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

4 files changed, 31 insertions, 43 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_cc.c b/src/mesa/drivers/dri/i965/brw_cc.c
index fa8121e02d3..abae4b32152 100644
--- a/src/mesa/drivers/dri/i965/brw_cc.c
+++ b/src/mesa/drivers/dri/i965/brw_cc.c
@@ -84,6 +84,7 @@ static void
 cc_unit_populate_key(struct brw_context *brw, struct brw_cc_unit_key *key)
 {
    struct gl_stencil_attrib *stencil = brw->attribs.Stencil;
+   const unsigned back = stencil->_BackFace;
 
    memset(key, 0, sizeof(*key));
 
@@ -100,13 +101,13 @@ cc_unit_populate_key(struct brw_context *brw, struct brw_cc_unit_key *key)
       key->stencil_test_mask[0] = stencil->ValueMask[0];
    }
    if (key->stencil_two_side) {
-      key->stencil_func[1] = stencil->Function[1];
-      key->stencil_fail_op[1] = stencil->FailFunc[1];
-      key->stencil_pass_depth_fail_op[1] = stencil->ZFailFunc[1];
-      key->stencil_pass_depth_pass_op[1] = stencil->ZPassFunc[1];
-      key->stencil_ref[1] = stencil->Ref[1];
-      key->stencil_write_mask[1] = stencil->WriteMask[1];
-      key->stencil_test_mask[1] = stencil->ValueMask[1];
+      key->stencil_func[1] = stencil->Function[back];
+      key->stencil_fail_op[1] = stencil->FailFunc[back];
+      key->stencil_pass_depth_fail_op[1] = stencil->ZFailFunc[back];
+      key->stencil_pass_depth_pass_op[1] = stencil->ZPassFunc[back];
+      key->stencil_ref[1] = stencil->Ref[back];
+      key->stencil_write_mask[1] = stencil->WriteMask[back];
+      key->stencil_test_mask[1] = stencil->ValueMask[back];
    }
 
    if (brw->attribs.Color->_LogicOpEnabled)
diff --git a/src/mesa/drivers/dri/i965/brw_wm.c b/src/mesa/drivers/dri/i965/brw_wm.c
index c50b0d2dd95..24149cf8a17 100644
--- a/src/mesa/drivers/dri/i965/brw_wm.c
+++ b/src/mesa/drivers/dri/i965/brw_wm.c
@@ -189,8 +189,7 @@ static void brw_wm_populate_key( struct brw_context *brw,
       lookup |= IZ_STENCIL_TEST_ENABLE_BIT;
 
       if (brw->attribs.Stencil->WriteMask[0] ||
-	  (brw->attribs.Stencil->_TestTwoSide &&
-	   brw->attribs.Stencil->WriteMask[1]))
+	  brw->attribs.Stencil->WriteMask[brw->attribs.Stencil->_BackFace])
 	 lookup |= IZ_STENCIL_WRITE_ENABLE_BIT;
    }
 
diff --git a/src/mesa/drivers/dri/r300/r300_render.c b/src/mesa/drivers/dri/r300/r300_render.c
index f9266e44c13..16ce4a11999 100644
--- a/src/mesa/drivers/dri/r300/r300_render.c
+++ b/src/mesa/drivers/dri/r300/r300_render.c
@@ -347,6 +347,8 @@ static GLboolean r300RunRender(GLcontext * ctx,
 static int r300Fallback(GLcontext * ctx)
 {
 	r300ContextPtr r300 = R300_CONTEXT(ctx);
+	const unsigned back = ctx->Stencil._BackFace;
+
 	/* Do we need to use new-style shaders?
 	 * Also is there a better way to do this? */
 	if (r300->radeon.radeonScreen->chip_family >= CHIP_FAMILY_RV515) {
@@ -371,12 +373,14 @@ static int r300Fallback(GLcontext * ctx)
 
 	FALLBACK_IF(ctx->RenderMode != GL_RENDER);
 
-	FALLBACK_IF(ctx->Stencil._TestTwoSide
-		    && (ctx->Stencil.Ref[0] != ctx->Stencil.Ref[1]
-			|| ctx->Stencil.ValueMask[0] !=
-			ctx->Stencil.ValueMask[1]
-			|| ctx->Stencil.WriteMask[0] !=
-			ctx->Stencil.WriteMask[1]));
+	/* If GL_EXT_stencil_two_side is disabled, this fallback check can
+	 * be removed.
+	 */
+	FALLBACK_IF(ctx->Stencil.Ref[0] != ctx->Stencil.Ref[back]
+		    || ctx->Stencil.ValueMask[0] !=
+		    ctx->Stencil.ValueMask[back]
+		    || ctx->Stencil.WriteMask[0] !=
+		    ctx->Stencil.WriteMask[back]);
 
