public override void Init()
{
t = new Texture("Content/Untitled.png");
spriteBatch = new SpriteBatch();
Gl.Viewport(0, 0, Window.ClientBounds.Width, Window.ClientBounds.Height);
Gl.ClearColor(1, 0, 0, 1);
}
/// <summary>
/// Allocate GL resources or GL states.
/// </summary>
/// <param name="sender">
/// The <see cref="object"/> that has rasied the event.
/// </param>
/// <param name="e">
/// The <see cref="GlControlEventArgs"/> that specifies the event arguments.
/// </param>
private void RenderControl_ContextCreated(object sender, GlControlEventArgs e)
{
GlControl glControl = (GlControl)sender;
// GL Debugging
if (Gl.CurrentExtensions != null && Gl.CurrentExtensions.DebugOutput_ARB)
{
Gl.DebugMessageCallback(GLDebugProc, IntPtr.Zero);
Gl.DebugMessageControl(DebugSource.DontCare, DebugType.DontCare, DebugSeverity.DontCare, 0, null, true);
}
_renderer = _rendererFactory.Create(Gl.CurrentVersion);
_renderer.Create();
ContextCreated?.Invoke(sender, e);
Gl.ClearColor(0.0f, 0.4f, 0.6f, 1.0f);
// Uses multisampling, if available
if (Gl.CurrentVersion != null && Gl.CurrentVersion.Api == KhronosVersion.ApiGl && glControl.MultisampleBits > 0)
{
Gl.Enable(EnableCap.Multisample);
}
}
/// <inheritdoc />
public override void Setup(Vector2 renderSize)
{
Gl.BindAPI(s => Glfw.GetProcAddress(s));
Gl.QueryContextVersion();
// Check if context was created.
if (Gl.CurrentVersion == null)
{
ErrorHandler.SubmitError(new Exception("Couldn't connect to OpenGL context."));
return;
}
// Bind current thread as the GLThread.
GLThread.BindThread();
// Renderer bootstrap.
Engine.Log.Info("Creating OpenGL GraphicsManager...", MessageSource.GL);
Engine.Log.Info($"GL: {Gl.CurrentVersion} on {Gl.CurrentRenderer}", MessageSource.GL);
Engine.Log.Info($"GLSL: {Gl.CurrentShadingVersion}", MessageSource.GL);
CreateDefaultShader();
CreateDefaultIbo();
// Set default state.
DefaultGLState();
ResetState();
// Clear to transparent black.
Gl.ClearColor(0, 0, 0, 0);
Engine.Log.Info("GraphicsManager ready.", MessageSource.GL);
}
/// <summary>
/// Allocate resources for rendering.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ObjectsControl_ContextCreated(object sender, GlControlEventArgs e)
{
// Wrap GL context with GraphicsContext
_Context = new GraphicsContext(e.DeviceContext, e.RenderContext);
// Scene
_CubeScene = new SceneGraph(SceneGraphFlags.None)
{
SceneRoot = new SceneObjectGeometry(),
CurrentView = new SceneObjectCamera()
};
// Root object
// _CubeScene.SceneRoot.ObjectState.DefineState(new DepthTestState(DepthFunction.Less));
// Camera object
_CubeScene.SceneRoot.Link(_CubeScene.CurrentView);
// Horizontal plane
_CubeScene.SceneRoot.Link(CreatePlane());
// Create scene resource
_CubeScene.Create(_Context);
Gl.ClearColor(0.1f, 0.1f, 0.1f, 0.0f);
Gl.Enable(EnableCap.Multisample);
}
private SDLWIndow(string title, int width, int height) : base(title, width, height)
{
SDL.SDL_Init(SDL.SDL_INIT_VIDEO);
SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_DOUBLEBUFFER, 1);
SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_DEPTH_SIZE, 24);
SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_ALPHA_SIZE, 8);
SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_STENCIL_SIZE, 8);
var flags = SDL.SDL_WindowFlags.SDL_WINDOW_OPENGL | SDL.SDL_WindowFlags.SDL_WINDOW_RESIZABLE;
if (FullScreen)
{
flags |= SDL.SDL_WindowFlags.SDL_WINDOW_FULLSCREEN;
}
_window = SDL.SDL_CreateWindow("title",
SDL.SDL_WINDOWPOS_CENTERED,
SDL.SDL_WINDOWPOS_CENTERED,
width,
height,
flags);
EntryPoint.CoreLogger.Assert(_window == IntPtr.Zero, "Could not create window!");
_glContext = SDL.SDL_GL_CreateContext(_window);
EntryPoint.CoreLogger.Assert(_glContext == IntPtr.Zero, "Could not create context!");
Gl.ClearColor(0f, 0f, 0f, 1f);
Gl.Clear(ClearBufferMask.ColorBufferBit);
SDL.SDL_GL_SwapWindow(_window);
}
/// <summary>
/// Clear surface buffers.
