Health/Assets/OpenCVForUnity/org/opencv/unity/Utils.cs

using AOT;
using OpenCVForUnity.CoreModule;
using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Runtime.InteropServices;
using UnityEngine;

#if OPENCV_USE_UNSAFE_CODE && UNITY_2018_1_OR_NEWER
using Unity.Collections.LowLevel.Unsafe;
using Unity.Collections;
#endif

namespace OpenCVForUnity.UnityUtils
{
    public static class Utils
    {
        /**
        * Returns this "OpenCV for Unity" version number.
        * 
        * @return this "OpenCV for Unity" version number
        */
        public static string getVersion()
        {
            return "2.5.7";
        }

        /**
        * Copies OpenCV Mat data to Pixel Data IntPtr.
        * <p>
        * <br>This method copies the OpenCV Mat data to the pixel data IntPtr.
        * <br>The pixel data must have the same byte size as the Mat data ([total() * elemSize()] byte).
        * <br>Because this method doesn't check bounds, is faster than Mat.get().
        *
        * @param mat a Mat object.
        * @param intPtr the pixel data must have the same byte size as the Mat data ([total() * elemSize()] byte).
        */
        [Obsolete("This method is obsolete. Call MatUtils.copyFromMat method instead.", false)]
        public static void copyFromMat(Mat mat, IntPtr intPtr)
        {
            if (mat == null)
                throw new ArgumentNullException("mat");
            if (mat != null)
                mat.ThrowIfDisposed();

            if (intPtr == IntPtr.Zero)
                throw new ArgumentException("intPtr == IntPtr.Zero");

            OpenCVForUnity_MatDataToByteArray(mat.nativeObj, intPtr);
        }

        /**
        * Copies Pixel Data IntPtr to OpenCV Mat data.
        * <p>
        * <br>This method copy the pixel data IntPtr to the OpenCV Mat data.
        * <br>The Mat object must have the same byte size as the pixel data ([total() * elemSize()] byte).
        * <br>Because this method doesn't check bounds, is faster than Mat.put().
        * 
        * @param intPtr a pixel data IntPtr.
        * @param mat the Mat object must have the same byte size as the pixel data ([total() * elemSize()] byte).
        */
        [Obsolete("This method is obsolete. Call MatUtils.copyFromMat method instead.", false)]
        public static void copyToMat(IntPtr intPtr, Mat mat)
        {
            if (intPtr == IntPtr.Zero)
                throw new ArgumentException("intPtr == IntPtr.Zero");

            if (mat == null)
                throw new ArgumentNullException("mat");
            if (mat != null)
                mat.ThrowIfDisposed();

            OpenCVForUnity_ByteArrayToMatData(intPtr, mat.nativeObj);
        }

        /**
        * Copies OpenCV Mat data to Pixel Data Array.
        * <p>
        * <br>This method copies the OpenCV Mat data to the pixel data Array.
        * <br>The pixel data Array must have the same byte size as the Mat data ([total() * elemSize()] byte).
        * <br>Because this method doesn't check bounds, is faster than Mat.get().
        *
        * @param mat a Mat object.
        * @param array the pixel data Array must have the same byte size as the Mat data ([total() * elemSize()] byte).
        */
        [Obsolete("This method is obsolete. Call MatUtils.copyFromMat method instead.", false)]
        public static void copyFromMat<T>(Mat mat, T[] array) where T : struct
        {
            if (mat == null)
                throw new ArgumentNullException("mat");
            if (mat != null)
                mat.ThrowIfDisposed();

            if (array == null)
                throw new ArgumentNullException("array");

            GCHandle arrayHandle = GCHandle.Alloc(array, GCHandleType.Pinned);
            OpenCVForUnity_MatDataToByteArray(mat.nativeObj, arrayHandle.AddrOfPinnedObject());
            arrayHandle.Free();
        }

        /**
        * Copies Pixel Data Array to OpenCV Mat data.
        * <p>
        * <br>This method copies the pixel data Array to the OpenCV Mat data.
        * <br>The Mat object must have the same byte size as the pixel data Array ([total() * elemSize()] byte).
        * <br>Because this method doesn't check bounds, is faster than Mat.put().
        * 
        * @param array a pixel data Array.
        * @param mat the Mat object must have the same byte size as the pixel data Array ([total() * elemSize()] byte).
        */
        [Obsolete("This method is obsolete. Call MatUtils.copyToMat method instead.", false)]
        public static void copyToMat<T>(T[] array, Mat mat) where T : struct
        {
            if (array == null)
                throw new ArgumentNullException("array");

            if (mat == null)
                throw new ArgumentNullException("mat");
            if (mat != null)
                mat.ThrowIfDisposed();

            GCHandle arrayHandle = GCHandle.Alloc(array, GCHandleType.Pinned);
            OpenCVForUnity_ByteArrayToMatData(arrayHandle.AddrOfPinnedObject(), mat.nativeObj);
            arrayHandle.Free();
        }

#if OPENCV_USE_UNSAFE_CODE && UNITY_2018_1_OR_NEWER
        /**
        * Copies OpenCV Mat data to Pixel Data NativeArray.
        * <p>
        * <br>This method copies the OpenCV Mat data to the pixel data NativeArray.
        * <br>The pixel data Array must have the same byte size as the Mat data ([total() * elemSize()] byte).
        * <br>Because this method doesn't check bounds, is faster than Mat.get().
        *
        * @param mat a Mat object.
        * @param array the pixel data Array must have the same byte size as the Mat data ([total() * elemSize()] byte).
        */
        [Obsolete("This method is obsolete. Call MatUtils.copyFromMat method instead.", false)]
        public static void copyFromMat<T>(Mat mat, NativeArray<T> array) where T : struct
        {
            if (mat == null)
                throw new ArgumentNullException("mat");
            if (mat != null)
                mat.ThrowIfDisposed();

            unsafe
            {
                OpenCVForUnity_MatDataToByteArray(mat.nativeObj, (IntPtr)NativeArrayUnsafeUtility.GetUnsafeReadOnlyPtr(array));
            }
        }

        /**
        * Copies Pixel Data NativeArray to OpenCV Mat data.
        * <p>
        * <br>This method copies the pixel data NativeArray to the OpenCV Mat data.
        * <br>The Mat object must have the same byte size as the pixel data Array ([total() * elemSize()] byte).
        * <br>Because this method doesn't check bounds, is faster than Mat.put().
        * 
        * @param array a pixel data Array.
        * @param mat the Mat object must have the same byte size as the pixel data Array ([total() * elemSize()] byte).
        */
        [Obsolete("This method is obsolete. Call MatUtils.copyToMat method instead.", false)]
        public static void copyToMat<T>(NativeArray<T> array, Mat mat) where T : struct
        {
            if (mat == null)
                throw new ArgumentNullException("mat");
            if (mat != null)
                mat.ThrowIfDisposed();

            unsafe
            {
                OpenCVForUnity_ByteArrayToMatData((IntPtr)NativeArrayUnsafeUtility.GetUnsafeReadOnlyPtr(array), mat.nativeObj);
            }
        }
#endif

