draw: specialized cliptesting routines

11 files changed, 267 insertions, 205 deletions

diff --git a/src/gallium/auxiliary/draw/draw_cliptest_tmp.h b/src/gallium/auxiliary/draw/draw_cliptest_tmp.h
new file mode 100644
index 00000000000..958ed20dc84
--- /dev/null
+++ b/src/gallium/auxiliary/draw/draw_cliptest_tmp.h
@@ -0,0 +1,114 @@
+/**************************************************************************
+ * 
+ * Copyright 2010, VMware, inc.
+ * 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"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * 
+ **************************************************************************/
+
+
+
+static boolean TAG(do_cliptest)( struct pt_post_vs *pvs,
+                                 struct draw_vertex_info *info )
+{
+   struct vertex_header *out = info->verts;
+   const float *scale = pvs->draw->viewport.scale;
+   const float *trans = pvs->draw->viewport.translate;
+   /* const */ float (*plane)[4] = pvs->draw->plane;
+   const unsigned pos = draw_current_shader_position_output(pvs->draw);
+   const unsigned ef = pvs->draw->vs.edgeflag_output;
+   const unsigned nr = pvs->draw->nr_planes;
+   const unsigned flags = (FLAGS);
+   unsigned need_pipeline = 0;
+   unsigned j;
+
+   for (j = 0; j < info->count; j++) {
+      float *position = out->data[pos];
+      unsigned mask = 0x0;
+  
+      initialize_vertex_header(out);
+
+      if (flags & (DO_CLIP_XY | DO_CLIP_FULL_Z | DO_CLIP_HALF_Z | DO_CLIP_USER)) {
+         out->clip[0] = position[0];
+         out->clip[1] = position[1];
+         out->clip[2] = position[2];
+         out->clip[3] = position[3];
+
+         /* Do the hardwired planes first:
+          */
+         if (flags & DO_CLIP_XY) {
+            if (-position[0] + position[3] < 0) mask |= (1<<0);
+            if ( position[0] + position[3] < 0) mask |= (1<<1);
+            if (-position[1] + position[3] < 0) mask |= (1<<2);
+            if ( position[1] + position[3] < 0) mask |= (1<<3);
+         }
+
+         /* Clip Z planes according to full cube, half cube or none.
+          */
+         if (flags & DO_CLIP_FULL_Z) {
+            if ( position[2] + position[3] < 0) mask |= (1<<4);
+            if (-position[2] + position[3] < 0) mask |= (1<<5);
+         }
+         else if (flags & DO_CLIP_HALF_Z) {
+            if ( position[2]               < 0) mask |= (1<<4);
+            if (-position[2] + position[3] < 0) mask |= (1<<5);
+         }
+
+         if (flags & DO_CLIP_USER) {
+            unsigned i;
+            for (i = 6; i < nr; i++) {
+               if (dot4(position, plane[i]) < 0) 
+                  mask |= (1<<i);
+            }
+         }
+
+         out->clipmask = mask;
+         need_pipeline |= out->clipmask;
+      }
+
+      if ((flags & DO_VIEWPORT) && mask == 0)
+      {
+	 /* divide by w */
+	 float w = 1.0f / position[3];
+
+	 /* Viewport mapping */
+	 position[0] = position[0] * w * scale[0] + trans[0];
+	 position[1] = position[1] * w * scale[1] + trans[1];
+	 position[2] = position[2] * w * scale[2] + trans[2];
+	 position[3] = w;
+      }
+
+      if ((flags & DO_EDGEFLAG) && ef) {
+         const float *edgeflag = out->data[ef];
+         out->edgeflag = !(edgeflag[0] != 1.0f);
+         need_pipeline |= !out->edgeflag;
+      }
+
+      out = (struct vertex_header *)( (char *)out + info->stride );
+   }
+
+   return need_pipeline != 0;
+}
+
+
+#undef FLAGS
+#undef TAG
diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c
index b39b835f052..937b0934798 100644
--- a/src/gallium/auxiliary/draw/draw_context.c
+++ b/src/gallium/auxiliary/draw/draw_context.c
@@ -106,6 +106,8 @@ boolean draw_init(struct draw_context *draw)
    ASSIGN_4V( draw->plane[4],  0,  0,  1, 1 ); /* yes these are correct */
    ASSIGN_4V( draw->plane[5],  0,  0, -1, 1 ); /* mesa's a bit wonky */
    draw->nr_planes = 6;
+   draw->clip_xy = 1;
+   draw->clip_z = 1;
 
 
    draw->reduced_prim = ~0; /* != any of PIPE_PRIM_x */
@@ -186,6 +188,14 @@ void draw_set_mrd(struct draw_context *draw, double mrd)
 }
 