/// </summary>
/// <param name="ctx">
/// A <see cref="GraphicsContext"/> used for clearing buffers.
/// </param>
/// <param name="bufferMask">
/// A <see cref="ClearBufferMask"/> indicating which buffers to clear.
/// </param>
public void Clear(GraphicsContext ctx, ClearBufferMask bufferMask)
{
// Update clear values (only what is necessary)
if ((bufferMask & ClearBufferMask.ColorBufferBit) != 0)
{
Gl.ClearColor(mClearColor.r, mClearColor.g, mClearColor.b, mClearColor.a);
}
#if !MONODROID
if ((bufferMask & ClearBufferMask.DepthBufferBit) != 0)
{
Gl.ClearDepth(mClearDepth);
}
#else
if ((bufferMask & ClearBufferMask.DepthBufferBit) != 0)
{
Gl.ClearDepth((float)mClearDepth);
}
#endif
if ((bufferMask & ClearBufferMask.StencilBufferBit) != 0)
{
Gl.ClearStencil(mClearStencil);
}
// Clear
Gl.Clear(bufferMask);
}
/// <summary>
/// Creates an OpenGL context in a valid SDL window.
/// </summary>
/// <param name="window">The valid SDL window.</param>
/// <param name="fullscreen">True if the window is already in fullscreen mode.</param>
public static ErrorCode CreateContextFromWindow(IntPtr window, bool fullscreen = false)
{
if (window == IntPtr.Zero)
{
return(ErrorCode.WindowWasNotInitialized);
}
int width, height;
SDL.SDL_GetWindowSize(window, out width, out height);
Width = width;
Height = height;
Fullscreen = fullscreen;
// create a valid OpenGL context within the newly created window
glContext = SDL.SDL_GL_CreateContext(window);
if (glContext == IntPtr.Zero)
{
return(ErrorCode.CouldNotCreateContext);
}
// initialize the screen to black as soon as possible
Gl.ClearColor(0f, 0f, 0f, 1f);
Gl.Clear(ClearBufferMask.ColorBufferBit);
SwapBuffers();
Open = true;
return(ErrorCode.Success);
}
public void InitializeRenderer(RendererWindow WindowHandle, IPreferredGraphicsDeviceFilter myPreferencesForDevice = null)
{
Gl.Enable(EnableCap.Multisample);
byte[] ShaderData = null;
Program myProgram = new Program(_VertexSourceGL, _FragmentSourceGL);
int linked;
Gl.GetProgram(ProgramName, ProgramProperty.LinkStatus, out linked);
if (linked == 0)
{
throw new Exception("Damn");
}
if ((LocationMVP = Gl.GetUniformLocation(ProgramName, "uMVP")) < 0)
{
throw new InvalidOperationException("no uniform uMVP");
}
// Get attributes locations
if ((LocationPosition = Gl.GetAttribLocation(ProgramName, "aPosition")) < 0)
{
throw new InvalidOperationException("no attribute aPosition");
}
if ((LocationColor = Gl.GetAttribLocation(ProgramName, "aColor")) < 0)
{
throw new InvalidOperationException("no attribute aColor");
}
this.WindowHandle = WindowHandle;
_VertexArray = new VertexArray(myProgram, _ArrayPosition, _ArrayColor);
Gl.Viewport(0, 0, WindowHandle.Width, WindowHandle.Height);
Gl.ClearColor(Color.AliceBlue.R, Color.AliceBlue.G, Color.AliceBlue.B, Color.AliceBlue.A);
}
public void Update()
{
Gl.BindFramebuffer(FramebufferTarget.Framebuffer, framebuffer);
Gl.Viewport(0, 0, screenWidth, screenHeight);
Color32 clrColor = sceneClear;
