Mesa (master): draw: disable depth clipping if depth clamp is enabled

[Marek Olšák]

Module: Mesa
Branch: master
Commit: 9ca48de1068d4ebce81853d29455c83b4898e25e
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=9ca48de1068d4ebce81853d29455c83b4898e25e

Author: Marek Olšák <maraeo at gmail.com>
Date:   Wed Jul 21 20:31:39 2010 +0200

draw: disable depth clipping if depth clamp is enabled

---

 src/gallium/auxiliary/draw/draw_context.c    |    1 +
 src/gallium/auxiliary/draw/draw_private.h    |    1 +
 src/gallium/auxiliary/draw/draw_pt_post_vs.c |   13 +++++++++----
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c
index aac1ed6..c127f74 100644
--- a/src/gallium/auxiliary/draw/draw_context.c
+++ b/src/gallium/auxiliary/draw/draw_context.c
@@ -216,6 +216,7 @@ void draw_set_clip_state( struct draw_context *draw,
    assert(clip->nr <= PIPE_MAX_CLIP_PLANES);
    memcpy(&draw->plane[6], clip->ucp, clip->nr * sizeof(clip->ucp[0]));
    draw->nr_planes = 6 + clip->nr;
+   draw->depth_clamp = clip->depth_clamp;
 }
 
 
diff --git a/src/gallium/auxiliary/draw/draw_private.h b/src/gallium/auxiliary/draw/draw_private.h
index 8af8859..058aeed 100644
--- a/src/gallium/auxiliary/draw/draw_private.h
+++ b/src/gallium/auxiliary/draw/draw_private.h
@@ -249,6 +249,7 @@ struct draw_context
     */
    float plane[12][4];
    unsigned nr_planes;
+   boolean depth_clamp;
 
    /* If a prim stage introduces new vertex attributes, they'll be stored here
     */
diff --git a/src/gallium/auxiliary/draw/draw_pt_post_vs.c b/src/gallium/auxiliary/draw/draw_pt_post_vs.c
index e850cc2..308f927 100644
--- a/src/gallium/auxiliary/draw/draw_pt_post_vs.c
+++ b/src/gallium/auxiliary/draw/draw_pt_post_vs.c
@@ -57,7 +57,8 @@ dot4(const float *a, const float *b)
 }
 
 static INLINE unsigned
-compute_clipmask_gl(const float *clip, /*const*/ float plane[][4], unsigned nr)
+compute_clipmask_gl(const float *clip, /*const*/ float plane[][4], unsigned nr,
+                    boolean clip_depth)
 {
    unsigned mask = 0x0;
    unsigned i;
@@ -74,8 +75,10 @@ compute_clipmask_gl(const float *clip, /*const*/ float plane[][4], unsigned nr)
    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[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 */
+   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 */
+   }
 
    /* Followed by any remaining ones:
     */
@@ -120,9 +123,11 @@ static boolean post_vs_cliptest_viewport_gl( struct pt_post_vs *pvs,
       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->nr_planes,
+                                          !pvs->draw->depth_clamp);
       clipped += out->clipmask;
 
       if (out->clipmask == 0)