Revert "Store clipping distance for user clip planes as part of vertex processing"

This reverts commit f058b25881e08c9d89a33345e5c84e1357396932.

This change is completely wrong in so many ways.  When clip distances
are generated as part of vertex processing, they must be interpolated
to perform clipping.  Geometric clipping goes right out the window.

4 files changed, 18 insertions, 132 deletions

diff --git a/src/mesa/tnl/t_context.h b/src/mesa/tnl/t_context.h
index ca4edcfcb9..6137c2d2fe 100644
--- a/src/mesa/tnl/t_context.h
+++ b/src/mesa/tnl/t_context.h
@@ -207,7 +207,6 @@ struct vertex_buffer
    GLvector4f  *EyePtr;		                /* _TNL_BIT_POS */
    GLvector4f  *ClipPtr;	                /* _TNL_BIT_POS */
    GLvector4f  *NdcPtr;                         /* _TNL_BIT_POS */
-   GLfloat     *ClipDistancePtr[MAX_CLIP_PLANES]; /* _TNL_BIT_POS */
    GLubyte     ClipOrMask;	                /* _TNL_BIT_POS */
    GLubyte     ClipAndMask;	                /* _TNL_BIT_POS */
    GLubyte     *ClipMask;		        /* _TNL_BIT_POS */
diff --git a/src/mesa/tnl/t_vb_cliptmp.h b/src/mesa/tnl/t_vb_cliptmp.h
index 0d2183a9e6..618b8b3130 100644
--- a/src/mesa/tnl/t_vb_cliptmp.h
+++ b/src/mesa/tnl/t_vb_cliptmp.h
@@ -80,58 +80,6 @@ do {									\
 } while (0)
 
 
-#define POLY_USERCLIP(PLANE)						\
-do {									\
-   if (mask & CLIP_USER_BIT) {						\
-      GLuint idxPrev = inlist[0];					\
-      GLfloat dpPrev = VB->ClipDistancePtr[PLANE][idxPrev];		\
-      GLuint outcount = 0;						\
-      GLuint i;								\
-									\
-      inlist[n] = inlist[0]; /* prevent rotation of vertices */		\
-      for (i = 1; i <= n; i++) {					\
-	 GLuint idx = inlist[i];					\
-	 GLfloat dp = VB->ClipDistancePtr[PLANE][idx];			\
-									\
-	 if (!IS_NEGATIVE(dpPrev)) {					\
-	    outlist[outcount++] = idxPrev;				\
-	 }								\
-									\
-	 if (DIFFERENT_SIGNS(dp, dpPrev)) {				\
-	    if (IS_NEGATIVE(dp)) {					\
-	       /* Going out of bounds.  Avoid division by zero as we	\
-		* know dp != dpPrev from DIFFERENT_SIGNS, above.	\
-		*/							\
-	       GLfloat t = dp / (dp - dpPrev);				\
-               INTERP_4F( t, coord[newvert], coord[idx], coord[idxPrev]); \
-	       interp( ctx, t, newvert, idx, idxPrev, GL_TRUE );	\
-	    } else {							\
-	       /* Coming back in.					\
-		*/							\
-	       GLfloat t = dpPrev / (dpPrev - dp);			\
-               INTERP_4F( t, coord[newvert], coord[idxPrev], coord[idx]); \
-	       interp( ctx, t, newvert, idxPrev, idx, GL_FALSE );	\
-	    }								\
-            outlist[outcount++] = newvert++;				\
-	 }								\
-									\
-	 idxPrev = idx;							\
-	 dpPrev = dp;							\
-      }									\
-									\
-      if (outcount < 3)							\
-	 return;							\
-									\
-      {									\
-	 GLuint *tmp = inlist;						\
-	 inlist = outlist;						\
-	 outlist = tmp;							\
-	 n = outcount;							\
-      }									\
-   }									\
-} while (0)
-
-
 #define LINE_CLIP(PLANE_BIT, A, B, C, D )				\
 do {									\
    if (mask & PLANE_BIT) {						\
@@ -163,37 +111,6 @@ do {									\
 } while (0)
 
