Module: Mesa Branch: master Commit: 38f65162af772af6d05627e3af6e8b7caf03ec8f URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=38f65162af772af6d05627e3af6e8b7caf03ec8f
Author: Chris Forbes <[email protected]> Date: Mon May 13 21:17:29 2013 +1200 mesa: add accessor for effective stencil ref Clamps the stencil reference value to the range representable in the currently-bound draw framebuffer's stencil attachment. V2: Add spec quote. NOTE: This is a candidate for stable branches. Signed-off-by: Chris Forbes <[email protected]> Reviewed-by: Paul Berry <[email protected]> Reviewed-by: Kenneth Graunke <[email protected]> Reviewed-by: Ian Romanick <[email protected]> --- src/mesa/main/stencil.h | 14 ++++++++++++++ 1 files changed, 14 insertions(+), 0 deletions(-) diff --git a/src/mesa/main/stencil.h b/src/mesa/main/stencil.h index 1d5e01c..f2f7d37 100644 --- a/src/mesa/main/stencil.h +++ b/src/mesa/main/stencil.h @@ -79,4 +79,18 @@ _mesa_update_stencil(struct gl_context *ctx); extern void _mesa_init_stencil( struct gl_context * ctx ); +/* From the GL 4.3 spec, 17.3.5: + * "Stencil comparison operations and queries of <ref> clamp its value + * to the range [0, 2^s-1], where <s> is the number of bits in the + * stencil buffer attached to the draw framebuffer." + */ + +static inline GLint +_mesa_get_stencil_ref(struct gl_context const *ctx, int face) +{ + GLint stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1; + GLint ref = ctx->Stencil.Ref[face]; + return CLAMP(ref, 0, stencilMax); +} + #endif _______________________________________________ mesa-commit mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/mesa-commit
