fix broken two-sided stencil

15 files changed, 49 insertions, 24 deletions

diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index 754b1a7d823..b599638c771 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -977,7 +977,6 @@ init_attrib_groups(GLcontext *ctx)
    /* Miscellaneous */
    ctx->NewState = _NEW_ALL;
    ctx->ErrorValue = (GLenum) GL_NO_ERROR;
-   ctx->_Facing = 0;
 
    return GL_TRUE;
 }
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 2cc0622ec8a..96c3515dd2c 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -3032,12 +3032,6 @@ struct __GLcontextRec
 
    struct gl_list_extensions ListExt; /**< driver dlist extensions */
 
-
-   GLuint _Facing; /**< This is a hack for 2-sided stencil test.
-		    *
-		    * We don't have a better way to communicate this value from
-		    * swrast_setup to swrast. */
-
    /** \name For debugging/development only */
    /*@{*/
    GLboolean FirstTimeCurrent;
diff --git a/src/mesa/swrast/s_aalinetemp.h b/src/mesa/swrast/s_aalinetemp.h
index 80cec0b31d4..074ffe8c9b1 100644
--- a/src/mesa/swrast/s_aalinetemp.h
+++ b/src/mesa/swrast/s_aalinetemp.h
@@ -141,6 +141,7 @@ NAME(line)(GLcontext *ctx, const SWvertex *v0, const SWvertex *v1)
       return;
 
    INIT_SPAN(line.span, GL_LINE, 0, 0, SPAN_XY | SPAN_COVERAGE);
+   line.span.facing = swrast->PointLineFacing;
 
    line.xAdj = line.dx / line.len * line.halfWidth;
    line.yAdj = line.dy / line.len * line.halfWidth;
diff --git a/src/mesa/swrast/s_aatritemp.h b/src/mesa/swrast/s_aatritemp.h
index 9278b5a157a..b26f21f5db0 100644
--- a/src/mesa/swrast/s_aatritemp.h
+++ b/src/mesa/swrast/s_aatritemp.h
@@ -78,7 +78,7 @@
    GLfloat texWidth[FRAG_ATTRIB_MAX];
    GLfloat texHeight[FRAG_ATTRIB_MAX];
 #endif
-   GLfloat bf = SWRAST_CONTEXT(ctx)->_BackfaceSign;
+   GLfloat bf = SWRAST_CONTEXT(ctx)->_BackfaceCullSign;
    
    (void) swrast;
 
@@ -116,6 +116,7 @@
    majDx = vMax->win[0] - vMin->win[0];
    majDy = vMax->win[1] - vMin->win[1];
 
+   /* front/back-face determination and cullling */
    {
       const GLfloat botDx = vMid->win[0] - vMin->win[0];
       const GLfloat botDy = vMid->win[1] - vMin->win[1];
@@ -124,6 +125,8 @@
       if (area * bf < 0 || area == 0 || IS_INF_OR_NAN(area))
 	 return;
       ltor = (GLboolean) (area < 0.0F);
+
+      span.facing = area * swrast->_BackfaceSign > 0.0F;
    }
 
    /* Plane equation setup:
diff --git a/src/mesa/swrast/s_context.c b/src/mesa/swrast/s_context.c
index 2f25edbd811..47d5035c02e 100644
--- a/src/mesa/swrast/s_context.c
+++ b/src/mesa/swrast/s_context.c
@@ -117,8 +117,8 @@ _swrast_update_rasterflags( GLcontext *ctx )
 
 
 /**
- * Examine polycon culls tate to compute the _BackfaceSign field.
- * _BackfaceSign will be 0 if no culling, -1 if culling back-faces,
+ * Examine polycon culls tate to compute the _BackfaceCullSign field.
+ * _BackfaceCullSign will be 0 if no culling, -1 if culling back-faces,
  * and 1 if culling front-faces.  The Polygon FrontFace state also
  * factors in.
  */
@@ -149,10 +149,15 @@ _swrast_update_polygon( GLcontext *ctx )
       backface_sign = 0.0;
    }
 
-   SWRAST_CONTEXT(ctx)->_BackfaceSign = backface_sign;
+   SWRAST_CONTEXT(ctx)->_BackfaceCullSign = backface_sign;
+
+   /* This is for front/back-face determination, but not for culling */
+   SWRAST_CONTEXT(ctx)->_BackfaceSign
+      = (ctx->Polygon.FrontFace == GL_CW) ? -1.0 : 1.0;
 }
 