        /**
        * Converts OpenCV Mat to Unity Texture2D.
        * <p>
        * <br>This method converts the OpenCV Mat to the Unity Texture2D image.
        * <br>The Mat object must have the types 'CV_8UC4' (RGBA) , 'CV_8UC3' (RGB) or 'CV_8UC1' (GRAY).
        * <br>The texture2D object supports the following formats. (<a href="https://docs.unity3d.com/ScriptReference/Texture2D.SetPixels32.html">https://docs.unity3d.com/ScriptReference/Texture2D.SetPixels32.html</a>)
        * <br>The Texture2D object must have the same size as the Mat (width * height).
        * <br>Enable the "unsafe" code if you want the conversion process to run the fastest; use NativeArray to run the conversion process several times faster with no overhead. If you want to use optimization code using NativeArray class, click the MenuItem[Tools/OpenCV for Unity/Open Setup Tools] - [Enable Use Unsafe Code] button.
        *
        * @param mat the Mat object must have the types 'CV_8UC4' (RGBA) , 'CV_8UC3' (RGB) or 'CV_8UC1' (GRAY)
        * @param texture2D the texture2D object supports the following formats. (<a href="https://docs.unity3d.com/ScriptReference/Texture2D.SetPixels32.html">https://docs.unity3d.com/ScriptReference/Texture2D.SetPixels32.html</a>) The Texture2D object must have the same size as the Mat (width * height).
        * @param flip if true, the mat is fliped before converting.
        * @param flipCode a flag to specify how to flip the array; 0 means flipping around the x-axis and positive value (for example, 1) means flipping around y-axis. Negative value (for example, -1) means flipping around both axes.
        * @param flipAfter if true, the mat is fliped after converting. If you want to use mat even after calling this method, set true.
        * @param updateMipmaps When set to true, mipmap levels are recalculated.
        * @param makeNoLongerReadable When set to true, system memory copy of a texture is released.
        */
        public static void matToTexture2D(Mat mat, Texture2D texture2D, bool flip = true, int flipCode = 0, bool flipAfter = false, bool updateMipmaps = false, bool makeNoLongerReadable = false)
        {
            matToTexture2D(mat, texture2D, null, null, flip, flipCode, flipAfter, updateMipmaps, makeNoLongerReadable);
        }

        /**
        * Converts OpenCV Mat to Unity Texture2D.
        * <p>
        * <br>This method converts the OpenCV Mat to the Unity Texture2D image.
        * <br>The Mat object must have the types 'CV_8UC4' (RGBA) , 'CV_8UC3' (RGB) or 'CV_8UC1' (GRAY).
        * <br>The texture2D object supports the following formats. (<a href="https://docs.unity3d.com/ScriptReference/Texture2D.SetPixels32.html">https://docs.unity3d.com/ScriptReference/Texture2D.SetPixels32.html</a>)
        * <br>The Texture2D object must have the same size as the Mat (width * height).
        * <br>Enable the "unsafe" code if you want the conversion process to run the fastest; use NativeArray to run the conversion process several times faster with no overhead. If you want to use optimization code using NativeArray class, click the MenuItem[Tools/OpenCV for Unity/Open Setup Tools] - [Enable Use Unsafe Code] button.
        *
        * @param mat the Mat object must have the types 'CV_8UC4' (RGBA) , 'CV_8UC3' (RGB) or 'CV_8UC1' (GRAY)
        * @param texture2D The texture2D object supports the following formats. (<a href="https://docs.unity3d.com/ScriptReference/Texture2D.SetPixels32.html">https://docs.unity3d.com/ScriptReference/Texture2D.SetPixels32.html</a>) The Texture2D object must have the same size as the Mat (width * height).
        * @param pixels32Buffer the optional array to receive pixels32 data. 
        * You can optionally pass in an array of Color32s to avoid allocating new memory each frame.
        * The array needs to be initialized to a length matching width * height of the texture. (<a href="http://docs.unity3d.com/ScriptReference/WebCamTexture.GetPixels32.html">http://docs.unity3d.com/ScriptReference/WebCamTexture.GetPixels32.html</a>)
        * @param rawTextureDataBuffer the optional array to receive raw texture data. 
        * You can optionally pass in an array of bytes to avoid allocating new memory each frame.
        * The array needs to be initialized to a length matching raw data of the texture. (<a href="https://docs.unity3d.com/ScriptReference/Texture2D.GetRawTextureData.html">https://docs.unity3d.com/ScriptReference/Texture2D.GetRawTextureData.html</a>)
        * @param flip if true, the mat is fliped before converting.
        * @param flipCode a flag to specify how to flip the array; 0 means flipping around the x-axis and positive value (for example, 1) means flipping around y-axis. Negative value (for example, -1) means flipping around both axes.
        * @param flipAfter if true, the mat is fliped after converting. If you want to use mat even after calling this method, set true.
        * @param updateMipmaps when set to true, mipmap levels are recalculated.
        * @param makeNoLongerReadable when set to true, system memory copy of a texture is released.
        */
        public static void matToTexture2D(Mat mat, Texture2D texture2D, Color32[] pixels32Buffer, byte[] rawTextureDataBuffer = null, bool flip = true, int flipCode = 0, bool flipAfter = false, bool updateMipmaps = false, bool makeNoLongerReadable = false)
        {
            if (mat == null)
                throw new ArgumentNullException("mat");
            if (mat != null)
                mat.ThrowIfDisposed();

            if (texture2D == null)
                throw new ArgumentNullException("texture2D");

            if (mat.cols() != texture2D.width || mat.rows() != texture2D.height)
                throw new ArgumentException("The Texture2D object must have the same size.");

            int type = mat.type();
            TextureFormat format = texture2D.format;
            if (!(type == CvType.CV_8UC1 || type == CvType.CV_8UC3 || type == CvType.CV_8UC4))
                throw new ArgumentException("The Mat object must have the types 'CV_8UC4' (RGBA) , 'CV_8UC3' (RGB) or 'CV_8UC1' (GRAY).");

#if !(OPENCV_USE_UNSAFE_CODE && UNITY_2018_2_OR_NEWER)
            if (((type == CvType.CV_8UC4 && format == TextureFormat.RGBA32) || (type == CvType.CV_8UC3 && format == TextureFormat.RGB24) || (type == CvType.CV_8UC1 && (format == TextureFormat.Alpha8 || format == TextureFormat.R8))) && texture2D.mipmapCount == 1 && mat.isContinuous())
            {
                if (flip)
                {
                    Core.flip(mat, mat, flipCode);
                }
                texture2D.LoadRawTextureData((IntPtr)mat.dataAddr(), (int)mat.total() * (int)mat.elemSize());
                texture2D.Apply(updateMipmaps, makeNoLongerReadable);
                if (flipAfter)
                {
                    Core.flip(mat, mat, flipCode);
                }

                return;
            }
#endif

            if (format == TextureFormat.RGBA32 || format == TextureFormat.BGRA32 || format == TextureFormat.RGB24 || format == TextureFormat.Alpha8 || format == TextureFormat.R8)
            {
#if OPENCV_USE_UNSAFE_CODE && UNITY_2018_2_OR_NEWER
                unsafe
                {
                    OpenCVForUnity_MatToTexture(mat.nativeObj, (IntPtr)NativeArrayUnsafeUtility.GetUnsafeReadOnlyPtr(texture2D.GetRawTextureData<byte>()), (int)format, flip, flipCode, flipAfter);
                }
                texture2D.Apply(updateMipmaps, makeNoLongerReadable);

