using UnityEngine;

namespace Artngame.SKYMASTER
{
	public class MeshCombineUtilitySKYMASTER
	{
		public struct MeshInstance
		{
			public Mesh mesh;

			public int subMeshIndex;

			public Matrix4x4 transform;
		}

		public static Mesh Combine(MeshInstance[] combines, bool generateStrips)
		{
			int num = 0;
			int num2 = 0;
			MeshInstance[] array = combines;
			for (int i = 0; i < array.Length; i++)
			{
				MeshInstance meshInstance = array[i];
				if ((bool)meshInstance.mesh)
				{
					num += meshInstance.mesh.vertexCount;
				}
			}
			array = combines;
			for (int i = 0; i < array.Length; i++)
			{
				MeshInstance meshInstance2 = array[i];
				if ((bool)meshInstance2.mesh)
				{
					num2 += meshInstance2.mesh.GetTriangles(meshInstance2.subMeshIndex).Length;
				}
			}
			Vector3[] array2 = new Vector3[num];
			Vector3[] array3 = new Vector3[num];
			Vector4[] array4 = new Vector4[num];
			Vector2[] array5 = new Vector2[num];
			Vector2[] array6 = new Vector2[num];
			Color[] array7 = new Color[num];
			int[] array8 = new int[num2];
			int offset = 0;
			array = combines;
			for (int i = 0; i < array.Length; i++)
			{
				MeshInstance meshInstance3 = array[i];
				if ((bool)meshInstance3.mesh)
				{
					Copy(meshInstance3.mesh.vertexCount, meshInstance3.mesh.vertices, array2, ref offset, meshInstance3.transform);
				}
			}
			offset = 0;
			array = combines;
			for (int i = 0; i < array.Length; i++)
			{
				MeshInstance meshInstance4 = array[i];
				if ((bool)meshInstance4.mesh)
				{
					Matrix4x4 transform = meshInstance4.transform;
					transform = transform.inverse.transpose;
					CopyNormal(meshInstance4.mesh.vertexCount, meshInstance4.mesh.normals, array3, ref offset, transform);
				}
			}
			offset = 0;
			array = combines;
			for (int i = 0; i < array.Length; i++)
			{
				MeshInstance meshInstance5 = array[i];
				if ((bool)meshInstance5.mesh)
				{
					Matrix4x4 transform2 = meshInstance5.transform;
					transform2 = transform2.inverse.transpose;
					CopyTangents(meshInstance5.mesh.vertexCount, meshInstance5.mesh.tangents, array4, ref offset, transform2);
				}
			}
			offset = 0;
			array = combines;
			for (int i = 0; i < array.Length; i++)
			{
				MeshInstance meshInstance6 = array[i];
				if ((bool)meshInstance6.mesh)
				{
					Copy(meshInstance6.mesh.vertexCount, meshInstance6.mesh.uv, array5, ref offset);
				}
			}
			offset = 0;
			array = combines;
			for (int i = 0; i < array.Length; i++)
			{
				MeshInstance meshInstance7 = array[i];
				if ((bool)meshInstance7.mesh)
				{
					Copy(meshInstance7.mesh.vertexCount, meshInstance7.mesh.uv2, array6, ref offset);
				}
			}
			offset = 0;
			array = combines;
			for (int i = 0; i < array.Length; i++)
			{
				MeshInstance meshInstance8 = array[i];
				if ((bool)meshInstance8.mesh)
				{
					CopyColors(meshInstance8.mesh.vertexCount, meshInstance8.mesh.colors, array7, ref offset);
				}
			}
			int num3 = 0;
			int num4 = 0;
			array = combines;
			for (int i = 0; i < array.Length; i++)
			{
				MeshInstance meshInstance9 = array[i];
				if ((bool)meshInstance9.mesh)
				{
					int[] triangles = meshInstance9.mesh.GetTriangles(meshInstance9.subMeshIndex);
					for (int j = 0; j < triangles.Length; j++)
					{
						array8[j + num3] = triangles[j] + num4;
					}
					num3 += triangles.Length;
					num4 += meshInstance9.mesh.vertexCount;
				}
			}
			return new Mesh
			{
				name = "Combined Mesh",
				vertices = array2,
				normals = array3,
				colors = array7,
				uv = array5,
				uv2 = array6,
				tangents = array4,
				triangles = array8
			};
		}

		private static void Copy(int vertexcount, Vector3[] src, Vector3[] dst, ref int offset, Matrix4x4 transform)
		{
			for (int i = 0; i < src.Length; i++)
			{
				dst[i + offset] = transform.MultiplyPoint(src[i]);
			}
			offset += vertexcount;
		}

		private static void CopyNormal(int vertexcount, Vector3[] src, Vector3[] dst, ref int offset, Matrix4x4 transform)
		{
			for (int i = 0; i < src.Length; i++)
			{
				dst[i + offset] = transform.MultiplyVector(src[i]).normalized;
			}
			offset += vertexcount;
		}

		private static void Copy(int vertexcount, Vector2[] src, Vector2[] dst, ref int offset)
		{
			for (int i = 0; i < src.Length; i++)
			{
				dst[i + offset] = src[i];
			}
			offset += vertexcount;
		}

		private static void CopyColors(int vertexcount, Color[] src, Color[] dst, ref int offset)
		{
			for (int i = 0; i < src.Length; i++)
			{
				dst[i + offset] = src[i];
			}
			offset += vertexcount;
		}

		private static void CopyTangents(int vertexcount, Vector4[] src, Vector4[] dst, ref int offset, Matrix4x4 transform)
		{
			for (int i = 0; i < src.Length; i++)
			{
				Vector4 vector = src[i];
				Vector3 vector2 = new Vector3(vector.x, vector.y, vector.z);
				vector2 = transform.MultiplyVector(vector2).normalized;
				dst[i + offset] = new Vector4(vector2.x, vector2.y, vector2.z, vector.w);
			}
			offset += vertexcount;
		}
	}
}