot.h"
#include "OgreViewport.h"
#include "OgreException.h"
#include "OgreRenderTarget.h"
#include "OgreRenderWindow.h"
#include "OgreMeshManager.h"
#include "OgreMaterial.h"
#include "OgreTimer.h"
#include "OgreHardwarePixelBuffer.h"
#include "OgreHardwareOcclusionQuery.h"

namespace Ogre {

    static const TexturePtr sNullTexPtr;

    //-----------------------------------------------------------------------
    RenderSystem::RenderSystem()
        : mActiveRenderTarget(0)
        , mTextureManager(0)
        , mActiveViewport(0)
        // This means CULL clockwise vertices, i.e. front of poly is counter-clockwise
        // This makes it the same as OpenGL and other right-handed systems
        , mCullingMode(CULL_CLOCKWISE)
        , mVSync(true)
		, mWBuffer(false)
        , mInvertVertexWinding(false)
        , mDisabledTexUnitsFrom(0)
        , mCurrentPassIterationCount(0)
		, mDerivedDepthBias(false)
        , mVertexProgramBound(false)
		, mGeometryProgramBound(false)
        , mFragmentProgramBound(false)
		, mClipPlanesDirty(true)
		, mRealCapabilities(0)
		, mCurrentCapabilities(0)
		, mUseCustomCapabilities(false)
		, mTexProjRelative(false)
		, mTexProjRelativeOrigin(Vector3::ZERO)
    {
    }

    //-----------------------------------------------------------------------
    RenderSystem::~RenderSystem()
    {
        shutdown();
		OGRE_DELETE mRealCapabilities;
		mRealCapabilities = 0;
		// Current capabilities managed externally
		mCurrentCapabilities = 0;
    }
    //-----------------------------------------------------------------------
    void RenderSystem::_initRenderTargets(void)
    {

        // Init stats
        for(
            RenderTargetMap::iterator it = mRenderTargets.begin();
            it != mRenderTargets.end();
            ++it )
        {
            it->second->resetStatistics();
        }

    }
    //-----------------------------------------------------------------------
    void RenderSystem::_updateAllRenderTargets(bool swapBuffers)
    {
        // Update all in order of priority
        // This ensures render-to-texture targets get updated before render windows
		RenderTargetPriorityMap::iterator itarg, itargend;
		itargend = mPrioritisedRenderTargets.end();
		for( itarg = mPrioritisedRenderTargets.begin(); itarg != itargend; ++itarg )
		{
			if( itarg->second->isActive() && itarg->second->isAutoUpdated())
				itarg->second->update(swapBuffers);
		}
    }
    //-----------------------------------------------------------------------
    void RenderSystem::_swapAllRenderTargetBuffers(bool waitForVSync)
    {
        // Update all in order of priority
        // This ensures render-to-texture targets get updated before render windows
		RenderTargetPriorityMap::iterator itarg, itargend;
		itargend = mPrioritisedRenderTargets.end();
		for( itarg = mPrioritisedRenderTargets.begin(); itarg != itargend; ++itarg )
		{
			if( itarg->second->isActive() && itarg->second->isAutoUpdated())
				itarg->second->swapBuffers(waitForVSync);
		}
    }
    //-----------------------------------------------------------------------
    RenderWindow* RenderSystem::_initialise(bool autoCreateWindow, const String& windowTitle)
    {
        // Have I been registered by call to Root::setRenderSystem?
		/** Don't do this anymore, just allow via Root
        RenderSystem* regPtr = Root::getSingleton().getRenderSystem();
        if (!regPtr || regPtr != this)
            // Register self - library user has come to me direct
            Root::getSingleton().setRenderSystem(this);
		*/


        // Subclasses should take it from here
        // They should ALL call this superclass method from
        //   their own initialise() implementations.
        
        mVertexProgramBound = false;
		mGeometryProgramBound = false;
        mFragmentProgramBound = false;

        return 0;
    }

		void RenderSystem::useCustomRenderSystemCapabilities(RenderSystemCapabilities* capabilities)
		{
				mCurrentCapabilities = capabilities;
				mUseCustomCapabilities = true;
		}
    //---------------------------------------------------------------------------------------------
    void RenderSystem::destroyRenderWindow(const String& name)
    {
        destroyRenderTarget(name);
    }
    //---------------------------------------------------------------------------------------------
    void RenderSystem::destroyRenderTexture(const String& name)
    {
        destroyRenderTarget(name);
    }
    //---------------------------------------------------------------------------------------------
    void RenderSystem::destroyRenderTarget(const String& name)
    {
        RenderTarget* rt = detachRenderTarget(name);
        OGRE_DELETE rt;
    }
    //---------------------------------------------------------------------------------------------
    void RenderSystem::attachRenderTarget( RenderTarget &target )
    {
		assert( target.getPriority() < OGRE_NUM_RENDERTARGET_GROUPS );

        mRenderTargets.insert( RenderTargetMap::value_type( target.getName(), &target ) );
        mPrioritisedRenderTargets.insert(
            RenderTargetPriorityMap::value_type(target.getPriority(), &target ));
    }

