Texture Error

cs

using System;
using System.IO;
using System.Runtime.InteropServices;
using OpenTK;
using OpenTK.Graphics.OpenGL;
using SharpFont;

namespace Ryujinx.Profiler.UI.SharpFontHelpers
{
    public class FontService
    {
        private int[] characterTextures;

        public void InitalizeTextures()
        {
            characterTextures = new int[94];
            var font = new FontFace(File.OpenRead(Path.Combine(Environment.GetFolderPath(
                Environment.SpecialFolder.ApplicationData), @"RyuFs\system\fonts\FontStandard.ttf")));

            for (int i = 33; i < 127; i++)
            {
                var surface = RenderSurface((char)i, font);

                characterTextures[i - 33] = LoadTexture(surface);
            }
        }

        public void DrawText(string text)
        {
            GL.Viewport(0, 0, 500, 500);
            GL.BindTexture(TextureTarget.Texture2D, characterTextures[text[0] - 33]);

            GL.Enable(EnableCap.Blend);
            GL.BlendFunc(BlendingFactor.SrcAlpha, BlendingFactor.OneMinusSrcAlpha);
            GL.Enable(EnableCap.DepthTest);
            GL.DepthFunc(DepthFunction.Lequal);
            GL.Enable(EnableCap.Texture2D);

            GL.ClearDepth(1);
            GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
            GL.ClearColor(Color.White);

            
            GL.Begin(PrimitiveType.Triangles);
            GL.Color4(Color.White);

            GL.TexCoord2(0, 0); GL.Vertex2(100, 100);
            GL.TexCoord2(0, 64); GL.Vertex2(100, 164);
            GL.TexCoord2(32, 64); GL.Vertex2(132, 164);

            GL.TexCoord2(32, 64); GL.Vertex2(132, 164);
            GL.TexCoord2(32, 0); GL.Vertex2(132, 100);
            GL.TexCoord2(0, 0); GL.Vertex2(100, 100);
            GL.End();

            GL.BindTexture(TextureTarget.Texture2D, 0);
            GL.Disable(EnableCap.Texture2D);
            GL.Disable(EnableCap.DepthTest);

        }

        private void DrawChar(char character)
        {

        }

        public unsafe Surface RenderSurface(char c, FontFace font)
        {
            var glyph = font.GetGlyph(c, 32);
            var surface = new Surface
            {
                Bits = Marshal.AllocHGlobal(glyph.RenderWidth * glyph.RenderHeight),
                Width = glyph.RenderWidth,
                Height = glyph.RenderHeight,
                Pitch = glyph.RenderWidth
            };

            var stuff = (byte*)surface.Bits;
            for (int i = 0; i < surface.Width * surface.Height; i++)
                *stuff++ = 0;

            glyph.RenderTo(surface);

            return surface;
        }

        private unsafe int LoadTexture(Surface surface)
        {
            int width = 32; //surface.Width;
            int height = 64; //surface.Height;
            int len = width * height;
            byte[] data = new byte[len];
            //Marshal.Copy(surface.Bits, data, 0, len);
            int[] pixels = new int[len];

            int index = 0;
            for (int i = 0; i < len; i++)
            {
                int c = (byte)i; //data[i];
                pixels[i] = (byte.MaxValue << 24) | (c << 16) | (c << 8) | c;
            }

            GL.Enable(EnableCap.Texture2D);
            int textureID = GL.GenTexture();
            GL.BindTexture(TextureTarget.Texture2D, textureID);

            GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear);
            GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear);
            GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, (int)TextureWrapMode.Clamp);
            GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapT, (int)TextureWrapMode.Clamp);

            fixed (int* dataptr = pixels)
                GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, width, height, 0, PixelFormat.Rgba, PixelType.UnsignedByte, (IntPtr)dataptr);
            GL.BindTexture(TextureTarget.Texture2D, 0);
            GL.Disable(EnableCap.Texture2D);

            Marshal.FreeHGlobal(surface.Bits); //Give the memory back!
            return textureID;
        }
    }
}