 
-#define LINE_USERCLIP(PLANE)						\
-do {									\
-   if (mask & CLIP_USER_BIT) {						\
-      const GLfloat dp0 = VB->ClipDistancePtr[PLANE][v0];		\
-      const GLfloat dp1 = VB->ClipDistancePtr[PLANE][v1];		\
-      const GLboolean neg_dp0 = IS_NEGATIVE(dp0);			\
-      const GLboolean neg_dp1 = IS_NEGATIVE(dp1);			\
-									\
-      /* For regular clipping, we know from the clipmask that one	\
-       * (or both) of these must be negative (otherwise we wouldn't	\
-       * be here).							\
-       * For userclip, there is only a single bit for all active	\
-       * planes, so we can end up here when there is nothing to do,	\
-       * hence the second IS_NEGATIVE() test:				\
-       */								\
-      if (neg_dp0 && neg_dp1)						\
-         return; /* both vertices outside clip plane: discard */	\
-									\
-      if (neg_dp1) {							\
-	 GLfloat t = dp1 / (dp1 - dp0);					\
-	 if (t > t1) t1 = t;						\
-      } else if (neg_dp0) {						\
-	 GLfloat t = dp0 / (dp0 - dp1);					\
-	 if (t > t0) t0 = t;						\
-      }									\
-      if (t0 + t1 >= 1.0)						\
-	 return; /* discard */						\
-   }									\
-} while (0)
-
-
 
 /* Clip a line against the viewport and user clip planes.
  */
@@ -222,7 +139,11 @@ TAG(clip_line)( GLcontext *ctx, GLuint v0, GLuint v1, GLubyte mask )
    if (mask & CLIP_USER_BIT) {
       for (p = 0; p < ctx->Const.MaxClipPlanes; p++) {
 	 if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
-	    LINE_USERCLIP(p);
+            const GLfloat a = ctx->Transform._ClipUserPlane[p][0];
+            const GLfloat b = ctx->Transform._ClipUserPlane[p][1];
+            const GLfloat c = ctx->Transform._ClipUserPlane[p][2];
+            const GLfloat d = ctx->Transform._ClipUserPlane[p][3];
+	    LINE_CLIP( CLIP_USER_BIT, a, b, c, d );
 	 }
       }
    }
@@ -307,7 +228,11 @@ TAG(clip_tri)( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLubyte mask )
    if (mask & CLIP_USER_BIT) {
       for (p = 0; p < ctx->Const.MaxClipPlanes; p++) {
          if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
-            POLY_USERCLIP(p);
+            const GLfloat a = ctx->Transform._ClipUserPlane[p][0];
+            const GLfloat b = ctx->Transform._ClipUserPlane[p][1];
+            const GLfloat c = ctx->Transform._ClipUserPlane[p][2];
+            const GLfloat d = ctx->Transform._ClipUserPlane[p][3];
+            POLY_CLIP( CLIP_USER_BIT, a, b, c, d );
          }
       }
    }
@@ -366,7 +291,11 @@ TAG(clip_quad)( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint v3,
    if (mask & CLIP_USER_BIT) {
       for (p = 0; p < ctx->Const.MaxClipPlanes; p++) {
 	 if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
-	    POLY_USERCLIP(p);
+            const GLfloat a = ctx->Transform._ClipUserPlane[p][0];
+            const GLfloat b = ctx->Transform._ClipUserPlane[p][1];
+            const GLfloat c = ctx->Transform._ClipUserPlane[p][2];
+            const GLfloat d = ctx->Transform._ClipUserPlane[p][3];
+	    POLY_CLIP( CLIP_USER_BIT, a, b, c, d );
 	 }
       }
    }
@@ -388,6 +317,4 @@ TAG(clip_quad)( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint v3,
 #undef SIZE
 #undef TAG
 #undef POLY_CLIP
-#undef POLY_USERCLIP
 #undef LINE_CLIP
-#undef LINE_USERCLIP
diff --git a/src/mesa/tnl/t_vb_program.c b/src/mesa/tnl/t_vb_program.c
index 5fb83c2b01..c10a27614f 100644
--- a/src/mesa/tnl/t_vb_program.c
+++ b/src/mesa/tnl/t_vb_program.c
@@ -66,7 +66,6 @@ struct vp_stage_data {
    GLvector4f results[VERT_RESULT_MAX];
 