                return;
#else

                if ((rawTextureDataBuffer != null) || (pixels32Buffer == null && texture2D.mipmapCount == 1))
                {
                    GCHandle rawTextureDataHandle;
                    if (rawTextureDataBuffer == null)
                    {
                        byte[] rawTextureData = texture2D.GetRawTextureData();
                        rawTextureDataHandle = GCHandle.Alloc(rawTextureData, GCHandleType.Pinned);
                        OpenCVForUnity_MatToTexture(mat.nativeObj, rawTextureDataHandle.AddrOfPinnedObject(), (int)format, flip, flipCode, flipAfter);
                        texture2D.LoadRawTextureData(rawTextureDataHandle.AddrOfPinnedObject(), rawTextureData.Length);
                    }
                    else
                    {
                        rawTextureDataHandle = GCHandle.Alloc(rawTextureDataBuffer, GCHandleType.Pinned);
                        OpenCVForUnity_MatToTexture(mat.nativeObj, rawTextureDataHandle.AddrOfPinnedObject(), (int)format, flip, flipCode, flipAfter);
                        texture2D.LoadRawTextureData(rawTextureDataHandle.AddrOfPinnedObject(), rawTextureDataBuffer.Length);
                    }
                    texture2D.Apply(updateMipmaps, makeNoLongerReadable);
                    rawTextureDataHandle.Free();

                    return;
                }
#endif
            }

            //You can use SetPixels32 with the following texture formats:
            //https://docs.unity3d.com/2020.3/Documentation/ScriptReference/Texture2D.SetPixels32.html
            GCHandle pixels32Handle;
            if (pixels32Buffer == null)
            {
                Color32[] pixels32 = texture2D.GetPixels32();

                pixels32Handle = GCHandle.Alloc(pixels32, GCHandleType.Pinned);
                OpenCVForUnity_MatToTexture(mat.nativeObj, pixels32Handle.AddrOfPinnedObject(), (int)TextureFormat.RGBA32, flip, flipCode, flipAfter);

                texture2D.SetPixels32(pixels32);
            }
            else
            {
                pixels32Handle = GCHandle.Alloc(pixels32Buffer, GCHandleType.Pinned);
                OpenCVForUnity_MatToTexture(mat.nativeObj, pixels32Handle.AddrOfPinnedObject(), (int)TextureFormat.RGBA32, flip, flipCode, flipAfter);

                texture2D.SetPixels32(pixels32Buffer);
            }
            texture2D.Apply(updateMipmaps, makeNoLongerReadable);
            pixels32Handle.Free();

        }

        /**
        * Fast converts OpenCV Mat to Unity Texture2D.
        * <p>
        * <br>This method simply copies the mat data to texture2D. Therefore, there are no restrictions on the mat's type and texture2D's format; it is faster than the matToTexture2D() method.
        * <br>The Mat object and the Texture2D object must have the same width, height, and data format.
        * <br>Enable the "unsafe" code if you want the conversion process to run the fastest; use NativeArray to run the conversion process several times faster with no overhead. If you want to use optimization code using NativeArray class, click the MenuItem[Tools/OpenCV for Unity/Open Setup Tools] - [Enable Use Unsafe Code] button.
        *
        * @param mat
        * @param texture2D the Texture2D object must have the same size and data format (width * height * channels) as the Mat.
        * @param flip if true, the mat is fliped before converting.
        * @param flipCode a flag to specify how to flip the array; 0 means flipping around the x-axis and positive value (for example, 1) means flipping around y-axis. Negative value (for example, -1) means flipping around both axes.
        * @param flipAfter if true, the mat is fliped after converting. If you want to use mat even after calling this method, set true.
        * @param updateMipmaps when set to true, mipmap levels are recalculated.
        * @param makeNoLongerReadable when set to true, system memory copy of a texture is released.
        */
        public static void fastMatToTexture2D(Mat mat, Texture2D texture2D, bool flip = true, int flipCode = 0, bool flipAfter = false, bool updateMipmaps = false, bool makeNoLongerReadable = false)
        {
            if (mat == null)
                throw new ArgumentNullException("mat");
            if (mat != null)
                mat.ThrowIfDisposed();

            if (texture2D == null)
                throw new ArgumentNullException("texture2D");

#if OPENCV_USE_UNSAFE_CODE && UNITY_2018_2_OR_NEWER
            int type = mat.type();
            TextureFormat format = texture2D.format;
            if ((type == CvType.CV_8UC4 && format == TextureFormat.RGBA32) || (type == CvType.CV_8UC3 && format == TextureFormat.RGB24) || (type == CvType.CV_8UC1 && (format == TextureFormat.Alpha8 || format == TextureFormat.R8)))
            {
                unsafe
                {
                    OpenCVForUnity_MatToTexture(mat.nativeObj, (IntPtr)NativeArrayUnsafeUtility.GetUnsafeReadOnlyPtr(texture2D.GetRawTextureData<byte>()), (int)texture2D.format, flip, flipCode, flipAfter);
                }
                texture2D.Apply(updateMipmaps, makeNoLongerReadable);
            }
            else
            {
                if (flip)
                {
                    Core.flip(mat, mat, flipCode);
                }
                unsafe
                {
                    OpenCVForUnity_MatDataToByteArray(mat.nativeObj, (IntPtr)NativeArrayUnsafeUtility.GetUnsafeReadOnlyPtr(texture2D.GetRawTextureData<byte>()));
                }
                texture2D.Apply(updateMipmaps, makeNoLongerReadable);
                if (flipAfter)
                {
                    Core.flip(mat, mat, flipCode);
                }
            }
#else
            if (!mat.isContinuous())
            {
                Debug.LogError("mat.isContinuous() must be true.");
                return;
            }

            if (texture2D.mipmapCount != 1)
            {
                Debug.LogError("texture2D.mipmapCount must be 1.");
                return;
            }

            if (flip)
            {
                Core.flip(mat, mat, flipCode);
            }
            texture2D.LoadRawTextureData((IntPtr)mat.dataAddr(), (int)mat.total() * (int)mat.elemSize());
            texture2D.Apply(updateMipmaps, makeNoLongerReadable);
            if (flipAfter)
            {
                Core.flip(mat, mat, flipCode);
            }
#endif
        }

        /**
        * Converts Unity Texture2D to OpenCV Mat.
        * <p>
        * <br>This method converts the Unity Texture2D image to the OpenCV Mat.
        * <br>The Texture object must have the read/write enabled flag set in the texture import settings, otherwise this function will fail. (GetPixels32() method is needed.)
        * <br>The Mat object must have the same size as the Texture2D (width * height).
        * <br>The Mat object must have the types 'CV_8UC4' (RGBA) , 'CV_8UC3' (RGB) or 'CV_8UC1' (GRAY).
        * <br>Enable the "unsafe" code if you want the conversion process to run the fastest; use NativeArray to run the conversion process several times faster with no overhead. If you want to use optimization code using NativeArray class, click the MenuItem[Tools/OpenCV for Unity/Open Setup Tools] - [Enable Use Unsafe Code] button.
        * 
        * @param texture2D the Texture2D object must have the read/write enabled flag set in the texture import settings, otherwise this function will fail. (GetPixels32() method is needed.)
        * @param mat the Mat object must have the same size as the Texture2D (width * height).
        * The Mat object must have the types 'CV_8UC4' (RGBA) , 'CV_8UC3' (RGB) or 'CV_8UC1' (GRAY).
        * @param flipAfter if true, the mat is fliped after converting.
        * @param flipCode a flag to specify how to flip the array; 0 means flipping around the x-axis and positive value (for example, 1) means flipping around y-axis. Negative value (for example, -1) means flipping around both axes.
        */
        public static void texture2DToMat(Texture2D texture2D, Mat mat, bool flipAfter = true, int flipCode = 0)
        {
            if (texture2D == null)
                throw new ArgumentNullException("texture2D");