Gl.ClearColor(clrColor.r / 255.0f, clrColor.g / 255.0f, clrColor.b / 255.0f, 255.0f);
Gl.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
ObjRenderer.RenderQueue();
Debug.Label("obj render");
drawScreen.Render();
Debug.Label("soft render");
Gl.BindFramebuffer(FramebufferTarget.Framebuffer, 0);
Gl.Viewport(0, 0, windowWidth, windowHeight);
Gl.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
Debug.Label("framebuffer swap");
Gl.UseProgram(shader);
Gl.BindBufferToShaderAttribute(vertices, shader, "pos");
Gl.BindBufferToShaderAttribute(uvs, shader, "uv");
Gl.BindBuffer(triangles);
Gl.BindTexture(TextureTarget.Texture2D, texture);
Gl.DrawElements(BeginMode.Triangles, 6, DrawElementsType.UnsignedInt, IntPtr.Zero);
Debug.Label("framebuffer render");
SDL.SDL_GL_SwapWindow(window);
Debug.Label("swap window");
}
private void OnRender(object sender, OpenGL.GlControlEventArgs e)
{
GlControl gl_control = (GlControl)sender;
if ((LastMotion == null) || (LastMotion.Finished == true))
{
// モーションをランダムに再生する
// 名前なしのモーショングループから0～9番のモーションを乱数で選ぶ
var motion_group = Asset.MotionGroups[""];
int number = new Random().Next() % motion_group.Length;
var motion = (CubismMotion)motion_group[number];
LastMotion = Asset.StartMotion(CubismAsset.MotionType.Base, motion, false);
}
// モデルを更新する
var elapsed = Timer.Elapsed;
Timer.Restart();
Asset.Update(elapsed.TotalSeconds);
// モデルを描画する
Gl.ClearColor(0.0f, 0.5f, 0.5f, 1.0f);
Gl.Clear(ClearBufferMask.ColorBufferBit);
Gl.Viewport(0, 0, gl_control.Width, gl_control.Height);
Matrix mvp_matrix = DenseMatrix.CreateIdentity(4);
mvp_matrix[0, 0] = 2.0f;
mvp_matrix[1, 1] = 2.0f * gl_control.Width / gl_control.Height;
RenderingManager.Draw(mvp_matrix);
}
protected void Run()
{
while (!_mainWindow.Closing)
{
if (!_mainWindow.HandleEvents())
{
return;
}
Gl.Clear(Gl.ColorBufferBit);
Gl.ClearColor(0.6901961f, 0.1921569f, 0.2470588f, 1);
Gl.MatrixMode(Gl.Projection);
Gl.LoadIdentity();
Gl.Ortho(0, 1, 0, 1, 0, 1);
Gl.Begin(Gl.Triangles);
Gl.Color3(1, 0, 0);
Gl.Vertex2(0, 0);
Gl.Color3(0, 1, 0);
Gl.Vertex2(0.5f, 1);
Gl.Color3(0, 0, 1);
Gl.Vertex2(1, 0);
Gl.End();
//Gl.Clear(Gl.ColorBufferBit);
_mainWindow.Swap();
}
}
private void RenderControl_Render_GLSL(object sender, GlControlEventArgs e)
{
Control control = (Control)sender;
PerspectiveProjectionMatrix projectionMatrix = new PerspectiveProjectionMatrix(45.0f, (float)control.Width / (float)control.Height, 0.1f, 100.0f);
ModelMatrix viewMatrix = new ModelMatrix();
ModelMatrix modelMatrix = new ModelMatrix();
modelMatrix.Translate(new Vertex3f(modelPosition.X, modelPosition.Y, modelPosition.Z));
modelMatrix.Scale(new Vertex3f(0.2f, 0.2f, 0.2f));
Gl.Viewport(0, 0, control.Width, control.Height);
Gl.ClearColor(0.05f, 0.05f, 0.05f, 1.0f);
Gl.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
modelShader.Use();
modelMatrix.RotateX(modelAngle.X);
modelMatrix.RotateY(modelAngle.Y);
modelMatrix.RotateZ(modelAngle.Z);
