CoordinateConversion.h

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// Copyright eeGeo Ltd (2012-2014), All Rights Reserved

#pragma once

#include "Rendering.h"
#include "Camera.h"
#include "Terrain.h"
#include "VectorMath.h"
#include "EarthConstants.h"
#include "LatLongAltitude.h"
#include "MortonKey.h"
#include "CubeMap.h"
#include <math.h>

namespace Eegeo
{
    namespace Space
    {
        inline Eegeo::dv3 ConvertLatLongAltitudeToEcef(double latitudeInRadians, double longitudeInRadians, double altitudeInMetres)
        {
            // Note: implementation is in .h due to client request.
            double radius = EarthConstants::Radius + altitudeInMetres;
            
            double x = radius * cos(latitudeInRadians) * cos(longitudeInRadians);
            double y = radius * cos(latitudeInRadians) * sin(longitudeInRadians);
            double z = radius * sin(latitudeInRadians);
            
            return Eegeo::dv3(-y, z, x);
        }

        inline dv3 ConvertLatLongAltitudeToEcef(const LatLongAltitude& latLongAltitude)
        {
            return ConvertLatLongAltitudeToEcef(latLongAltitude.GetLatitude(), latLongAltitude.GetLongitude(), latLongAltitude.GetAltitude());
        }

        inline Eegeo::Streaming::MortonKey ConvertLatLongAltitudeToMortonKey(
                const LatLongAltitude& latLongAltitude,
                int level)
        {
            dv3 ecefPosition = ConvertLatLongAltitudeToEcef(latLongAltitude);
            return Eegeo::Space::CubeMap::EcefToKey(ecefPosition, level);
        }

        inline LatLongAltitude ConvertEcefToLatLongAltitude(double x, double y, double z)
        {
            // Note: implementation is in .h due to client request.
            double p = sqrt((z * z) + (-x * -x));
            
            double lat = atan(y / p);
            double lon = atan2(-x, z);
            double alt = (p / cos(lat)) - EarthConstants::Radius;
            
            return LatLongAltitude(lat, lon, alt);
        }

        inline LatLongAltitude ConvertEcefToLatLongAltitude(const dv3& ecefPosition)
        {
            return ConvertEcefToLatLongAltitude(ecefPosition.GetX(), ecefPosition.GetY(), ecefPosition.GetZ());
        }

        inline dv3 ConvertMortonKeyCenterToEcef(const Eegeo::Streaming::MortonKey& key)
        {
            return Space::CubeMap::KeyToECEF(key);
        }

        v3 ConvertLatLongAltitudeToScreenCoordinates(const LatLongAltitude& latLongAltitude,
                                                     const Eegeo::Camera::RenderCamera& renderCamera,
                                                     const Eegeo::Rendering::ScreenProperties& screenProperties);
        
        bool TryConvertScreenCoordinatesToLatLongAltitude(int screenPixelCoordinateX,
                                                          int screenPixelCoordinateY,
                                                          const Eegeo::Camera::RenderCamera& renderCamera,
                                                          const Eegeo::Resources::Terrain::Heights::TerrainHeightProvider& terrainHeightProvider,
                                                          LatLongAltitude& result);
    }
}