            if (mat == null)
                throw new ArgumentNullException("mat");
            if (mat != null)
                mat.ThrowIfDisposed();

            if (mat.cols() != texture2D.width || mat.rows() != texture2D.height)
                throw new ArgumentException($"The Mat object must have the same size. texture width:{texture2D.width} height:{texture2D.height}. Mat width:{mat.cols()} height:{mat.rows()} ");

            int type = mat.type();
            TextureFormat format = texture2D.format;
            if (!(type == CvType.CV_8UC1 || type == CvType.CV_8UC3 || type == CvType.CV_8UC4))
                throw new ArgumentException("The Mat object must have the types 'CV_8UC4' (RGBA) , 'CV_8UC3' (RGB) or 'CV_8UC1' (GRAY).");

            if (format == TextureFormat.RGBA32 || format == TextureFormat.BGRA32 || format == TextureFormat.RGB24 || format == TextureFormat.Alpha8 || format == TextureFormat.R8)
            {
#if OPENCV_USE_UNSAFE_CODE && UNITY_2018_2_OR_NEWER
                unsafe
                {
                    OpenCVForUnity_TextureToMat((IntPtr)NativeArrayUnsafeUtility.GetUnsafeReadOnlyPtr(texture2D.GetRawTextureData<byte>()), mat.nativeObj, (int)format, flipAfter, flipCode);
                }
#else
                GCHandle RawTextureDataHandle = GCHandle.Alloc(texture2D.GetRawTextureData(), GCHandleType.Pinned);
                OpenCVForUnity_TextureToMat(RawTextureDataHandle.AddrOfPinnedObject(), mat.nativeObj, (int)format, flipAfter, flipCode);
                RawTextureDataHandle.Free();
#endif

                return;
            }

            Color32[] pixels32 = texture2D.GetPixels32();

            GCHandle pixels32Handle = GCHandle.Alloc(pixels32, GCHandleType.Pinned);
            OpenCVForUnity_TextureToMat(pixels32Handle.AddrOfPinnedObject(), mat.nativeObj, (int)TextureFormat.RGBA32, flipAfter, flipCode);
            pixels32Handle.Free();

        }

        /**
        * Fast converts Unity Texture2D to OpenCV Mat.
        * <p>
        * <br>This method simply copies the texture2D data to mat. Therefore, there are no restrictions on the mat's type and texture2D's format; it is faster than the texture2DToMat() method.
        * <br>The Texture2D object and the Mat object must have the same width, height, and data format.
        * <br>Enable the "unsafe" code if you want the conversion process to run the fastest; use NativeArray to run the conversion process several times faster with no overhead. If you want to use optimization code using NativeArray class, click the MenuItem[Tools/OpenCV for Unity/Open Setup Tools] - [Enable Use Unsafe Code] button.
        * 
        * @param texture2D
        * @param mat the Mat object must have the same size and data format (width * height * channels) as the Texture2D.
        * @param flipAfter if true, the mat is fliped after converting.
        * @param flipCode a flag to specify how to flip the array; 0 means flipping around the x-axis and positive value (for example, 1) means flipping around y-axis. Negative value (for example, -1) means flipping around both axes.
        */
        public static void fastTexture2DToMat(Texture2D texture2D, Mat mat, bool flipAfter = true, int flipCode = 0)
        {
            if (texture2D == null)
                throw new ArgumentNullException("texture2D");

            if (mat == null)
                throw new ArgumentNullException("mat");
            if (mat != null)
                mat.ThrowIfDisposed();

#if OPENCV_USE_UNSAFE_CODE && UNITY_2018_2_OR_NEWER
            int type = mat.type();
            TextureFormat format = texture2D.format;
            if ((type == CvType.CV_8UC4 && format == TextureFormat.RGBA32) || (type == CvType.CV_8UC3 && format == TextureFormat.RGB24) || (type == CvType.CV_8UC1 && (format == TextureFormat.Alpha8 || format == TextureFormat.R8)))
            {
                unsafe
                {
                    OpenCVForUnity_TextureToMat((IntPtr)NativeArrayUnsafeUtility.GetUnsafeReadOnlyPtr(texture2D.GetRawTextureData<byte>()), mat.nativeObj, (int)texture2D.format, flipAfter, flipCode);
                }
            }
            else
            {
                unsafe
                {
                    OpenCVForUnity_ByteArrayToMatData((IntPtr)NativeArrayUnsafeUtility.GetUnsafeReadOnlyPtr(texture2D.GetRawTextureData<byte>()), mat.nativeObj);
                }
                if (flipAfter)
                {
                    Core.flip(mat, mat, flipCode);
                }
            }
#else
            int type = mat.type();
            TextureFormat format = texture2D.format;
            if ((type == CvType.CV_8UC4 && format == TextureFormat.RGBA32) || (type == CvType.CV_8UC3 && format == TextureFormat.RGB24) || (type == CvType.CV_8UC1 && (format == TextureFormat.Alpha8 || format == TextureFormat.R8)))
            {
                GCHandle RawTextureDataHandle = GCHandle.Alloc(texture2D.GetRawTextureData(), GCHandleType.Pinned);
                OpenCVForUnity_TextureToMat(RawTextureDataHandle.AddrOfPinnedObject(), mat.nativeObj, (int)texture2D.format, flipAfter, flipCode);
                RawTextureDataHandle.Free();
            }
            else
            {
                GCHandle RawTextureDataHandle = GCHandle.Alloc(texture2D.GetRawTextureData(), GCHandleType.Pinned);
                OpenCVForUnity_ByteArrayToMatData(RawTextureDataHandle.AddrOfPinnedObject(), mat.nativeObj);
                RawTextureDataHandle.Free();
                if (flipAfter)
                {
                    Core.flip(mat, mat, flipCode);
                }
            }
#endif

        }

#if !OPENCV_DONT_USE_WEBCAMTEXTURE_API

        /**
        * Converts Unity WebCamTexture to OpenCV Mat.
        * <p>
        * <br>This method converts the Unity WebCamTexture image to the OpenCV Mat.
        * <br>The Mat object must have the same size as the WebCamTexture (width * height).
        * <br>The Mat object must have the types 'CV_8UC4' (RGBA) , 'CV_8UC3' (RGB) or 'CV_8UC1' (GRAY).
        * 
        * @param webcamTexture a WebCamTexture object.
        * @param mat the Mat object must have the same size as the WebCamTexture (width * height).
        * The Mat object must have the types 'CV_8UC4' (RGBA) , 'CV_8UC3' (RGB) or 'CV_8UC1' (GRAY).
        * @param flipAfter if true, the mat is fliped after converting.
        * @param flipCode a flag to specify how to flip the array; 0 means flipping around the x-axis and positive value (for example, 1) means flipping around y-axis. Negative value (for example, -1) means flipping around both axes.
        */
        public static void webCamTextureToMat(WebCamTexture webCamTexture, Mat mat, bool flipAfter = true, int flipCode = 0)
        {
            webCamTextureToMat(webCamTexture, mat, null, flipAfter, flipCode);
        }

