FM/Assets/Scripts/Runtime/Helper/TextureHelper.cs

using System;
using System.IO;
using Cysharp.Threading.Tasks;
using UnityEngine;

namespace ZXL.Helper
{
    public static class TextureHelper
    {
        /// <summary>
        /// 精灵图片转纹理
        /// </summary>
        /// <param name="sprite"></param>
        /// <returns></returns>
        public static Texture2D SpriteToTexture2D(Sprite sprite)
        {
            // 获取 Sprite 的纹理
            Texture2D texture = sprite.texture;
            // 创建一个新的 Texture2D 用于存储 Sprite 的图像数据
            Texture2D texture2D = new Texture2D((int)sprite.rect.width, (int)sprite.rect.height);
            // 读取 Sprite 的像素数据到新的 Texture2D
            Color[] pixels = texture.GetPixels(
                (int)sprite.rect.x,
                (int)sprite.rect.y,
                (int)sprite.rect.width,
                (int)sprite.rect.height
            );
            // 将像素数据设置到新的 Texture2D 中
            texture2D.SetPixels(pixels);
            texture2D.Apply(); // 应用更改
            return texture2D;
        }

        /// <summary>
        /// 纹理转精灵图片
        /// </summary>
        /// <param name="texture"></param>
        /// <returns></returns>
        public static Sprite SpriteFromTexture2D(Texture2D texture)
        {
            Sprite sprite = Sprite.Create(texture, new Rect(0, 0, texture.width, texture.height),
                new Vector2(0.5f, 0.5f));
            return sprite;
        }

        /// <summary>
        /// 截取相机画面并返回纹理图片
        /// </summary>
        /// <param name="camera"></param>
        /// <returns></returns>
        public static Texture2D SaveCameraToTexture(Camera camera, bool generateMipMaps = false, 
            TextureFormat textureFormat = TextureFormat.RGBA32)
        {
            if (camera == null)
            {
                Debug.LogError("Camera is null!");
                return null;
            }

            RenderTexture originalTargetTexture = camera.targetTexture;
            RenderTexture tempRenderTexture = null;
            Texture2D capturedImage = null;

            try
            {
                // 创建临时RenderTexture
                tempRenderTexture = RenderTexture.GetTemporary(
                    camera.pixelWidth, camera.pixelHeight, 24, RenderTextureFormat.Default);
        
                // 设置相机渲染到临时RenderTexture
                camera.targetTexture = tempRenderTexture;
        
                // 强制相机渲染一帧
                camera.Render();

                // 创建Texture2D
                capturedImage = new Texture2D(
                    tempRenderTexture.width, 
                    tempRenderTexture.height, 
                    textureFormat, 
                    generateMipMaps);

                // 保存当前激活的RenderTexture
                RenderTexture previousActive = RenderTexture.active;
        
                // 设置临时RenderTexture为当前激活的，以便读取像素
                RenderTexture.active = tempRenderTexture;
        
                // 读取像素并应用
                capturedImage.ReadPixels(new Rect(0, 0, tempRenderTexture.width, tempRenderTexture.height), 0, 0);
                capturedImage.Apply();
        
                // 恢复之前的RenderTexture
                RenderTexture.active = previousActive;
            }
            catch (System.Exception e)
            {
                Debug.LogError($"Error capturing camera: {e.Message}");
                if (capturedImage != null)
                {
                    UnityEngine.Object.DestroyImmediate(capturedImage);
                    capturedImage = null;
                }
            }
            finally
            {
                // 恢复相机的原始设置
                camera.targetTexture = originalTargetTexture;
        
                // 释放临时RenderTexture
                if (tempRenderTexture != null)
                {
                    RenderTexture.ReleaseTemporary(tempRenderTexture);
                    tempRenderTexture = null;
                }
            }

            return capturedImage;
        }

        /// <summary>
        /// Texture转Texture2D
        /// </summary>
        /// <param name="texture"></param>
        /// <returns></returns>
        public static Texture2D ConvertTextureToTexture2D(Texture texture)
        {
            Texture2D texture2D = new Texture2D(texture.width, texture.height, TextureFormat.RGBA32, false);
            RenderTexture currentRT = RenderTexture.active;

            // 创建一个新的 RenderTexture
            RenderTexture renderTexture = RenderTexture.GetTemporary(texture.width, texture.height, 32);
            Graphics.Blit(texture, renderTexture);