 
+static void update_clip_flags( struct draw_context *draw )
+{
+   draw->clip_xy = !draw->driver.bypass_clip_xy;
+   draw->clip_z = (!draw->driver.bypass_clip_z &&
+                   !draw->depth_clamp);
+   draw->clip_user = (draw->nr_planes > 6);
+}
+
 /**
  * Register new primitive rasterization/rendering state.
  * This causes the drawing pipeline to be rebuilt.
@@ -200,18 +210,25 @@ void draw_set_rasterizer_state( struct draw_context *draw,
       draw->rasterizer = raster;
       draw->rast_handle = rast_handle;
 
-      draw->bypass_clipping = draw->driver.bypass_clipping;
-   }
+  }
 }
 
-
+/* With a little more work, llvmpipe will be able to turn this off and
+ * do its own x/y clipping.  
+ *
+ * Some hardware can turn off clipping altogether - in particular any
+ * hardware with a TNL unit can do its own clipping, even if it is
+ * relying on the draw module for some other reason.
+ */
 void draw_set_driver_clipping( struct draw_context *draw,
-                               boolean bypass_clipping )
+                               boolean bypass_clip_xy,
+                               boolean bypass_clip_z )
 {
    draw_do_flush( draw, DRAW_FLUSH_STATE_CHANGE );
 
-   draw->driver.bypass_clipping = bypass_clipping;
-   draw->bypass_clipping = draw->driver.bypass_clipping;
+   draw->driver.bypass_clip_xy = bypass_clip_xy;
+   draw->driver.bypass_clip_z = bypass_clip_z;
+   update_clip_flags(draw);
 }
 
 
@@ -241,6 +258,8 @@ void draw_set_clip_state( struct draw_context *draw,
    memcpy(&draw->plane[6], clip->ucp, clip->nr * sizeof(clip->ucp[0]));
    draw->nr_planes = 6 + clip->nr;
    draw->depth_clamp = clip->depth_clamp;
+
+   update_clip_flags(draw);
 }
 
 
diff --git a/src/gallium/auxiliary/draw/draw_context.h b/src/gallium/auxiliary/draw/draw_context.h
index ea55320c427..4c780e4dcb4 100644
--- a/src/gallium/auxiliary/draw/draw_context.h
+++ b/src/gallium/auxiliary/draw/draw_context.h
@@ -212,7 +212,8 @@ void draw_set_render( struct draw_context *draw,
 		      struct vbuf_render *render );
 
 void draw_set_driver_clipping( struct draw_context *draw,
-                               boolean bypass_clipping );
+                               boolean bypass_clip_xy,
+                               boolean bypass_clip_z );
 
 void draw_set_force_passthrough( struct draw_context *draw, 
                                  boolean enable );
diff --git a/src/gallium/auxiliary/draw/draw_pipe_validate.c b/src/gallium/auxiliary/draw/draw_pipe_validate.c
index eafa29276ff..8b925439876 100644
--- a/src/gallium/auxiliary/draw/draw_pipe_validate.c
+++ b/src/gallium/auxiliary/draw/draw_pipe_validate.c
@@ -265,7 +265,7 @@ static struct draw_stage *validate_pipeline( struct draw_stage *stage )
 
