diff --git a/src/CodeGenerator/TypeInfo.cs b/src/CodeGenerator/TypeInfo.cs
index 52e68f7..de90495 100644
--- a/src/CodeGenerator/TypeInfo.cs
+++ b/src/CodeGenerator/TypeInfo.cs
@@ -138,7 +138,9 @@ namespace CodeGenerator
         public static readonly HashSet<string> SkippedFunctions = new HashSet<string>()
         {
             "igInputText",
-            "igInputTextMultiline"
+            "igInputTextMultiline",
+            "igCalcTextSize",
+            "igInputTextWithHint"
         };
     }
 }
\ No newline at end of file
diff --git a/src/ImGui.NET.SampleProgram/ImGuiController.cs b/src/ImGui.NET.SampleProgram/ImGuiController.cs
index 3c600ad..4cbe615 100644
--- a/src/ImGui.NET.SampleProgram/ImGuiController.cs
+++ b/src/ImGui.NET.SampleProgram/ImGuiController.cs
@@ -99,8 +99,8 @@ namespace ImGuiNET
 
             byte[] vertexShaderBytes = LoadEmbeddedShaderCode(gd.ResourceFactory, "imgui-vertex", ShaderStages.Vertex);
             byte[] fragmentShaderBytes = LoadEmbeddedShaderCode(gd.ResourceFactory, "imgui-frag", ShaderStages.Fragment);
-            _vertexShader = factory.CreateShader(new ShaderDescription(ShaderStages.Vertex, vertexShaderBytes, "VS"));
-            _fragmentShader = factory.CreateShader(new ShaderDescription(ShaderStages.Fragment, fragmentShaderBytes, "FS"));
+            _vertexShader = factory.CreateShader(new ShaderDescription(ShaderStages.Vertex, vertexShaderBytes, gd.BackendType == GraphicsBackend.Metal ? "VS" : "main"));
+            _fragmentShader = factory.CreateShader(new ShaderDescription(ShaderStages.Fragment, fragmentShaderBytes, gd.BackendType == GraphicsBackend.Metal ? "FS" : "main"));
 
             VertexLayoutDescription[] vertexLayouts = new VertexLayoutDescription[]
             {
@@ -123,7 +123,8 @@ namespace ImGuiNET
                 PrimitiveTopology.TriangleList,
                 new ShaderSetDescription(vertexLayouts, new[] { _vertexShader, _fragmentShader }),
                 new ResourceLayout[] { _layout, _textureLayout },
-                outputDescription);
+                outputDescription,
+                ResourceBindingModel.Default);
             _pipeline = factory.CreateGraphicsPipeline(ref pd);
 
             _mainResourceSet = factory.CreateResourceSet(new ResourceSetDescription(_layout,
diff --git a/src/ImGui.NET.SampleProgram/Program.cs b/src/ImGui.NET.SampleProgram/Program.cs
index 9d69b8a..0781b9f 100644
--- a/src/ImGui.NET.SampleProgram/Program.cs
+++ b/src/ImGui.NET.SampleProgram/Program.cs
@@ -38,7 +38,7 @@ namespace ImGuiNET
             // Create window, GraphicsDevice, and all resources necessary for the demo.
