Track two sets of back-face stencil state

Track separate back-face stencil state for OpenGL 2.0 /
GL_ATI_separate_stencil and GL_EXT_stencil_two_side.  This allows all
three to be enabled in a driver.  One set of state is set via the 2.0
or ATI functions and is used when STENCIL_TEST_TWO_SIDE_EXT is
disabled.  The other is set by StencilFunc and StencilOp when the
active stencil face is set to BACK.  The GL_EXT_stencil_two_side spec has
more details.

http://opengl.org/registry/specs/EXT/stencil_two_side.txt

1 files changed, 4 insertions, 2 deletions

diff --git a/src/mesa/swrast/s_stencil.c b/src/mesa/swrast/s_stencil.c
index c925922463e..2e84ddec71f 100644
--- a/src/mesa/swrast/s_stencil.c
+++ b/src/mesa/swrast/s_stencil.c
@@ -997,10 +997,12 @@ stencil_and_ztest_pixels( GLcontext *ctx, SWspan *span, GLuint face )
 GLboolean
 _swrast_stencil_and_ztest_span(GLcontext *ctx, SWspan *span)
 {
+   const GLuint face = (span->facing == 0) ? 0 : ctx->Stencil._BackFace;
+
    if (span->arrayMask & SPAN_XY)
-      return stencil_and_ztest_pixels(ctx, span, span->facing);
+      return stencil_and_ztest_pixels(ctx, span, face);
    else
-      return stencil_and_ztest_span(ctx, span, span->facing);
+      return stencil_and_ztest_span(ctx, span, face);
 }