    //---------------------------------------------------------------------------------------------
    RenderTarget * RenderSystem::getRenderTarget( const String &name )
    {
        RenderTargetMap::iterator it = mRenderTargets.find( name );
        RenderTarget *ret = NULL;

        if( it != mRenderTargets.end() )
        {
            ret = it->second;
        }

        return ret;
    }

    //---------------------------------------------------------------------------------------------
    RenderTarget * RenderSystem::detachRenderTarget( const String &name )
    {
        RenderTargetMap::iterator it = mRenderTargets.find( name );
        RenderTarget *ret = NULL;

        if( it != mRenderTargets.end() )
        {
            ret = it->second;
			
			/* Remove the render target from the priority groups. */
            RenderTargetPriorityMap::iterator itarg, itargend;
            itargend = mPrioritisedRenderTargets.end();
			for( itarg = mPrioritisedRenderTargets.begin(); itarg != itargend; ++itarg )
            {
				if( itarg->second == ret ) {
					mPrioritisedRenderTargets.erase( itarg );
					break;
				}
            }

            mRenderTargets.erase( it );
        }
        /// If detached render target is the active render target, reset active render target
        if(ret == mActiveRenderTarget)
            mActiveRenderTarget = 0;

        return ret;
    }
    //-----------------------------------------------------------------------
    Viewport* RenderSystem::_getViewport(void)
    {
        return mActiveViewport;
    }
    //-----------------------------------------------------------------------
    void RenderSystem::_setTextureUnitSettings(size_t texUnit, TextureUnitState& tl)
    {
        // This method is only ever called to set a texture unit to valid details
        // The method _disableTextureUnit is called to turn a unit off

        const TexturePtr& tex = tl._getTexturePtr();
		// Vertex texture binding?
		if (mCurrentCapabilities->hasCapability(RSC_VERTEX_TEXTURE_FETCH) &&
			!mCurrentCapabilities->getVertexTextureUnitsShared())
		{
			if (tl.getBindingType() == TextureUnitState::BT_VERTEX)
			{
				// Bind vertex texture
				_setVertexTexture(texUnit, tex);
				// bind nothing to fragment unit (hardware isn't shared but fragment
				// unit can't be using the same index
				_setTexture(texUnit, true, sNullTexPtr);
			}
			else
			{
				// vice versa
				_setVertexTexture(texUnit, sNullTexPtr);
				_setTexture(texUnit, true, tex);
			}
		}
		else
		{
			// Shared vertex / fragment textures or no vertex texture support
			// Bind texture (may be blank)
			_setTexture(texUnit, true, tex);
		}

        // Set texture coordinate set
        _setTextureCoordSet(texUnit, tl.getTextureCoordSet());

        // Set texture layer filtering
        _setTextureUnitFiltering(texUnit, 
            tl.getTextureFiltering(FT_MIN), 
            tl.getTextureFiltering(FT_MAG), 
            tl.getTextureFiltering(FT_MIP));

        // Set texture layer filtering
        _setTextureLayerAnisotropy(texUnit, tl.getTextureAnisotropy());

		// Set mipmap biasing
		_setTextureMipmapBias(texUnit, tl.getTextureMipmapBias());

		// Set blend modes
		// Note, colour before alpha is important
        _setTextureBlendMode(texUnit, tl.getColourBlendMode());
        _setTextureBlendMode(texUnit, tl.getAlphaBlendMode());

        // Texture addressing mode
        const TextureUnitState::UVWAddressingMode& uvw = tl.getTextureAddressingMode();
        _setTextureAddressingMode(texUnit, uvw);
        // Set texture border colour only if required
        if (uvw.u == TextureUnitState::TAM_BORDER ||
            uvw.v == TextureUnitState::TAM_BORDER ||
            uvw.w == TextureUnitState::TAM_BORDER)
        {
            _setTextureBorderColour(texUnit, tl.getTextureBorderColour());
        }