    GLvector4f ndcCoords;              /**< normalized device coords */
-   GLfloat *clipdistance[MAX_CLIP_PLANES];
    GLubyte *clipmask;                 /**< clip flags */
    GLubyte ormask, andmask;           /**< for clipping */
 };
@@ -78,7 +77,6 @@ struct vp_stage_data {
 static void
 userclip( GLcontext *ctx,
           GLvector4f *clip,
-          GLfloat *clipdistance[MAX_CLIP_PLANES],
           GLubyte *clipmask,
           GLubyte *clipormask,
           GLubyte *clipandmask )
@@ -107,8 +105,6 @@ userclip( GLcontext *ctx,
 	       clipmask[i] |= CLIP_USER_BIT;
 	    }
 
-	    clipdistance[p][i] = dp;
-
 	    STRIDE_F(coord, stride);
 	 }
 
@@ -168,7 +164,6 @@ do_ndc_cliptest(GLcontext *ctx, struct vp_stage_data *store)
       ctx->VertexProgram.Current->IsPositionInvariant)) {
       userclip( ctx,
 		VB->ClipPtr,
-		store->clipdistance,
 		store->clipmask,
 		&store->ormask,
 		&store->andmask );
@@ -176,9 +171,6 @@ do_ndc_cliptest(GLcontext *ctx, struct vp_stage_data *store)
       if (store->andmask) {
 	 return GL_FALSE;
       }
-
-      memcpy(VB->ClipDistancePtr, store->clipdistance,
-	     sizeof(store->clipdistance));
    }
 
    VB->ClipAndMask = store->andmask;
@@ -522,10 +514,6 @@ init_vp(GLcontext *ctx, struct tnl_pipeline_stage *stage)
    _mesa_vector4f_alloc( &store->ndcCoords, 0, size, 32 );
    store->clipmask = (GLubyte *) ALIGN_MALLOC(sizeof(GLubyte)*size, 32 );
 
-   for (i = 0; i < MAX_CLIP_PLANES; i++)
-      store->clipdistance[i] =
-	 (GLfloat *) ALIGN_MALLOC(sizeof(GLfloat) * size, 32);
-
    return GL_TRUE;
 }
 
@@ -549,9 +537,6 @@ dtr(struct tnl_pipeline_stage *stage)
       _mesa_vector4f_free( &store->ndcCoords );
       ALIGN_FREE( store->clipmask );
 
-      for (i = 0; i < MAX_CLIP_PLANES; i++)
-	 ALIGN_FREE(store->clipdistance[i]);
-
       FREE( store );
       stage->privatePtr = NULL;
    }
diff --git a/src/mesa/tnl/t_vb_vertex.c b/src/mesa/tnl/t_vb_vertex.c
index 2a61ff1177..4734754ea4 100644
--- a/src/mesa/tnl/t_vb_vertex.c
+++ b/src/mesa/tnl/t_vb_vertex.c
@@ -44,7 +44,6 @@ struct vertex_stage_data {
    GLvector4f eye;
    GLvector4f clip;
    GLvector4f proj;
-   GLfloat *clipdistance[MAX_CLIP_PLANES];
    GLubyte *clipmask;
    GLubyte ormask;
    GLubyte andmask;
@@ -57,12 +56,11 @@ struct vertex_stage_data {
 
