Initial commit

LibDgf.Graphics/Aqualead/Image/Conversion/PkmConverter.cs

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+using LibDgf.Aqualead.Image;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+
+namespace LibDgf.Aqualead.Image.Conversion
+{
+    public class PkmConverter : IAlImageConverter
+    {
+        public string FileExtension => ".pkm";
+
+        public void ConvertFromAl(AlImage image, Stream destStream)
+        {
+            List<byte[]> mips;
+            if (image.PixelFormat == "ETC1")
+            {
+                mips = image.Mipmaps;
+            }
+            else if (image.PixelFormat == "EC1A")
+            {
+                // Give first half of the mips
+                mips = new List<byte[]>();
+                byte[] newMip = new byte[image.Mipmaps[0].Length / 2];
+                Buffer.BlockCopy(image.Mipmaps[0], 0, newMip, 0, newMip.Length);
+                mips.Add(newMip);
+            }
+            else
+            {
+                throw new ArgumentException("Pixel format not supported.", nameof(image));
+            }
+
+            WritePkm(destStream, mips[0], image.Width, image.Height);
+        }
+
+        public void ConvertFromAlAlt(AlImage image, Stream destStream)
+        {
+            if (image.PixelFormat != "EC1A")
+                throw new ArgumentException("Pixel format does not have alternate representation.", nameof(image));
+
+            // Give second half of the mips
+            byte[] newMip = new byte[image.Mipmaps[0].Length / 2];
+            Buffer.BlockCopy(image.Mipmaps[0], newMip.Length, newMip, 0, newMip.Length);
+
+            WritePkm(destStream, newMip, image.Width, image.Height);
+        }
+
+        public bool CanConvert(string pixelFormat)
+        {
+            return pixelFormat == "EC1A" || pixelFormat == "ETC1";
+        }
+
+        public bool HasAlternativeFile(AlImage image)
+        {
+            return image.PixelFormat == "EC1A";
+        }
+
+        const ushort ETC1_RGB_NO_MIPMAPS = 0;
+
+        static void WritePkm(Stream stream, byte[] data, uint width, uint height)
+        {
+            BinaryWriter bw = new BinaryWriter(stream);
+            bw.Write("PKM 10".ToCharArray());
+            WriteBeUInt16(bw, ETC1_RGB_NO_MIPMAPS);
+            WriteBeUInt16(bw, (ushort)((width + 3) & ~3));
+            WriteBeUInt16(bw, (ushort)((height + 3) & ~3));
+            WriteBeUInt16(bw, (ushort)width);
+            WriteBeUInt16(bw, (ushort)height);
+            bw.Write(data);
+        }
+
+        static void WriteBeUInt16(BinaryWriter bw, ushort value)
+        {
+            bw.Write((byte)(value >> 8));
+            bw.Write((byte)value);
+        }
+    }
+}