Beispiel #1
0
bool
TileNode::inheritState(EngineContext* context)
{
    // Find the parent node. It will only be null if this is a "first LOD" tile.
    TileNode* parent = getNumParents() > 0 ? dynamic_cast<TileNode*>(getParent(0)) : 0L;

    bool changesMade = false;

    // which quadrant is this tile in?
    unsigned quadrant = getTileKey().getQuadrant();

    // default inheritance of the elevation data for bounding purposes:
    osg::ref_ptr<const osg::Image> elevRaster;
    osg::Matrixf                   elevMatrix;
    if ( parent )
    {
        elevRaster = parent->getElevationRaster();
        elevMatrix = parent->getElevationMatrix();
        elevMatrix.preMult( scaleBias[quadrant] );
    }

    // Find all the sampler matrix uniforms and scale/bias them to the current quadrant.
    // This will inherit textures and use the proper sub-quadrant until new data arrives (later).
    for( RenderBindings::const_iterator binding = context->getRenderBindings().begin(); binding != context->getRenderBindings().end(); ++binding )
    {
        if ( binding->usage().isSetTo(binding->COLOR) )
        {
            if ( parent && parent->getStateSet() )
            {
                MPTexture* parentMPTex = parent->getMPTexture();
                _mptex->inheritState( parentMPTex, scaleBias[quadrant] );
                changesMade = true;
            }
        }

        else if ( binding->usage().isSetTo(binding->COLOR_PARENT) )
        {
            //nop -- this is handled as part of the COLOR binding
        }

        else
        {
            osg::StateAttribute* sa = getStateSet()->getTextureAttribute(binding->unit(), osg::StateAttribute::TEXTURE);        

            // If the attribute isn't present, that means we are inheriting it from above.
            // So construct a new scale/bias matrix.
            if ( sa == 0L )
            {
                osg::Matrixf matrix;

                // Find the parent's matrix and scale/bias it to this quadrant:
                if ( parent && parent->getStateSet() )
                {
                    const osg::Uniform* matrixUniform = parent->getStateSet()->getUniform( binding->matrixName() );
                    if ( matrixUniform )
                    {
                        matrixUniform->get( matrix );
                        matrix.preMult( scaleBias[quadrant] );
                    }
                }

                // Add a new uniform with the scale/bias'd matrix:
                osg::StateSet* stateSet = getOrCreateStateSet();
                stateSet->removeUniform( binding->matrixName() );
                stateSet->addUniform( context->getOrCreateMatrixUniform(binding->matrixName(), matrix) );
                changesMade = true;
            }

            // If this is elevation data, record the new raster so we can apply it to the node.
            else if ( binding->usage().isSetTo(binding->ELEVATION) )
            {
                osg::Texture* t = static_cast<osg::Texture*>(sa);
                elevRaster = t->getImage(0);
                elevMatrix = osg::Matrixf::identity();
            }
        }
    }

    // If we found one, communicate it to the node and its children.
    if (elevRaster.valid())
    {
        if (elevRaster.get() != getElevationRaster() || elevMatrix != getElevationMatrix() )
        {
            setElevationRaster( elevRaster.get(), elevMatrix );
            changesMade = true;
        }
    }

    // finally, update the uniforms for terrain morphing
    updateTileUniforms( context->getSelectionInfo() );

    if ( !changesMade )
    {
        OE_INFO << LC << _key.str() << ", good, no changes :)\n";
    }
    else
    {
        dirtyBound();
    }

    return changesMade;
}
// Generates the main shader code for rendering the terrain.
void
RexTerrainEngineNode::updateState()
{
    if ( _batchUpdateInProgress )
    {
        _stateUpdateRequired = true;
    }
    else
    {
        osg::StateSet* terrainStateSet   = _terrain->getOrCreateStateSet();   // everything
        osg::StateSet* surfaceStateSet   = getSurfaceStateSet();    // just the surface
        
        // required for multipass tile rendering to work
        surfaceStateSet->setAttributeAndModes(
            new osg::Depth(osg::Depth::LEQUAL, 0, 1, true) );

