STATIC SUB StencilMask ( Mask AS Integer )
Gl.StencilMask controls the writing of individual bits in the stencil planes. The least significant n bits of mask, where n is the number of bits in the stencil buffer, specify a mask. Wherever a one appears in the mask, the corresponding bit in the stencil buffer is made writable. Where a zero appears, the bit is write-protected. Initially, all bits are enabled for writing.
Gl.GL_INVALID_OPERATION is generated if Gl.StencilMask is called between a call to Gl.Begin and the corresponding call to Gl.End.
Gl.GetStencilWritemask
Gl.GetStencilBits