//---------------------------------------------------------------------
	bool Technique::checkHardwareSupport(bool autoManageTextureUnits, StringUtil::StrStreamType& compileErrors)
	{
		// Go through each pass, checking requirements
		Passes::iterator i;
		unsigned short passNum = 0;
		const RenderSystemCapabilities* caps =
			Root::getSingleton().getRenderSystem()->getCapabilities();
		unsigned short numTexUnits = caps->getNumTextureUnits();
		for (i = mPasses.begin(); i != mPasses.end(); ++i, ++passNum)
		{
			Pass* currPass = *i;
			// Adjust pass index
			currPass->_notifyIndex(passNum);
			// Check for advanced blending operation support
			if((currPass->getSceneBlendingOperation() != SBO_ADD || currPass->getSceneBlendingOperationAlpha() != SBO_ADD) && 
				!caps->hasCapability(RSC_ADVANCED_BLEND_OPERATIONS))
			{
				return false;		
			}
			// Check texture unit requirements
			size_t numTexUnitsRequested = currPass->getNumTextureUnitStates();
			// Don't trust getNumTextureUnits for programmable
			if(!currPass->hasFragmentProgram())
			{
#if defined(OGRE_PRETEND_TEXTURE_UNITS) && OGRE_PRETEND_TEXTURE_UNITS > 0
				if (numTexUnits > OGRE_PRETEND_TEXTURE_UNITS)
					numTexUnits = OGRE_PRETEND_TEXTURE_UNITS;
#endif
				if (numTexUnitsRequested > numTexUnits)
				{
					if (!autoManageTextureUnits)
					{
						// The user disabled auto pass split
						compileErrors << "Pass " << passNum << 
							": Too many texture units for the current hardware and no splitting allowed."
							<< std::endl;
						return false;
					}
					else if (currPass->hasVertexProgram())
					{
						// Can't do this one, and can't split a programmable pass
						compileErrors << "Pass " << passNum << 
							": Too many texture units for the current hardware and "
							"cannot split programmable passes."
							<< std::endl;
						return false;
					}
				}
			}

			if (currPass->hasVertexProgram())
			{
				// Check vertex program version
				if (!currPass->getVertexProgram()->isSupported() )
				{
					// Can't do this one
					compileErrors << "Pass " << passNum << 
						": Vertex program " << currPass->getVertexProgram()->getName()
						<< " cannot be used - ";
					if (currPass->getVertexProgram()->hasCompileError())
						compileErrors << "compile error.";
					else
						compileErrors << "not supported.";

					compileErrors << std::endl;
					return false;
				}
			}
			if (currPass->hasGeometryProgram())
			{
				// Check geometry program version
				if (!currPass->getGeometryProgram()->isSupported() )
				{
					// Can't do this one
					compileErrors << "Pass " << passNum << 
						": Geometry program " << currPass->getGeometryProgram()->getName()
						<< " cannot be used - ";
					if (currPass->getGeometryProgram()->hasCompileError())
						compileErrors << "compile error.";
					else
						compileErrors << "not supported.";

					compileErrors << std::endl;
					return false;
				}
			}
			if (currPass->hasFragmentProgram())
			{
				// Check fragment program version
				if (!currPass->getFragmentProgram()->isSupported())
				{
					// Can't do this one
					compileErrors << "Pass " << passNum << 
						": Fragment program " << currPass->getFragmentProgram()->getName()
						<< " cannot be used - ";
					if (currPass->getFragmentProgram()->hasCompileError())
						compileErrors << "compile error.";
					else
						compileErrors << "not supported.";

					compileErrors << std::endl;
					return false;
				}
			}
			else
			{
				// Check a few fixed-function options in texture layers
				Pass::TextureUnitStateIterator texi = currPass->getTextureUnitStateIterator();
				size_t texUnit = 0;
				while (texi.hasMoreElements())
				{
					TextureUnitState* tex = texi.getNext();
					// Any Cube textures? NB we make the assumption that any
					// card capable of running fragment programs can support
					// cubic textures, which has to be true, surely?
					if (tex->is3D() && !caps->hasCapability(RSC_CUBEMAPPING))
					{
						// Fail
						compileErrors << "Pass " << passNum << 
							" Tex " << texUnit <<
							": Cube maps not supported by current environment."
							<< std::endl;
						return false;
					}
					// Any 3D textures? NB we make the assumption that any
					// card capable of running fragment programs can support
					// 3D textures, which has to be true, surely?
					if (tex->getTextureType() == TEX_TYPE_3D && !caps->hasCapability(RSC_TEXTURE_3D))
					{
						// Fail
						compileErrors << "Pass " << passNum << 
							" Tex " << texUnit <<
							": Volume textures not supported by current environment."
							<< std::endl;
						return false;
					}
					// Any Dot3 blending?
					if (tex->getColourBlendMode().operation == LBX_DOTPRODUCT &&
						!caps->hasCapability(RSC_DOT3))
					{
						// Fail
						compileErrors << "Pass " << passNum << 
							" Tex " << texUnit <<
							": DOT3 blending not supported by current environment."
							<< std::endl;
						return false;
					}
					++texUnit;
				}

				// We're ok on operations, now we need to check # texture units
				if (!currPass->hasFragmentProgram())
				{
					// Keep splitting this pass so long as units requested > gpu units
					while (numTexUnitsRequested > numTexUnits)
					{
						// chop this pass into many passes
						currPass = currPass->_split(numTexUnits);
						numTexUnitsRequested = currPass->getNumTextureUnitStates();
						// Advance pass number
						++passNum;
						// Reset iterator
						i = mPasses.begin() + passNum;
						// Move the new pass to the right place (will have been created
						// at the end, may be other passes in between)
						assert(mPasses.back() == currPass);
						std::copy_backward(i, (mPasses.end()-1), mPasses.end());
						*i = currPass;
						// Adjust pass index
						currPass->_notifyIndex(passNum);
					}
				}
			}

		}
		// If we got this far, we're ok
		return true;
	}
    //-----------------------------------------------------------------------
    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());


    }