protected override void OnLoad()
{
base.OnLoad();
// initialize and bind framebuffer
_framebuffer = new Framebuffer();
_framebuffer.Bind(FramebufferTarget.Framebuffer);
// initialize a renderbuffer and bind it to the depth attachment
// to support depth testing while rendering to the texture
_depthBuffer = new Renderbuffer();
_depthBuffer.Init(RenderbufferStorage.DepthComponent, FramebufferWidth, FramebufferHeight);
_framebuffer.Attach(FramebufferTarget.Framebuffer, FramebufferAttachment.DepthAttachment, _depthBuffer);
// initialize texture and bind it to the color attachment
_texture = new Texture2D(SizedInternalFormat.Rgba8, FramebufferWidth, FramebufferHeight, 1);
_framebuffer.Attach(FramebufferTarget.Framebuffer, FramebufferAttachment.ColorAttachment0, _texture);
Framebuffer.Unbind(FramebufferTarget.Framebuffer);
// initialize shaders
_colorProgram = ProgramFactory.Create <SimpleColorProgram>();
_textureProgram = ProgramFactory.Create <SimpleTextureProgram>();
// initialize demonstration geometry
_cube = ShapeBuilder.CreateColoredCube(_colorProgram.InPosition, _colorProgram.InColor);
_quad = ShapeBuilder.CreateTexturedQuad(_textureProgram.InPosition, _textureProgram.InTexCoord);
// set camera position
ActiveCamera.Position = new Vector3(0, 0, 3);
// enable depth testing
GL.Enable(EnableCap.DepthTest);
}