/*
	After calling this func, you draw a mask
*/
function matcore.StencilStart()
	render.ClearStencil()
	render.SetStencilEnable( true )
	render.SetStencilWriteMask( 1 )
	render.SetStencilTestMask( 1 )
	render.SetStencilFailOperation( STENCILOPERATION_KEEP )
	render.SetStencilZFailOperation( STENCILOPERATION_KEEP )
	render.SetStencilPassOperation( STENCILOPERATION_REPLACE )
	render.SetStencilCompareFunction( STENCILCOMPARISONFUNCTION_ALWAYS )
	render.SetStencilReferenceValue( 1 )
	render.SetColorModulation( 1, 1, 1 )
end

/*
	When your mask is done, call this and draw something (like the model in CircularHUD)
*/
function matcore.StencilReplace(v)
	render.SetStencilCompareFunction( STENCILCOMPARISONFUNCTION_EQUAL )
	render.SetStencilPassOperation( STENCILOPERATION_REPLACE )
	render.SetStencilReferenceValue(v or 1)
end

/*
	After all, disable stencil buffer
*/
function matcore.StencilEnd()
	render.SetStencilEnable( false )
end