Fix sorting of custom type declarations in HLSL

Sergio0694 · Dec 18, 2023 · fc567fc · fc567fc
1 parent fb415b6
commit fc567fc
Showing 1 changed file with 12 additions and 9 deletions.
diff --git a/src/ComputeSharp.SourceGeneration.Hlsl/SyntaxProcessors/HlslSourceSyntaxRewriter.cs b/src/ComputeSharp.SourceGeneration.Hlsl/SyntaxProcessors/HlslSourceSyntaxRewriter.cs
@@ -68,6 +68,18 @@ public static void WriteTopDeclarations(
             writer.WriteLine(skipIfPresent: true);
         }
 
+        // Declared types (these have to be declared early on in the shader so that even if
+        // forward declarations for types are not supported, like is the case for D2D shaders
+        // using the FXC compiler, the resulting HLSL code is valid in case any forward
+        // declaration of methods in the shader has one of these types in its signature).
+        foreach (HlslUserType userType in typeDeclarations)
+        {
+            writer.WriteLine(skipIfPresent: true);
+            writer.WriteLine(userType.Definition);
+        }
+
+        writer.WriteLine(skipIfPresent: true);
+
         // Forward declarations of shader/static methods
         foreach (HlslMethod method in processedMethods)
         {
@@ -91,15 +103,6 @@ public static void WriteTopDeclarations(
         }
 
         writer.WriteLine(skipIfPresent: true);
-
-        // Declared types
-        foreach (HlslUserType userType in typeDeclarations)
-        {
-            writer.WriteLine(skipIfPresent: true);
-            writer.WriteLine(userType.Definition);
-        }
-
-        writer.WriteLine(skipIfPresent: true);
     }
 
     /// <summary>