draw: handle nan clipdistance

If clipdistance for one of the vertices is nan (or inf) then the
entire primitive should be discarded.

Signed-off-by: Zack Rusin <[email protected]>
Reviewed-by: Roland Scheidegger <[email protected]>

3 files changed, 16 insertions, 4 deletions

diff --git a/src/gallium/auxiliary/draw/draw_cliptest_tmp.h b/src/gallium/auxiliary/draw/draw_cliptest_tmp.h
index e4500dbd971..fc548102f2b 100644
--- a/src/gallium/auxiliary/draw/draw_cliptest_tmp.h
+++ b/src/gallium/auxiliary/draw/draw_cliptest_tmp.h
@@ -140,7 +140,7 @@ static boolean TAG(do_cliptest)( struct pt_post_vs *pvs,
                      clipdist = out->data[cd[0]][i];
                   else
                      clipdist = out->data[cd[1]][i-4];
-                  if (clipdist < 0)
+                  if (clipdist < 0 || util_is_inf_or_nan(clipdist))
                      mask |= 1 << plane_idx;
                } else {
                   if (dot4(clipvertex, plane[plane_idx]) < 0)
diff --git a/src/gallium/auxiliary/draw/draw_llvm.c b/src/gallium/auxiliary/draw/draw_llvm.c
index 84e33926a2b..820d6b0013e 100644
--- a/src/gallium/auxiliary/draw/draw_llvm.c
+++ b/src/gallium/auxiliary/draw/draw_llvm.c
@@ -1261,6 +1261,7 @@ generate_clipmask(struct draw_llvm *llvm,
    if (clip_user) {
       LLVMValueRef planes_ptr = draw_jit_context_planes(gallivm, context_ptr);
       LLVMValueRef indices[3];
+      LLVMValueRef is_nan_or_inf;
 
       /* userclip planes */
       while (ucp_enable) {
@@ -1280,6 +1281,8 @@ generate_clipmask(struct draw_llvm *llvm,
                clipdist = LLVMBuildLoad(builder, outputs[cd[1]][i-4], "");
             }
             test = lp_build_compare(gallivm, f32_type, PIPE_FUNC_GREATER, zero, clipdist);
+            is_nan_or_inf = lp_build_is_inf_or_nan(gallivm, vs_type, clipdist);
+            test = LLVMBuildOr(builder, test, is_nan_or_inf, "");
             temp = lp_build_const_int_vec(gallivm, i32_type, 1 << plane_idx);
             test = LLVMBuildAnd(builder, test, temp, "");
             mask = LLVMBuildOr(builder, mask, test, "");
diff --git a/src/gallium/auxiliary/draw/draw_pipe_clip.c b/src/gallium/auxiliary/draw/draw_pipe_clip.c
index b76e9a501ac..0f90bfdff08 100644
--- a/src/gallium/auxiliary/draw/draw_pipe_clip.c
+++ b/src/gallium/auxiliary/draw/draw_pipe_clip.c
@@ -104,7 +104,7 @@ static void interp_attr( float dst[4],
 			 float t,
 			 const float in[4],
 			 const float out[4] )
-{  
+{
    dst[0] = LINTERP( t, out[0], in[0] );
    dst[1] = LINTERP( t, out[1], in[1] );
    dst[2] = LINTERP( t, out[2], in[2] );
@@ -380,6 +380,9 @@ do_clip_tri( struct draw_stage *stage,
       dp_prev = getclipdist(clipper, vert_prev, plane_idx);
       clipmask &= ~(1<<plane_idx);
 
+      if (util_is_inf_or_nan(dp_prev))
+         return; //discard nan
+
       assert(n < MAX_CLIPPED_VERTICES);
       if (n >= MAX_CLIPPED_VERTICES)
          return;
@@ -392,6 +395,9 @@ do_clip_tri( struct draw_stage *stage,
 
          float dp = getclipdist(clipper, vert, plane_idx);
 
+         if (util_is_inf_or_nan(dp))
+            return; //discard nan
+
 	 if (!IS_NEGATIVE(dp_prev)) {
             assert(outcount < MAX_CLIPPED_VERTICES);
             if (outcount >= MAX_CLIPPED_VERTICES)
@@ -522,6 +528,9 @@ do_clip_line( struct draw_stage *stage,
       const float dp0 = getclipdist(clipper, v0, plane_idx);
       const float dp1 = getclipdist(clipper, v1, plane_idx);
 
+      if (util_is_inf_or_nan(dp0) || util_is_inf_or_nan(dp1))
+         return; //discard nan
+
       if (dp1 < 0.0F) {
 	 float t = dp1 / (dp1 - dp0);
          t1 = MAX2(t1, t);
@@ -574,7 +583,7 @@ clip_line( struct draw_stage *stage,
 {
    unsigned clipmask = (header->v[0]->clipmask | 
                         header->v[1]->clipmask);
-   
+
    if (clipmask == 0) {
       /* no clipping needed */
       stage->next->line( stage->next, header );
@@ -594,7 +603,7 @@ clip_tri( struct draw_stage *stage,
    unsigned clipmask = (header->v[0]->clipmask | 
                         header->v[1]->clipmask | 
                         header->v[2]->clipmask);
-   
+
    if (clipmask == 0) {
       /* no clipping needed */
       stage->next->tri( stage->next, header );