TgaFileFormat decoupled from TgaImage

which allows saving another image sources and also provides simplified interface for loading TgaImage somewhere else using the same IImage interface.

tgalib-core/IImage.cs

@@ -0,0 +1,28 @@
+namespace tgalib_core;
+
+/// <summary>
+/// Abstraction of the image usable for simplified loading and saving routines.
+/// </summary>
+public interface IImage
+{
+    /// <summary>
+    /// Width of the image in pixels.
+    /// </summary>
+    int Width { get; }
+
+    /// <summary>
+    /// Height of the image in pixels.
+    /// </summary>
+    int Height { get; }
+
+    /// <summary>
+    /// Pixel access.
+    /// </summary>
+    /// <param name="x">X coordinate of a pixel within the image.</param>
+    /// <param name="y">Y coordinate of a pixel within the image. Note: TGA coordinate [0, 0] is a bottom left corner.</param>
+    /// <param name="r">Red component (8 bit).</param>
+    /// <param name="g">Green component (8 bit).</param>
+    /// <param name="b">Blue component (8 bit).</param>
+    /// <param name="a">Alpha component (8 bit).</param>
+    void GetPixelRgba(int x, int y, out int r, out int g, out int b, out int a);
+}

tgalib-core/TgaFileFormat.cs

@@ -44,7 +44,7 @@
 public static class TgaFileFormat
 {
 	// Common save routine.
-	public static void CommonSave(TgaMode curTgaMode, Stream stream, TgaImage g)
+	public static void CommonSave(TgaMode curTgaMode, Stream stream, IImage g)
 	{
 		// ReSharper disable once SwitchStatementHandlesSomeKnownEnumValuesWithDefault
 		switch (curTgaMode)
@@ -58,10 +58,10 @@ public static void CommonSave(TgaMode curTgaMode, Stream stream, TgaImage g)
 	}
 
 	// TGA RGB 24 RLE save code.
-	private static void TgaRgb24RleSave(Stream tgaFile, TgaImage image)
+	private static void TgaRgb24RleSave(Stream tgaFile, IImage image)
 	{
-		int width = image.TgaHeader.Width;
-		int height = image.TgaHeader.Height;
+		int width = image.Width;
+		int height = image.Height;
 
 		//                1| 2| 3| 4| 5| 6| 7| 8| 9|10|11|12|               13|                    14|                15|                     16|17|18		    
 		byte[] header = [ 0, 0,10, 0, 0, 0, 0, 0, 0, 0, 0, 0,(byte)(width&255),(byte)((width>>8)&255),(byte)(height&255),(byte)((height>>8)&255),24, 0];		
@@ -84,10 +84,10 @@ private static void TgaRgb24RleSave(Stream tgaFile, TgaImage image)
 	// Stops when entire image is searched or palette is full (max 256 colors)
 	// Colors which are not in palette are written as color 0 (there should be no more than 256 colors in image)
 	// Performs RLE compression
-	private static void TgaPal8RleSave(Stream tgaFile, TgaImage image)
+	private static void TgaPal8RleSave(Stream tgaFile, IImage image)
 	{
-		int width = image.TgaHeader.Width;
-		int height = image.TgaHeader.Height;
+		int width = image.Width;
+		int height = image.Height;
 		const int maxColors = 256;
 
 		//palette (BGR)
@@ -130,11 +130,11 @@ private static void TgaPal8RleSave(Stream tgaFile, TgaImage image)
 	// Seraches image for unique colors.
 	// Stops when entire image is searched or palette is full (max 256 colors)
 	//   Colors which are not in palette are written as color 0 (there should be no more than 256 colors in image)
-	private static void TgaPal8UncSave(Stream tgaFile, TgaImage image)
+	private static void TgaPal8UncSave(Stream tgaFile, IImage image)
 	{
 		//header
-		int width = image.TgaHeader.Width;
-		int height = image.TgaHeader.Height;
+		int width = image.Width;
+		int height = image.Height;
 		const int maxColors = 256;
 
 		//palette ( colors are stored as BGR in file )
@@ -172,10 +172,10 @@ private static void TgaPal8UncSave(Stream tgaFile, TgaImage image)
 	}
 
 	// TGA RGB 24 UNC save code.
-	private static void TgaRgb24UncSave(Stream tgaFile, TgaImage image)
+	private static void TgaRgb24UncSave(Stream tgaFile, IImage image)
 	{
-		int width = image.TgaHeader.Width;
-		int height = image.TgaHeader.Height;
+		int width = image.Width;
+		int height = image.Height;
 
 		//               1| 2| 3| 4| 5| 6| 7| 8| 9|10|11|12|               13|                    14|                15|                     16|17|18
 		byte[] header = [0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0,(byte)(width&255),(byte)((width>>8)&255),(byte)(height&255),(byte)((height>>8)&255),24, 0];		
@@ -185,9 +185,9 @@ private static void TgaRgb24UncSave(Stream tgaFile, TgaImage image)
 			for (int x = 0; x < width; ++x)
 			{ 
 				image.GetPixelRgba(x, y, out int r, out int g, out int b, out int a);
-				tgaFile.Write([(byte)(r & 255), (byte)(g & 255), (byte)(b & 255)]); // TODO: check if byte order is correct
+				tgaFile.Write([(byte)(r & 255), (byte)(g & 255), (byte)(b & 255)]);
 			}
 
 		tgaFile.Close();
 	}
-}
+}

tgalib-core/TgaHeader.cs

@@ -10,7 +10,7 @@ public class TgaHeader
     /// <summary>
     /// Gets or sets a length of Image ID field.
     /// </summary>
-    public byte IDLength { get; set; }
+    public byte IdLength { get; set; }
 
     /// <summary>
     /// Gets or sets a Color Map type(<see cref="ColorMapTypes"/>).
@@ -83,7 +83,7 @@ public class TgaHeader
     /// <param name="reader">A binary reader that contains TGA file. Caller must dipose the binary reader.</param>
     public TgaHeader(BinaryReader reader)
     {
-        IDLength = reader.ReadByte();
+        IdLength = reader.ReadByte();
         ColorMapType = reader.ReadByte();
         ImageType = (TgaMode)reader.ReadByte();
         ColorMapStart = reader.ReadUInt16();
@@ -104,7 +104,7 @@ public TgaHeader(BinaryReader reader)
     public override string ToString()
     {
         StringBuilder sb = new StringBuilder();
-        sb.Append($"IDLength       : {IDLength}\r\n");
+        sb.Append($"IDLength       : {IdLength}\r\n");
         sb.Append($"ColorMapType   : {ColorMapType}({ColorMapTypes.ToFormattedText(ColorMapType)})\r\n");
         sb.Append($"ImageType      : {ImageType}({ImageTypes.ToFormattedText(ImageType)})\r\n");
         sb.Append($"ColorMapStart  : {ColorMapStart}\r\n");

tgalib-core/TgaImage.cs

@@ -5,7 +5,7 @@ namespace tgalib_core
     /// <summary>
     /// Represents TGA image.
     /// </summary>
-    public class TgaImage
+    public class TgaImage : IImage
     {
         /// <summary>
         /// Use the alpha channel forcefully, if true.
@@ -72,7 +72,7 @@ private void Init(BinaryReader reader)
         {
             TgaHeader = new TgaHeader(reader);
 
-            ImageId = new byte[TgaHeader.IDLength];
+            ImageId = new byte[TgaHeader.IdLength];
             reader.Read(ImageId, 0, ImageId.Length);
             PixelFormat = DecodePixelFormat();
             imageWidth = TgaHeader.Width;