Chapter 3 Part 1: Model Loading

.gitattributes

@@ -43,6 +43,7 @@
 #*.jpg   binary
 #*.png   binary
 #*.gif   binary
+*.obj binary
 
 ###############################################################################
 # diff behavior for common document formats

Chapter1/2-HelloTriangle/Window.cs

@@ -209,7 +209,7 @@ protected override void OnUnload()
             GL.DeleteBuffer(_vertexBufferObject);
             GL.DeleteVertexArray(_vertexArrayObject);
 
-            GL.DeleteProgram(_shader.ID);
+            GL.DeleteProgram(_shader.Handle);
 
             base.OnUnload();
         }

Chapter1/4-Shaders-Uniforms/Window.cs

@@ -83,7 +83,7 @@ protected override void OnRenderFrame(FrameEventArgs e)
 
             // This gets the uniform variable location from the frag shader so that we can 
             // assign the new green value to it.
-            int vertexColorLocation = GL.GetUniformLocation(_shader.ID, "ourColor");
+            int vertexColorLocation = GL.GetUniformLocation(_shader.Handle, "ourColor");
 
             // Here we're assigning the ourColor variable in the frag shader 
             // via the OpenGL Uniform method which takes in the value as the individual vec values (which total 4 in this instance).

Chapter1/5-Textures/Window.cs

@@ -77,7 +77,7 @@ protected override void OnLoad()
             GL.EnableVertexAttribArray(texCoordLocation);
             GL.VertexAttribPointer(texCoordLocation, 2, VertexAttribPointerType.Float, false, 5 * sizeof(float), 3 * sizeof(float));
 
-            _texture = Texture.LoadFromFile("Resources/container.png");
+            _texture = Texture.LoadFromFile("container.png", "Resources", "diffuse");
             _texture.Use(TextureUnit.Texture0);
         }
 

Chapter3/1-ModelLoading/1-ModelLoading.csproj

@@ -3,7 +3,7 @@
     <OutputType>WinExe</OutputType>
     <RootNamespace>LearnOpenTK</RootNamespace>
     <AssemblyName>LearnOpenTK</AssemblyName>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <ApplicationIcon />
     <StartupObject />
   </PropertyGroup>

Chapter3/1-ModelLoading/Window.cs

@@ -172,8 +172,6 @@ protected override void OnRenderFrame(FrameEventArgs e)
             // First we setup the shader, including the texture uniform and then call the Draw() method on the imported model to draw all the contained meshes
             _backPackShader.Use();
             Matrix4 model = Matrix4.Identity;
-            //Matrix4.CreateScale(2.0f, 2.0f, 2.0f, out model);
-            //Matrix4.CreateTranslation(0.0f, 0.0f, 2.8f, out model);
 
             _backPackShader.SetMatrix4("model", model);
             _backPackShader.SetMatrix4("view", _camera.GetViewMatrix());
@@ -189,7 +187,7 @@ protected override void OnRenderFrame(FrameEventArgs e)
             _shader.Use();
 
             // Change triangle color
-            int vertexColorLocation = GL.GetUniformLocation(_shader.ID, "ourColor");
+            int vertexColorLocation = GL.GetUniformLocation(_shader.Handle, "ourColor");
             GL.Uniform4(vertexColorLocation, _color.X, _color.Y, _color.Z, 1.0f);
 
             // Bind the VAO

Common/Model.cs

@@ -194,17 +194,17 @@ private List<Texture> loadMaterialTextures(Material mat, TextureType type, strin
         {
             List<Texture> textures = new List<Texture>();
 
-
             for (int i = 0; i < mat.GetMaterialTextureCount(type); i++)
             {
                 TextureSlot str;
                 mat.GetMaterialTexture(type, i, out str);
+                string filename = directory + "/" + str.FilePath;
                 // check if texture was loaded before and if so, continue to next iteration: skip loading a new texture
                 bool skip = false;
                 for (int j = 0; j < textures_loaded.Count; j++)
                 {
 
-                    if (textures_loaded[j].path.CompareTo(str.FilePath)==0)
+                    if (textures_loaded[j].path.CompareTo(filename) ==0)
                     {
                         textures.Add(textures_loaded[j]);
                         skip = true; // a texture with the same filepath has already been loaded, continue to next one. (optimization)
@@ -213,7 +213,7 @@ private List<Texture> loadMaterialTextures(Material mat, TextureType type, strin
                 }
                 if (!skip)
                 {   // if texture hasn't been loaded already, load it
-                    Texture texture = Texture.LoadFromFile(str.FilePath, directory, typeName);
+                    Texture texture = Texture.LoadFromFile(filename, typeName);
                     textures.Add(texture);
                     textures_loaded.Add(texture);  // store it as texture loaded for entire model, to ensure we won't unnecessary load duplicate textures.
                 }

Common/Shader.cs

@@ -10,7 +10,7 @@ namespace LearnOpenTK.Common
     // A simple class meant to help create shaders.
     public class Shader
     {
-        public readonly int ID;
+        public readonly int Handle;
 
         private readonly Dictionary<string, int> _uniformLocations;
 
@@ -46,19 +46,19 @@ public Shader(string vertPath, string fragPath)
 
             // These two shaders must then be merged into a shader program, which can then be used by OpenGL.
             // To do this, create a program...
-            ID = GL.CreateProgram();
+            Handle = GL.CreateProgram();
 
             // Attach both shaders...
-            GL.AttachShader(ID, vertexShader);
-            GL.AttachShader(ID, fragmentShader);
+            GL.AttachShader(Handle, vertexShader);
+            GL.AttachShader(Handle, fragmentShader);
 
             // And then link them together.
-            LinkProgram(ID);
+            LinkProgram(Handle);
 
             // When the shader program is linked, it no longer needs the individual shaders attached to it; the compiled code is copied into the shader program.
             // Detach them, and then delete them.
-            GL.DetachShader(ID, vertexShader);
-            GL.DetachShader(ID, fragmentShader);
+            GL.DetachShader(Handle, vertexShader);
+            GL.DetachShader(Handle, fragmentShader);
             GL.DeleteShader(fragmentShader);
             GL.DeleteShader(vertexShader);
 
@@ -67,7 +67,7 @@ public Shader(string vertPath, string fragPath)
             // later.
 