 /* This function implements cliptesting for user-defined clip planes.
  * The clipping of primitives to these planes is implemented in
- * t_vp_cliptmp.h.
+ * t_render_clip.h.
  */
 #define USER_CLIPTEST(NAME, SZ)					\
 static void NAME( GLcontext *ctx,				\
 		  GLvector4f *clip,				\
-		  GLfloat *clipdistances[MAX_CLIP_PLANES],	\
 		  GLubyte *clipmask,				\
 		  GLubyte *clipormask,				\
 		  GLubyte *clipandmask )			\
@@ -90,8 +88,6 @@ static void NAME( GLcontext *ctx,				\
 	       clipmask[i] |= CLIP_USER_BIT;			\
 	    }							\
 								\
-	    clipdistances[p][i] = dp;				\
-								\
 	    STRIDE_F(coord, stride);				\
 	 }							\
 								\
@@ -111,9 +107,8 @@ USER_CLIPTEST(userclip3, 3)
 USER_CLIPTEST(userclip4, 4)
 
 static void (*(usercliptab[5]))( GLcontext *,
-				 GLvector4f *,
-				 GLfloat *[MAX_CLIP_PLANES],
-				 GLubyte *, GLubyte *, GLubyte * ) =
+				 GLvector4f *, GLubyte *,
+				 GLubyte *, GLubyte * ) =
 {
    NULL,
    NULL,
@@ -219,16 +214,12 @@ static GLboolean run_vertex_stage( GLcontext *ctx,
    if (ctx->Transform.ClipPlanesEnabled) {
       usercliptab[VB->ClipPtr->size]( ctx,
 				      VB->ClipPtr,
-				      store->clipdistance,
 				      store->clipmask,
 				      &store->ormask,
 				      &store->andmask );
 
       if (store->andmask)
 	 return GL_FALSE;
-
-      memcpy(VB->ClipDistancePtr, store->clipdistance,
-	     sizeof(store->clipdistance));
    }
 
    VB->ClipAndMask = store->andmask;
@@ -245,7 +236,6 @@ static GLboolean init_vertex_stage( GLcontext *ctx,
    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
    struct vertex_stage_data *store;
    GLuint size = VB->Size;
-   unsigned i;
 
    stage->privatePtr = CALLOC(sizeof(*store));
    store = VERTEX_STAGE_DATA(stage);
@@ -257,17 +247,8 @@ static GLboolean init_vertex_stage( GLcontext *ctx,
    _mesa_vector4f_alloc( &store->proj, 0, size, 32 );
 
    store->clipmask = (GLubyte *) ALIGN_MALLOC(sizeof(GLubyte)*size, 32 );
-   for (i = 0; i < MAX_CLIP_PLANES; i++)
-      store->clipdistance[i] =
-	 (GLfloat *) ALIGN_MALLOC(sizeof(GLfloat) * size, 32);
 
    if (!store->clipmask ||
-       !store->clipdistance[0] ||
-       !store->clipdistance[1] ||
-       !store->clipdistance[2] ||
-       !store->clipdistance[3] ||
-       !store->clipdistance[4] ||
-       !store->clipdistance[5] ||
        !store->eye.data ||
        !store->clip.data ||
        !store->proj.data)
@@ -281,16 +262,10 @@ static void dtr( struct tnl_pipeline_stage *stage )
    struct vertex_stage_data *store = VERTEX_STAGE_DATA(stage);
 
    if (store) {
-      unsigned i;
-
       _mesa_vector4f_free( &store->eye );
       _mesa_vector4f_free( &store->clip );
       _mesa_vector4f_free( &store->proj );
       ALIGN_FREE( store->clipmask );
-
-      for (i = 0; i < MAX_CLIP_PLANES; i++)
-	 ALIGN_FREE(store->clipdistance[i]);
-
       FREE(store);
       stage->privatePtr = NULL;
       stage->run = init_vertex_stage;