Utilities.cs

using System.Collections.Generic;
using System;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Text;

namespace NuklearSharp
{
    public static partial class NuklearNative
    {
        public static unsafe string GetStringUTF8Z(byte* stringStart)
        {
            int characters = 0;
            while (stringStart[characters] != 0)
            {
                characters++;
            }

            return Encoding.UTF8.GetString(stringStart, characters);
        }

		public static string MakeSizeDebugComparerC()
		{
			// Produces a .c file that when compiled & run should help compare sizes of structures
			// Useful for debugging, or so I hope... as of writing my nk_context struct is a few hundred bytes out

			Dictionary<string, int> sizes = new Dictionary<string, int>();
			Dictionary<string, string> structPfx = new Dictionary<string, string>();

			var ass = Assembly.GetAssembly(typeof(NuklearNative));
			foreach (var ty in ass.DefinedTypes) {
				if (ty.IsValueType && ty.Name.StartsWith("nk_", System.StringComparison.Ordinal) && !ty.Name.Contains("<") && !ty.Name.Contains("`")) {
					if (ty.Name == "nk_bool") {
						continue;  // not a real nuklear C type
					}
					if (ty.IsEnum) {
						structPfx[ty.Name] = "enum";
						sizes[ty.Name] = Marshal.SizeOf(ty.GetEnumUnderlyingType());
					} else {
						if (ty.Name == "nk_style_item_data" || ty.Name == "nk_page_data") {
							structPfx[ty.Name] = "union";
						} else if (ty.Name == "nk_handle" || ty.Name == "nk_glyph") {
							structPfx[ty.Name] = "";
						} else {
							structPfx[ty.Name] = "struct";
						}
						sizes[ty.Name] = Marshal.SizeOf(ty.UnderlyingSystemType);
					}
				}
			}

			StringBuilder sb = new StringBuilder();
			sb.AppendLine("#include \"nuklear_impl.c\"");
			sb.AppendLine("#include \"stdint.h\"");
			sb.AppendLine("#include \"stdio.h\"");
			sb.AppendLine();
			sb.AppendLine("int main() {");
			sb.AppendLine("  ");
			sb.AppendLine($"  printf(\"\\nBefore we begin: SIZE OF UINTPTR_T: C# {UIntPtr.Size} bytes, C %lu bytes\\n==========\\n\", sizeof(uintptr_t));");
			var lkeys = new List<string>(sizes.Keys);
			lkeys.Sort();
			foreach (var k in lkeys) {
				sb.AppendLine($"  printf(\"{k}: c# size {sizes[k]}, C size %lu\\n\", sizeof({structPfx[k]} {k}));");
				sb.AppendLine($"  if ({sizes[k]} != sizeof({structPfx[k]} {k})) {{ printf(\"!!!!! ^^^^^ SIZE DIFFERS! ^^^^^ !!!!!\\n\"); }}");
			}
			sb.AppendLine("  return 0;");
			sb.AppendLine("}");
			sb.AppendLine();

			return sb.ToString();
		}
    }
}