public class DepthStencilStates : Dictionary<string,DepthStencilState>
{
    /// <summary>
    /// Setup default DepthStencilStates: DepthOn, DepthOff
    /// </summary>
    /// <param name="window"></param>
    public DepthStencilStates(Window window) : base()
    {
        DepthStencilOperationDescription frontFaceOp = new DepthStencilOperationDescription()
        {
            Comparison = Comparison.Always,
            DepthFailOperation = StencilOperation.Decrement,
            FailOperation = StencilOperation.Keep,
            PassOperation = StencilOperation.Keep
        };

        DepthStencilOperationDescription backFaceOp = new DepthStencilOperationDescription()
        {
            Comparison = Comparison.Always,
            DepthFailOperation = StencilOperation.Decrement,
            FailOperation = StencilOperation.Keep,
            PassOperation = StencilOperation.Keep
        };

        // depth on
        DepthStencilStateDescription dsStateDesc = new DepthStencilStateDescription()
        {
            // depth test parameters
            IsDepthEnabled = true,
            DepthWriteMask = DepthWriteMask.All,
            DepthComparison = Comparison.Less,

            // stencil test parameters
            IsStencilEnabled = false,
            StencilReadMask = 0xFF,
            StencilWriteMask = 0xFF,

            // stencil operations if pixel is front-facing
            FrontFace = frontFaceOp,

            // stencil operations if pixel is back-facing
            BackFace = backFaceOp
        };

        DepthStencilState depthStateOn = new DepthStencilState(window.Device3D, dsStateDesc);
        depthStateOn.DebugName = "DepthStencilState.DepthOn";
        this.Add(depthStateOn.DebugName, depthStateOn);

        // depth off
        dsStateDesc = new DepthStencilStateDescription()
        {
            // depth test parameters
            IsDepthEnabled = false,
            DepthWriteMask = DepthWriteMask.All,
            DepthComparison = Comparison.Less,

            // stencil test parameters
            IsStencilEnabled = false,
            StencilReadMask = 0xFF,
            StencilWriteMask = 0xFF,

            // stencil operations if pixel is front-facing
            FrontFace = frontFaceOp,

            // stencil operations if pixel is back-facing
            BackFace = backFaceOp
        };

        DepthStencilState depthStateOff = new DepthStencilState(window.Device3D, dsStateDesc);
        depthStateOff.DebugName = "DepthStencilState.DepthOff";
        this.Add(depthStateOff.DebugName, depthStateOff);
    }
}