551455-graphics-programming-2526-the-repo-Zyb3rWolfi/TheRepo/TheLabs/MyExampleWindow.cs

using Assimp;
using OpenTK.Graphics.OpenGL4;
using OpenTK.Windowing.Common;
using OpenTK.Windowing.GraphicsLibraryFramework;
using OpenTK.Windowing.Desktop;
using LearnOpenTK.Common;
using OpenTK.Mathematics;
using TheLabs.Shapes;

namespace TheLabs
{
    public class MyExampleWindow : GameWindow
    {
        // Create the vertices for our triangle. These are listed in normalized device coordinates (NDC)
        // In NDC, (0, 0) is the center of the screen.
        // Negative X coordinates move to the left, positive X move to the right.
        // Negative Y coordinates move to the bottom, positive Y move to the top.
        // OpenGL only supports rendering in 3D, so to create a flat triangle, the Z coordinate will be kept as 0.
        
        private SceneNode _rootNode;
        private SceneNode _characterNode;
        private SceneNode _buildingNode;
        private Shader _shader;
        private Camera _camera;
        // - Resources that only need to be created once
        private Mesh _exampleObject;
        private Mesh _buildingObject;
        private Texture _texture;
        private RenderObject _render;
        private RenderObject _buildingRender;
        float _rotation = 0.0f;
        
        // -- Scene Objects
        
        private Vector3 _cameraPosition = new Vector3(0.0f, 0.0f, -3.0f);
        private Vector3 _cameraFront = new Vector3(0.0f, 0.0f, -1.0f);

        private Vector3 _cameraUp = Vector3.UnitY;
        
        private float _yaw = -90.0f;
        private float _pitch = 0.0f;
        
        private float _cameraSpeed = 2.5f;
        private float _rotationSpeed = 50.0f;
        
        private float _mouseSensitivity = 0.1f; 

        // This prevents a large camera jump when the window first gets focus
        private bool _firstMove = true;

        public MyExampleWindow(GameWindowSettings gameWindowSettings, NativeWindowSettings nativeWindowSettings)
            : base(gameWindowSettings, nativeWindowSettings)
        {
        }

        // Now, we start initializing OpenGL.
        protected override void OnLoad()
        { 
            // This is called when the window is created and is where we can set up OpenGL resources.
            base.OnLoad();
            //GL.Disable(EnableCap.CullFace);
            
            //GL.PolygonMode(MaterialFace.FrontAndBack, PolygonMode.Line);
            GL.ClearColor(0.2f, 0.3f, 0.3f, 1.0f); 
            GL.Enable(EnableCap.DepthTest);
            _camera = new Camera(_cameraPosition, _cameraFront, _cameraUp);
            _shader = new Shader("Shaders/shader.vert", "Shaders/shader.frag");
            _texture = new Texture("Textures/texture-a.png");
            
            _rootNode = new SceneNode();
            _exampleObject = ModelLoader.LoadMesh("Objects/cat.obj");
            _buildingObject = ModelLoader.LoadMesh("Objects/building1.obj");
            _render = new RenderObject(_exampleObject, _shader, _texture);
            _buildingRender = new RenderObject(_buildingObject, _shader, _texture);
            
            _characterNode = new SceneNode(_render);
            _characterNode.Position = new Vector3(0.0f, -1.0f, 0.0f);
            _rootNode.AddChild(_characterNode);
            
            _buildingNode = new SceneNode(_buildingRender);
            _buildingNode.Position = new Vector3(2.0f, -1.0f, 0.0f);
            _rootNode.AddChild(_buildingNode);
            
            
            
            
            CursorState = CursorState.Grabbed;



        }

        // Now that initialization is done, let's create our render loop.
        protected override void OnRenderFrame(FrameEventArgs e)
        {
            // This is called once per frame and is where all the rendering code goes.
            base.OnRenderFrame(e);
            // Clear the color buffer and the depth buffer
            GL.Clear(ClearBufferMask.DepthBufferBit | ClearBufferMask.ColorBufferBit);
            //_cubeObject.Rotation = Quaternion.FromEulerAngles(_rotation * 0.5f, _rotation, 0); //
            //_cubeObject2.Rotation = Quaternion.FromEulerAngles(-_rotation * 0.5f, -_rotation, 0);
            
            // --- Set up Camera ---
            Matrix4 view = _camera.LookAt();        
            float aspectRatio = (float)Size.X / Size.Y;