        // Set texture effects
        TextureUnitState::EffectMap::iterator effi;
        // Iterate over new effects
        bool anyCalcs = false;
        for (effi = tl.mEffects.begin(); effi != tl.mEffects.end(); ++effi)
        {
            switch (effi->second.type)
            {
            case TextureUnitState::ET_ENVIRONMENT_MAP:
                if (effi->second.subtype == TextureUnitState::ENV_CURVED)
                {
                    _setTextureCoordCalculation(texUnit, TEXCALC_ENVIRONMENT_MAP);
                    anyCalcs = true;
                }
                else if (effi->second.subtype == TextureUnitState::ENV_PLANAR)
                {
                    _setTextureCoordCalculation(texUnit, TEXCALC_ENVIRONMENT_MAP_PLANAR);
                    anyCalcs = true;
                }
                else if (effi->second.subtype == TextureUnitState::ENV_REFLECTION)
                {
                    _setTextureCoordCalculation(texUnit, TEXCALC_ENVIRONMENT_MAP_REFLECTION);
                    anyCalcs = true;
                }
                else if (effi->second.subtype == TextureUnitState::ENV_NORMAL)
                {
                    _setTextureCoordCalculation(texUnit, TEXCALC_ENVIRONMENT_MAP_NORMAL);
                    anyCalcs = true;
                }
                break;
            case TextureUnitState::ET_UVSCROLL:
			case TextureUnitState::ET_USCROLL:
			case TextureUnitState::ET_VSCROLL:
            case TextureUnitState::ET_ROTATE:
            case TextureUnitState::ET_TRANSFORM:
                break;
            case TextureUnitState::ET_PROJECTIVE_TEXTURE:
                _setTextureCoordCalculation(texUnit, TEXCALC_PROJECTIVE_TEXTURE, 
                    effi->second.frustum);
                anyCalcs = true;
                break;
            }
        }
        // Ensure any previous texcoord calc settings are reset if there are now none
        if (!anyCalcs)
        {
            _setTextureCoordCalculation(texUnit, TEXCALC_NONE);
        }

        // Change tetxure matrix 
        _setTextureMatrix(texUnit, tl.getTextureTransform());


    }
    //-----------------------------------------------------------------------
	void RenderSystem::_setTexture(size_t unit, bool enabled, 
		const String &texname)
	{
		TexturePtr t = TextureManager::getSingleton().getByName(texname);
		_setTexture(unit, enabled, t);
	}
	//-----------------------------------------------------------------------
	void RenderSystem::_setVertexTexture(size_t unit, const TexturePtr& tex)
	{
		OGRE_EXCEPT(Exception::ERR_NOT_IMPLEMENTED, 
			"This rendersystem does not support separate vertex texture samplers, "
			"you should use the regular texture samplers which are shared between "
			"the vertex and fragment units.", 
			"RenderSystem::_setVertexTexture");
	}
    //-----------------------------------------------------------------------
    void RenderSystem::_disableTextureUnit(size_t texUnit)
    {
        _setTexture(texUnit, false, sNullTexPtr);
    }
    //---------------------------------------------------------------------
    void RenderSystem::_disableTextureUnitsFrom(size_t texUnit)
    {
        size_t disableTo = OGRE_MAX_TEXTURE_LAYERS;
        if (disableTo > mDisabledTexUnitsFrom)
            disableTo = mDisabledTexUnitsFrom;
        mDisabledTexUnitsFrom = texUnit;
        for (size_t i = texUnit; i < disableTo; ++i)
        {
            _disableTextureUnit(i);
        }
    }
    //-----------------------------------------------------------------------
    void RenderSystem::_setTextureUnitFiltering(size_t unit, FilterOptions minFilter,
            FilterOptions magFilter, FilterOptions mipFilter)
    {
        _setTextureUnitFiltering(unit, FT_MIN, minFilter);
        _setTextureUnitFiltering(unit, FT_MAG, magFilter);
        _setTextureUnitFiltering(unit, FT_MIP, mipFilter);
    }
    //-----------------------------------------------------------------------
    CullingMode RenderSystem::_getCullingMode(void) const
    {
        return mCullingMode;
    }
    //-----------------------------------------------------------------------
    bool RenderSystem::getWaitForVerticalBlank(void) const
    {
        return mVSync;
    }
    //-----------------------------------------------------------------------
    void RenderSystem::setWaitForVerticalBlank(bool enabled)
    {
        mVSync = enabled;
    }
    bool RenderSystem::getWBufferEnabled(void) const
    {
        return mWBuffer;
    }
    //-----------------------------------------------------------------------
    void RenderSystem::setWBufferEnabled(bool enabled)
    {
        mWBuffer = enabled;
    }
    //-----------------------------------------------------------------------
    void RenderSystem::shutdown(void)
    {
		// Remove occlusion queries
		for (HardwareOcclusionQueryList::iterator i = mHwOcclusionQueries.begin();
			i != mHwOcclusionQueries.end(); ++i)
		{
			OGRE_DELETE *i;
		}
		mHwOcclusionQueries.clear();