 	if (ctx->Extensions.NV_point_sprite || ctx->Extensions.ARB_point_sprite)
 		FALLBACK_IF(ctx->Point.PointSprite);
diff --git a/src/mesa/drivers/dri/r300/r300_state.c b/src/mesa/drivers/dri/r300/r300_state.c
index a63dbac3436..d02034f039b 100644
--- a/src/mesa/drivers/dri/r300/r300_state.c
+++ b/src/mesa/drivers/dri/r300/r300_state.c
@@ -974,15 +974,9 @@ static void r300StencilFuncSeparate(GLcontext * ctx, GLenum face,
 {
 	r300ContextPtr rmesa = R300_CONTEXT(ctx);
 	GLuint refmask =
-	    (((ctx->Stencil.
-	       Ref[0] & 0xff) << R300_STENCILREF_SHIFT) | ((ctx->
-							    Stencil.
-							    ValueMask
-							    [0] &
-							    0xff)
-							   <<
-							   R300_STENCILMASK_SHIFT));
-
+	    ((ctx->Stencil.Ref[0] & 0xff) << R300_STENCILREF_SHIFT)
+	     | ((ctx->Stencil.ValueMask[0] & 0xff) << R300_STENCILMASK_SHIFT);
+	const unsigned back = ctx->Stencil._BackFace;
 	GLuint flag;
 
 	R300_STATECHANGE(rmesa, zs);
@@ -1000,8 +994,7 @@ static void r300StencilFuncSeparate(GLcontext * ctx, GLenum face,
 	rmesa->hw.zs.cmd[R300_ZS_CNTL_1] |=
 	    (flag << R300_S_FRONT_FUNC_SHIFT);
 
-	if (ctx->Stencil._TestTwoSide)
-		flag = translate_func(ctx->Stencil.Function[1]);
+	flag = translate_func(ctx->Stencil.Function[back]);
 
 	rmesa->hw.zs.cmd[R300_ZS_CNTL_1] |=
 	    (flag << R300_S_BACK_FUNC_SHIFT);
@@ -1026,6 +1019,7 @@ static void r300StencilOpSeparate(GLcontext * ctx, GLenum face,
 				  GLenum fail, GLenum zfail, GLenum zpass)
 {
 	r300ContextPtr rmesa = R300_CONTEXT(ctx);
+	const unsigned back = ctx->Stencil._BackFace;
 
 	R300_STATECHANGE(rmesa, zs);
 	/* It is easier to mask what's left.. */
@@ -1042,23 +1036,13 @@ static void r300StencilOpSeparate(GLcontext * ctx, GLenum face,
 	    | (translate_stencil_op(ctx->Stencil.ZPassFunc[0]) <<
 	       R300_S_FRONT_ZPASS_OP_SHIFT);
 
-	if (ctx->Stencil._TestTwoSide) {
-		rmesa->hw.zs.cmd[R300_ZS_CNTL_1] |=
-		    (translate_stencil_op(ctx->Stencil.FailFunc[1]) <<
-		     R300_S_BACK_SFAIL_OP_SHIFT)
-		    | (translate_stencil_op(ctx->Stencil.ZFailFunc[1]) <<
-		       R300_S_BACK_ZFAIL_OP_SHIFT)
-		    | (translate_stencil_op(ctx->Stencil.ZPassFunc[1]) <<
-		       R300_S_BACK_ZPASS_OP_SHIFT);
-	} else {
-		rmesa->hw.zs.cmd[R300_ZS_CNTL_1] |=
-		    (translate_stencil_op(ctx->Stencil.FailFunc[0]) <<
-		     R300_S_BACK_SFAIL_OP_SHIFT)
-		    | (translate_stencil_op(ctx->Stencil.ZFailFunc[0]) <<
-		       R300_S_BACK_ZFAIL_OP_SHIFT)
-		    | (translate_stencil_op(ctx->Stencil.ZPassFunc[0]) <<
-		       R300_S_BACK_ZPASS_OP_SHIFT);
-	}
+	rmesa->hw.zs.cmd[R300_ZS_CNTL_1] |=
+	    (translate_stencil_op(ctx->Stencil.FailFunc[back]) <<
+	     R300_S_BACK_SFAIL_OP_SHIFT)
+	    | (translate_stencil_op(ctx->Stencil.ZFailFunc[back]) <<
+	       R300_S_BACK_ZFAIL_OP_SHIFT)
+	    | (translate_stencil_op(ctx->Stencil.ZPassFunc[back]) <<
+	       R300_S_BACK_ZPASS_OP_SHIFT);
 }
 
 /* =============================================================