source: experimental/TerrainTest/rampedEllipsoidTechnique.cpp @ 271

#include "rampedEllipsoidTechnique.h"



rampedEllipsoidTechnique::rampedEllipsoidTechnique()
{
        _height = 0.0;
        _rampWidthFactor = 0.4; // 10% of ROI is ramp.
}

rampedEllipsoidTechnique::~rampedEllipsoidTechnique()
{
}

void rampedEllipsoidTechnique::modifyHeightfield(region& modificationROI, osg::HeightField* h, region tileExtends)
{
        //OSG_NOTIFY( osg::ALWAYS ) << "rampedEllipsoidTechnique::modifyHeightfield()" << std::endl;
        //OSG_NOTIFY( osg::ALWAYS ) << "LAT: " << tileExtends._lat_min << " | " << tileExtends._lat_max << std::endl;
        //OSG_NOTIFY( osg::ALWAYS ) << "LON: " << tileExtends._lon_min << " | " << tileExtends._lon_max << std::endl;

        // Determine modificationROI without ramp
        double deltaLatPerSide = modificationROI.delta_lat() * _rampWidthFactor / 2.0;
        double deltaLonPerSide = modificationROI.delta_lon() * _rampWidthFactor / 2.0;
        region coreROI = modificationROI;
        coreROI._lat_min+=deltaLatPerSide;
        coreROI._lat_max-=deltaLatPerSide;
        coreROI._lon_min+=deltaLonPerSide;
        coreROI._lon_max-=deltaLonPerSide;

        // Calculate colum start/end and row start/end of affected vertices
        int Y_start=0, Y_startRamp=0, Y_startCore=0, Y_endCore=0, Y_endRamp=0, Y_end=h->getNumRows();           // Lat
        int X_start=0, X_startRamp=0, X_startCore=0, X_endCore=0, X_endRamp=0, X_end=h->getNumColumns();        // Lon

        // Lat
        Y_startRamp = round((modificationROI._lat_min-tileExtends._lat_min) / h->getYInterval());
        Y_startCore = round((coreROI._lat_min-tileExtends._lat_min) / h->getYInterval());
        Y_endCore   = round((coreROI._lat_max-tileExtends._lat_min) / h->getYInterval());
        Y_endRamp   = round((modificationROI._lat_max-tileExtends._lat_min) / h->getYInterval());

        clampValue(Y_startRamp, Y_start, Y_end);
        clampValue(Y_startCore, Y_start, Y_end);
        clampValue(Y_endCore, Y_start, Y_end);
        clampValue(Y_endRamp, Y_start, Y_end);

        // Lon
        X_startRamp = round((modificationROI._lon_min-tileExtends._lon_min) / h->getXInterval());
        X_startCore = round((coreROI._lon_min-tileExtends._lon_min) / h->getXInterval());
        X_endCore   = round((coreROI._lon_max-tileExtends._lon_min) / h->getXInterval());
        X_endRamp   = round((modificationROI._lon_max-tileExtends._lon_min) / h->getXInterval());

        clampValue(X_startRamp, X_start, X_end);
        clampValue(X_startCore, X_start, X_end);
        clampValue(X_endCore, X_start, X_end);
        clampValue(X_endRamp, X_start, X_end);


        // Modify height value of affected vertices in the core ROI
        for(int x=X_startRamp;x<X_endRamp;x++)
        {
                for(int y=Y_startRamp;y<Y_endRamp;y++)
                {
                        // Calculate vertex position in global coordinate system (lat/lon)
                        double vertex_lat = y*h->getYInterval()+tileExtends._lat_min;
                        double vertex_lon = x*h->getXInterval()+tileExtends._lon_min;
                        // Calculate vertex delta h: h_dest - h_org
                        double height_org = h->getHeight(x,y);
                        double delta_h = _height - height_org;
                        // preset offsetvalue to max and let every region try to lower it...
                        double destination_height = std::numeric_limits<double>::max();

                        // Calculate vertex height according to the region it is in.
                        if( Y_startCore<=y && y<Y_endCore && X_startCore<=x && x<X_endCore )    // If vertex is inside core: Apply final height
                        {
                                        if(_height<destination_height)
                                        destination_height = _height;
                        }
                        if(Y_startRamp<=y && y<Y_startCore) // Vertex is inside Y start ramp
                        {
                                double delta_s = abs(modificationROI._lat_min-vertex_lat);
                                double gradient = delta_h/deltaLatPerSide;
                                double dest = delta_s*gradient + height_org;
                                if(dest<destination_height)
                                        destination_height = dest;                      
                        }
                        if(X_startRamp<=x && x<X_startCore)     // Vertex is inside X start ramp
                        {
                                double delta_s = abs(modificationROI._lon_min-vertex_lon);
                                double gradient = delta_h/deltaLonPerSide;
                                double dest = delta_s*gradient + height_org;
                                if(dest<destination_height)
                                        destination_height = dest;
                        }
                        if(Y_endCore<=y && y<Y_endRamp)  // Vertex is inside Y end ramp
                        {
                                double delta_s = abs(modificationROI._lat_max-vertex_lat);
                                double gradient = delta_h/deltaLatPerSide;
                                double dest = delta_s*gradient + height_org;
                                if(dest<destination_height)
                                        destination_height = dest;
                        }
                        if (X_endCore<=x && x<X_endRamp) // Vertex is inside X end ramp
                        {
                                double delta_s = abs(modificationROI._lon_max-vertex_lon);
                                double gradient = delta_h/deltaLonPerSide;
                                double dest = delta_s*gradient + height_org;
                                if(dest<destination_height)
                                        destination_height = dest;
                        }
                        
                        // Set height to calculated value
                        h->setHeight( x, y, destination_height);
                }
        }
}