star-enclosures-3d

commit 90edf161d38fa7bb9e1a0e2e8aba9996bcba5bf9
parent bf92ade10d11e306b21aedaca255d37f7a3ae8b3
Author: Christophe Coustet <christophe.coustet@meso-star.com>
Date:   Fri,  5 Apr 2024 15:12:40 +0200

Continue bugfixes on connec components grouping

Fixes include:
- first inner component volume test was wrong
- outer prevalence over inner not inforced
- unexpected NaN occurences on side computation

Diffstat:
M
src/senc3d_scene_analyze.c
 | 
57
+++++++++++++++++++++++++++++++++++++++++++++------------

1 file changed, 45 insertions(+), 12 deletions(-)
diff --git a/src/senc3d_scene_analyze.c b/src/senc3d_scene_analyze.c
@@ -218,7 +218,11 @@ get_side_not_in_connex_component
 
 /* Here unsigned are required by s3d API */
 static void
-get_scn_indices(const unsigned itri, unsigned ids[3], void* ctx) {
+get_scn_indices
+  (const unsigned itri,
+   unsigned ids[3],
+   void* ctx)
+{
   int i;
   const struct senc3d_scene* scene = ctx;
   const struct triangle_in* trg =
@@ -232,7 +236,11 @@ get_scn_indices(const unsigned itri, unsigned ids[3], void* ctx) {
 
 /* Here unsigned are required by s3d API */
 static void
-get_scn_position(const unsigned ivert, float pos[3], void* ctx) {
+get_scn_position
+  (const unsigned ivert,
+   float pos[3],
+   void* ctx)
+{
   const struct senc3d_scene* scene = ctx;
   const union double3* pt =
     darray_position_cdata_get(&scene->vertices) + ivert;
@@ -337,6 +345,11 @@ self_hit_filter
       ASSERT(hit->prim.prim_id
         < darray_triangle_comp_size_get(ctx->triangles_comp));
 
+      if(hit->distance > ctx->hit_dist) {
+        /* No improvement */
+        return 1;
+      }
+
       if(hit_comp[SENC3D_FRONT] == ctx->origin_component
         || hit_comp[SENC3D_BACK] == ctx->origin_component)
       {
@@ -359,6 +372,10 @@ self_hit_filter
           const enum senc3d_side sides[2] = { SENC3D_FRONT, SENC3D_BACK };
           component_id_t c = hit_comp[sides[n]];
           ASSERT(c < darray_ptr_component_descriptor_size_get(ctx->components));
+          if(c == ctx->hit_component) {
+            /* Cannot change ctx->hit_component */
+            continue;
+          }
           if(comp_descriptors[c]->is_outer_border) {
             double v;
             /* The inner component we are trying to link can only be linked to
@@ -369,14 +386,20 @@ self_hit_filter
               continue;
             }
             v = fabs(comp_descriptors[c]->_6volume);
-            /* If origin_component is inside several outer components, the one
+            /* If already linked to an inner component, prefer an outer one
+             * regardless of their respective volumes.
+             * If origin_component is inside several outer components, the one
              * we are looking for is the smallest one (to manage outer component
-             * inside another outer component) */
-            if(v < ctx->current_6volume) {
+             * inside another outer component). */
+            if((ctx->hit_component != COMPONENT_NULL__
+                  && !comp_descriptors[ctx->hit_component]->is_outer_border )
+                || v < ctx->current_6volume) {
               ctx->hit_component = c;
               ctx->current_6volume = v;
               ctx->hit_dist = 0;
               ctx->hit_prim = hit->prim;
+            } else {
+              continue;
             }
           } else {
             /* c is an inner component */
@@ -409,11 +432,13 @@ self_hit_filter
             /* If origin_component is facing several inner components, the one
              * we are looking for is the largest one (to manage inner component
              * inside another inner component) */
-            if(v > ctx->current_6volume) {
+            if(ctx->current_6volume == DBL_MAX || v > ctx->current_6volume) {
               ctx->hit_component = c;
               ctx->current_6volume = v;
               ctx->hit_dist = 0;
               ctx->hit_prim = hit->prim;
+            } else {
+              continue;
             }
           }
         }
@@ -435,14 +460,22 @@ self_hit_filter
       /* For s to be comparable, vectors must be normailzed */
       f3_normalize(hit_normal, hit->normal);
       f3_normalize(rdir, ray_dir);
-      s = f3_dot(rdir, hit_normal);
+      s = f3_dot(rdir, hit_normal); /* Can be NaN for tiny distances */
+      if(isnan(s)) {
+        /* Try to fix it */
+        f3_divf(rdir, ray_dir, hit->distance);
+        f3_normalize(rdir, rdir);
+        s = f3_dot(rdir, hit_normal);
+        ASSERT(!isnan(s));
+      }
+
+      if(ctx->hit_dist == hit->distance && fabsf(ctx->s) >= fabsf(s)) {
+        /* Same distance with no s improvement: keep the previous hit */
+        return 1;
+      }
 
       if(fabsf(s) < DOT_THRESHOLD) {
         /* We cannot know for sure which side to consider */
-        if(ctx->hit_dist == hit->distance && fabsf(ctx->s) > fabsf(s)) {
-          /* Same distance with worse s: keep the previous hit */
-          return 1;
-        }
         ctx->hit_component = COMPONENT_NULL__;
         ctx->s = s;
         f3_set(ctx->hit_dir, ray_dir);
@@ -1014,12 +1047,12 @@ group_connex_components
   }
   if(*res != RES_OK) return;
 #endif
-
   descriptors = darray_ptr_component_descriptor_data_get(connex_components);
   tmp = darray_ptr_component_descriptor_size_get(connex_components);
   ASSERT(tmp <= COMPONENT_MAX__);
   cc_count = (component_id_t)tmp;
   positions = darray_position_cdata_get(&scn->vertices);
+
   ctx0.type = FCTX0;
   ctx0.c.ctx0.triangles_comp = triangles_comp;
   ctx1.type = FCTX1;