        // activate standard mix blending.
        terrainStateSet->setAttributeAndModes( 
            new osg::BlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA),
            osg::StateAttribute::ON );

        // install patch param if we are tessellation on the GPU.
        if ( _terrainOptions.gpuTessellation() == true )
        {
            #ifdef HAVE_PATCH_PARAMETER
              terrainStateSet->setAttributeAndModes( new osg::PatchParameter(3) );
            #endif
        }

        // install shaders, if we're using them.
        if ( Registry::capabilities().supportsGLSL() )
        {
            Shaders package;

            VirtualProgram* terrainVP = VirtualProgram::getOrCreate(terrainStateSet);
            terrainVP->setName( "Rex Terrain" );
            package.load(terrainVP, package.ENGINE_VERT_MODEL);

            //moved to CTOR so it's always available
            //package.load(terrainVP, package.SDK);
            
            bool useTerrainColor = _terrainOptions.color().isSet();
            package.define("OE_REX_USE_TERRAIN_COLOR", useTerrainColor);
            if ( useTerrainColor )
            {
                surfaceStateSet->addUniform(new osg::Uniform("oe_terrain_color", _terrainOptions.color().get()));
            }

            bool useBlending = _terrainOptions.enableBlending().get();
            package.define("OE_REX_GL_BLENDING", useBlending);

            bool morphImagery = _terrainOptions.morphImagery().get();
            package.define("OE_REX_MORPH_IMAGERY", morphImagery);

            // Funtions that affect only the terrain surface:
            VirtualProgram* surfaceVP = VirtualProgram::getOrCreate(surfaceStateSet);
            surfaceVP->setName("Rex Surface");

            // Functions that affect the terrain surface only:
            package.load(surfaceVP, package.ENGINE_VERT_VIEW);
            package.load(surfaceVP, package.ENGINE_FRAG);

            // Normal mapping shaders:
            if ( this->normalTexturesRequired() )
            {
                package.load(surfaceVP, package.NORMAL_MAP_VERT);
                package.load(surfaceVP, package.NORMAL_MAP_FRAG);
            }

            // Morphing?
            if (_terrainOptions.morphTerrain() == true ||
                _terrainOptions.morphImagery() == true)
            {
                package.define("OE_REX_VERTEX_MORPHING", (_terrainOptions.morphTerrain() == true));
                package.load(surfaceVP, package.MORPHING_VERT);
            }

            for(LandCoverZones::iterator zone = _landCoverData._zones.begin(); zone != _landCoverData._zones.end(); ++zone)
            {
                for(LandCoverBins::iterator bin = zone->_bins.begin(); bin != zone->_bins.end(); ++bin)
                {
                    osg::StateSet* landCoverStateSet = bin->_binProto->getStateSet();

                    // enable alpha-to-coverage multisampling for vegetation.
                    landCoverStateSet->setMode(GL_SAMPLE_ALPHA_TO_COVERAGE_ARB, 1);

                    // uniform that communicates the availability of multisampling.
                    landCoverStateSet->addUniform( new osg::Uniform(
                        "oe_terrain_hasMultiSamples",
                        osg::DisplaySettings::instance()->getMultiSamples()) );

                    landCoverStateSet->setAttributeAndModes(
                        new osg::BlendFunc(GL_ONE, GL_ZERO, GL_ONE, GL_ZERO),
                        osg::StateAttribute::OVERRIDE );

                    #ifdef HAVE_OSG_PATCH_PARAMETER
                        landCoverStateSet->setAttributeAndModes( new osg::PatchParameter(3) );
                    #endif
                }
            }

            // assemble color filter code snippets.
            bool haveColorFilters = false;
            {
                // Color filter frag function:
                std::string fs_colorfilters =
                    "#version " GLSL_VERSION_STR "\n"
                    GLSL_DEFAULT_PRECISION_FLOAT "\n"
                    "uniform int oe_layer_uid; \n"
                    "$COLOR_FILTER_HEAD"
                    "void oe_rexEngine_applyFilters(inout vec4 color) \n"
                    "{ \n"
                        "$COLOR_FILTER_BODY"
                    "} \n";

                std::stringstream cf_head;
                std::stringstream cf_body;
                const char* I = "    ";