//viewMatrix.Translate(new Vertex3f(-2.0f * (float)Math.Sin(modelAngle.Y * PI_OVER_180), 0.0f, -2.0f*(float)Math.Cos(modelAngle.Y*PI_OVER_180)));
Gl.UniformMatrix4(modelShader.uLocation_Projection, 1, false, projectionMatrix.ToArray());
Gl.UniformMatrix4(modelShader.uLocation_View, 1, false, viewMatrix.ToArray());
Gl.UniformMatrix4(modelShader.uLocation_Model, 1, false, modelMatrix.ToArray());
modelNanosuit.Draw(modelShader);
}
private static void OnRenderFrame()
{
// calculate how much time has elapsed since the last frame
watch.Stop();
float deltaTime = (float)watch.ElapsedTicks / System.Diagnostics.Stopwatch.Frequency;
watch.Restart();
Matrix4 modelMatrix = CreateModelMatrix(time_);
time_ += deltaTime;
effect_.update(deltaTime, Neutrino._math.vec3_(modelMatrix[3].x, modelMatrix[3].y, modelMatrix[3].z), null);
// set up the OpenGL viewport and clear both the color and depth bits
Gl.Viewport(0, 0, width, height);
//Gl.ClearColor(0.5F, 0.5F, 0.5F, 0.0F);
Gl.ClearColor(0.4F, 0.4F, 0.4F, 0.0F);
Gl.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
Matrix4 projMatrix = Matrix4.CreatePerspectiveFieldOfView(60F * (float)Math.PI / 180F, (float)width / height, 1F, 10000F); //.CreateOrthographic(width, height, 1F, 10000F);
Matrix4 viewMatrix = Matrix4.LookAt(new Vector3(0, 0, 1000), Vector3.Zero, Vector3.Up);
effect_.render(ref projMatrix, ref viewMatrix, ref modelMatrix);
Glut.glutSwapBuffers();
}
/// <summary>
/// Update framebuffer.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ObjectsControl_Render(object sender, GlControlEventArgs e)
{
GlControl senderControl = (GlControl)sender;
float senderAspectRatio = (float)senderControl.Width / senderControl.Height;
// Clear
Gl.Viewport(0, 0, senderControl.Width, senderControl.Height);
Gl.ClearColor(1.0f, 0.0f, 0.0f, 1.0f);
Gl.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
_CubeScene.CurrentView.ProjectionMatrix = Matrix4x4f.Perspective(45.0f, senderAspectRatio, 0.1f, 100.0f);
// _CubeScene.CurrentView.LocalModelView = Matrix4x4f.Translated(0.0f, 0.0f, 10.0f);
//_CubeScene.CurrentView.LocalModelView =
// Matrix4x4f.Translated(_ViewStrideLat, _ViewStrideAlt, 0.0f) *
// Matrix4x4f.RotatedY(_ViewAzimuth) *
// Matrix4x4f.RotatedX(_ViewElevation) *
// Matrix4x4f.Translated(0.0f, 0.0f, _ViewLever);
//_CubeScene.CurrentView.LocalModelView =
// Matrix4x4f.Translated(0.0f, 0.0f, _ViewLever) *
// Matrix4x4f.RotatedX(_ViewElevation) *
// Matrix4x4f.RotatedY(_ViewAzimuth) *
// Matrix4x4f.Translated(_ViewStrideLat, _ViewStrideAlt, 0.0f);
_CubeScene.UpdateViewMatrix();
_CubeScene.Draw(_Context);
}
private void Render()
{
_transform *= Mat4F.Rotation(1, new Vec3 <float>(0.0f, 0.0f, 1.0f));
_root.Transform = _transform;
Gl.ClearColor(0.2f, 0.3f, 0.3f, 1.0f);
Gl.Clear(Gl.ColorBufferBit);
_root.Render();
}
private void glClear(uint color, float alpha)
{
uint r = ((color & 0x00ff0000) >> 16);
uint g = ((color & 0x0000ff00) >> 8);
uint b = ((color & 0x000000ff));
Gl.ClearColor(r / 255f, g / 255f, b / 255f, alpha);
}
static void Main(string[] args)
