From 21b018298c4fc75a02a65b57b77451debb79c4db Mon Sep 17 00:00:00 2001
From: Jarrod Doyle <thejarroddoyle@gmail.com>
Date: Mon, 12 Aug 2024 19:02:20 +0100
Subject: [PATCH] Use family palettes for PCX textures

---
 project/code/TMV/TextureLoader.Pcx.cs | 77 ++++++++++++++++-----------
 1 file changed, 46 insertions(+), 31 deletions(-)

diff --git a/project/code/TMV/TextureLoader.Pcx.cs b/project/code/TMV/TextureLoader.Pcx.cs
index 34f490a..449bd9d 100644
--- a/project/code/TMV/TextureLoader.Pcx.cs
+++ b/project/code/TMV/TextureLoader.Pcx.cs
@@ -1,20 +1,55 @@
 using System.IO;
 using System.Linq;
-using System.Numerics;
 using System.Text;
+using Godot;
 
 namespace KeepersCompound.TMV;
 
 public partial class TextureLoader
 {
     // TODO: Support more types of PCX just in case
-    // TODO: We need to load the palette from an external file!!!
 
     // References:
     // - https://www.fileformat.info/format/pcx/egff.htm
     // - http://www.fysnet.net/pcxfile.htm
-    private static Godot.ImageTexture LoadPcx(string path)
+    private static ImageTexture LoadPcx(string path)
     {
+        static Color[] LoadFamilyPalette(string famPath)
+        {
+            var numColors = 256;
+            var bytesPerColor = 3;
+            var paletteSize = numColors * bytesPerColor;
+            var palette = new Color[numColors];
+
+            var options = new EnumerationOptions
+            {
+                MatchCasing = MatchCasing.CaseInsensitive
+            };
+            var paths = Directory.GetFiles(famPath, "full.pcx", options);
+            if (paths.Length != 0)
+            {
+                var palettePath = paths[0];
+                using MemoryStream stream = new(File.ReadAllBytes(palettePath));
+                using BinaryReader reader = new(stream, Encoding.UTF8, false);
+                stream.Seek(-paletteSize, SeekOrigin.End);
+
+                for (var i = 0; i < numColors; i++)
+                {
+                    var r = reader.ReadByte() / 255.0f;
+                    var g = reader.ReadByte() / 255.0f;
+                    var b = reader.ReadByte() / 255.0f;
+                    palette[i] = new Color(r, g, b);
+                }
+            }
+
+            return palette;
+        }
+
+        static System.Numerics.Vector2 ReadVec2(BinaryReader reader)
+        {
+            return new(reader.ReadUInt16(), reader.ReadUInt16());
+        }
+
         using MemoryStream stream = new(File.ReadAllBytes(path));
         using BinaryReader reader = new(stream, Encoding.UTF8, false);
 
@@ -23,17 +58,16 @@ public partial class TextureLoader
         var version = reader.ReadByte();
         var compression = reader.ReadByte();
         var bytesPerPixel = reader.ReadByte();
-        var min = new Vector2(reader.ReadUInt16(), reader.ReadUInt16());
-        var max = new Vector2(reader.ReadUInt16(), reader.ReadUInt16());
-        var dpi = new Vector2(reader.ReadUInt16(), reader.ReadUInt16());
+        var min = ReadVec2(reader);
+        var max = ReadVec2(reader);
+        var dpi = ReadVec2(reader);
         var headerPalette = reader.ReadBytes(48);
         reader.ReadByte();
         var numPlanes = reader.ReadByte();
         var bytesPerRow = reader.ReadUInt16();
         var paletteMode = reader.ReadUInt16();
-        var dpiSrc = new Vector2(reader.ReadUInt16(), reader.ReadUInt16());
+        var dpiSrc = ReadVec2(reader);
         reader.ReadBytes(54);
-        var dataOffset = stream.Position;
 
         // Validation
         if (tag != 0x0A)
@@ -54,13 +88,12 @@ public partial class TextureLoader
             throw new System.Exception("Unsupported bpp/plane format");
         }
 
-        var palette = LoadPcxPalette(reader);
+        var palette = LoadFamilyPalette(path.GetBaseDir());
 
-        // Read pixels
-        stream.Seek(dataOffset, SeekOrigin.Begin);
+        // Read run length encoded pixel Data
         var width = (int)(max.X - min.X + 1);
         var height = (int)(max.Y - min.Y + 1);
-        var image = Godot.Image.Create(width, height, false, Godot.Image.Format.Rgba8);
+        var image = Image.Create(width, height, false, Image.Format.Rgba8);
         for (var y = 0; y < height; y++)
         {
             var x = 0;
@@ -85,24 +118,6 @@ public partial class TextureLoader
             }
         }
 
-        return Godot.ImageTexture.CreateFromImage(image);
-    }
-
-    private static Godot.Color[] LoadPcxPalette(BinaryReader reader)
-    {
-        var numColors = 256;
-        var bytesPerColor = 3;
-        var paletteSize = numColors * bytesPerColor;
-        reader.BaseStream.Seek(-paletteSize, SeekOrigin.End);
-
-        var palette = new Godot.Color[numColors];
-        for (var i = 0; i < numColors; i++)
-        {
-            var r = reader.ReadByte() / 255.0f;
-            var g = reader.ReadByte() / 255.0f;
-            var b = reader.ReadByte() / 255.0f;
-            palette[i] = new Godot.Color(r, g, b);
-        }
-        return palette;
+        return ImageTexture.CreateFromImage(image);
     }
 }
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