 
+
 /**
  * Update the _PreferPixelFog field to indicate if we need to compute
  * fog blend factors (from the fog coords) per-fragment.
@@ -721,6 +726,12 @@ _swrast_ResetLineStipple( GLcontext *ctx )
 }
 
 void
+_swrast_SetFacing(GLcontext *ctx, GLuint facing)
+{
+   SWRAST_CONTEXT(ctx)->PointLineFacing = facing;
+}
+
+void
 _swrast_allow_vertex_fog( GLcontext *ctx, GLboolean value )
 {
    if (SWRAST_DEBUG) {
diff --git a/src/mesa/swrast/s_context.h b/src/mesa/swrast/s_context.h
index c8333b8e0a1..58841ad4af9 100644
--- a/src/mesa/swrast/s_context.h
+++ b/src/mesa/swrast/s_context.h
@@ -128,7 +128,8 @@ typedef struct
     * _swrast_validate_derived():
     */
    GLbitfield _RasterMask;
-   GLfloat _BackfaceSign;
+   GLfloat _BackfaceSign;      /** +1 or -1 */
+   GLfloat _BackfaceCullSign;  /** +1, 0, or -1 */
    GLboolean _PreferPixelFog;    /* Compute fog blend factor per fragment? */
    GLboolean _AnyTextureCombine;
    GLboolean _FogEnabled;
@@ -151,6 +152,7 @@ typedef struct
    /* Working values:
     */
    GLuint StippleCounter;    /**< Line stipple counter */
+   GLuint PointLineFacing;
    GLbitfield NewState;
    GLuint StateChanges;
    GLenum Primitive;    /* current primitive being drawn (ala glBegin) */
diff --git a/src/mesa/swrast/s_fragprog.c b/src/mesa/swrast/s_fragprog.c
index 7fd94c87096..324afb9c761 100644
--- a/src/mesa/swrast/s_fragprog.c
+++ b/src/mesa/swrast/s_fragprog.c
@@ -118,7 +118,7 @@ init_machine(GLcontext *ctx, struct gl_program_machine *machine,
 
    if (ctx->Shader.CurrentProgram) {
       /* Store front/back facing value in register FOGC.Y */
-      machine->Attribs[FRAG_ATTRIB_FOGC][col][1] = (GLfloat) ctx->_Facing;
+      machine->Attribs[FRAG_ATTRIB_FOGC][col][1] = (GLfloat) span->facing;
    }
 
    machine->CurElement = col;
diff --git a/src/mesa/swrast/s_linetemp.h b/src/mesa/swrast/s_linetemp.h
index b6e8f287f45..9e240a7d2bb 100644
--- a/src/mesa/swrast/s_linetemp.h
+++ b/src/mesa/swrast/s_linetemp.h
@@ -317,6 +317,9 @@ NAME( GLcontext *ctx, const SWvertex *vert0, const SWvertex *vert1 )
    span.attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0F;
    span.attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0F;
 
+   span.facing = swrast->PointLineFacing;
+
+
    /*
     * Draw
     */
diff --git a/src/mesa/swrast/s_pointtemp.h b/src/mesa/swrast/s_pointtemp.h
index 94364643d4b..7dcc1fc9449 100644
--- a/src/mesa/swrast/s_pointtemp.h
+++ b/src/mesa/swrast/s_pointtemp.h
@@ -105,6 +105,7 @@ NAME ( GLcontext *ctx, const SWvertex *vert )
     */
    span->interpMask = SPAN_FOG;
    span->arrayMask = SPAN_XY | SPAN_Z;
+   span->facing = swrast->PointLineFacing;
    span->attrStart[FRAG_ATTRIB_FOGC][0] = vert->attrib[FRAG_ATTRIB_FOGC][0];
    span->attrStepX[FRAG_ATTRIB_FOGC][0] = 0.0;
    span->attrStepY[FRAG_ATTRIB_FOGC][0] = 0.0;
diff --git a/src/mesa/swrast/s_triangle.c b/src/mesa/swrast/s_triangle.c
index fc9d29bbf7f..fc40084bebd 100644
--- a/src/mesa/swrast/s_triangle.c
+++ b/src/mesa/swrast/s_triangle.c
@@ -58,7 +58,7 @@ _swrast_culltriangle( GLcontext *ctx,
    GLfloat fy = v2->win[1] - v0->win[1];
    GLfloat c = ex*fy-ey*fx;
 
-   if (c * SWRAST_CONTEXT(ctx)->_BackfaceSign > 0)
+   if (c * SWRAST_CONTEXT(ctx)->_BackfaceCullSign > 0)
       return 0;
 
    return 1;
diff --git a/src/mesa/swrast/s_tritemp.h b/src/mesa/swrast/s_tritemp.h
index dcc3e958cb1..ae30fe5e597 100644
--- a/src/mesa/swrast/s_tritemp.h
+++ b/src/mesa/swrast/s_tritemp.h
@@ -172,7 +172,7 @@ static void NAME(GLcontext *ctx, const SWvertex *v0,
    EdgeT eMaj, eTop, eBot;
    GLfloat oneOverArea;
    const SWvertex *vMin, *vMid, *vMax;  /* Y(vMin)<=Y(vMid)<=Y(vMax) */
-   GLfloat bf = SWRAST_CONTEXT(ctx)->_BackfaceSign;
+   GLfloat bf = SWRAST_CONTEXT(ctx)->_BackfaceCullSign;
 #if !TRIANGLE_WALK_DOUBLE
    const GLint snapMask = ~((FIXED_ONE / (1 << SUB_PIXEL_BITS)) - 1); /* for x/y coord snapping */
 #endif
@@ -293,6 +293,7 @@ static void NAME(GLcontext *ctx, const SWvertex *v0,
       const GLfloat area = eMaj.dx * eBot.dy - eBot.dx * eMaj.dy;
 #endif
       /* Do backface culling */
+
       if (area * bf < 0.0)
          return;
 