             VeldridStartup.CreateWindowAndGraphicsDevice(
                 new WindowCreateInfo(50, 50, 1280, 720, WindowState.Normal, "ImGui.NET Sample Program"),
-                new GraphicsDeviceOptions(true, null, true),
+                new GraphicsDeviceOptions(true, null, true, ResourceBindingModel.Improved, true, true),
                 out _window,
                 out _gd);
             _window.Resized += () =>
diff --git a/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-frag.glsl b/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-frag.glsl
index 2d1c1d7..f94fa48 100644
--- a/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-frag.glsl
+++ b/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-frag.glsl
@@ -13,4 +13,4 @@ layout (location = 0) out vec4 outputColor;
 void main()
 {
     outputColor = color * texture(sampler2D(FontTexture, FontSampler), texCoord);
-}
+}
\ No newline at end of file
diff --git a/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-frag.spv b/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-frag.spv
index c8d71cc..5d3d96f 100644
Binary files a/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-frag.spv and b/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-frag.spv differ
diff --git a/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-vertex.glsl b/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-vertex.glsl
index 6fdab3f..6249a36 100644
--- a/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-vertex.glsl
+++ b/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-vertex.glsl
@@ -3,27 +3,26 @@
 #extension GL_ARB_separate_shader_objects : enable
 #extension GL_ARB_shading_language_420pack : enable
 
-layout (location = 0) in vec2 vsin_position;
-layout (location = 1) in vec2 vsin_texCoord;
-layout (location = 2) in vec4 vsin_color;
+layout (location = 0) in vec2 in_position;
+layout (location = 1) in vec2 in_texCoord;
+layout (location = 2) in vec4 in_color;
 
-layout (binding = 0) uniform Projection
+layout (binding = 0) uniform ProjectionMatrixBuffer
 {
-    mat4 projection;
+    mat4 projection_matrix;
 };
 
-layout (location = 0) out vec4 vsout_color;
-layout (location = 1) out vec2 vsout_texCoord;
+layout (location = 0) out vec4 color;
+layout (location = 1) out vec2 texCoord;
 
-out gl_PerVertex 
+out gl_PerVertex
 {
     vec4 gl_Position;
 };
 
 void main() 
 {
-    gl_Position = projection * vec4(vsin_position, 0, 1);
-    vsout_color = vsin_color;
-    vsout_texCoord = vsin_texCoord;
-    gl_Position.y = -gl_Position.y;
+    gl_Position = projection_matrix * vec4(in_position, 0, 1);
+    color = in_color;
+    texCoord = in_texCoord;
 }
diff --git a/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-vertex.spv b/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-vertex.spv
index 795cd0e..b40ec8c 100644
Binary files a/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-vertex.spv and b/src/ImGui.NET.SampleProgram/Shaders/SPIR-V/imgui-vertex.spv differ
diff --git a/src/ImGui.NET/Generated/ImGui.gen.cs b/src/ImGui.NET/Generated/ImGui.gen.cs
index 5cc7a0a..d355fcf 100644
--- a/src/ImGui.NET/Generated/ImGui.gen.cs
+++ b/src/ImGui.NET/Generated/ImGui.gen.cs
@@ -1262,37 +1262,6 @@ namespace ImGuiNET
             float ret = ImGuiNative.igCalcItemWidth();
             return ret;
         }
-        public static Vector2 CalcTextSize(string text)
-        {
-            Vector2 __retval;
-            byte* native_text;
-            int text_byteCount = 0;
-            if (text != null)
-            {
-                text_byteCount = Encoding.UTF8.GetByteCount(text);
-                if (text_byteCount > Util.StackAllocationSizeLimit)
-                {
-                    native_text = Util.Allocate(text_byteCount + 1);
-                }
-                else
-                {
-                    byte* native_text_stackBytes = stackalloc byte[text_byteCount + 1];
-                    native_text = native_text_stackBytes;
-                }
-                int native_text_offset = Util.GetUtf8(text, native_text, text_byteCount);
-                native_text[native_text_offset] = 0;
-            }
-            else { native_text = null; }
-            byte* native_text_end = null;
-            byte hide_text_after_double_hash = 0;
-            float wrap_width = -1.0f;
-            ImGuiNative.igCalcTextSize(&__retval, native_text, native_text_end, hide_text_after_double_hash, wrap_width);
-            if (text_byteCount > Util.StackAllocationSizeLimit)
-            {