                // second, install the per-layer color filter functions AND shared layer bindings.
                bool ifStarted = false;
                int numImageLayers = _update_mapf->imageLayers().size();
                for( int i=0; i<numImageLayers; ++i )
                {
                    ImageLayer* layer = _update_mapf->getImageLayerAt(i);
                    if ( layer->getEnabled() )
                    {
                        // install Color Filter function calls:
                        const ColorFilterChain& chain = layer->getColorFilters();
                        if ( chain.size() > 0 )
                        {
                            haveColorFilters = true;
                            if ( ifStarted ) cf_body << I << "else if ";
                            else             cf_body << I << "if ";
                            cf_body << "(oe_layer_uid == " << layer->getUID() << ") {\n";
                            for( ColorFilterChain::const_iterator j = chain.begin(); j != chain.end(); ++j )
                            {
                                const ColorFilter* filter = j->get();
                                cf_head << "void " << filter->getEntryPointFunctionName() << "(inout vec4 color);\n";
                                cf_body << I << I << filter->getEntryPointFunctionName() << "(color);\n";
                                filter->install( surfaceStateSet );
                            }
                            cf_body << I << "}\n";
                            ifStarted = true;
                        }
                    }
                }

                if ( haveColorFilters )
                {
                    std::string cf_head_str, cf_body_str;
                    cf_head_str = cf_head.str();
                    cf_body_str = cf_body.str();

                    replaceIn( fs_colorfilters, "$COLOR_FILTER_HEAD", cf_head_str );
                    replaceIn( fs_colorfilters, "$COLOR_FILTER_BODY", cf_body_str );

                    surfaceVP->setFunction(
                        "oe_rexEngine_applyFilters",
                        fs_colorfilters,
                        ShaderComp::LOCATION_FRAGMENT_COLORING,
                        0.0 );
                }
            }

            // Apply uniforms for sampler bindings:
            OE_DEBUG << LC << "Render Bindings:\n";
            for(RenderBindings::const_iterator b = _renderBindings.begin(); b != _renderBindings.end(); ++b)
            {
                if ( b->isActive() )
                {
                    terrainStateSet->addUniform( new osg::Uniform(b->samplerName().c_str(), b->unit()) );
                    OE_DEBUG << LC << " > Bound \"" << b->samplerName() << "\" to unit " << b->unit() << "\n";
                }
            }

            // uniform that controls per-layer opacity
            terrainStateSet->addUniform( new osg::Uniform("oe_layer_opacity", 1.0f) );

            // uniform that conveys the layer UID to the shaders; necessary
            // for per-layer branching (like color filters)
            // UID -1 => no image layer (no texture)
            terrainStateSet->addUniform( new osg::Uniform("oe_layer_uid", (int)-1 ) );

            // uniform that conveys the render order, since the shaders
            // need to know which is the first layer in order to blend properly
            terrainStateSet->addUniform( new osg::Uniform("oe_layer_order", (int)0) );

            // default min/max range uniforms. (max < min means ranges are disabled)
            terrainStateSet->addUniform( new osg::Uniform("oe_layer_minRange", 0.0f) );
            terrainStateSet->addUniform( new osg::Uniform("oe_layer_maxRange", -1.0f) );
            
            terrainStateSet->getOrCreateUniform(
                "oe_min_tile_range_factor",
                osg::Uniform::FLOAT)->set( *_terrainOptions.minTileRangeFactor() );

            terrainStateSet->addUniform(new osg::Uniform("oe_tile_size", (float)_terrainOptions.tileSize().get()));

            // special object ID that denotes the terrain surface.
            surfaceStateSet->addUniform( new osg::Uniform(
                Registry::objectIndex()->getObjectIDUniformName().c_str(), OSGEARTH_OBJECTID_TERRAIN) );
        }

        _stateUpdateRequired = false;
    }
}