        /**
        * Converts Unity WebCamTexture to OpenCV Mat.
        * <p>
        * <br>This method converts the Unity WebCamTexture image to the OpenCV Mat.
        * <br>The Mat object must have the same size as the WebCamTexture (width * height).
        * <br>The Mat object must have the types 'CV_8UC4' (RGBA) , 'CV_8UC3' (RGB) or 'CV_8UC1' (GRAY).
        * 
        * @param webcamTexture a WebCamTexture object.
        * @param mat the Mat object must have the same size as the WebCamTexture' (width * height).
        * The Mat object must have the types 'CV_8UC4' (RGBA) , 'CV_8UC3' (RGB) or 'CV_8UC1' (GRAY).
        * @param bufferColors the optional array to receive pixel data.
        * You can optionally pass in an array of Color32s to use in colors to avoid allocating new memory each frame.
        * The array needs to be initialized to a length matching width * height of the texture. (http://docs.unity3d.com/ScriptReference/WebCamTexture.GetPixels32.html)
        * @param flipAfter if true, the mat is fliped after converting.
        * @param flipCode a flag to specify how to flip the array; 0 means flipping around the x-axis and positive value (for example, 1) means flipping around y-axis. Negative value (for example, -1) means flipping around both axes.
        */
        public static void webCamTextureToMat(WebCamTexture webCamTexture, Mat mat, Color32[] pixels32Buffer, bool flipAfter = true, int flipCode = 0)
        {
            if (webCamTexture == null)
                throw new ArgumentNullException("webCamTexture");

            if (mat == null)
                throw new ArgumentNullException("mat");
            if (mat != null)
                mat.ThrowIfDisposed();

            if (mat.cols() != webCamTexture.width || mat.rows() != webCamTexture.height)
                throw new ArgumentException("The Mat object must have the same size.");

            GCHandle pixels32Handle;
            if (pixels32Buffer == null)
            {

                Color32[] colors = webCamTexture.GetPixels32();

                pixels32Handle = GCHandle.Alloc(colors, GCHandleType.Pinned);
            }
            else
            {
                webCamTexture.GetPixels32(pixels32Buffer);

                pixels32Handle = GCHandle.Alloc(pixels32Buffer, GCHandleType.Pinned);
            }

            OpenCVForUnity_TextureToMat(pixels32Handle.AddrOfPinnedObject(), mat.nativeObj, (int)TextureFormat.RGBA32, flipAfter, flipCode);

            pixels32Handle.Free();
        }

#endif

        /**
        * Converts Texture to Texture2D.
        * <p>
        * <br>This method converts the Texture image to the Texture2D image.
        * <br>The texture and texture2D need to be the same size.
        * <br>The texture2D's TextureFormat needs to be RGBA32, ARGB32, RGB24, RGBAFloat or RGBAHalf.
        * 
        * @param texture a texture object.
        * @param texture2D a texture2D object.
        */
        public static void textureToTexture2D(Texture texture, Texture2D texture2D)
        {
            if (texture == null)
                throw new ArgumentNullException("texture");

            if (texture2D == null)
                throw new ArgumentNullException("texture2D");

            if (texture.width != texture2D.width || texture.height != texture2D.height)
                throw new ArgumentException("texture and texture2D need to be the same size.");

            RenderTexture prevRT = RenderTexture.active;

            if (texture is RenderTexture)
            {
                RenderTexture.active = (RenderTexture)texture;
                texture2D.ReadPixels(new UnityEngine.Rect(0f, 0f, texture.width, texture.height), 0, 0, false);
                texture2D.Apply(false, false);
            }
            else
            {
                RenderTexture tempRT = RenderTexture.GetTemporary(texture.width, texture.height, 0, RenderTextureFormat.ARGB32);
                Graphics.Blit(texture, tempRT);

                RenderTexture.active = tempRT;
                texture2D.ReadPixels(new UnityEngine.Rect(0f, 0f, texture.width, texture.height), 0, 0, false);
                texture2D.Apply(false, false);
                RenderTexture.ReleaseTemporary(tempRT);
            }

            RenderTexture.active = prevRT;
        }

        /**
        * Gets the readable path of a file in the "StreamingAssets" folder.
        * <p>
        * <br>Set a relative file path from the starting point of the "StreamingAssets" folder. e.g. "foobar.txt" or "hogehoge/foobar.txt".
        * <br>[Android] The target file that exists in the "StreamingAssets" folder is copied into the folder of the Application.persistentDataPath. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * <br>[WebGL] If the target file has not yet been copied to WebGL's virtual filesystem, you need to use getFilePathAsync() at first.
        * 
        * @param filepath a relative file path starting from "StreamingAssets" folder.
        * @param refresh [Android] If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied.
        * @param timeout [Android 2017.1+] Sets UnityWebRequest to attempt to abort after the number of seconds in timeout has passed. No timeout is applied when timeout is set to 0 and this property defaults to 0. 
        * @return returns a readable file path in case of success and returns empty in case of error.
        */
        public static string getFilePath(string filepath, bool refresh = false, int timeout = 0)
        {
            if (filepath == null)
                filepath = string.Empty;

            filepath = filepath.TrimStart(chTrims);

            if (string.IsNullOrEmpty(filepath) || string.IsNullOrEmpty(Path.GetExtension(filepath)))
                return String.Empty;

#if UNITY_ANDROID && !UNITY_EDITOR
            string srcPath = Path.Combine(Application.streamingAssetsPath, filepath);
            string destPath = Path.Combine(Application.persistentDataPath, "opencvforunity");
            destPath = Path.Combine(destPath, filepath);

            if (!refresh && File.Exists(destPath))
                return destPath;

#if UNITY_2017_1_OR_NEWER
            using (UnityEngine.Networking.UnityWebRequest request = UnityEngine.Networking.UnityWebRequest.Get(srcPath))
            {
                request.timeout = timeout;

#if UNITY_2018_2_OR_NEWER
                request.SendWebRequest ();
#else
                request.Send();
#endif

                while (!request.isDone) {; }

#if UNITY_2020_2_OR_NEWER
                if (request.result == UnityEngine.Networking.UnityWebRequest.Result.ProtocolError ||
                    request.result == UnityEngine.Networking.UnityWebRequest.Result.ConnectionError ||
                    request.result == UnityEngine.Networking.UnityWebRequest.Result.DataProcessingError)
                {
#elif UNITY_2017_1_OR_NEWER
                if (request.isHttpError || request.isNetworkError) 
                {
#else
                if (request.isError)
                {
#endif
                    Debug.LogWarning(request.error);
                    Debug.LogWarning(request.responseCode);
                    return String.Empty;
                }

                //create Directory
                String dirPath = Path.GetDirectoryName(destPath);
                if (!Directory.Exists(dirPath))
                    Directory.CreateDirectory(dirPath);

                File.WriteAllBytes(destPath, request.downloadHandler.data);
            }
#else // UNITY_2017_1_OR_NEWER
            using (WWW request = new WWW(srcPath))
            {
                while (!request.isDone) {; }

                if (!string.IsNullOrEmpty(request.error))
                {
                    Debug.LogWarning(request.error);
                    return String.Empty;
                }

                //create Directory
                String dirPath = Path.GetDirectoryName(destPath);
                if (!Directory.Exists(dirPath))
                    Directory.CreateDirectory(dirPath);

                File.WriteAllBytes(destPath, request.bytes);
            }
#endif // UNITY_2017_1_OR_NEWER
            return destPath;
#elif UNITY_WEBGL && !UNITY_EDITOR
            string destPath = Path.Combine(Path.DirectorySeparatorChar.ToString(), "opencvforunity");
            destPath = Path.Combine(destPath, filepath);

            if (File.Exists(destPath))
            {
                return destPath;
            }
            else
            {
                return String.Empty;
            }
#else // UNITY_ANDROID && !UNITY_EDITOR
            string destPath = Path.Combine(Application.streamingAssetsPath, filepath);

            if (File.Exists(destPath))
            {
                return destPath;
            }
            else
            {
                return String.Empty;
            }
#endif // UNITY_ANDROID && !UNITY_EDITOR
        }