-                Util.Free(native_text);
-            }
-            return __retval;
-        }
         public static void CaptureKeyboardFromApp()
         {
             byte want_capture_keyboard_value = 1;
@@ -8305,297 +8274,6 @@ namespace ImGuiNET
             }
             return ret != 0;
         }
-        public static bool InputTextWithHint(string label, string hint, string buf, uint buf_size)
-        {
-            byte* native_label;
-            int label_byteCount = 0;
-            if (label != null)
-            {
-                label_byteCount = Encoding.UTF8.GetByteCount(label);
-                if (label_byteCount > Util.StackAllocationSizeLimit)
-                {
-                    native_label = Util.Allocate(label_byteCount + 1);
-                }
-                else
-                {
-                    byte* native_label_stackBytes = stackalloc byte[label_byteCount + 1];
-                    native_label = native_label_stackBytes;
-                }
-                int native_label_offset = Util.GetUtf8(label, native_label, label_byteCount);
-                native_label[native_label_offset] = 0;
-            }
-            else { native_label = null; }
-            byte* native_hint;
-            int hint_byteCount = 0;
-            if (hint != null)
-            {
-                hint_byteCount = Encoding.UTF8.GetByteCount(hint);
-                if (hint_byteCount > Util.StackAllocationSizeLimit)
-                {
-                    native_hint = Util.Allocate(hint_byteCount + 1);
-                }
-                else
-                {
-                    byte* native_hint_stackBytes = stackalloc byte[hint_byteCount + 1];
-                    native_hint = native_hint_stackBytes;
-                }
-                int native_hint_offset = Util.GetUtf8(hint, native_hint, hint_byteCount);
-                native_hint[native_hint_offset] = 0;
-            }
-            else { native_hint = null; }
-            byte* native_buf;
-            int buf_byteCount = 0;
-            if (buf != null)
-            {
-                buf_byteCount = Encoding.UTF8.GetByteCount(buf);
-                if (buf_byteCount > Util.StackAllocationSizeLimit)
-                {
-                    native_buf = Util.Allocate(buf_byteCount + 1);
-                }
-                else
-                {
-                    byte* native_buf_stackBytes = stackalloc byte[buf_byteCount + 1];
-                    native_buf = native_buf_stackBytes;
-                }
-                int native_buf_offset = Util.GetUtf8(buf, native_buf, buf_byteCount);
-                native_buf[native_buf_offset] = 0;
-            }
-            else { native_buf = null; }
-            ImGuiInputTextFlags flags = (ImGuiInputTextFlags)0;
-            ImGuiInputTextCallback callback = null;
-            void* user_data = null;
-            byte ret = ImGuiNative.igInputTextWithHint(native_label, native_hint, native_buf, buf_size, flags, callback, user_data);
-            if (label_byteCount > Util.StackAllocationSizeLimit)
-            {
-                Util.Free(native_label);
-            }
-            if (hint_byteCount > Util.StackAllocationSizeLimit)
-            {
-                Util.Free(native_hint);
-            }
-            if (buf_byteCount > Util.StackAllocationSizeLimit)
-            {
-                Util.Free(native_buf);
-            }
-            return ret != 0;
-        }
-        public static bool InputTextWithHint(string label, string hint, string buf, uint buf_size, ImGuiInputTextFlags flags)
-        {
-            byte* native_label;
-            int label_byteCount = 0;
-            if (label != null)
-            {
-                label_byteCount = Encoding.UTF8.GetByteCount(label);
-                if (label_byteCount > Util.StackAllocationSizeLimit)
-                {
-                    native_label = Util.Allocate(label_byteCount + 1);
-                }
-                else
-                {
-                    byte* native_label_stackBytes = stackalloc byte[label_byteCount + 1];
-                    native_label = native_label_stackBytes;
-                }
-                int native_label_offset = Util.GetUtf8(label, native_label, label_byteCount);
-                native_label[native_label_offset] = 0;
-            }
-            else { native_label = null; }
-            byte* native_hint;
-            int hint_byteCount = 0;
-            if (hint != null)
-            {
-                hint_byteCount = Encoding.UTF8.GetByteCount(hint);
