Decal rendering #5: Render decal colours

Sledge.Editor/Editor.cs

@@ -136,8 +136,8 @@ private void EditorLoad(object sender, EventArgs e)
             TextureProvider.Register(new SprProvider());
 
             var spritesFolder = System.IO.Path.Combine(System.IO.Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), "Sprites");
-            TexturePackage.Load(spritesFolder);
-            TexturePackage.LoadTextureData(TexturePackage.GetLoadedItems().Select(x => x.Name));
+            //TexturePackage.Load(spritesFolder);
+            //TexturePackage.LoadTextureData(TexturePackage.GetLoadedItems().Select(x => x.Name));
 
             Subscribe();
         }

Sledge.Editor/Rendering/RenderManager.cs

@@ -67,6 +67,7 @@ void main()
     vertexLighting = (vec4(1,1,1,1) * light1intensity * incidence1) * 0.5
                    + (vec4(1,1,1,1) * light2intensity * incidence2) * 0.5
                    + (vec4(1,1,1,1) * ambient);
+    vertexLighting.w = 1; // Reset the alpha channel or transparency gets messed up later
     texCoord = texture;
     vertexSelected = selected;
 }

Sledge.Graphics/Helpers/TextureHelper.cs

@@ -91,6 +91,7 @@ private static int CreateAndBindTexture()
 
         private static void SetTextureParameters()
         {
+            GL.TexEnv(TextureEnvTarget.TextureEnv, TextureEnvParameter.TextureEnvMode, (int)TextureEnvMode.Modulate);
             GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.LinearMipmapLinear);
             GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear);
             GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, (int)TextureWrapMode.Repeat);

Sledge.Providers/Texture/WadProvider.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Drawing.Imaging;
 using System.Linq;
 using System.IO;
 using Sledge.Graphics;
@@ -11,6 +12,54 @@ namespace Sledge.Providers.Texture
 {
     public class WadProvider : TextureProvider
     {
+        private static Bitmap PostProcessBitmap(string name, Bitmap bmp)
+        {
+            // Transparent textures are named like: {Name
+            if (name.StartsWith("{"))
+            {
+                var palette = bmp.Palette;
+
+                // Two transparency types: "blue" transparency and "decal" transparency
+                // Decal transparency is all greyscale and doesn't contain any of palette #255 colour
+                var blueTransparency = false;
+                for (var i = 0; i < palette.Entries.Length - 1; i++)
+                {
+                    var color = palette.Entries[i];
+                    if (color.R != color.B || color.R != color.G || color.B != color.G)
+                    {
+                        blueTransparency = true;
+                        break;
+                    }
+                }
+
+                if (blueTransparency)
+                {
+                    // We found the last index, therefore it should be transparent
+                    palette.Entries[palette.Entries.Length - 1] = Color.Transparent;
+                }
+                else
+                {
+                    // If we didn't find the last index, we have a decal
+                    var last = palette.Entries[palette.Entries.Length - 1];
+                    for (var i = 0; i < palette.Entries.Length - 1; i++)
+                    {
+                        palette.Entries[i] = Color.FromArgb(255 - palette.Entries[i].R, last);
+                    }
+                }
+                bmp.Palette = palette;
+
+                // Copy the bitmap to a new one with a proper alpha channel
+                var clone = new Bitmap(bmp.Width, bmp.Height, PixelFormat.Format32bppArgb);
+                using (var g = System.Drawing.Graphics.FromImage(clone))
+                {
+                    g.DrawImage(bmp, new Rectangle(0, 0, clone.Width, clone.Height));
+                }
+                bmp.Dispose();
+                return clone;
+            }
+            return bmp;
+        }
+
         public class WadStreamSource : TextureStreamSource
         {
             private readonly Dictionary<string, Tuple<HLLib.Package, HLLib.Folder>> _packages;
@@ -34,7 +83,8 @@ public override Bitmap GetImage(TextureItem item)
                 {
                     using (var stream = root.Item1.CreateStream(search))
                     {
-                        return new Bitmap(new MemoryStream(stream.ReadAll()));
+                        var bmp = new Bitmap(new MemoryStream(stream.ReadAll()));
+                        return PostProcessBitmap(item.Name, bmp);
                     }
                 }
                 return null;
@@ -72,10 +122,10 @@ protected override void LoadTexture(TexturePackage package, string name)
                     var item = pack.GetRootFolder().GetItemByName(name + ".bmp", HLLib.FindType.Files);
                     using (var stream = pack.CreateStream(item))
                     {
-                        using (var bmp = new Bitmap(new MemoryStream(stream.ReadAll())))
-                        {
-                            TextureHelper.Create(name, bmp);
-                        }
+                        var bmp = new Bitmap(new MemoryStream(stream.ReadAll()));
+                        bmp = PostProcessBitmap(name, bmp);
+                        TextureHelper.Create(name, bmp);
+                        bmp.Dispose();
                     }
                 }
             }
@@ -99,10 +149,10 @@ protected override void LoadTextures(TexturePackage package, IEnumerable<string>
                         if (!item.Exists) continue;
                         using (var stream = pack.CreateStream(item))
                         {
-                            using (var bmp = new Bitmap(new MemoryStream(stream.ReadAll())))
-                            {
-                                TextureHelper.Create(name, bmp);
-                            }
+                            var bmp = new Bitmap(new MemoryStream(stream.ReadAll()));
+                            bmp = PostProcessBitmap(name, bmp);
+                            TextureHelper.Create(name, bmp);
+                            bmp.Dispose();
                         }
                     }
                 }