使用System.Drawing解码和编码纹理

使用 Aspose.3D for .NET，开发人员使用外部图像编码器和解码器来加载纹理或将纹理保存为不同的图像格式。

使用System.Drawing实现纹理编解码器

使用以下类定义纹理编码器和纹理解码器:

using System;
using System.Collections.Generic;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
using Aspose.ThreeD.Render;
using System.Runtime.InteropServices;

namespace Aspose.ThreeD
{
    /// <summary>
    /// Uses System.Drawing for encoding/decoding textures for Aspose.3D textures.
    /// </summary>
    public class GdiPlusCodec : ITextureCodec, ITextureDecoder
    {
        class GdiPlusEncoder : ITextureEncoder
        {
            public string FileExtension { get; }
            private ImageCodecInfo encoder;
            public GdiPlusEncoder(ImageCodecInfo encoder, string ext)
            {
                this.encoder = encoder;
                FileExtension = ext;
            }

            public void Encode(TextureData texture, Stream stream)
            {
                var bmp = ToBitmap(texture);
                bmp.Save(stream, encoder, null);
            }
        }
        /// <summary>
        /// Convert <see cref="TextureData"/> to <see cref="Bitmap"/>
        /// </summary>
        /// <param name="td"></param>
        /// <returns></returns>
        public static Bitmap ToBitmap(TextureData td)
        {
            using (var map = td.MapPixels(PixelMapMode.ReadOnly, Render.PixelFormat.A8R8G8B8))
            {
                var ret = new Bitmap(td.Width, td.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
                var bits = ret.LockBits(new Rectangle(0, 0, td.Width, td.Height), ImageLockMode.WriteOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
                for (int y = 0; y < td.Height; y++)
                {
                    var srcOffset = y * map.Stride;
                    var destination = bits.Scan0 + y * bits.Stride;
                    Marshal.Copy(map.Data, srcOffset, destination, map.Stride);
                }
                ret.UnlockBits(bits);
                return ret;
            }
        }

        /// <summary>
        /// Convert <see cref="Bitmap"/> to <see cref="TextureData"/>
        /// </summary>
        /// <param name="img"></param>
        /// <param name="reverseY"></param>
        /// <returns></returns>
        public static TextureData ToTextureData(Bitmap img, bool reverseY)
        {
            var ret = new TextureData(img.Width, img.Height, Render.PixelFormat.A8R8G8B8);
            var bits = img.LockBits(new Rectangle(0, 0, img.Width, img.Height), ImageLockMode.ReadWrite, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
            using (var map = ret.MapPixels(PixelMapMode.WriteOnly))
            {
                for (int y = 0; y < map.Height; y++)
                {
                    IntPtr srcPtr = bits.Scan0;
                    if(reverseY)
                        srcPtr += (map.Height - y - 1) * bits.Stride;
                    else
                        srcPtr += y * bits.Stride;
                    var dstOffset = y * map.Stride;
                    Marshal.Copy(srcPtr, map.Data, dstOffset, map.Stride);
                }
            }
            img.UnlockBits(bits);
            return ret;
        }
        /// <summary>
        /// Decode texture from stream, return null if failed to decode.
        /// </summary>
        /// <param name="stream">Texture data source stream</param>
        /// <param name="reverseY">Flip the texture</param>
        /// <returns>Decoded texture data or null if not supported.</returns>
        public TextureData Decode(Stream stream, bool reverseY)
        {
            using (var img = (Bitmap)Image.FromStream(stream))
            {
                var ret = ToTextureData(img, reverseY);
                return ret;
            }
        }
        /// <summary>
        /// Gets supported texture decoders.
        /// </summary>
        /// <returns></returns>
        public ITextureDecoder[] GetDecoders()
        {
            return new ITextureDecoder[] { this };
        }
        /// <summary>
        /// Gets supported texture encoders. 
        /// </summary>
        /// <returns></returns>
        public ITextureEncoder[] GetEncoders()
        {
            List<ITextureEncoder> ret = new List<ITextureEncoder>();
            foreach (var encoder in ImageCodecInfo.GetImageEncoders())
            {
                if (encoder.FilenameExtension == null)
                    continue;
                var exts = encoder.FilenameExtension.Split(';');
                foreach(var fileExt in exts)
                {
                    var ext = fileExt;
                    int p = ext.IndexOf('.');
                    if (p != -1)
                        ext = ext.Substring(p + 1);
                    ret.Add(new GdiPlusEncoder(encoder, ext.ToLowerInvariant()));
                }
            }
            return ret.ToArray();
        }
    }
}

将其注册到 Aspose。3D

现在让我们将其注册到Aspsoe.3D:

    Aspose.ThreeD.Render.TextureCodec.RegisterCodec(new Aspose.ThreeD.GdiPlusCodec());

注册此编解码器后，所有System.Drawing支持的图像格式都可以在TextureData.Save中使用。