#include "rampedEllipsoidTechnique.h"



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

rampedEllipsoidTechnique::~rampedEllipsoidTechnique()
{
}

void rampedEllipsoidTechnique::modifyHeightfield(osg::Vec4d& modificationROI, osg::HeightField* h, osg::Vec4d tileExtends)
{
	//OSG_NOTIFY( osg::ALWAYS ) << "rampedEllipsoidTechnique::modifyHeightfield()" << std::endl;
	//OSG_NOTIFY( osg::ALWAYS ) << "LAT: " << tileExtends[0] << " | " << tileExtends[1] << std::endl;
	//OSG_NOTIFY( osg::ALWAYS ) << "LON: " << tileExtends[2] << " | " << tileExtends[3] << std::endl;

	// Determine modificationROI without ramp
	double deltaLatPerSide = (modificationROI[1] - modificationROI[0]) * _rampWidthFactor / 2.0;
	double deltaLonPerSide = (modificationROI[3] - modificationROI[2]) * _rampWidthFactor / 2.0;
	osg::Vec4d coreROI = modificationROI;
	coreROI[0]+=deltaLatPerSide;
	coreROI[1]-=deltaLatPerSide;
	coreROI[2]+=deltaLonPerSide;
	coreROI[3]-=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[0]-tileExtends[0]) / h->getYInterval());
	Y_startCore = round((coreROI[0]-tileExtends[0]) / h->getYInterval());
	Y_endCore   = round((coreROI[1]-tileExtends[0]) / h->getYInterval());
	Y_endRamp   = round((modificationROI[1]-tileExtends[0]) / 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[2]-tileExtends[2]) / h->getXInterval());
	X_startCore = round((coreROI[2]-tileExtends[2]) / h->getXInterval());
	X_endCore   = round((coreROI[3]-tileExtends[2]) / h->getXInterval());
	X_endRamp   = round((modificationROI[3]-tileExtends[2]) / 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[0];
			double vertex_lon = x*h->getXInterval()+tileExtends[2];
			// 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[0]-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[2]-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[1]-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[3]-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);
		}
	}
}