glStencilOp -- GL_INCR_WRAP GL_DECR_WRAP. stencil mask behaviour

OpenGL documentation for gl开发者_Go百科StencilOp isn't clear on what happens for increment and decrement operations in the presence of stencil masks. It seems to imply that the mask will be ignored for increment and decrement operation.

Can anyone confirm/refute that?

Thanks

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The mask will not be ignored. Instead, the increment or decrement operation is performed as though there was no mask, but the only bits in the stencil buffer that will be set to the incremented value are those allowed by the mask.