            // 2. Add a safety check for divide-by-zero
            if (Size.Y == 0 || Size.X == 0)
            {
                aspectRatio = 1.0f; // Default to 1:1 if window is minimized
            }
            Matrix4 projection = Matrix4.CreatePerspectiveFieldOfView(
                MathHelper.DegreesToRadians(45f),
                aspectRatio,
                0.1f,
                100.0f
            );
            // --- Draw Scene Objects ---
            _rootNode.Draw(view, projection, Matrix4.Identity);
            
            SwapBuffers();
        }

        protected override void OnUpdateFrame(FrameEventArgs e)
        {
            base.OnUpdateFrame(e);
            _rotation += (float)e.Time;
            var input = KeyboardState;

            if (input.IsKeyDown(Keys.Escape))
            {
                Close();
            }

            if (!IsFocused)
            {
                _firstMove = true;
                return;
            }

            var mouuse = MouseState;
            
            if (_firstMove)
            {
                mouuse = MouseState;
                _firstMove = false;
            }
            else
            {
                // Get the mouse's movement delta
                float deltaX = mouuse.Delta.X;
                float deltaY = mouuse.Delta.Y;
        
                // Apply sensitivity
                _yaw += deltaX * _mouseSensitivity;
                _pitch -= deltaY * _mouseSensitivity; // Y-axis is inverted
            }
            
            
            // --- Rotation (Arrow Keys) ---
            if (input.IsKeyDown(Keys.Left))
            {
                _yaw -= _rotationSpeed * (float)e.Time;
            }
            if (input.IsKeyDown(Keys.Right))
            {
                _yaw += _rotationSpeed * (float)e.Time;
            }
            if (input.IsKeyDown(Keys.Up))
            {
                _pitch += _rotationSpeed * (float)e.Time;
            }
            if (input.IsKeyDown(Keys.Down))
            {
                _pitch -= _rotationSpeed * (float)e.Time;
            }
            _pitch = MathHelper.Clamp(_pitch, -89.0f, 89.0f);
            Vector3 front;
            _camera._target.X = MathF.Cos(MathHelper.DegreesToRadians(_yaw)) * MathF.Cos(MathHelper.DegreesToRadians(_pitch));
            _camera._target.Y = MathF.Sin(MathHelper.DegreesToRadians(_pitch));
            _camera._target.Z = MathF.Sin(MathHelper.DegreesToRadians(_yaw)) * MathF.Cos(MathHelper.DegreesToRadians(_pitch));
            
            _cameraFront = Vector3.Normalize(_camera._target);
            var _cameraRight = Vector3.Normalize(Vector3.Cross(_cameraFront, _camera._up));            
            if (input.IsKeyDown(Keys.W)) _camera._position += _cameraFront * _cameraSpeed * (float)e.Time;
            if (input.IsKeyDown(Keys.S)) _camera._position -= _cameraFront * _cameraSpeed * (float)e.Time;
            if (input.IsKeyDown(Keys.A)) _camera._position -= _cameraRight * _cameraSpeed * (float)e.Time;
            if (input.IsKeyDown(Keys.D)) _camera._position += _cameraRight * _cameraSpeed * (float)e.Time;
        
        }
        

        protected override void OnResize(ResizeEventArgs e)
        {
            base.OnResize(e);

            // When the window gets resized, we have to call GL.Viewport to resize OpenGL's viewport to match the new size.
            // If we don't, the NDC will no longer be correct.
            GL.Viewport(0, 0, Size.X, Size.Y);
        }

        // Now, for cleanup.
        // You should generally not do cleanup of opengl resources when exiting an application,
        // as that is handled by the driver and operating system when the application exits.
        // 
        // There are reasons to delete opengl resources, but exiting the application is not one of them.
        // This is provided here as a reference on how resource cleanup is done in opengl, but
        // should not be done when exiting the application.
        //
        // Places where cleanup is appropriate would be: to delete textures that are no
        // longer used for whatever reason (e.g. a new scene is loaded that doesn't use a texture).
        // This would free up video ram (VRAM) that can be used for new textures.
        //
        // The coming chapters will not have this code.
        protected override void OnUnload()
        {
            // Unbind all the resources by binding the targets to 0/null.
            GL.BindBuffer(BufferTarget.ArrayBuffer, 0);
            GL.BindVertexArray(0);
            GL.UseProgram(0);

            GL.DeleteProgram(_shader.Handle);

            base.OnUnload();
        }
    }
}