-                if (hint_byteCount > Util.StackAllocationSizeLimit)
-                {
-                    native_hint = Util.Allocate(hint_byteCount + 1);
-                }
-                else
-                {
-                    byte* native_hint_stackBytes = stackalloc byte[hint_byteCount + 1];
-                    native_hint = native_hint_stackBytes;
-                }
-                int native_hint_offset = Util.GetUtf8(hint, native_hint, hint_byteCount);
-                native_hint[native_hint_offset] = 0;
-            }
-            else { native_hint = null; }
-            byte* native_buf;
-            int buf_byteCount = 0;
-            if (buf != null)
-            {
-                buf_byteCount = Encoding.UTF8.GetByteCount(buf);
-                if (buf_byteCount > Util.StackAllocationSizeLimit)
-                {
-                    native_buf = Util.Allocate(buf_byteCount + 1);
-                }
-                else
-                {
-                    byte* native_buf_stackBytes = stackalloc byte[buf_byteCount + 1];
-                    native_buf = native_buf_stackBytes;
-                }
-                int native_buf_offset = Util.GetUtf8(buf, native_buf, buf_byteCount);
-                native_buf[native_buf_offset] = 0;
-            }
-            else { native_buf = null; }
-            ImGuiInputTextCallback callback = null;
-            void* user_data = null;
-            byte ret = ImGuiNative.igInputTextWithHint(native_label, native_hint, native_buf, buf_size, flags, callback, user_data);
-            if (label_byteCount > Util.StackAllocationSizeLimit)
-            {
-                Util.Free(native_label);
-            }
-            if (hint_byteCount > Util.StackAllocationSizeLimit)
-            {
-                Util.Free(native_hint);
-            }
-            if (buf_byteCount > Util.StackAllocationSizeLimit)
-            {
-                Util.Free(native_buf);
-            }
-            return ret != 0;
-        }
-        public static bool InputTextWithHint(string label, string hint, string buf, uint buf_size, ImGuiInputTextFlags flags, ImGuiInputTextCallback callback)
-        {
-            byte* native_label;
-            int label_byteCount = 0;
-            if (label != null)
-            {
-                label_byteCount = Encoding.UTF8.GetByteCount(label);
-                if (label_byteCount > Util.StackAllocationSizeLimit)
-                {
-                    native_label = Util.Allocate(label_byteCount + 1);
-                }
-                else
-                {
-                    byte* native_label_stackBytes = stackalloc byte[label_byteCount + 1];
-                    native_label = native_label_stackBytes;
-                }
-                int native_label_offset = Util.GetUtf8(label, native_label, label_byteCount);
-                native_label[native_label_offset] = 0;
-            }
-            else { native_label = null; }
-            byte* native_hint;
-            int hint_byteCount = 0;
-            if (hint != null)
-            {
-                hint_byteCount = Encoding.UTF8.GetByteCount(hint);
-                if (hint_byteCount > Util.StackAllocationSizeLimit)
-                {
-                    native_hint = Util.Allocate(hint_byteCount + 1);
-                }
-                else
-                {
-                    byte* native_hint_stackBytes = stackalloc byte[hint_byteCount + 1];
-                    native_hint = native_hint_stackBytes;
-                }
-                int native_hint_offset = Util.GetUtf8(hint, native_hint, hint_byteCount);
-                native_hint[native_hint_offset] = 0;
-            }
-            else { native_hint = null; }
-            byte* native_buf;
-            int buf_byteCount = 0;
-            if (buf != null)
-            {
-                buf_byteCount = Encoding.UTF8.GetByteCount(buf);
-                if (buf_byteCount > Util.StackAllocationSizeLimit)
-                {
-                    native_buf = Util.Allocate(buf_byteCount + 1);
-                }
-                else
-                {
-                    byte* native_buf_stackBytes = stackalloc byte[buf_byteCount + 1];
-                    native_buf = native_buf_stackBytes;
-                }
-                int native_buf_offset = Util.GetUtf8(buf, native_buf, buf_byteCount);
-                native_buf[native_buf_offset] = 0;
-            }
-            else { native_buf = null; }
-            void* user_data = null;
