SpaceHelpers.h

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

#pragma once

#include "Space.h"
#include "VectorMathDecl.h"
#include "MortonKey.h"
#include "Geometry.h"

#include <vector>

namespace Eegeo
{
    namespace Space
    {
        namespace SpaceHelpers
        {
            double GetAltitude(const dv3& pointEcef);
            
            v3 LocalEcefToZeroAltitudeLocalEcef(const v3& localEcef, const dv3& ecefCellOrigin);

            double PrincipleAngle(double angleRadians);

            double PrincipleAngleDegrees(double angleDegrees);

            double AngleDifference(double radiansA, double radiansB);
            
            double AngleDifferenceDegrees(double degreesA, double degreesB);

            double GreatCircleDistance(const LatLong& a, const LatLong& b, double sphereRadius);
            
            void LatLongBounds(const LatLong& p, double greatCircleRadius, double sphereRadius, LatLong& out_min, LatLong& out_max);
            
            void LatLongBoundsFromPoints(const std::vector<LatLong>& points, LatLong& out_southwest, LatLong& out_northeast);

            void InflatedLatLongBounds(
                const LatLong& southwest,
                const LatLong& northeast,
                double inflatePercent,
                LatLong& out_southwest,
                LatLong& out_northeast
            );

            bool LatLongBoundsIntersect(const Space::LatLong& southWestA, const Space::LatLong& northEastA,
                                        const Space::LatLong& southWestB, const Space::LatLong& northEastB);

            std::vector<Streaming::MortonKey> CalculateMortonKeysIntersectingBounds(const int keyDepth, const Space::LatLong& southWestLatLong, const Space::LatLong& northEastLatLong);
            
            bool IsEcefPointBehindGlobeHorizon(const dv3& pointEcef, const dv3& viewLocationEcef);

            Eegeo::Geometry::Ray LatLongToVerticallyDownRay(const Space::LatLong& point);

            Eegeo::dv3 DirectionFromHeadingDegreesAtPoint(double headingDegrees, const dv3& pointEcef);

            double HeadingDegreesFromDirectionAtPoint(const dv3& directionEcef, const dv3& pointEcef);
        }
    }
}