Tactica/Source/Tactica/Private/GridState.cpp

#include "GridState.h"
#include "GridMath.h"

void FGridState::Init(int32 InSizeX, int32 InSizeY)
{
	SizeX = FMath::Max(InSizeX, 0);
	SizeY = FMath::Max(InSizeY, 0);
	Cells.Reset();
	Cells.SetNum(SizeX * SizeY);
}

bool FGridState::IsInBounds(FIntPoint Coord) const
{
	return FGridMath::IsInBounds(Coord, SizeX, SizeY);
}

const FGridCellData* FGridState::GetCell(FIntPoint Coord) const
{
	const int32 Index = FGridMath::CoordToIndex(Coord, SizeX, SizeY);
	return Cells.IsValidIndex(Index) ? &Cells[Index] : nullptr;
}

FGridCellData* FGridState::GetCellMutable(FIntPoint Coord)
{
	const int32 Index = FGridMath::CoordToIndex(Coord, SizeX, SizeY);
	return Cells.IsValidIndex(Index) ? &Cells[Index] : nullptr;
}

void FGridState::SetWalkable(FIntPoint Coord, bool bWalkable)
{
	if (FGridCellData* Cell = GetCellMutable(Coord))
	{
		Cell->bWalkable = bWalkable;
	}
}

int32 FGridState::GetOccupant(FIntPoint Coord) const
{
	const FGridCellData* Cell = GetCell(Coord);
	return Cell ? Cell->OccupantId : INDEX_NONE;
}

bool FGridState::PlaceUnit(int32 UnitId, FIntPoint Coord)
{
	FGridCellData* Cell = GetCellMutable(Coord);
	if (!Cell || !Cell->bWalkable || Cell->OccupantId != INDEX_NONE)
	{
		return false;
	}
	Cell->OccupantId = UnitId;
	return true;
}

bool FGridState::MoveUnit(int32 UnitId, FIntPoint From, FIntPoint To)
{
	FGridCellData* FromCell = GetCellMutable(From);
	FGridCellData* ToCell = GetCellMutable(To);
	if (!FromCell || !ToCell || FromCell->OccupantId != UnitId)
	{
		return false;
	}
	if (From == To)
	{
		return true;
	}
	if (!ToCell->bWalkable || ToCell->OccupantId != INDEX_NONE)
	{
		return false;
	}
	FromCell->OccupantId = INDEX_NONE;
	ToCell->OccupantId = UnitId;
	return true;
}