HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 404

S glStencilFunc The following values are accepted by func: GL_NEVER Always fails. GL_LESS Passes if (ref & mask) < (stencil & mask). GL_LEQUAL Passes if (ref & mask) ≤(stencil & mask). GL_GREATER Passes if (ref & mask) > (stencil & mask). GL_GEQUAL Passes if (ref & mask) ≥ (stencil & mask). GL_EQUAL Passes if (ref & mask) = (stencil & mask). GL_NOTEQUAL Passes if (ref & mask) ≠ (stencil & mask). GL_ALWAYS Always passes. Notes Initially, the stencil test is disabled. If there is no stencil buffer, no stencil modification can occur and it is as if the stencil test always passes. Errors • GL_INVALID_ENUM is generated if func is not one of the eight accepted values. • GL_INVALID_OPERATION is generated if glStencilFunc is executed between the execution of glBegin and the corresponding execution of glEnd. Associated Gets glGet with argument GL_STENCIL_FUNC glGet with argument GL_STENCIL_VALUE_MASK glGet with argument GL_STENCIL_REF glGet with argument GL_STENCIL_BITS glIsEnabled with argument GL_STENCIL_TEST See Also glAlphaFunc, glBlendFunc, glDepthFunc, glEnable, glIsEnabled, glLogicOp, glStencilOp 404 Chapter 17