{
Glfw.Init();
Glfw.WindowHint(Hint.ContextVersionMajor, 4);
Glfw.WindowHint(Hint.ContextVersionMinor, 6);
Glfw.WindowHint(Hint.OpenglProfile, Profile.Compatibility);
Window window = Glfw.CreateWindow(1080, 720, "Yeet", Monitor.None, Window.None);
// `Gl.Initialize()` has to be don before `Glfw.MakeContextCurrent(window)`
// [How Do I Initialize OpenGL.NET with GLFW.Net?](https://stackoverflow.com/questions/61318104/how-do-i-initialize-opengl-net-with-glfw-net/61319044?noredirect=1#comment108476826_61319044)
Gl.Initialize();
Glfw.MakeContextCurrent(window);
var v = Gl.GetString(StringName.Version);
Console.WriteLine(v);
uint vao = Gl.CreateVertexArray();
Gl.BindVertexArray(vao);
uint vbo = Gl.GenBuffer();
Gl.BindBuffer(BufferTarget.ArrayBuffer, vbo);
var vertices = new float[] { -0.5f, -0.5f, 0.5f, -0.5f, 0.0f, 0.5f };
Gl.BufferData(BufferTarget.ArrayBuffer, (uint)(4 * vertices.Length), null, BufferUsage.StaticDraw);
IntPtr unmanagedPointer = Marshal.AllocHGlobal(4 * vertices.Length);
Marshal.Copy(vertices, 0, unmanagedPointer, vertices.Length);
Gl.BufferSubData(BufferTarget.ArrayBuffer, new IntPtr(0), (uint)(4 * vertices.Length), unmanagedPointer);
Marshal.FreeHGlobal(unmanagedPointer);
//Gl.BufferSubData(BufferTarget.ArrayBuffer, new IntPtr(0), (uint)(4 * vertices.Length), vertices);
Gl.VertexAttribPointer(0, 2, VertexAttribType.Float, false, 0, null);
while (!Glfw.WindowShouldClose(window))
{
Glfw.PollEvents();
Gl.ClearColor(0.0f, 1.0f, 1.0f, 1.0f);
Gl.Clear(ClearBufferMask.ColorBufferBit);
Gl.BindVertexArray(vao);
Gl.EnableVertexAttribArray(0);
Gl.DrawArrays(PrimitiveType.Triangles, 0, 3);
Gl.DisableVertexAttribArray(0);
Gl.BindVertexArray(0);
Glfw.SwapBuffers(window);
}
Glfw.DestroyWindow(window);
Glfw.Terminate();
}
public void ClearBuffer(Pixel p, bool bDepth)
{
Gl.ClearColor((float)p.r / 255.0f, (float)p.g / 255.0f, (float)p.b / 255.0f, (float)p.a / 255.0f);
Gl.Clear(ClearBufferMask.ColorBufferBit);
if (bDepth)
{
Gl.Clear(ClearBufferMask.DepthBufferBit);
}
}
private void glClear(uint color)
{
uint a = ((color & 0xff000000) >> 24);
uint r = ((color & 0x00ff0000) >> 16);
uint g = ((color & 0x0000ff00) >> 8);
uint b = ((color & 0x000000ff));
Gl.ClearColor(r / 255f, g / 255f, b / 255f, a);
}
public override void Draw(int viewPortWidth, int viewPortHeight)
{
UserProgram(_program);
Gl.ClearColor(0.0f, 0.5f, 1.0f, 1.0f);
Gl.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
Gl.BindTexture(TextureTarget.Texture2d, _texture1);
base.Draw(viewPortWidth, viewPortHeight);
Gl.BindVertexArray(_vertexAttrObject);
Gl.DrawArrays(PrimitiveType.Triangles, 0, _figureResult.Figure.Length);
}
private void WindowOnRender(double deltaTime)
{
Controller.Update((float)deltaTime);
Gl.ClearColor(Color.FromArgb(255, 0, 32, 40));
Gl.Clear((uint)(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit | ClearBufferMask.StencilBufferBit));
ImGuiNET.ImGui.ShowDemoWindow();
Controller.Render();
}
public void ClearFrameBuffer(float r, float g, float b, float a)