        /**
        * Gets the multiple readable paths of files in the "StreamingAssets" folder.
        * <p>
        * <br>Set a relative file path from the starting point of the "StreamingAssets" folder. e.g. "foobar.txt" or "hogehoge/foobar.txt".
        * <br>[Android] The target file that exists in the "StreamingAssets" folder is copied into the folder of the Application.persistentDataPath. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * <br>[WebGL] If the target file has not yet been copied to WebGL's virtual filesystem, you need to use getFilePathAsync() at first.
        * 
        * @param filepaths a list of relative file paths starting from the "StreamingAssets" folder.
        * @param refresh [Android] If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied.
        * @param timeout [Android 2017.1+] Sets UnityWebRequest to attempt to abort after the number of seconds in timeout has passed. No timeout is applied when timeout is set to 0 and this property defaults to 0. 
        * @return returns a list of readable file paths. Returns a readable file path in case of success and returns empty in case of error.
        */
        public static List<string> getMultipleFilePaths(IList<string> filepaths, bool refresh = false, int timeout = 0)
        {
            if (filepaths == null)
                throw new ArgumentNullException("filepaths");

            List<string> result = new List<string>();

            for (int i = 0; i < filepaths.Count; i++)
            {
                result.Add(getFilePath(filepaths[i], refresh, timeout));
            }

            return result;
        }

        /**
        * Gets the readable path of a file in the "StreamingAssets" folder by using coroutines.
        * <p>
        * <br>Set a relative file path from the starting point of the "StreamingAssets" folder.  e.g. "foobar.txt" or "hogehoge/foobar.txt".
        * <br>[Android] The target file that exists in the "StreamingAssets" folder is copied into the folder of the Application.persistentDataPath. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * <br>[WebGL] The target file in the "StreamingAssets" folder is copied to the WebGL's virtual filesystem. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * 
        * @param filepath a relative file path starting from the "StreamingAssets" folder.
        * @param completed a callback method that is called when the process is completed. Returns a readable file path in case of success and returns empty in case of error.
        * @param refresh [Android][WebGL] If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied.
        * @param timeout [Android 2017.1+][WebGL] Sets UnityWebRequest to attempt to abort after the number of seconds in timeout has passed. No timeout is applied when timeout is set to 0 and this property defaults to 0. 
        * @return returns an IEnumerator object. Yielding the IEnumerator inside a coroutine will cause the coroutine to pause until the UnityWebRequest encounters a system error or finishes communicating.
        */
        public static IEnumerator getFilePathAsync(string filepath, Action<string> completed, bool refresh = false, int timeout = 0)
        {
            return getFilePathAsync(filepath, completed, null, null, refresh, timeout);
        }

        /**
        * Gets the readable path of a file in the "StreamingAssets" folder by using coroutines.
        * <p>
        * <br>Set a relative file path from the starting point of the "StreamingAssets" folder.  e.g. "foobar.txt" or "hogehoge/foobar.txt".
        * <br>[Android] The target file that exists in the "StreamingAssets" folder is copied into the folder of the Application.persistentDataPath. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * <br>[WebGL] The target file in the "StreamingAssets" folder is copied to the WebGL's virtual filesystem. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * 
        * @param filepath a relative file path starting from the "StreamingAssets" folder.
        * @param completed a callback method that is called when the process is completed. Returns a readable file path in case of success and returns empty in case of error.
        * @param progressChanged a callback method that is called when the process is the progress. Returns the file path and a progress value (0.0 to 1.0).
        * @param refresh [Android][WebGL] If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied.
        * @param timeout [Android 2017.1+][WebGL] Sets UnityWebRequest to attempt to abort after the number of seconds in timeout has passed. No timeout is applied when timeout is set to 0 and this property defaults to 0. 
        * @return returns an IEnumerator object. Yielding the IEnumerator inside a coroutine will cause the coroutine to pause until the UnityWebRequest encounters a system error or finishes communicating.
        */
        public static IEnumerator getFilePathAsync(string filepath, Action<string> completed, Action<string, float> progressChanged, bool refresh = false, int timeout = 0)
        {
            return getFilePathAsync(filepath, completed, progressChanged, null, refresh, timeout);
        }

        /**
        * Gets the readable path of a file in the "StreamingAssets" folder by using coroutines.
        * <p>
        * <br>Set a relative file path from the starting point of the "StreamingAssets" folder.  e.g. "foobar.txt" or "hogehoge/foobar.txt".
        * <br>[Android] The target file that exists in the "StreamingAssets" folder is copied into the folder of the Application.persistentDataPath. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * <br>[WebGL] The target file in the "StreamingAssets" folder is copied to the WebGL's virtual filesystem. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * 
        * @param filepath a relative file path starting from the "StreamingAssets" folder.
        * @param completed a callback method that is called when the process is completed. Returns a readable file path in case of success and returns empty in case of error.
        * @param progressChanged a callback method that is called when the process is the progress. Returns the file path and a progress value (0.0 to 1.0).
        * @param errorOccurred a callback method that is called when the process is error occurred. Returns the file path and an error string and an error response code.
        * @param refresh [Android][WebGL] If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied.
        * @param timeout [Android 2017.1+][WebGL] Sets UnityWebRequest to attempt to abort after the number of seconds in timeout has passed. No timeout is applied when timeout is set to 0 and this property defaults to 0. 
        * @return returns an IEnumerator object. Yielding the IEnumerator inside a coroutine will cause the coroutine to pause until the UnityWebRequest encounters a system error or finishes communicating.
        */
        public static IEnumerator getFilePathAsync(string filepath, Action<string> completed, Action<string, float> progressChanged, Action<string, string, long> errorOccurred, bool refresh = false, int timeout = 0)
        {
            if (filepath == null)
                filepath = string.Empty;

            filepath = filepath.TrimStart(chTrims);

            if (string.IsNullOrEmpty(filepath) || string.IsNullOrEmpty(Path.GetExtension(filepath)))
            {
                if (progressChanged != null)
                    progressChanged(filepath, 0);
                yield return null;
                if (progressChanged != null)
                    progressChanged(filepath, 1);

                if (errorOccurred != null)
                {
                    errorOccurred(filepath, "Invalid file path.", 0);
                }
                else
                {
                    if (completed != null)
                        completed(String.Empty);
                }
                yield break;
            }

#if (UNITY_ANDROID || UNITY_WEBGL) && !UNITY_EDITOR
            string srcPath = Path.Combine(Application.streamingAssetsPath, filepath);
#if UNITY_ANDROID
            string destPath = Path.Combine(Application.persistentDataPath, "opencvforunity");
#else
            string destPath = Path.Combine(Path.DirectorySeparatorChar.ToString(), "opencvforunity");
#endif
            destPath = Path.Combine(destPath, filepath);

            if (!refresh && File.Exists(destPath))
            {
                if (progressChanged != null)
                    progressChanged(filepath, 0);
                yield return null;
                if (progressChanged != null)
                    progressChanged(filepath, 1);
                if (completed != null)
                    completed(destPath);
            }
            else
            {