             // First, we have to get the number of active uniforms in the shader.
-            GL.GetProgram(ID, GetProgramParameterName.ActiveUniforms, out var numberOfUniforms);
+            GL.GetProgram(Handle, GetProgramParameterName.ActiveUniforms, out var numberOfUniforms);
 
             // Next, allocate the dictionary to hold the locations.
             _uniformLocations = new Dictionary<string, int>();
@@ -76,10 +76,10 @@ public Shader(string vertPath, string fragPath)
             for (var i = 0; i < numberOfUniforms; i++)
             {
                 // get the name of this uniform,
-                var key = GL.GetActiveUniform(ID, i, out _, out _);
+                var key = GL.GetActiveUniform(Handle, i, out _, out _);
 
                 // get the location,
-                var location = GL.GetUniformLocation(ID, key);
+                var location = GL.GetUniformLocation(Handle, key);
 
                 // and then add it to the dictionary.
                 _uniformLocations.Add(key, location);
@@ -118,14 +118,14 @@ private static void LinkProgram(int program)
         // A wrapper function that enables the shader program.
         public void Use()
         {
-            GL.UseProgram(ID);
+            GL.UseProgram(Handle);
         }
 
         // The shader sources provided with this project use hardcoded layout(location)-s. If you want to do it dynamically,
         // you can omit the layout(location=X) lines in the vertex shader, and use this in VertexAttribPointer instead of the hardcoded values.
         public int GetAttribLocation(string attribName)
         {
-            return GL.GetAttribLocation(ID, attribName);
+            return GL.GetAttribLocation(Handle, attribName);
         }
 
         // Uniform setters
@@ -144,7 +144,7 @@ public int GetAttribLocation(string attribName)
         /// <param name="data">The data to set</param>
         public void SetInt(string name, int data)
         {
-            GL.UseProgram(ID);
+            GL.UseProgram(Handle);
             GL.Uniform1(_uniformLocations[name], data);
         }
 
@@ -155,7 +155,7 @@ public void SetInt(string name, int data)
         /// <param name="data">The data to set</param>
         public void SetFloat(string name, float data)
         {
-            GL.UseProgram(ID);
+            GL.UseProgram(Handle);
             GL.Uniform1(_uniformLocations[name], data);
         }
 
@@ -171,7 +171,7 @@ public void SetFloat(string name, float data)
         /// </remarks>
         public void SetMatrix4(string name, Matrix4 data)
         {
-            GL.UseProgram(ID);
+            GL.UseProgram(Handle);
             GL.UniformMatrix4(_uniformLocations[name], true, ref data);
         }
 
@@ -182,7 +182,7 @@ public void SetMatrix4(string name, Matrix4 data)
         /// <param name="data">The data to set</param>
         public void SetVector3(string name, Vector3 data)
         {
-            GL.UseProgram(ID);
+            GL.UseProgram(Handle);
             GL.Uniform3(_uniformLocations[name], data);
         }
     }

Common/Texture.cs

@@ -12,10 +12,8 @@ public class Texture
         public string type;
         public string path;
 
-        public static Texture LoadFromFile(string path, string directory, string type)
+        public static Texture LoadFromFile(string filename, string type = "texture_diffuse")
         {
-            string filename = new string(path);
-            filename = directory + '/' + filename;
 
             // Generate handle ID
             int ID = GL.GenTexture();
@@ -29,7 +27,7 @@ public static Texture LoadFromFile(string path, string directory, string type)
             // OpenGL has it's texture origin in the lower left corner instead of the top left corner,
             // so we tell StbImageSharp to flip the image when loading.
             // StbImage.stbi_set_flip_vertically_on_load(1);
-            
+
             // Here we open a stream to the file and pass it to StbImageSharp to load.
             using (Stream stream = File.OpenRead(filename))
             {
@@ -48,7 +46,7 @@ public static Texture LoadFromFile(string path, string directory, string type)
                 //   And finally, the actual pixels.
                 GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, image.Width, image.Height, 0, PixelFormat.Rgba, PixelType.UnsignedByte, image.Data);
             }
-            
+
             // Now that our texture is loaded, we can set a few settings to affect how the image appears on rendering.
 
             // First, we set the min and mag filter. These are used for when the texture is scaled down and up, respectively.
@@ -73,10 +71,9 @@ public static Texture LoadFromFile(string path, string directory, string type)
             // Here is an example of mips in action https://en.wikipedia.org/wiki/File:Mipmap_Aliasing_Comparison.png
             GL.GenerateMipmap(GenerateMipmapTarget.Texture2D);
 
-            return new Texture(ID, path, type);
+            return new Texture(ID, filename, type);
         }
 
-
         public Texture(int glHandle, string path, string type)
         {
             this.ID = glHandle;