-            byte ret = ImGuiNative.igInputTextWithHint(native_label, native_hint, native_buf, buf_size, flags, callback, user_data);
-            if (label_byteCount > Util.StackAllocationSizeLimit)
-            {
-                Util.Free(native_label);
-            }
-            if (hint_byteCount > Util.StackAllocationSizeLimit)
-            {
-                Util.Free(native_hint);
-            }
-            if (buf_byteCount > Util.StackAllocationSizeLimit)
-            {
-                Util.Free(native_buf);
-            }
-            return ret != 0;
-        }
-        public static bool InputTextWithHint(string label, string hint, string buf, uint buf_size, ImGuiInputTextFlags flags, ImGuiInputTextCallback callback, IntPtr user_data)
-        {
-            byte* native_label;
-            int label_byteCount = 0;
-            if (label != null)
-            {
-                label_byteCount = Encoding.UTF8.GetByteCount(label);
-                if (label_byteCount > Util.StackAllocationSizeLimit)
-                {
-                    native_label = Util.Allocate(label_byteCount + 1);
-                }
-                else
-                {
-                    byte* native_label_stackBytes = stackalloc byte[label_byteCount + 1];
-                    native_label = native_label_stackBytes;
-                }
-                int native_label_offset = Util.GetUtf8(label, native_label, label_byteCount);
-                native_label[native_label_offset] = 0;
-            }
-            else { native_label = null; }
-            byte* native_hint;
-            int hint_byteCount = 0;
-            if (hint != null)
-            {
-                hint_byteCount = Encoding.UTF8.GetByteCount(hint);
-                if (hint_byteCount > Util.StackAllocationSizeLimit)
-                {
-                    native_hint = Util.Allocate(hint_byteCount + 1);
-                }
-                else
-                {
-                    byte* native_hint_stackBytes = stackalloc byte[hint_byteCount + 1];
-                    native_hint = native_hint_stackBytes;
-                }
-                int native_hint_offset = Util.GetUtf8(hint, native_hint, hint_byteCount);
-                native_hint[native_hint_offset] = 0;
-            }
-            else { native_hint = null; }
-            byte* native_buf;
-            int buf_byteCount = 0;
-            if (buf != null)
-            {
-                buf_byteCount = Encoding.UTF8.GetByteCount(buf);
-                if (buf_byteCount > Util.StackAllocationSizeLimit)
-                {
-                    native_buf = Util.Allocate(buf_byteCount + 1);
-                }
-                else
-                {
-                    byte* native_buf_stackBytes = stackalloc byte[buf_byteCount + 1];
-                    native_buf = native_buf_stackBytes;
-                }
-                int native_buf_offset = Util.GetUtf8(buf, native_buf, buf_byteCount);
-                native_buf[native_buf_offset] = 0;
-            }
-            else { native_buf = null; }
-            void* native_user_data = (void*)user_data.ToPointer();
-            byte ret = ImGuiNative.igInputTextWithHint(native_label, native_hint, native_buf, buf_size, flags, callback, native_user_data);
-            if (label_byteCount > Util.StackAllocationSizeLimit)
-            {
-                Util.Free(native_label);
-            }
-            if (hint_byteCount > Util.StackAllocationSizeLimit)
-            {
-                Util.Free(native_hint);
-            }
-            if (buf_byteCount > Util.StackAllocationSizeLimit)
-            {
-                Util.Free(native_buf);
-            }
-            return ret != 0;
-        }
         public static bool InvisibleButton(string str_id, Vector2 size)
         {
             byte* native_str_id;
diff --git a/src/ImGui.NET/ImGui.Manual.cs b/src/ImGui.NET/ImGui.Manual.cs
index 8fac3de..cec21cf 100644
--- a/src/ImGui.NET/ImGui.Manual.cs
+++ b/src/ImGui.NET/ImGui.Manual.cs
@@ -355,6 +355,79 @@ namespace ImGuiNET
             return result != 0;
         }
 
+        public static Vector2 CalcTextSize(string text)
+            => CalcTextSizeImpl(text);
+
+        public static Vector2 CalcTextSize(string text, int start)
+            => CalcTextSizeImpl(text, start);
+
+        public static Vector2 CalcTextSize(string text, float wrapWidth)
+            => CalcTextSizeImpl(text, wrapWidth: wrapWidth);
+
+        public static Vector2 CalcTextSize(string text, bool hideTextAfterDoubleHash)