        // Remove all the render targets.
		// (destroy primary target last since others may depend on it)
		RenderTarget* primary = 0;
		for (RenderTargetMap::iterator it = mRenderTargets.begin(); it != mRenderTargets.end(); ++it)
		{
			if (!primary && it->second->isPrimary())
				primary = it->second;
			else
				OGRE_DELETE it->second;
		}
		OGRE_DELETE primary;
		mRenderTargets.clear();

		mPrioritisedRenderTargets.clear();
    }
    //-----------------------------------------------------------------------
    void RenderSystem::_beginGeometryCount(void)
    {
        mBatchCount = mFaceCount = mVertexCount = 0;

    }
    //-----------------------------------------------------------------------
    unsigned int RenderSystem::_getFaceCount(void) const
    {
        return static_cast< unsigned int >( mFaceCount );
    }
    //-----------------------------------------------------------------------
    unsigned int RenderSystem::_getBatchCount(void) const
    {
        return static_cast< unsigned int >( mBatchCount );
    }
    //-----------------------------------------------------------------------
    unsigned int RenderSystem::_getVertexCount(void) const
    {
        return static_cast< unsigned int >( mVertexCount );
    }
    //-----------------------------------------------------------------------
	void RenderSystem::convertColourValue(const ColourValue& colour, uint32* pDest)
	{
		*pDest = VertexElement::convertColourValue(colour, getColourVertexElementType());

	}
    //-----------------------------------------------------------------------
    void RenderSystem::_setWorldMatrices(const Matrix4* m, unsigned short count)
    {
        // Do nothing with these matrices here, it never used for now,
		// derived class should take care with them if required.

        // Set hardware matrix to nothing
        _setWorldMatrix(Matrix4::IDENTITY);
    }
    //-----------------------------------------------------------------------
    void RenderSystem::_render(const RenderOperation& op)
    {
        // Update stats
        size_t val;

        if (op.useIndexes)
            val = op.indexData->indexCount;
        else
            val = op.vertexData->vertexCount;

        // account for a pass having multiple iterations
        if (mCurrentPassIterationCount > 1)
            val *= mCurrentPassIterationCount;
		mCurrentPassIterationNum = 0;

        switch(op.operationType)
        {
		case RenderOperation::OT_TRIANGLE_LIST:
            mFaceCount += val / 3;
            break;
        case RenderOperation::OT_TRIANGLE_STRIP:
        case RenderOperation::OT_TRIANGLE_FAN:
            mFaceCount += val - 2;
            break;
	    case RenderOperation::OT_POINT_LIST:
	    case RenderOperation::OT_LINE_LIST:
	    case RenderOperation::OT_LINE_STRIP:
	        break;
	    }

        mVertexCount += op.vertexData->vertexCount;
        mBatchCount += mCurrentPassIterationCount;

		// sort out clip planes
		// have to do it here in case of matrix issues
		if (mClipPlanesDirty)
		{
			setClipPlanesImpl(mClipPlanes);
			mClipPlanesDirty = false;
		}
    }
    //-----------------------------------------------------------------------
    void RenderSystem::setInvertVertexWinding(bool invert)
    {
        mInvertVertexWinding = invert;
    }
	//---------------------------------------------------------------------
	void RenderSystem::addClipPlane (const Plane &p)
	{
		mClipPlanes.push_back(p);
		mClipPlanesDirty = true;
	}
	//---------------------------------------------------------------------
	void RenderSystem::addClipPlane (Real A, Real B, Real C, Real D)
	{
		addClipPlane(Plane(A, B, C, D));
	}
	//---------------------------------------------------------------------
	void RenderSystem::setClipPlanes(const PlaneList& clipPlanes)
	{
		if (clipPlanes != mClipPlanes)
		{
			mClipPlanes = clipPlanes;
			mClipPlanesDirty = true;
		}
	}
	//---------------------------------------------------------------------
	void RenderSystem::resetClipPlanes()
	{
		if (!mClipPlanes.empty())
		{
			mClipPlanes.clear();
			mClipPlanesDirty = true;
		}
	}
    //-----------------------------------------------------------------------
    void RenderSystem::_notifyCameraRemoved(const Camera* cam)
    {
        RenderTargetMap::iterator i, iend;
        iend = mRenderTargets.end();
        for (i = mRenderTargets.begin(); i != iend; ++i)
        {
            RenderTarget* target = i->second;
            target->_notifyCameraRemoved(cam);
        }
    }

