/* -*-c++-*- osgVisual - Copyright (C) 2009-2011 Torben Dannhauer
 *
 * This library is based on OpenSceneGraph, open source and may be redistributed and/or modified under 
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 *
 * osgVisual requires for some proprietary modules a license from the correspondig manufacturer.
 * You have to aquire licenses for all used proprietary modules.
 * 
 * This library 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
 * OpenSceneGraph Public License for more details.
*/

#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);
	//OSG_NOTIFY( osg::ALWAYS ) << "Y_startRamp:" << Y_startRamp << " Y_startCore:" << Y_startCore << " Y_endCore:" << Y_endCore << " Y_endRamp:" << Y_endRamp << std::endl;

	// 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);
	//OSG_NOTIFY( osg::ALWAYS ) << "X_startRamp:" << X_startRamp << " X_startCore:" << X_startCore << " X_endCore:" << X_endCore << " X_endRamp:" << X_endRamp << std::endl;

	// 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 offset value to max and let every ramp function try to lower it...
			double current_vertex_delta = std::numeric_limits<double>::max();

			// Calculate vertex height according to the region it is in.
			//// Estimated height in the core ROI
			double destination_height = _height;
			//// Startramp
			if(Y_startRamp<=y && y<=Y_startCore && Y_startRamp != Y_startCore) // Vertex is inside Y start ramp
			{
				double delta_s = abs(modificationROI._lat_min-vertex_lat);
				double gradient = delta_h/deltaLatPerSide;
				double calculated_height = delta_s*gradient + height_org;
				double local_test_delta = abs(calculated_height-height_org);
				if(local_test_delta<current_vertex_delta)
				{
					current_vertex_delta = local_test_delta;
					destination_height = calculated_height;			
				}
			}
			if(X_startRamp<=x && x<=X_startCore && X_startRamp != X_startCore)	// Vertex is inside X start ramp
			{
				double delta_s = abs(modificationROI._lon_min-vertex_lon);
				double gradient = delta_h/deltaLonPerSide;
				double calculated_height = delta_s*gradient + height_org;
				double local_test_delta = abs(calculated_height-height_org);
				if(local_test_delta<current_vertex_delta)
				{
					current_vertex_delta = local_test_delta;
					destination_height = calculated_height;			
				}
			}
			//// End ramp
			if(Y_endCore<=y && y<=Y_endRamp && Y_endCore != Y_endRamp)  // Vertex is inside Y end ramp
			{
				double delta_s = abs(modificationROI._lat_max-vertex_lat);
				double gradient = delta_h/deltaLatPerSide;
				double calculated_height = delta_s*gradient + height_org;
				double local_test_delta = abs(calculated_height-height_org);
				if(local_test_delta<current_vertex_delta)
				{
					current_vertex_delta = local_test_delta;
					destination_height = calculated_height;			
				}
			}
			if (X_endCore<=x && x<=X_endRamp && X_endCore != X_endRamp) // Vertex is inside X end ramp
			{
				double delta_s = abs(modificationROI._lon_max-vertex_lon);
				double gradient = delta_h/deltaLonPerSide;
				double calculated_height = delta_s*gradient + height_org;
				double local_test_delta = abs(calculated_height-height_org);
				if(local_test_delta<current_vertex_delta)
				{
					current_vertex_delta = local_test_delta;
					destination_height = calculated_height;			
				}
			}
			
			// Set height to calculated value
			//OSG_NOTIFY( osg::ALWAYS ) << "rampedEllipsoidTechnique: X,Y:"<<x<<","<<y<<" destination_height=" << destination_height << std::endl;
			h->setHeight( x, y, destination_height);
		}
	}
}