    /* Clip stage
     */
-   if (!draw->bypass_clipping)
+   if (draw->clip_xy || draw->clip_z || draw->clip_user)
    {
       draw->pipeline.clip->next = next;
       next = draw->pipeline.clip;
diff --git a/src/gallium/auxiliary/draw/draw_private.h b/src/gallium/auxiliary/draw/draw_private.h
index 7bc3923692d..362f563ba6a 100644
--- a/src/gallium/auxiliary/draw/draw_private.h
+++ b/src/gallium/auxiliary/draw/draw_private.h
@@ -176,13 +176,19 @@ struct draw_context
    } pt;
 
    struct {
-      boolean bypass_clipping;
-      boolean bypass_vs;
+      boolean bypass_clip_xy;
+      boolean bypass_clip_z;
    } driver;
 
    boolean flushing;         /**< debugging/sanity */
    boolean suspend_flushing; /**< internally set */
-   boolean bypass_clipping;  /**< set if either api or driver bypass_clipping true */
+
+   /* Flags set if API requires clipping in these planes and the
+    * driver doesn't indicate that it can do it for us.
+    */
+   boolean clip_xy;
+   boolean clip_z;
+   boolean clip_user;
 
    boolean force_passthrough; /**< never clip or shade */
 
diff --git a/src/gallium/auxiliary/draw/draw_pt.c b/src/gallium/auxiliary/draw/draw_pt.c
index f81714d6b48..f44bf2507c6 100644
--- a/src/gallium/auxiliary/draw/draw_pt.c
+++ b/src/gallium/auxiliary/draw/draw_pt.c
@@ -86,7 +86,9 @@ draw_pt_arrays(struct draw_context *draw,
          opt |= PT_PIPELINE;
       }
 
-      if (!draw->bypass_clipping && !draw->pt.test_fse) {
+      if ((draw->clip_xy ||
+           draw->clip_z ||
+           draw->clip_user) && !draw->pt.test_fse) {
          opt |= PT_CLIPTEST;
       }
 
diff --git a/src/gallium/auxiliary/draw/draw_pt.h b/src/gallium/auxiliary/draw/draw_pt.h
index 0db56665296..5fbb4242915 100644
--- a/src/gallium/auxiliary/draw/draw_pt.h
+++ b/src/gallium/auxiliary/draw/draw_pt.h
@@ -221,7 +221,9 @@ boolean draw_pt_post_vs_run( struct pt_post_vs *pvs,
 			     struct draw_vertex_info *info );
 
 void draw_pt_post_vs_prepare( struct pt_post_vs *pvs,
-			      boolean bypass_clipping,
+			      boolean clip_xy,
+			      boolean clip_z,
+			      boolean clip_user,
 			      boolean bypass_viewport,
 			      boolean opengl,
 			      boolean need_edgeflags );
diff --git a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_emit.c b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_emit.c
index 4fbf88844a3..7c198c6026d 100644
--- a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_emit.c
+++ b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_emit.c
@@ -102,7 +102,7 @@ static void fse_prepare( struct draw_pt_middle_end *middle,
                                fse->key.nr_inputs);     /* inputs - fetch from api format */
 
    fse->key.viewport = !draw->identity_viewport;
-   fse->key.clip = !draw->bypass_clipping;
+   fse->key.clip = draw->clip_xy || draw->clip_z || draw->clip_user;
    fse->key.const_vbuffers = 0;
 
    memset(fse->key.element, 0, 
diff --git a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c
index 96b40fb3630..b72fd612451 100644
--- a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c
+++ b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c
@@ -100,8 +100,10 @@ static void fetch_pipeline_prepare( struct draw_pt_middle_end *middle,
     * but gl vs dx9 clip spaces.
     */
    draw_pt_post_vs_prepare( fpme->post_vs,
-			    (boolean)draw->bypass_clipping,
-			    (boolean)draw->identity_viewport,
+			    draw->clip_xy,
+			    draw->clip_z,
+			    draw->clip_user,
+			    draw->identity_viewport,
 			    (boolean)draw->rasterizer->gl_rasterization_rules,
 			    (draw->vs.edgeflag_output ? TRUE : FALSE) );
 
diff --git a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c
index cc0b4e52325..77291e304e1 100644
--- a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c
+++ b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c
@@ -107,8 +107,10 @@ llvm_middle_end_prepare( struct draw_pt_middle_end *middle,
     * but gl vs dx9 clip spaces.
     */
    draw_pt_post_vs_prepare( fpme->post_vs,
-			    (boolean)draw->bypass_clipping,
-			    (boolean)(draw->identity_viewport),
+			    draw->clip_xy,
+			    draw->clip_z,
+			    draw->clip_user,
+			    draw->identity_viewport,
 			    (boolean)draw->rasterizer->gl_rasterization_rules,
 			    (draw->vs.edgeflag_output ? TRUE : FALSE) );
 
diff --git a/src/gallium/auxiliary/draw/draw_pt_post_vs.c b/src/gallium/auxiliary/draw/draw_pt_post_vs.c
index 308f927b778..769409cfd67 100644
--- a/src/gallium/auxiliary/draw/draw_pt_post_vs.c
+++ b/src/gallium/auxiliary/draw/draw_pt_post_vs.c
@@ -26,14 +26,26 @@
  **************************************************************************/
 
