Stencil buffer write operations. 
| Enumerator | 
|---|
| MFStencilOp_Unknown | Unknown stencil operation.  | 
| MFStencilOp_Keep | Keep the existing stencil data.  | 
| MFStencilOp_Zero | Set the stencil data to 0.  | 
| MFStencilOp_Replace | Set the stencil data to the reference value.  | 
| MFStencilOp_IncrementClamp | Increment the stencil value by 1, and clamp the result.  | 
| MFStencilOp_DecrementClamp | Decrement the stencil value by 1, and clamp the result.  | 
| MFStencilOp_Invert | Invert the stencil data.  | 
| MFStencilOp_Increment | Increment the stencil value by 1, and wrap the result if necessary.  | 
| MFStencilOp_Decrement | Increment the stencil value by 1, and wrap the result if necessary.  | 
| MFStencilOp_Max | Maximum stencil op.  | 
| MFStencilOp_ForceInt | Force MFStencilOp to an int type.  |