public void CreateTextureRender(GLContext control, EventHandler thumbnailUpdate, int width = 50, int height = 50)
        {
            var shader = GlobalShaders.GetShader("SCREEN");

            Framebuffer frameBuffer = new Framebuffer(FramebufferTarget.Framebuffer, width, height);

            frameBuffer.Bind();

            GL.ClearColor(0, 0, 0, 0);
            GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
            GL.Viewport(0, 0, width, height);

            GL.Disable(EnableCap.Blend);

            shader.Enable();

            //Draw the texture onto the framebuffer
            ScreenQuadRender.Draw(shader, RenderableTex.ID);

            //Disable shader and textures
            GL.UseProgram(0);
            GL.BindTexture(TextureTarget.Texture2D, 0);

            var thumbnail = frameBuffer.ReadImagePixels(true);

            thumbnail.RotateFlip(System.Drawing.RotateFlipType.RotateNoneFlipY);

            //Dispose frame buffer
            frameBuffer.Dispoe();
            frameBuffer.DisposeRenderBuffer();

            this.Thumbnail = thumbnail;
            thumbnailUpdate?.Invoke(this, EventArgs.Empty);
        }
        private void GenerateRender(GLContext control, EventHandler thumbnailUpdate)
        {
            Framebuffer frameBuffer = new Framebuffer(FramebufferTarget.Framebuffer, Width, Height);

            frameBuffer.Bind();

            GL.ClearColor(0, 0, 0, 0);
            GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
            GL.Viewport(0, 0, control.Width, control.Height);

            var camMtx  = Camera.ViewMatrix;
            var projMtx = Camera.ProjectionMatrix;

            //Draw all the models into the current camera screen
            //     scene.Draw(control, Pass.OPAQUE);
            //     scene.Draw(control, Pass.TRANSPARENT);

            //Disable shader and textures
            GL.UseProgram(0);
            GL.BindTexture(TextureTarget.Texture2D, 0);

            RenderedScreen = (GLTexture2D)frameBuffer.Attachments[1];
            var thumbnail = frameBuffer.ReadImagePixels(true);

            //Dispose frame buffer
            frameBuffer.Dispoe();
            frameBuffer.DisposeRenderBuffer();

            this.Thumbnail = thumbnail;
            thumbnailUpdate?.Invoke(this, EventArgs.Empty);
        }
        public void CreateMaterialRender(GLContext control, GenericPickableMesh mesh,
                                         RenderObject renderObject, EventHandler thumbnailUpdated, int width = 50, int height = 50)
        {
            ShaderProgram shader = this.GetShader();

            if (shader == null)
            {
                return;
            }

            Framebuffer frameBuffer = new Framebuffer(FramebufferTarget.Framebuffer, width, height);

            frameBuffer.Bind();

            //Create a simple mvp matrix to render the material data
            Matrix4 modelMatrix = Matrix4.CreateTranslation(0, 0, -12);
            Matrix4 viewMatrix  = Matrix4.Identity;
            Matrix4 mtxProj     = Matrix4.CreatePerspectiveFieldOfView(MathHelper.DegreesToRadians(90), 1.0f, 1.0f, 1000f);
            Matrix4 viewProj    = mtxProj * viewMatrix;

            GL.UseProgram(shader.program);
            shader.SetMatrix4x4("mtxCam", ref viewProj);
            shader.SetMatrix4x4("mtxMdl", ref modelMatrix);
            shader.SetVector3("camPosition", control.Camera.TargetPosition);
            shader.SetVector2("iResolution", new Vector2(control.Width, control.Height));
            shader.SetInt("materialRenderDisplay", 1);

            GL.ClearColor(0, 0, 0, 0);
            GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
            GL.Viewport(0, 0, width, height);

            //Render material data onto a textured sphere
            Render(control, shader, mesh);

            GL.Enable(EnableCap.Blend);
            GL.BlendFuncSeparate(
                BlendingFactorSrc.SrcAlpha, BlendingFactorDest.OneMinusSrcAlpha,
                BlendingFactorSrc.One, BlendingFactorDest.OneMinusSrcAlpha);

            //Draw the model to render onto
            switch (renderObject)
            {
            case RenderObject.Sphere:
                DrawSphere(control);
                break;

            case RenderObject.Plane:
                DrawPlane(control);
                break;
            }

            //Disable the uniform data
            shader.SetInt("materialRenderDisplay", 0);

            //Disable shader and textures
            GL.UseProgram(0);
            GL.BindTexture(TextureTarget.Texture2D, 0);

            var thumbnail = frameBuffer.ReadImagePixels(true);

            //Dispose frame buffer
            frameBuffer.Dispoe();
            frameBuffer.DisposeRenderBuffer();

            this.Thumbnail = thumbnail;
            thumbnailUpdated?.Invoke(this, EventArgs.Empty);
        }