{
FrameBuffer.Bind();
Gl.ClearColor(r, g, b, a);
Gl.ClearDepth(1.0f);
Gl.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
FrameBuffer.Unbind();
}
public ImageBoxWindow()
{
InitializeComponent();
GlWindow = new GlWindow(Handle);
GlWindow.Begin();
Gl.ClearColor(Color.WhiteSmoke);
GlWindow.End();
}
private void SurfaceView_Render(object sender, GLSurfaceViewEventArgs e)
{
GLSurfaceView glSurfaceView = (GLSurfaceView)sender;
Gl.Viewport(0, 0, glSurfaceView.Width, glSurfaceView.Height);
Gl.ClearColor(0.0f, 0.0f, 0.0f, 1.0f);
Gl.Clear(ClearBufferMask.ColorBufferBit);
Es2_Render();
}
public override void Draw(int viewPortWidth, int viewPortHeight)
{
UserProgram(_program);
Gl.ClearColor(0.0f, 0.5f, 1.0f, 1.0f);
Gl.Clear(ClearBufferMask.ColorBufferBit);
int vertexCount = _figureResult.Figure.Length / _figureResult.VertexPerLineCount;
Gl.BindVertexArray(_vertexAttrObject);
Gl.DrawArrays(PrimitiveType.Triangles, 0, vertexCount);
}
/// <summary>
/// Clears the render context with a certain color and alpha value. Since this also
/// clears the stencil buffer, the stencil reference value is also reset to '0'.
/// </summary>
public void Clear(uint rgb = 0, float alpha = 0.0f)
{
ApplyRenderTarget();
float red = ColorUtil.GetR(rgb) / 255.0f;
float green = ColorUtil.GetG(rgb) / 255.0f;
float blue = ColorUtil.GetB(rgb) / 255.0f;
Gl.ClearColor(red, green, blue, alpha);
Gl.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.StencilBufferBit | ClearBufferMask.DepthBufferBit);
}
/// <summary>
/// Allocate resources for rendering.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ObjectsControl_ContextCreated(object sender, GlControlEventArgs e)
{
// Wrap GL context with GraphicsContext
_Context = new GraphicsContext(e.DeviceContext, e.RenderContext);
// Create resources
CreateResources(_Context);
Gl.ClearColor(0.1f, 0.1f, 0.1f, 0.0f);
Gl.Enable(EnableCap.Multisample);
}
internal ImageBoxMiniMap(ImageBoxWindow imageBoxWindow)
{
InitializeComponent();
m_glWindow = new GlWindow(Handle);
m_glWindow.Begin();
Gl.ClearColor(Color.WhiteSmoke);
m_glWindow.End();
m_imageBoxWindow = imageBoxWindow;
Win32.wglShareLists(m_imageBoxWindow.GlWindow.Hglrc, m_glWindow.Hglrc);
}
private void GlControl_OnContextCreated(object sender, GlControlEventArgs e)
{
var control = (GlControl)sender;
Gl.MatrixMode(MatrixMode.Modelview);
Gl.LoadIdentity();
Gl.ClearColor(_bgColorVec.X, _bgColorVec.Y, _bgColorVec.Z, _bgColorVec.W);
Shader = new ShaderHelper();
AdjustOrtho(new Size(control.Height, control.Width));
}
private static void OnRenderFrame()
{
// set up the OpenGL viewport and clear both the color and depth bits
Gl.Viewport(0, 0, Window.Width, Window.Height);
Gl.ClearColor(0.2f, 0.2f, 0.2f, 1.0f);
Gl.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
// draw the user interface after everything else
OpenGL.UI.UserInterface.Draw();
// finally, swap the back buffer to the front so that the screen displays
Window.SwapBuffers();
}