 #include "util/u_memory.h"
+#include "util/u_math.h"
 #include "pipe/p_context.h"
 #include "draw/draw_context.h"
 #include "draw/draw_private.h"
 #include "draw/draw_pt.h"
 
+
+#define DO_CLIP_XY           0x1
+#define DO_CLIP_FULL_Z       0x2
+#define DO_CLIP_HALF_Z       0x4
+#define DO_CLIP_USER         0x8
+#define DO_VIEWPORT          0x10
+#define DO_EDGEFLAG          0x20
+
+
 struct pt_post_vs {
    struct draw_context *draw;
 
+   unsigned flags;
+
    boolean (*run)( struct pt_post_vs *pvs,
                    struct draw_vertex_info *info );
 };
@@ -56,186 +68,47 @@ dot4(const float *a, const float *b)
            a[3]*b[3]);
 }
 
-static INLINE unsigned
-compute_clipmask_gl(const float *clip, /*const*/ float plane[][4], unsigned nr,
-                    boolean clip_depth)
-{
-   unsigned mask = 0x0;
-   unsigned i;
+#define FLAGS (0)
+#define TAG(x) x##_none
+#include "draw_cliptest_tmp.h"
 
-#if 0
-   debug_printf("compute clipmask %f %f %f %f\n",
-                clip[0], clip[1], clip[2], clip[3]);
-   assert(clip[3] != 0.0);
-#endif
+#define FLAGS (DO_CLIP_XY | DO_CLIP_FULL_Z | DO_VIEWPORT)
+#define TAG(x) x##_xy_fullz_viewport
+#include "draw_cliptest_tmp.h"
 
-   /* Do the hardwired planes first:
-    */
-   if (-clip[0] + clip[3] < 0) mask |= (1<<0);
-   if ( clip[0] + clip[3] < 0) mask |= (1<<1);
-   if (-clip[1] + clip[3] < 0) mask |= (1<<2);
-   if ( clip[1] + clip[3] < 0) mask |= (1<<3);
-   if (clip_depth) {
-      if ( clip[2] + clip[3] < 0) mask |= (1<<4); /* match mesa clipplane numbering - for now */
-      if (-clip[2] + clip[3] < 0) mask |= (1<<5); /* match mesa clipplane numbering - for now */
-   }
+#define FLAGS (DO_CLIP_XY | DO_CLIP_HALF_Z | DO_VIEWPORT)
+#define TAG(x) x##_xy_halfz_viewport
+#include "draw_cliptest_tmp.h"
 
-   /* Followed by any remaining ones:
-    */
-   for (i = 6; i < nr; i++) {
-      if (dot4(clip, plane[i]) < 0) 
-         mask |= (1<<i);
-   }
+#define FLAGS (DO_CLIP_FULL_Z | DO_VIEWPORT)
+#define TAG(x) x##_fullz_viewport
+#include "draw_cliptest_tmp.h"
 
-   return mask;
-}
+#define FLAGS (DO_CLIP_HALF_Z | DO_VIEWPORT)
+#define TAG(x) x##_halfz_viewport
+#include "draw_cliptest_tmp.h"
 
+#define FLAGS (DO_CLIP_XY | DO_CLIP_FULL_Z | DO_CLIP_USER | DO_VIEWPORT)
+#define TAG(x) x##_xy_fullz_user_viewport
+#include "draw_cliptest_tmp.h"
 