            // 将 RenderTexture 内容复制到 Texture2D
            RenderTexture.active = renderTexture;
            texture2D.ReadPixels(new Rect(0, 0, renderTexture.width, renderTexture.height), 0, 0);
            texture2D.Apply();

            // 清理
            RenderTexture.active = currentRT;
            RenderTexture.ReleaseTemporary(renderTexture);

            return texture2D;
        }

        /// <summary>
        /// 纹理图片转二进制数据
        /// </summary>
        /// <param name="texture"></param>
        /// <returns></returns>
        public static byte[] ConvertTextureToByteArray(Texture2D texture)
        {
            return texture.EncodeToPNG();
        }

        /// <summary>
        /// 二进制数据转纹理图片
        /// </summary>
        /// <param name="bytes"></param>
        /// <returns></returns>
        public static Texture2D ConvertByteArrayToTexture2D(byte[] bytes)
        {
            Texture2D texture = new Texture2D(2, 2); // 初始化一个临时的 Texture2D
            if (texture.LoadImage(bytes)) // 使用 LoadImage 来加载字节数据
            {
                return texture;
            }
            else
            {
                Debug.LogError("加载图片失败！");
                return null;
            }
        }

        public static async UniTask TransparentCaptureSystem(TransparentCaptureSystemOption option)
        {
            /*
            if (option.targetCamera == null)
            {
                throw new NullReferenceException("targetCamera is null");
                return;
            }

            async UniTask CaptureAndCrop()
            {
                // 确保尺寸有效
                ValidateSizes();

                // 创建原始截图
                await (CaptureOriginalScreenshot());

                // 裁剪图片（保留透明通道）
                CropWithTransparency();

                // 保存结果
                SaveCroppedImage();

                // 清理资源
                CleanupResources();
            }

            async UniTask CaptureOriginalScreenshot()
            {
                // 创建RenderTexture（带alpha通道）
                option._renderTexture = new RenderTexture(option.captureWidth, option.captureHeight, 32, RenderTextureFormat.ARGB32);
                option._renderTexture.Create();

                // 保存原始相机设置
                RenderTexture originalRT = option.targetCamera.targetTexture;
                CameraClearFlags originalClearFlags = option.targetCamera.clearFlags;
                Color originalBackgroundColor = option.targetCamera.backgroundColor;

                // 配置相机透明背景
                option.targetCamera.targetTexture = option._renderTexture;
                option.targetCamera.clearFlags = CameraClearFlags.SolidColor;
                option.targetCamera.backgroundColor = option.preserveAlpha ? option.backgroundColor : Color.black;

                // 渲染相机
                option.targetCamera.Render();

                // 创建Texture2D（带alpha通道）
                option._originalTexture = new Texture2D(option.captureWidth, option.captureHeight,
                    option.preserveAlpha ? TextureFormat.ARGB32 : TextureFormat.RGB24,
                    false);

                // 读取像素（包括alpha）
                RenderTexture.active = option._renderTexture;
                option._originalTexture.ReadPixels(new Rect(0, 0, option.captureWidth, option.captureHeight), 0, 0);
                option._originalTexture.Apply();
                RenderTexture.active = null;

                // 恢复相机设置
                option.targetCamera.targetTexture = originalRT;
                option.targetCamera.clearFlags = originalClearFlags;
                option.targetCamera.backgroundColor = originalBackgroundColor;
            }

            string fullPath;

            void CropWithTransparency()
            {
                if (option._originalTexture == null)
                {
                    Debug.LogError("原始截图未创建!");
                    return;
                }

                // 计算裁剪起始位置
                int startX = Mathf.FloorToInt((option._originalTexture.width - option.cropWidth) * option.cropOffset.x);
                int startY = Mathf.FloorToInt((option._originalTexture.height - option.cropHeight) * option.cropOffset.y);

                // 确保在有效范围内
                startX = Mathf.Clamp(startX, 0, option._originalTexture.width - option.cropWidth);
                startY = Mathf.Clamp(startY, 0, option._originalTexture.height - option.cropHeight);

                // 创建裁剪后的纹理（带alpha通道）
                option._croppedTexture = new Texture2D(option.cropWidth, option.cropHeight,
                    option.preserveAlpha ? TextureFormat.ARGB32 : TextureFormat.RGB24,
                    false);

                // 获取原始纹理的像素数据（包括alpha）
                Color[] pixels = option._originalTexture.GetPixels(startX, startY, option.cropWidth, option.cropHeight);

