GridIndexing2.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
 
// Port of geometry3Sharp GridIndexing2
 
#pragma once
 
#include "VectorTypes.h"
#include "IntVectorTypes.h"
#include "Math/IntRect.h"
 
namespace UE
{
namespace Geometry
{
 
using namespace UE::Math;
 
template<typename RealType>
struct TScaleGridIndexer2
{
    RealType CellSize;
 
    TScaleGridIndexer2() : CellSize((RealType)1) 
    {
        ensure(CellSize >= TMathUtil<RealType>::ZeroTolerance);
    }
 
    TScaleGridIndexer2(RealType CellSize) : CellSize(CellSize)
    {
        ensure(CellSize >= TMathUtil<RealType>::ZeroTolerance);
    }
 
    inline FVector2i ToGrid(const TVector2<RealType>& P) const
    {
        return FVector2i(
            (int)TMathUtil<RealType>::Floor(P.X / CellSize),
            (int)TMathUtil<RealType>::Floor(P.Y / CellSize));
    }
 
    inline TVector2<RealType> FromGrid(const FVector2i& GridPoint) const
    {
        return TVector2<RealType>(GridPoint.X*CellSize, GridPoint.Y*CellSize);
    }
};
typedef TScaleGridIndexer2<float> FScaleGridIndexer2f;
typedef TScaleGridIndexer2<double> FScaleGridIndexer2d;
 
 
template<typename RealType>
struct TShiftGridIndexer2
{
    RealType CellSize;
    TVector2<RealType> Origin;
 
    TShiftGridIndexer2(const TVector2<RealType>& origin, RealType cellSize)
    {
        Origin = origin;
        CellSize = cellSize;
        ensure(CellSize >= TMathUtil<RealType>::ZeroTolerance);
    }
 
    inline FVector2i ToGrid(const TVector2<RealType>& Point) const
    {
        return FVector2i(
            (int)TMathUtil<RealType>::Floor((Point.X - Origin.X) / CellSize),
            (int)TMathUtil<RealType>::Floor((Point.Y - Origin.Y) / CellSize));
    }
 
    inline FIntRect ToGrid(const TBox2<RealType>& Box) const
    {
        const FVector2i Min = ToGrid(Box.Min);
        const FVector2i Max = ToGrid(Box.Max);
        return FIntRect(Min.X, Min.Y, Max.X, Max.Y);
    }
 
    inline FIntRect ToGrid(const TBox<RealType>& Box) const
    {
        const FVector2i Min = ToGrid(TVector2<RealType>(Box.Min));
        const FVector2i Max = ToGrid(TVector2<RealType>(Box.Max));
        return FIntRect(Min.X, Min.Y, Max.X, Max.Y);
    }
 
    inline TVector2<RealType> FromGrid(const FVector2i& GridPoint) const
    {
        return TVector2<RealType>(
            ((RealType)GridPoint.X * CellSize) + Origin.X,
            ((RealType)GridPoint.Y * CellSize) + Origin.Y);
    }
 
    inline TVector2<RealType> FromGrid(const TVector2<RealType>& RealGridPoint) const
    {
        return TVector2<RealType>(
            ((RealType)RealGridPoint.X * CellSize) + Origin.X,
            ((RealType)RealGridPoint.Y * CellSize) + Origin.Y);
    }
 
    inline TBox2<RealType> BoxFromGrid(const FVector2i& GridPoint) const
    {
        const TVector2<RealType> Min = FromGrid(GridPoint);
        const TVector2<RealType> Max = Min + TVector2<RealType>(CellSize);
        return TBox2<RealType>(Min, Max);
    }
};
typedef TShiftGridIndexer2<float> FShiftGridIndexer2f;
typedef TShiftGridIndexer2<double> FShiftGridIndexer2d;
 
 
} // end namespace UE::Geometry
} // end namespace UE