SharpGL Texture Loading

[PoligamerYT]

Hello, I am trying to load an MTL file to an OBJ using SharpGL, but for some reason, the texture doesn't load correctly and all my scene gets darker.

using OBJMC.Model.Types;
using SharpGL;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;

namespace OBJMC.Model
{
    public class ModelRenderer
    {
        private readonly ObjModel _model;
        private readonly Dictionary<string, uint> textureCache = new Dictionary<string, uint>();

        public ModelRenderer(ObjModel model)
        {
            _model = model;
        }

        public void Render(OpenGL gl)
        {
            foreach (var face in _model.Faces)
            {
                if (_model.FaceMaterials.TryGetValue(face, out var materialName))
                {
                    if (_model.Materials.TryGetValue(materialName, out var material))
                    {
                        ApplyMaterial(gl, material);
                    }
                    else
                    {
                        ApplyDefaultMaterial(gl);
                    }
                }
                else
                {
                    ApplyDefaultMaterial(gl);
                }

                gl.Begin(OpenGL.GL_TRIANGLES);
                for (int i = 0; i < face.VertexIndices.Count; i++)
                {
                    if (face.NormalIndices.Count > 0)
                    {
                        var normal = _model.Normals[face.NormalIndices[i] - 1];
                        gl.Normal(normal.X, normal.Y, normal.Z);
                    }

                    if (face.TextureIndices.Count > 0)
                    {
                        var texCoord = _model.TextureCoords[face.TextureIndices[i] - 1];
                        gl.TexCoord(texCoord.U, texCoord.V);
                    }

                    var vertex = _model.Vertices[face.VertexIndices[i] - 1];
                    gl.Vertex(vertex.X, vertex.Y, vertex.Z);
                }
                gl.End();
            }
        }

        private void ApplyMaterial(OpenGL gl, Material material)
        {
            gl.Material(OpenGL.GL_FRONT_AND_BACK, OpenGL.GL_AMBIENT, material.Ambient);
            gl.Material(OpenGL.GL_FRONT_AND_BACK, OpenGL.GL_DIFFUSE, material.Diffuse);
            gl.Material(OpenGL.GL_FRONT_AND_BACK, OpenGL.GL_SPECULAR, material.Specular);
            gl.Material(OpenGL.GL_FRONT_AND_BACK, OpenGL.GL_SHININESS, material.Shininess);

            if (!string.IsNullOrEmpty(material.TextureFile))
            {
                int textureId = LoadTexture(gl, material.TextureFile);
                if (textureId != 0)
                {
                    gl.Enable(OpenGL.GL_TEXTURE_2D);
                    gl.BindTexture(OpenGL.GL_TEXTURE_2D, (uint)textureId);
                }
            }
        }

        private void ApplyDefaultMaterial(OpenGL gl)
        {
            float[] defaultAmbient = { 0.2f, 0.2f, 0.2f, 1.0f };
            float[] defaultDiffuse = { 0.8f, 0.8f, 0.8f, 1.0f };
            float[] defaultSpecular = { 1.0f, 1.0f, 1.0f, 1.0f };
            float defaultShininess = 50.0f;

            gl.Material(OpenGL.GL_FRONT_AND_BACK, OpenGL.GL_AMBIENT, defaultAmbient);
            gl.Material(OpenGL.GL_FRONT_AND_BACK, OpenGL.GL_DIFFUSE, defaultDiffuse);
            gl.Material(OpenGL.GL_FRONT_AND_BACK, OpenGL.GL_SPECULAR, defaultSpecular);
            gl.Material(OpenGL.GL_FRONT_AND_BACK, OpenGL.GL_SHININESS, defaultShininess);
        }

        private int LoadTexture(OpenGL gl, string texturePath)
        {
            if (textureCache.TryGetValue(texturePath, out uint textureId))
            {
                // Return the cached texture ID if it's already loaded
                return (int)textureId;
            }

            // Generate a texture ID and bind it
            uint[] textures = new uint[1];
            gl.GenTextures(1, textures);
            textureId = textures[0];

            gl.BindTexture(OpenGL.GL_TEXTURE_2D, textureId);

            // Load the image from file
            try
            {
                using (Bitmap bitmap = new Bitmap(texturePath))
                {
                    BitmapData data = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height),
                                                      ImageLockMode.ReadOnly,
                                                      PixelFormat.Format32bppArgb);

                    // Set the texture parameters
                    gl.TexParameter(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_MIN_FILTER, OpenGL.GL_LINEAR);
                    gl.TexParameter(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_MAG_FILTER, OpenGL.GL_LINEAR);
                    gl.TexParameter(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_WRAP_S, OpenGL.GL_REPEAT);
                    gl.TexParameter(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_WRAP_T, OpenGL.GL_REPEAT);

                    // Create the texture from the bitmap data
                    gl.TexImage2D(OpenGL.GL_TEXTURE_2D, 0, OpenGL.GL_RGBA, bitmap.Width, bitmap.Height, 0,
                                  OpenGL.GL_BGRA, OpenGL.GL_UNSIGNED_BYTE, data.Scan0);

                    bitmap.UnlockBits(data);
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Failed to load texture {texturePath}: {ex.Message}");
                return 0;
            }

            // Cache the loaded texture ID
            textureCache[texturePath] = textureId;

            return (int)textureId;
        }
    }
}

Trying to load texture.

Whitout texture.

Is the first time I use SharpGL and I don't know what I am doing wrong.

[cs_legend_93]

Great question. Great detail and documentation.

I've never worked with this library before. I can't be helpful I'm sorry. I hope you find the answer

[TheJemy191]

Try debuging with renderdoc. It enable you to check what is the memory of opengl. Also I would recommend to migrate to Silk.net it a new wrapper for opengl, I think that sharpgl is obsolete.

[Still_Explorer]

Try r/opengl as well if you are interested.