@@ -300,10 +301,10 @@ static void NAME(GLcontext *ctx, const SWvertex *v0,
          return;
 
       oneOverArea = 1.0F / area;
-   }
 
-
-   span.facing = ctx->_Facing; /* for 2-sided stencil test */
+      /* 0 = front, 1 = back */
+      span.facing = oneOverArea * swrast->_BackfaceSign > 0.0F;
+   }
 
    /* Edge setup.  For a triangle strip these could be reused... */
    {
diff --git a/src/mesa/swrast/swrast.h b/src/mesa/swrast/swrast.h
index 12264a159ad..86405503afc 100644
--- a/src/mesa/swrast/swrast.h
+++ b/src/mesa/swrast/swrast.h
@@ -140,6 +140,13 @@ _swrast_Accum(GLcontext *ctx, GLenum op, GLfloat value);
 extern void
 _swrast_ResetLineStipple( GLcontext *ctx );
 
+/**
+ * Indicates front/back facing for subsequent points/lines when drawing
+ * unfilled polygons.  Needed for two-side stencil.
+ */
+extern void
+_swrast_SetFacing(GLcontext *ctx, GLuint facing);
+
 /* These will always render the correct point/line/triangle for the
  * current state.
  *
diff --git a/src/mesa/swrast_setup/ss_context.c b/src/mesa/swrast_setup/ss_context.c
index 3f6d29403cc..43f2696da95 100644
--- a/src/mesa/swrast_setup/ss_context.c
+++ b/src/mesa/swrast_setup/ss_context.c
@@ -186,6 +186,9 @@ _swsetup_RenderStart( GLcontext *ctx )
 
    swsetup->NewState = 0;
 
+   /* This will change if drawing unfilled tris */
+   _swrast_SetFacing(ctx, 0);
+
    _swrast_render_start(ctx);
 
    /* Important */
diff --git a/src/mesa/swrast_setup/ss_triangle.c b/src/mesa/swrast_setup/ss_triangle.c
index 628e9288e87..830e0645db1 100644
--- a/src/mesa/swrast_setup/ss_triangle.c
+++ b/src/mesa/swrast_setup/ss_triangle.c
@@ -1,8 +1,8 @@
 /*
  * Mesa 3-D graphics library
- * Version:  6.1
+ * Version:  7.1
  *
- * Copyright (C) 1999-2004  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -68,6 +68,8 @@ static void _swsetup_render_line_tri( GLcontext *ctx,
          return;
    }
 
+   _swrast_SetFacing(ctx, facing);
+
    if (ctx->Light.ShadeModel == GL_FLAT) {
       COPY_CHAN4(c[0], v0->color);
       COPY_CHAN4(c[1], v1->color);
@@ -127,6 +129,8 @@ static void _swsetup_render_point_tri( GLcontext *ctx,
          return;
    }
 
+   _swrast_SetFacing(ctx, facing);
+
    if (ctx->Light.ShadeModel == GL_FLAT) {
       /* save colors/indexes for v0, v1 vertices */
       COPY_CHAN4(c[0], v0->color);
@@ -311,6 +315,4 @@ void _swsetup_choose_trifuncs( GLcontext *ctx )
    tnl->Driver.Render.Quad = quad_tab[ind];
    tnl->Driver.Render.Line = swsetup_line;
    tnl->Driver.Render.Points = swsetup_points;
-
-   ctx->_Facing = 0;
 }
diff --git a/src/mesa/swrast_setup/ss_tritmp.h b/src/mesa/swrast_setup/ss_tritmp.h
index 59c534ee5ee..0e0cbce3c14 100644
--- a/src/mesa/swrast_setup/ss_tritmp.h
+++ b/src/mesa/swrast_setup/ss_tritmp.h
@@ -43,7 +43,6 @@ static void TAG(triangle)(GLcontext *ctx, GLuint e0, GLuint e1, GLuint e2 )
    v[1] = &verts[e1];
    v[2] = &verts[e2];
 
-
    if (IND & (SS_TWOSIDE_BIT | SS_OFFSET_BIT | SS_UNFILLED_BIT))
    {
       GLfloat ex = v[0]->win[0] - v[2]->win[0];
@@ -55,7 +54,6 @@ static void TAG(triangle)(GLcontext *ctx, GLuint e0, GLuint e1, GLuint e2 )
       if (IND & (SS_TWOSIDE_BIT | SS_UNFILLED_BIT))
       {
 	 facing = (cc < 0.0) ^ ctx->Polygon._FrontBit;
-         ctx->_Facing = facing;
 
 	 if (IND & SS_UNFILLED_BIT)
 	    mode = facing ? ctx->Polygon.BackMode : ctx->Polygon.FrontMode;