#if UNITY_WEBGL || (UNITY_ANDROID && UNITY_2017_1_OR_NEWER)
                using (UnityEngine.Networking.UnityWebRequest request = UnityEngine.Networking.UnityWebRequest.Get(srcPath))
                {
                    request.timeout = timeout;

#if UNITY_2018_2_OR_NEWER
                    request.SendWebRequest ();
#else
                    request.Send();
#endif

                    while (!request.isDone)
                    {

                        if (progressChanged != null)
                            progressChanged(filepath, request.downloadProgress);

                        yield return null;
                    }

                    if (progressChanged != null)
                        progressChanged(filepath, request.downloadProgress);

#if UNITY_2020_2_OR_NEWER
                if (request.result == UnityEngine.Networking.UnityWebRequest.Result.ProtocolError ||
                    request.result == UnityEngine.Networking.UnityWebRequest.Result.ConnectionError ||
                    request.result == UnityEngine.Networking.UnityWebRequest.Result.DataProcessingError)
                {
#elif UNITY_2017_1_OR_NEWER
                if (request.isHttpError || request.isNetworkError) 
                {
#else
                if (request.isError)
                {
#endif
                        Debug.LogWarning(request.error);
                        Debug.LogWarning(request.responseCode);

                        if (errorOccurred != null)
                        {
                            errorOccurred(filepath, request.error, request.responseCode);
                        }
                        else
                        {
                            if (completed != null)
                                completed(String.Empty);
                        }
                        yield break;
                    }

                    //create Directory
                    String dirPath = Path.GetDirectoryName(destPath);
                    if (!Directory.Exists(dirPath))
                        Directory.CreateDirectory(dirPath);

                    File.WriteAllBytes(destPath, request.downloadHandler.data);
                }
#else // UNITY_WEBGL || (UNITY_ANDROID && UNITY_2017_1_OR_NEWER)
                using (WWW request = new WWW(srcPath))
                {

                    while (!request.isDone)
                    {
                        if (progressChanged != null)
                            progressChanged(filepath, request.progress);

                        yield return null;
                    }

                    if (progressChanged != null)
                        progressChanged(filepath, request.progress);

                    if (!string.IsNullOrEmpty(request.error))
                    {
                        Debug.LogWarning(request.error);

                        if (errorOccurred != null)
                        {
                            errorOccurred(filepath, request.error, 0);
                        }
                        else
                        {
                            if (completed != null)
                                completed(String.Empty);
                        }
                        yield break;
                    }

                    //create Directory
                    String dirPath = Path.GetDirectoryName(destPath);
                    if (!Directory.Exists(dirPath))
                        Directory.CreateDirectory(dirPath);

                    File.WriteAllBytes(destPath, request.bytes);
                }
#endif // UNITY_WEBGL || (UNITY_ANDROID && UNITY_2017_1_OR_NEWER)
                if (completed != null)
                    completed(destPath);
            }
#else // (UNITY_ANDROID || UNITY_WEBGL) && !UNITY_EDITOR
            string destPath = Path.Combine(Application.streamingAssetsPath, filepath);

            if (progressChanged != null)
                progressChanged(filepath, 0);
            yield return null;
            if (progressChanged != null)
                progressChanged(filepath, 1);

            if (File.Exists(destPath))
            {
                if (completed != null)
                    completed(destPath);
            }
            else
            {
                if (errorOccurred != null)
                {
                    errorOccurred(filepath, "File does not exist.", 0);
                }
                else
                {
                    if (completed != null)
                        completed(String.Empty);
                }
            }
#endif // (UNITY_ANDROID || UNITY_WEBGL) && !UNITY_EDITOR

            yield break;
        }

        /**
        * Gets the multiple readable paths of files in the "StreamingAssets" folder by using coroutines.
        * <p>
        * <br>Set a relative file path from the starting point of the "StreamingAssets" folder.  e.g. "foobar.txt" or "hogehoge/foobar.txt".
        * <br>[Android] The target file that exists in the "StreamingAssets" folder is copied into the folder of the Application.persistentDataPath. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * <br>[WebGL] The target file in the "StreamingAssets" folder is copied to the WebGL's virtual filesystem. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * 
        * @param filepaths a list of relative file paths starting from the "StreamingAssets" folder.
        * @param allCompleted a callback method that is called when all processes are completed. Returns a list of file paths. Returns a readable file path in case of success and returns empty in case of error.
        * @param refresh [Android][WebGL] If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied.
        * @param timeout [Android 2017.1+][WebGL] Sets UnityWebRequest to attempt to abort after the number of seconds in timeout has passed. No timeout is applied when timeout is set to 0 and this property defaults to 0. 
        * @return returns an IEnumerator object. Yielding the IEnumerator inside a coroutine will cause the coroutine to pause until the UnityWebRequest encounters a system error or finishes communicating.
        */
        public static IEnumerator getMultipleFilePathsAsync(IList<string> filepaths, Action<List<string>> allCompleted, bool refresh = false, int timeout = 0)
        {
            return getMultipleFilePathsAsync(filepaths, allCompleted, null, null, null, refresh, timeout);
        }

        /**
        * Gets the multiple readable paths of files in the "StreamingAssets" folder by using coroutines.
        * <p>
        * <br>Set a relative file path from the starting point of the "StreamingAssets" folder.  e.g. "foobar.txt" or "hogehoge/foobar.txt".
        * <br>[Android] The target file that exists in the "StreamingAssets" folder is copied into the folder of the Application.persistentDataPath. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * <br>[WebGL] The target file in the "StreamingAssets" folder is copied to the WebGL's virtual filesystem. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * 
        * @param filepaths a list of relative file paths starting from the "StreamingAssets" folder.
        * @param allCompleted a callback method that is called when all processes are completed. Returns a list of file paths. Returns a readable file path in case of success and returns empty in case of error.
        * @param completed a callback method that is called when one process is completed. Returns a readable file path in case of success and returns empty in case of error.
        * @param refresh [Android][WebGL] If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied.
        * @param timeout [Android 2017.1+][WebGL] Sets UnityWebRequest to attempt to abort after the number of seconds in timeout has passed. No timeout is applied when timeout is set to 0 and this property defaults to 0. 
        * @return returns an IEnumerator object. Yielding the IEnumerator inside a coroutine will cause the coroutine to pause until the UnityWebRequest encounters a system error or finishes communicating.
        */
        public static IEnumerator getMultipleFilePathsAsync(IList<string> filepaths, Action<List<string>> allCompleted, Action<string> completed, bool refresh = false, int timeout = 0)
        {
            return getMultipleFilePathsAsync(filepaths, allCompleted, completed, null, null, refresh, timeout);
        }

        /**
        * Gets the multiple readable paths of files in the "StreamingAssets" folder by using coroutines.
        * <p>
        * <br>Set a relative file path from the starting point of the "StreamingAssets" folder.  e.g. "foobar.txt" or "hogehoge/foobar.txt".
        * <br>[Android] The target file that exists in the "StreamingAssets" folder is copied into the folder of the Application.persistentDataPath. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * <br>[WebGL] The target file in the "StreamingAssets" folder is copied to the WebGL's virtual filesystem. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * 
        * @param filepaths a list of relative file paths starting from the "StreamingAssets" folder.
        * @param allCompleted a callback method that is called when all processes are completed. Returns a list of file paths. Returns a readable file path in case of success and returns empty in case of error.
        * @param completed a callback method that is called when one process is completed. Returns a readable file path in case of success and returns empty in case of error.
        * @param progressChanged a callback method that is called when one process is the progress. Returns the file path and a progress value (0.0 to 1.0).
        * @param timeout [Android 2017.1+][WebGL] Sets UnityWebRequest to attempt to abort after the number of seconds in timeout has passed. No timeout is applied when timeout is set to 0 and this property defaults to 0. 
        * @return returns an IEnumerator object. Yielding the IEnumerator inside a coroutine will cause the coroutine to pause until the UnityWebRequest encounters a system error or finishes communicating.
        */
        public static IEnumerator getMultipleFilePathsAsync(IList<string> filepaths, Action<List<string>> allCompleted, Action<string> completed, Action<string, float> progressChanged, bool refresh = false, int timeout = 0)
        {
            return getMultipleFilePathsAsync(filepaths, allCompleted, completed, progressChanged, null, refresh, timeout);
        }

