StructGen.cs

// structgen
// generates simple vtable structures for directx objects
// run in a linqpad query or whatever

class VTableInfo {
	public readonly string Name;
	public readonly List<string> Methods;
	
	public VTableInfo(string name) {
		Name = name;
		Methods = new List<string>();
	}
}

void Main()
{
	const string dir = @"<directory with header file names>"; // copy whatever you need from include path
	const string file = "dxgi"; // header file name
	
	var structNameRegex = new Regex(@"typedef struct ([^\s]*)");
	var interfaceNameRegex = new Regex(@"interface ([^\s]*)");
	var methodNameRegex = new Regex(@"[*]([^\s]*)");
	
	string currentName = null;
	bool hasBegun = false;
	bool waitForSemi = false;
	
	List<VTableInfo> vTables = new List<VTableInfo>();
	VTableInfo currentVTable = null;
	
	using (StreamReader reader = new StreamReader(Path.Combine(dir, file+".h"))) {
		foreach (string rawLine in reader.ReadToEnd().Split('\n')) {
			if (string.IsNullOrWhiteSpace(rawLine)) continue;
			
			var line = rawLine.Trim();
			
			if (!hasBegun) {
				if (line.Contains("typedef struct")) {
					currentName = structNameRegex.Match(line).Groups[1].Value;
				}
				if (line.Contains("BEGIN_INTERFACE")) {
					hasBegun = true;
					currentVTable = new VTableInfo(currentName);
					vTables.Add(currentVTable);
				}
			} else {
				if (line.Contains("END_INTERFACE")) {
					hasBegun = false;
					continue;
				}
				if (!waitForSemi) {
					var match = methodNameRegex.Match(line);
					currentVTable.Methods.Add(match.Groups[1].Value);
					waitForSemi = true;
				} else if (line.Contains(';')) {
					waitForSemi = false;
				}
			}
		}
	}
	
	StringBuilder builder = new StringBuilder();
	
	for (int i = 0; i < vTables.Count; i++) {
		if (i != 0) builder.AppendLine();
		var vTable = vTables[i];
		builder.AppendLine($"typedef struct {vTable.Name} {{");
		for (int j = 0; j < vTable.Methods.Count; j++) {
			builder.AppendLine($"   void* {vTable.Methods[j]};  // {j*8}");
		}
		builder.AppendLine($"}} {vTable.Name};");
	}
	using (StreamWriter writer = new StreamWriter(Path.Combine(dir, file + "_vtable.h"))) {
		writer.Write(builder.ToString());
	}
}