+            => CalcTextSizeImpl(text, hideTextAfterDoubleHash: hideTextAfterDoubleHash);
+
+        public static Vector2 CalcTextSize(string text, int start, int length)
+            => CalcTextSizeImpl(text, start, length);
+
+        public static Vector2 CalcTextSize(string text, int start, bool hideTextAfterDoubleHash)
+            => CalcTextSizeImpl(text, start, hideTextAfterDoubleHash: hideTextAfterDoubleHash);
+
+        public static Vector2 CalcTextSize(string text, int start, float wrapWidth)
+            => CalcTextSizeImpl(text, start, wrapWidth: wrapWidth);
+
+        public static Vector2 CalcTextSize(string text, bool hideTextAfterDoubleHash, float wrapWidth)
+            => CalcTextSizeImpl(text, hideTextAfterDoubleHash: hideTextAfterDoubleHash, wrapWidth: wrapWidth);
+
+        public static Vector2 CalcTextSize(string text, int start, int length, bool hideTextAfterDoubleHash)
+            => CalcTextSizeImpl(text, start, length, hideTextAfterDoubleHash);
+
+        public static Vector2 CalcTextSize(string text, int start, int length, float wrapWidth)
+            => CalcTextSizeImpl(text, start, length, wrapWidth: wrapWidth);
+
+        public static Vector2 CalcTextSize(string text, int start, int length, bool hideTextAfterDoubleHash, float wrapWidth)
+            => CalcTextSizeImpl(text, start, length, hideTextAfterDoubleHash, wrapWidth);
+
+        private static Vector2 CalcTextSizeImpl(
+            string text,
+            int start = 0,
+            int? length = null,
+            bool hideTextAfterDoubleHash = false,
+            float wrapWidth = -1.0f)
+        {
+            Vector2 ret;
+            byte* nativeTextStart = null;
+            byte* nativeTextEnd = null;
+            int textByteCount = 0;
+            if (text != null)
+            {
+
+                int textToCopyLen = length.HasValue ? length.Value : text.Length;
+                textByteCount = Util.CalcSizeInUtf8(text, start, textToCopyLen);
+                if (textByteCount > Util.StackAllocationSizeLimit)
+                {
+                    nativeTextStart = Util.Allocate(textByteCount + 1);
+                }
+                else
+                {
+                    byte* nativeTextStackBytes = stackalloc byte[textByteCount + 1];
+                    nativeTextStart = nativeTextStackBytes;
+                }
+
+                int nativeTextOffset = Util.GetUtf8(text, start, textToCopyLen, nativeTextStart, textByteCount);
+                nativeTextStart[nativeTextOffset] = 0;
+                nativeTextEnd = nativeTextStart + nativeTextOffset;
+            }
+
+            ImGuiNative.igCalcTextSize(&ret, nativeTextStart, nativeTextEnd, *((byte*)(&hideTextAfterDoubleHash)), wrapWidth);
+            if (textByteCount > Util.StackAllocationSizeLimit)
+            {
+                Util.Free(nativeTextStart);
+            }
+
+            return ret;
+        }
+
         public static bool InputText(
             string label,
             IntPtr buf,
diff --git a/src/ImGui.NET/Util.cs b/src/ImGui.NET/Util.cs
index 34280a0..52785b6 100644
--- a/src/ImGui.NET/Util.cs
+++ b/src/ImGui.NET/Util.cs
@@ -32,7 +32,22 @@ namespace ImGuiNET
         }
 
         internal static byte* Allocate(int byteCount) => (byte*)Marshal.AllocHGlobal(byteCount);
+
         internal static void Free(byte* ptr) => Marshal.FreeHGlobal((IntPtr)ptr);
+
+        internal static int CalcSizeInUtf8(string s, int start, int length)
+        {
+            if (start < 0 || length < 0 || start + length > s.Length)
+            {
+                throw new ArgumentOutOfRangeException();
+            }
+
+            fixed (char* utf16Ptr = s)
+            {
+                return Encoding.UTF8.GetByteCount(utf16Ptr + start, length);
+            }
+        }
+
         internal static int GetUtf8(string s, byte* utf8Bytes, int utf8ByteCount)
         {
             fixed (char* utf16Ptr = s)
@@ -40,5 +55,18 @@ namespace ImGuiNET
                 return Encoding.UTF8.GetBytes(utf16Ptr, s.Length, utf8Bytes, utf8ByteCount);
             }
         }
+
+        internal static int GetUtf8(string s, int start, int length, byte* utf8Bytes, int utf8ByteCount)
+        {
+            if (start < 0 || length < 0 || start + length > s.Length)
+            {
+                throw new ArgumentOutOfRangeException();
+            }
+
+            fixed (char* utf16Ptr = s)
+            {
+                return Encoding.UTF8.GetBytes(utf16Ptr + start, length, utf8Bytes, utf8ByteCount);
+            }
+        }
     }
 }