private void RenderFrame()
{
//Set the defaul render target and the depth stencil buffers
device.SetRenderTarget(device.BackBuffer, device.BackDepthBuffer);
//Specify the ViewPort
device.ViewPort = new ViewPort(0, 0, Width, Height);
//Clear the render target and depth stencil buffers
device.Clear(ClearFlags.Target | ClearFlags.ZBuffer, new Color4(0, 0, 0, 0), 1, 0);
//Set the primitive type and vertex buffer
device.PrimitiveTopology = IAPrimitive.TriangleList;
device.SetVertexBuffer(0, vertexBuffer, 0);
//Set the shader program to use
device.Program = shaderProgram;
//Pass the tranformation values to the shader code
input.WorldViewProj = world * view * projection;
//Draw the geometry
device.Draw(3, 0);
//Present the render target buffer to the screen
device.Present();
}