	//---------------------------------------------------------------------
    bool RenderSystem::updatePassIterationRenderState(void)
    {
        if (mCurrentPassIterationCount <= 1)
            return false;

        --mCurrentPassIterationCount;
		++mCurrentPassIterationNum;
        if (!mActiveVertexGpuProgramParameters.isNull())
        {
            mActiveVertexGpuProgramParameters->incPassIterationNumber();
            bindGpuProgramPassIterationParameters(GPT_VERTEX_PROGRAM);
        }
        if (!mActiveGeometryGpuProgramParameters.isNull())
        {
            mActiveGeometryGpuProgramParameters->incPassIterationNumber();
            bindGpuProgramPassIterationParameters(GPT_GEOMETRY_PROGRAM);
        }
        if (!mActiveFragmentGpuProgramParameters.isNull())
        {
            mActiveFragmentGpuProgramParameters->incPassIterationNumber();
            bindGpuProgramPassIterationParameters(GPT_FRAGMENT_PROGRAM);
        }
        return true;
    }

	//-----------------------------------------------------------------------
	void RenderSystem::addListener(Listener* l)
	{
		mEventListeners.push_back(l);
	}
	//-----------------------------------------------------------------------
	void RenderSystem::removeListener(Listener* l)
	{
		mEventListeners.remove(l);
	}
	//-----------------------------------------------------------------------
	void RenderSystem::fireEvent(const String& name, const NameValuePairList* params)
	{
		for(ListenerList::iterator i = mEventListeners.begin(); 
			i != mEventListeners.end(); ++i)
		{
			(*i)->eventOccurred(name, params);
		}
	}
	//-----------------------------------------------------------------------
	void RenderSystem::destroyHardwareOcclusionQuery( HardwareOcclusionQuery *hq)
	{
		HardwareOcclusionQueryList::iterator i =
			std::find(mHwOcclusionQueries.begin(), mHwOcclusionQueries.end(), hq);
		if (i != mHwOcclusionQueries.end())
		{
			mHwOcclusionQueries.erase(i);
			OGRE_DELETE hq;
		}
	}
	//-----------------------------------------------------------------------
	void RenderSystem::bindGpuProgram(GpuProgram* prg)
	{
	    switch(prg->getType())
	    {
        case GPT_VERTEX_PROGRAM:
			// mark clip planes dirty if changed (programmable can change space)
			if (!mVertexProgramBound && !mClipPlanes.empty())
				mClipPlanesDirty = true;

            mVertexProgramBound = true;
	        break;
        case GPT_GEOMETRY_PROGRAM:
			mGeometryProgramBound = true;
			break;
        case GPT_FRAGMENT_PROGRAM:
            mFragmentProgramBound = true;
	        break;
	    }
	}
	//-----------------------------------------------------------------------
	void RenderSystem::unbindGpuProgram(GpuProgramType gptype)
	{
	    switch(gptype)
	    {
        case GPT_VERTEX_PROGRAM:
			// mark clip planes dirty if changed (programmable can change space)
			if (mVertexProgramBound && !mClipPlanes.empty())
				mClipPlanesDirty = true;
            mVertexProgramBound = false;
	        break;
        case GPT_GEOMETRY_PROGRAM:
			mGeometryProgramBound = false;
			break;
        case GPT_FRAGMENT_PROGRAM:
            mFragmentProgramBound = false;
	        break;
	    }
	}
	//-----------------------------------------------------------------------
	bool RenderSystem::isGpuProgramBound(GpuProgramType gptype)
	{
	    switch(gptype)
	    {
        case GPT_VERTEX_PROGRAM:
            return mVertexProgramBound;
        case GPT_GEOMETRY_PROGRAM:
            return mGeometryProgramBound;
        case GPT_FRAGMENT_PROGRAM:
            return mFragmentProgramBound;
	    }
        // Make compiler happy
        return false;
	}
	//---------------------------------------------------------------------
	void RenderSystem::_setTextureProjectionRelativeTo(bool enabled, const Vector3& pos)
	{
		mTexProjRelative = enabled;
		mTexProjRelativeOrigin = pos;

	}

}