-/* The normal case - cliptest, rhw divide, viewport transform.
- *
- * Also handle identity viewport here at the expense of a few wasted
- * instructions
- */
-static boolean post_vs_cliptest_viewport_gl( struct pt_post_vs *pvs,
-                                             struct draw_vertex_info *info )
-{
-   struct vertex_header *out = info->verts;
-   const float *scale = pvs->draw->viewport.scale;
-   const float *trans = pvs->draw->viewport.translate;
-   const unsigned pos = draw_current_shader_position_output(pvs->draw);
-   unsigned clipped = 0;
-   unsigned j;
-
-   if (0) debug_printf("%s count, %d\n", __FUNCTION__, info->count);
-
-   for (j = 0; j < info->count; j++) {
-      float *position = out->data[pos];
-
-      initialize_vertex_header(out);
-#if 0
-      debug_printf("%d) io = %p, data = %p = [%f, %f, %f, %f]\n",
-                   j, out, position, position[0], position[1], position[2], position[3]);
-#endif
-
-      out->clip[0] = position[0];
-      out->clip[1] = position[1];
-      out->clip[2] = position[2];
-      out->clip[3] = position[3];
-
-      out->vertex_id = 0xffff;
-      /* Disable depth clipping if depth clamping is enabled. */
-      out->clipmask = compute_clipmask_gl(out->clip, 
-					  pvs->draw->plane,
-                                          pvs->draw->nr_planes,
-                                          !pvs->draw->depth_clamp);
-      clipped += out->clipmask;
-
-      if (out->clipmask == 0)
-      {
-	 /* divide by w */
-	 float w = 1.0f / position[3];
-
-	 /* Viewport mapping */
-	 position[0] = position[0] * w * scale[0] + trans[0];
-	 position[1] = position[1] * w * scale[1] + trans[1];
-	 position[2] = position[2] * w * scale[2] + trans[2];
-	 position[3] = w;
-#if 0
-         debug_printf("post viewport: %f %f %f %f\n",
-                      position[0],
-                      position[1],
-                      position[2],
-                      position[3]);
-#endif
-      }
-
-      out = (struct vertex_header *)( (char *)out + info->stride );
-   }
-
-   return clipped != 0;
-}
+#define FLAGS (DO_CLIP_XY | DO_CLIP_FULL_Z | DO_CLIP_USER | DO_VIEWPORT | DO_EDGEFLAG)
+#define TAG(x) x##_xy_fullz_user_viewport_edgeflag
+#include "draw_cliptest_tmp.h"
 
 
 
-/* As above plus edgeflags
+/* Don't want to create 64 versions of this function, so catch the
+ * less common ones here.  This is looking like something which should
+ * be code-generated, perhaps appended to the end of the vertex
+ * shader.
  */
-static boolean
-post_vs_cliptest_viewport_gl_edgeflag(struct pt_post_vs *pvs,
-                                      struct draw_vertex_info *info)
-{
-   unsigned j;
-   boolean needpipe;
-
-   needpipe = post_vs_cliptest_viewport_gl(pvs, info);
-
-   /* If present, copy edgeflag VS output into vertex header.
-    * Otherwise, leave header as is.
-    */
-   if (pvs->draw->vs.edgeflag_output) {
-      struct vertex_header *out = info->verts;
-      int ef = pvs->draw->vs.edgeflag_output;
-
-      for (j = 0; j < info->count; j++) {
-         const float *edgeflag = out->data[ef];
-         out->edgeflag = !(edgeflag[0] != 1.0f);
-         needpipe |= !out->edgeflag;
-         out = (struct vertex_header *)( (char *)out + info->stride );
-      }
-   }
-   return needpipe;
-}
-
+#define FLAGS (pvs->flags)
+#define TAG(x) x##_generic
+#include "draw_cliptest_tmp.h"
 
 
 
