using System.IO;
using UnityEngine;

namespace Gaia
{
	public class UnityHeightMap : HeightMap
	{
		public Bounds m_boundsWU;

		public UnityHeightMap()
		{
		}

		public UnityHeightMap(string path)
			: base(path)
		{
			m_boundsWU.size = new Vector3(m_widthX, 0f, m_depthZ);
			m_isDirty = false;
		}

		public UnityHeightMap(TextAsset source)
			: base(source.bytes)
		{
			m_boundsWU.size = new Vector3(m_widthX, 0f, m_depthZ);
			m_isDirty = false;
		}

		public UnityHeightMap(UnityHeightMap source)
			: base(source)
		{
			m_boundsWU = source.m_boundsWU;
			m_isDirty = false;
		}

		public UnityHeightMap(Terrain terrain)
		{
			LoadFromTerrain(terrain);
		}

		public UnityHeightMap(Bounds bounds, string sourceFile)
			: base(sourceFile)
		{
			m_boundsWU = bounds;
			m_isDirty = false;
		}

		public UnityHeightMap(Texture2D texture)
		{
			LoadFromTexture2D(texture);
			m_isDirty = false;
		}

		public Bounds GetBoundsWU()
		{
			return m_boundsWU;
		}

		public Vector3 GetPositionWU()
		{
			return m_boundsWU.center - m_boundsWU.extents;
		}

		public void SetBoundsWU(Bounds bounds)
		{
			m_boundsWU = bounds;
			m_isDirty = true;
		}

		public void SetPositionWU(Vector3 position)
		{
			m_boundsWU.center = position;
			m_isDirty = true;
		}

		public void LoadFromTerrain(Terrain terrain)
		{
			Reset();
			m_boundsWU.center = terrain.transform.position;
			m_boundsWU.size = terrain.terrainData.size;
			m_boundsWU.center += m_boundsWU.extents;
			m_widthX = terrain.terrainData.heightmapResolution;
			m_depthZ = terrain.terrainData.heightmapResolution;
			m_widthInvX = 1f / (float)m_widthX;
			m_depthInvZ = 1f / (float)m_depthZ;
			m_heights = terrain.terrainData.GetHeights(0, 0, m_widthX, m_depthZ);
			m_isPowerOf2 = GaiaUtils.Math_IsPowerOf2(m_widthX) && GaiaUtils.Math_IsPowerOf2(m_depthZ);
			m_isDirty = false;
		}

		public void SaveToTerrain(Terrain terrain)
		{
			int heightmapResolution = terrain.terrainData.heightmapResolution;
			int heightmapResolution2 = terrain.terrainData.heightmapResolution;
			if (m_widthX == heightmapResolution && m_depthZ == heightmapResolution2)
			{
				terrain.terrainData.SetHeights(0, 0, m_heights);
				m_isDirty = false;
				return;
			}
			float[,] array = new float[heightmapResolution, heightmapResolution2];
			for (int i = 0; i < heightmapResolution; i++)
			{
				for (int j = 0; j < heightmapResolution2; j++)
				{
					array[i, j] = base[(float)i / (float)heightmapResolution, (float)j / (float)heightmapResolution2];
				}
			}
			terrain.terrainData.SetHeights(0, 0, array);
			m_isDirty = false;
		}

		public void LoadFromTexture2D(Texture2D texture)
		{
			GaiaUtils.MakeTextureReadable(texture);
			GaiaUtils.MakeTextureUncompressed(texture);
			m_widthX = texture.width;
			m_depthZ = texture.height;
			m_widthInvX = 1f / (float)m_widthX;
			m_depthInvZ = 1f / (float)m_depthZ;
			m_heights = new float[m_widthX, m_depthZ];
			m_isPowerOf2 = GaiaUtils.Math_IsPowerOf2(m_widthX) && GaiaUtils.Math_IsPowerOf2(m_depthZ);
			for (int i = 0; i < m_widthX; i++)
			{
				for (int j = 0; j < m_depthZ; j++)
				{
					m_heights[i, j] = texture.GetPixel(i, j).grayscale;
				}
			}
			m_isDirty = false;
		}

		public void ReadRawFromTextAsset(TextAsset asset)
		{
			using (Stream stream = new MemoryStream(asset.bytes))
			{
				using (BinaryReader binaryReader = new BinaryReader(stream))
				{
					m_widthX = (m_depthZ = Mathf.CeilToInt(Mathf.Sqrt(stream.Length / 2)));
					m_widthInvX = 1f / (float)m_widthX;
					m_depthInvZ = 1f / (float)m_depthZ;
					m_heights = new float[m_widthX, m_depthZ];
					m_isPowerOf2 = GaiaUtils.Math_IsPowerOf2(m_widthX) && GaiaUtils.Math_IsPowerOf2(m_depthZ);
					for (int i = 0; i < m_widthX; i++)
					{
						for (int j = 0; j < m_depthZ; j++)
						{
							m_heights[i, j] = (float)(int)binaryReader.ReadUInt16() / 65535f;
						}
					}
				}
				stream.Close();
			}
			m_isDirty = false;
		}

		public Texture2D CalculateNormals()
		{
			float num = (float)m_widthX / 2f;
			int widthX = m_widthX;
			int depthZ = m_depthZ;
			float num2 = 1f / ((float)widthX - 1f);
			float num3 = 1f / ((float)depthZ - 1f);
			float num4 = num / (float)m_widthX;
			float num5 = num / (float)m_depthZ;
			float[] array = Heights1D();
			Texture2D texture2D = new Texture2D(widthX, depthZ, TextureFormat.RGBAFloat, mipChain: false, linear: true);
			Vector3 vector = default(Vector3);
			Color color = default(Color);
			for (int i = 0; i < depthZ; i++)
			{
				for (int j = 0; j < widthX; j++)
				{
					int num6 = ((j == widthX - 1) ? j : (j + 1));
					int num7 = ((j == 0) ? j : (j - 1));
					int num8 = ((i == depthZ - 1) ? i : (i + 1));
					int num9 = ((i == 0) ? i : (i - 1));
					float num10 = array[num7 + i * widthX] * num4;
					float num11 = array[num6 + i * widthX] * num4;
					float num12 = array[j + num9 * widthX] * num5;
					float num13 = array[j + num8 * widthX] * num5;
					float num14 = (num11 - num10) / (2f * num2);
					float num15 = (num13 - num12) / (2f * num3);
					vector.x = 0f - num14;
					vector.y = 0f - num15;
					vector.z = 1f;
					vector.Normalize();
					color.r = vector.x * 0.5f + 0.5f;
					color.g = vector.y * 0.5f + 0.5f;
					color.b = vector.z;
					color.a = 1f;
					texture2D.SetPixel(j, i, color);
				}
			}
			texture2D.Apply();
			return texture2D;
		}
	}
}