qstbak/Auspex/Auspex/AxTerrainMap.cs

using System;
using System.Numerics;

namespace Auspex;

public sealed class AxTerrainMap
{
	private readonly float[] _heights;

	public float WorldMinX { get; }

	public float WorldMinZ { get; }

	public int GridWidth { get; }

	public int GridHeight { get; }

	public float CellSize { get; }

	public bool IsEmpty { get; }

	private AxTerrainMap(float[] heights, float worldMinX, float worldMinZ, int gridWidth, int gridHeight, float cellSize, bool isEmpty)
	{
		_heights = heights;
		WorldMinX = worldMinX;
		WorldMinZ = worldMinZ;
		GridWidth = gridWidth;
		GridHeight = gridHeight;
		CellSize = cellSize;
		IsEmpty = isEmpty;
	}

	public static AxTerrainMap Generate(Vector3 center, float halfExtentX, float halfExtentZ, float cellSize = 1f)
	{
		float num = center.X - halfExtentX;
		float num2 = center.Z - halfExtentZ;
		int num3 = (int)MathF.Ceiling(halfExtentX * 2f / cellSize);
		int num4 = (int)MathF.Ceiling(halfExtentZ * 2f / cellSize);
		if (num3 <= 0 || num4 <= 0)
		{
			return new AxTerrainMap(Array.Empty<float>(), 0f, 0f, 0, 0, cellSize, isEmpty: true);
		}
		float[] array = new float[num3 * num4];
		int num5 = num3;
		int num6 = num4;
		int num7 = -1;
		int num8 = -1;
		for (int i = 0; i < num4; i++)
		{
			float z = num2 + ((float)i + 0.5f) * cellSize;
			for (int j = 0; j < num3; j++)
			{
				if (!float.IsNaN(array[i * num3 + j] = AxTerrainQuery.GetTerrainYRaw(num + ((float)j + 0.5f) * cellSize, z)))
				{
					if (j < num5)
					{
						num5 = j;
					}
					if (j > num7)
					{
						num7 = j;
					}
					if (i < num6)
					{
						num6 = i;
					}
					if (i > num8)
					{
						num8 = i;
					}
				}
			}
		}
		if (num7 < 0)
		{
			return new AxTerrainMap(Array.Empty<float>(), 0f, 0f, 0, 0, cellSize, isEmpty: true);
		}
		int num9 = num7 - num5 + 1;
		int num10 = num8 - num6 + 1;
		float[] array2 = new float[num9 * num10];
		for (int k = 0; k < num10; k++)
		{
			int sourceIndex = (k + num6) * num3 + num5;
			Array.Copy(array, sourceIndex, array2, k * num9, num9);
		}
		float worldMinX = num + (float)num5 * cellSize;
		float worldMinZ = num2 + (float)num6 * cellSize;
		return new AxTerrainMap(array2, worldMinX, worldMinZ, num9, num10, cellSize, isEmpty: false);
	}

	public float GetHeight(int cellX, int cellZ)
	{
		if ((uint)cellX >= (uint)GridWidth || (uint)cellZ >= (uint)GridHeight)
		{
			return float.NaN;
		}
		return _heights[cellZ * GridWidth + cellX];
	}

	public bool IsWalkable(int cellX, int cellZ)
	{
		return !float.IsNaN(GetHeight(cellX, cellZ));
	}

	public bool IsWalkable(float worldX, float worldZ)
	{
		var (cellX, cellZ) = WorldToCell(worldX, worldZ);
		return IsWalkable(cellX, cellZ);
	}

	public (int cellX, int cellZ) WorldToCell(float worldX, float worldZ)
	{
		int item = (int)MathF.Floor((worldX - WorldMinX) / CellSize);
		int item2 = (int)MathF.Floor((worldZ - WorldMinZ) / CellSize);
		return (cellX: item, cellZ: item2);
	}

	public (float worldX, float worldZ) CellToWorld(int cellX, int cellZ)
	{
		float item = WorldMinX + ((float)cellX + 0.5f) * CellSize;
		float item2 = WorldMinZ + ((float)cellZ + 0.5f) * CellSize;
		return (worldX: item, worldZ: item2);
	}
}