-/* If bypass_clipping is set, skip cliptest and rhw divide.
- */
-static boolean post_vs_viewport( struct pt_post_vs *pvs,
-                                 struct draw_vertex_info *info )
-{
-   struct vertex_header *out = info->verts;
-   const float *scale = pvs->draw->viewport.scale;
-   const float *trans = pvs->draw->viewport.translate;
-   const unsigned pos = draw_current_shader_position_output(pvs->draw);
-   unsigned j;
-
-   if (0) debug_printf("%s\n", __FUNCTION__);
-   for (j = 0; j < info->count; j++) {
-      float *position = out->data[pos];
-
-      initialize_vertex_header(out);
-      /* Viewport mapping only, no cliptest/rhw divide
-       */
-      position[0] = position[0] * scale[0] + trans[0];
-      position[1] = position[1] * scale[1] + trans[1];
-      position[2] = position[2] * scale[2] + trans[2];
-
-      out = (struct vertex_header *)((char *)out + info->stride);
-   }
-
-   return FALSE;
-}
-
-
-/* If bypass_clipping is set and we have an identity viewport, nothing
- * to do.
- */
-static boolean post_vs_none( struct pt_post_vs *pvs,
-			     struct draw_vertex_info *info )
-{
-   struct vertex_header *out = info->verts;
-   unsigned j;
-
-   if (0) debug_printf("%s\n", __FUNCTION__);
-   /* just initialize the vertex_id in all headers */
-   for (j = 0; j < info->count; j++) {
-      initialize_vertex_header(out);
-
-      out = (struct vertex_header *)((char *)out + info->stride);
-   }
-   return FALSE;
-}
-
 boolean draw_pt_post_vs_run( struct pt_post_vs *pvs,
 			     struct draw_vertex_info *info )
 {
@@ -244,31 +117,72 @@ boolean draw_pt_post_vs_run( struct pt_post_vs *pvs,
 
 
 void draw_pt_post_vs_prepare( struct pt_post_vs *pvs,
-			      boolean bypass_clipping,
+			      boolean clip_xy,
+			      boolean clip_z,
+                              boolean clip_user,
 			      boolean bypass_viewport,
 			      boolean opengl,
 			      boolean need_edgeflags )
 {
-   if (!need_edgeflags) {
-      if (bypass_clipping) {
-         if (bypass_viewport)
-            pvs->run = post_vs_none;
-         else
-            pvs->run = post_vs_viewport;
-      }
-      else {
-         /* if (opengl) */
-         pvs->run = post_vs_cliptest_viewport_gl;
-      }
+   pvs->flags = 0;
+
+   if (clip_xy)
+      pvs->flags |= DO_CLIP_XY;
+   
+   if (clip_z && opengl) {
+      pvs->flags |= DO_CLIP_FULL_Z;
+      ASSIGN_4V( pvs->draw->plane[4],  0,  0,  1, 1 );
+   }
+
+   if (clip_z && !opengl) {
+      pvs->flags |= DO_CLIP_HALF_Z;
+      ASSIGN_4V( pvs->draw->plane[4],  0,  0,  1, 0 );
    }
-   else {
-      /* If we need to copy edgeflags to the vertex header, it should
-       * mean we're running the primitive pipeline.  Hence the bypass
-       * flags should be false.
-       */
-      assert(!bypass_clipping);
-      assert(!bypass_viewport);
-      pvs->run = post_vs_cliptest_viewport_gl_edgeflag;
+
+   if (clip_user)
+      pvs->flags |= DO_CLIP_USER;
+
+   if (!bypass_viewport)
+      pvs->flags |= DO_VIEWPORT;
+
+   if (need_edgeflags)
+      pvs->flags |= DO_EDGEFLAG;
+
+   /* Now select the relevant function:
+    */
+   switch (pvs->flags) {
+   case 0:
+      pvs->run = do_cliptest_none;
+      break;
+
+   case DO_CLIP_XY | DO_CLIP_FULL_Z | DO_VIEWPORT:
+      pvs->run = do_cliptest_xy_fullz_viewport;
+      break;
+
+   case DO_CLIP_XY | DO_CLIP_HALF_Z | DO_VIEWPORT:
+      pvs->run = do_cliptest_xy_halfz_viewport;
+      break;
+
+   case DO_CLIP_FULL_Z | DO_VIEWPORT:
+      pvs->run = do_cliptest_fullz_viewport;
+      break;
+
+   case DO_CLIP_HALF_Z | DO_VIEWPORT:
+      pvs->run = do_cliptest_halfz_viewport;
+      break;
+
+   case DO_CLIP_XY | DO_CLIP_FULL_Z | DO_CLIP_USER | DO_VIEWPORT:
+      pvs->run = do_cliptest_xy_fullz_user_viewport;
+      break;
+
+   case (DO_CLIP_XY | DO_CLIP_FULL_Z | DO_CLIP_USER |
+         DO_VIEWPORT | DO_EDGEFLAG):
+      pvs->run = do_cliptest_xy_fullz_user_viewport_edgeflag;
+      break;
+      
+   default:
+      pvs->run = do_cliptest_generic;
+      break;
    }
 }