        /**
        * Gets the multiple readable paths of files in the "StreamingAssets" folder by using coroutines.
        * <p>
        * <br>Set a relative file path from the starting point of the "StreamingAssets" folder.  e.g. "foobar.txt" or "hogehoge/foobar.txt".
        * <br>[Android] The target file that exists in the "StreamingAssets" folder is copied into the folder of the Application.persistentDataPath. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * <br>[WebGL] The target file in the "StreamingAssets" folder is copied to the WebGL's virtual filesystem. If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied. 
        * 
        * @param filepaths a list of relative file paths starting from the "StreamingAssets" folder.
        * @param allCompleted a callback method that is called when all processes are completed. Returns a list of file paths. Returns a readable file path in case of success and returns empty in case of error.
        * @param completed a callback method that is called when one process is completed. Returns a readable file path in case of success and returns empty in case of error.
        * @param progressChanged a callback method that is called when one process is the progress. Returns the file path and a progress value (0.0 to 1.0).
        * @param errorOccurred a callback method that is called when one process is error occurred. Returns the file path and an error string and an error response code.
        * @param refresh [Android][WebGL] If refresh flag is false, when the file has already been copied, the file is not copied. If refresh flag is true, the file is always copied.
        * @param timeout [Android 2017.1+][WebGL] Sets UnityWebRequest to attempt to abort after the number of seconds in timeout has passed. No timeout is applied when timeout is set to 0 and this property defaults to 0. 
        * @return returns an IEnumerator object. Yielding the IEnumerator inside a coroutine will cause the coroutine to pause until the UnityWebRequest encounters a system error or finishes communicating.
        */
        public static IEnumerator getMultipleFilePathsAsync(IList<string> filepaths, Action<List<string>> allCompleted, Action<string> completed, Action<string, float> progressChanged, Action<string, string, long> errorOccurred, bool refresh = false, int timeout = 0)
        {
            if (filepaths == null)
                throw new ArgumentNullException("filepaths");

            List<string> readableFilePaths = new List<string>();

            for (int i = 0; i < filepaths.Count; i++)
            {
                yield return getFilePathAsync(filepaths[i],
                (path) =>
                {
                    readableFilePaths.Add(path);

                    if (completed != null)
                        completed(path);
                },
                progressChanged,
                (path, error, code) =>
                {
                    readableFilePaths.Add(string.Empty);

                    if (errorOccurred != null)
                        errorOccurred(path, error, code);
                }
                , refresh, timeout);
            }

            if (allCompleted != null)
                allCompleted(readableFilePaths);
        }

        private static char[] chTrims = {
            '.',
#if UNITY_WINRT_8_1 && !UNITY_EDITOR
            '/',
            '\\'
#else
            System.IO.Path.DirectorySeparatorChar,
            System.IO.Path.AltDirectorySeparatorChar
#endif
        };

        /// <summary>
        /// if true, CvException is thrown instead of calling Debug.LogError (msg).
        /// </summary>
#pragma warning disable 0414
        private static bool throwOpenCVException = false;
#pragma warning restore 0414

        /**
        * Sets the debug mode.
        * <p>
        * <br>if debugMode is true, The error log of the Native side OpenCV will be displayed on the Unity Editor Console.However, if throwException is true, CvException is thrown instead of calling Debug.LogError (msg).
        * <br>Please use as follows.
        * <br>Utils.setDebugMode(true);
        * <br>aaa
        * <br>bbb
        * <br>ccc
        * <br>Utils.setDebugMode(false);
        * 
        * @param debugMode if true, The error log of the Native side OpenCV will be displayed on the Unity Editor Console.
        * @param throwException if true, CvException is thrown instead of calling Debug.LogError (msg).
        */
        public static void setDebugMode(bool debugMode, bool throwException = false)
        {
            OpenCVForUnity_SetDebugMode(debugMode);

            if (debugMode)
            {
                OpenCVForUnity_SetDebugLogFunc(debugLogFunc);
                //OpenCVForUnity_DebugLogTest ();
            }
            else
            {
                OpenCVForUnity_SetDebugLogFunc(null);
            }

            throwOpenCVException = throwException;
        }

        private delegate void DebugLogDelegate(string str);

        [MonoPInvokeCallback(typeof(DebugLogDelegate))]
        private static void debugLogFunc(string str)
        {
            if (throwOpenCVException)
            {
#if UNITY_2022_2_OR_NEWER && UNITY_ANDROID && ENABLE_IL2CPP
                Debug.LogError(str);
#else
                throw new CvException(str);
#endif
            }
            else
            {
                Debug.LogError(str);
            }
        }

        internal static int URShift(int number, int bits)
        {
            if (number >= 0)
                return number >> bits;
            else
                return (number >> bits) + (2 << ~bits);
        }

        internal static long URShift(long number, int bits)//TODO:@check
        {
            if (number >= 0)
                return number >> bits;
            else
                return (number >> bits) + (2 << ~bits);
        }

        internal static int HashContents<T>(this IEnumerable<T> enumerable)//TODO:@check
        {
            int hash = 0x218A9B2C;
            foreach (var item in enumerable)
            {
                int thisHash = item.GetHashCode();
                //mix up the bits.
                hash = thisHash ^ ((hash << 5) + hash);
            }
            return hash;
        }


#if (UNITY_IOS || UNITY_WEBGL) && !UNITY_EDITOR
        const string LIBNAME = "__Internal";
#else
        const string LIBNAME = "opencvforunity";
#endif

        [DllImport(LIBNAME)]
        private static extern void OpenCVForUnity_SetDebugMode([MarshalAs(UnmanagedType.U1)] bool flag);

        [DllImport(LIBNAME)]
        private static extern void OpenCVForUnity_SetDebugLogFunc(DebugLogDelegate func);

        [DllImport(LIBNAME)]
        private static extern void OpenCVForUnity_DebugLogTest();

        [DllImport(LIBNAME)]
        private static extern void OpenCVForUnity_MatToTexture(IntPtr mat, IntPtr textureColors, int textureFormat, [MarshalAs(UnmanagedType.U1)] bool flip, int flipCode, bool flipAfter);

        [DllImport(LIBNAME)]
        private static extern void OpenCVForUnity_TextureToMat(IntPtr textureColors, IntPtr Mat, int textureFormat, [MarshalAs(UnmanagedType.U1)] bool flip, int flipCode);

        [DllImport(LIBNAME)]
        private static extern void OpenCVForUnity_MatDataToByteArray(IntPtr mat, IntPtr byteArray);

        [DllImport(LIBNAME)]
        private static extern void OpenCVForUnity_ByteArrayToMatData(IntPtr byteArray, IntPtr Mat);

    }
}