                // 设置到裁剪纹理
                option._croppedTexture.SetPixels(pixels);
                option._croppedTexture.Apply();
            }

            void SaveCroppedImage()
            {
                if (option._croppedTexture == null)
                {
                    Debug.LogError("裁剪后的纹理未创建!");
                    return;
                }

                // 创建保存目录
                string folderPath = option.saveFolder;
                if (!Directory.Exists(folderPath)) Directory.CreateDirectory(folderPath);

                // 生成文件名
                string timestamp = DateTime.Now.ToString("yyyyMMdd_HHmmss");
                string extension = option.saveAsPNG ? ".png" : ".jpg";
                string fileName;
                if (string.IsNullOrEmpty(option.onlyFileName))
                    fileName = $"{option.fileNamePrefix}_{option.cropWidth}x{option.cropHeight}_{timestamp}{extension}";
                else
                    fileName = $"{option.onlyFileName}{extension}";

                fullPath = Path.Combine(folderPath, fileName);

                // 编码保存
                byte[] imageBytes;

                if (option.saveAsPNG)
                {
                    imageBytes = option._croppedTexture.EncodeToPNG();
                }
                else
                {
                    // JPG不支持透明通道，强制去除alpha
                    Texture2D jpgTexture =
                        new Texture2D(option._croppedTexture.width, option._croppedTexture.height, TextureFormat.RGB24, false);
                    jpgTexture.SetPixels(option._croppedTexture.GetPixels());
                    jpgTexture.Apply();
                    imageBytes = jpgTexture.EncodeToJPG(90);
                }

                File.WriteAllBytes(fullPath, imageBytes);

                // 验证透明度
                if (option.saveAsPNG && option.preserveAlpha)
                {
                    // 检查左上角像素是否透明
                    Color topLeft = option._croppedTexture.GetPixel(0, option._croppedTexture.height - 1);
                    Debug.Log($"保存的图片左上角透明度: {topLeft.a}");

                    // 检查中心像素是否透明
                    Color center = option._croppedTexture.GetPixel(option._croppedTexture.width / 2, option._croppedTexture.height / 2);
                    Debug.Log($"保存的图片中心透明度: {center.a}");
                }

                Debug.Log($"截图已保存至: {fullPath}");

#if UNITY_EDITOR
                UnityEditor.EditorUtility.RevealInFinder(fullPath);
#endif
            }

            void ValidateSizes()
            {
                // 确保原始尺寸有效
                option.captureWidth = Mathf.Clamp(option.captureWidth, 32, SystemInfo.maxTextureSize);
                option. captureHeight = Mathf.Clamp(option.captureHeight, 32, SystemInfo.maxTextureSize);

                // 确保裁剪尺寸有效
                option.cropWidth = Mathf.Clamp(option.cropWidth, 32,option. captureWidth);
                option.cropHeight = Mathf.Clamp(option.cropHeight, 32, option.captureHeight);

                // 确保偏移量在0-1范围
                option.cropOffset.x = Mathf.Clamp01(option.cropOffset.x);
                option.cropOffset.y = Mathf.Clamp01(option.cropOffset.y);
            }

            void CleanupResources()
            {
                if (option._renderTexture != null)
                {
                    Destroy(_renderTexture);
                    option._renderTexture = null;
                }

                if (option._originalTexture != null)
                {
                    Destroy(_originalTexture);
                    option._originalTexture = null;
                }

                // 保留裁剪纹理用于预览或后续使用
                // 如果不再需要，可以取消注释下面一行
                Destroy(_croppedTexture);
            }

            UniTask.Run(CaptureAndCrop);
            */
        }
    }

    public class TransparentCaptureSystemOption
    {
        // 相机设置
        public Camera targetCamera;
        public KeyCode captureKey = KeyCode.C;

        // 原始截图设置
        public int captureWidth = 1080;
        public int captureHeight = 1920;

        // 裁剪设置
        public int cropWidth = 800;
        public int cropHeight = 300;
        public Vector2 cropOffset = Vector2.zero; // 裁剪偏移量 (0-1)

        // 透明通道
        public bool preserveAlpha = true;
        public Color backgroundColor = new Color(0, 0, 0, 0); // 透明背景

        // 输出设置
        public string saveFolder = "Screenshots";
        public string fileNamePrefix = "Screenshot";
        public bool saveAsPNG = true;
        public string onlyFileName = "";

        public RenderTexture _renderTexture;
        public Texture2D _originalTexture;
        public Texture2D _croppedTexture;
    }
}