stencil-state
GPU-accelerated rendering » GPU state

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Vocabulary
gpu.state

Class description
The stencil-state controls how incoming fragments interact with the stencil buffer. The front-mode and back-mode slots are both stencil-mode tuples that define the stencil buffer interaction for front- and back-facing triangle fragments, respectively. If both slots are f, stencil testing is disabled.

See also
<stencil-state>, get-stencil-state

Definition

IN: gpu.state

TUPLE: stencil-state
    { front-mode maybe{ stencil-mode } read-only initial: f }
    { back-mode maybe{ stencil-mode } read-only initial: f } ;

Methods

USING: accessors combinators.short-circuit gpu.state
gpu.state.private kernel opengl.gl ;

M: stencil-state set-gpu-state*
    dup { [ front-mode>> ] [ back-mode>> ] } 1|| [
        GL_STENCIL_TEST glEnable
        [ front-mode>> GL_FRONT swap (set-stencil-mode) ]
        [ back-mode>> GL_BACK swap (set-stencil-mode) ] bi
    ] [ drop GL_STENCIL_TEST glDisable ] if ;