light: ray stream api: allow getting hit face

include/light/trace.hh

@@ -66,6 +66,7 @@ public:
     virtual float getPushedRayDist(size_t j) = 0;
     virtual float getPushedRayHitDist(size_t j) = 0;
     virtual hittype_t getPushedRayHitType(size_t j) = 0;
+    virtual const bsp2_dface_t *getPushedRayHitFace(size_t j) = 0;
     virtual void getPushedRayDir(size_t j, vec3_t out) = 0;
     virtual int getPushedRayPointIndex(size_t j) = 0;
     virtual void getPushedRayColor(size_t j, vec3_t out) = 0;

light/trace.cc

@@ -800,6 +800,7 @@ public:
     // hit info
     float _hitdist;
     hittype_t _hittype;
+    const bsp2_dface_t *_hitface;
     bool _hit_occluded;
     
     bsp_ray_t(int i, const vec_t *origin, const vec3_t dir, float dist, const dmodel_t *selfshadow, const vec_t *color, const vec_t *normalcontrib) :
@@ -808,6 +809,7 @@ public:
         _selfshadow{selfshadow},
         _hitdist{dist},
         _hittype{hittype_t::NONE},
+        _hitface(nullptr),
         _hit_occluded{false} {
 			VectorCopy(origin, _origin);
 			VectorCopy(dir, _dir);
@@ -857,7 +859,7 @@ public:
             return;
         
         for (bsp_ray_t &ray : _rays) {
-            ray._hittype = BSP_DirtTrace(ray._origin, ray._dir, ray._maxdist, ray._selfshadow, &ray._hitdist, nullptr, nullptr);
+            ray._hittype = BSP_DirtTrace(ray._origin, ray._dir, ray._maxdist, ray._selfshadow, &ray._hitdist, nullptr, &ray._hitface);
         }
     }
     
@@ -877,6 +879,10 @@ public:
         return _rays.at(j)._hittype;
     }
     
+    virtual const bsp2_dface_t *getPushedRayHitFace(size_t j) {
+        return _rays.at(j)._hitface;
+    }
+    
     virtual void getPushedRayDir(size_t j, vec3_t out) {
         for (int i=0; i<3; i++) {
             out[i] = _rays.at(j)._dir[i];

light/trace_embree.cc

@@ -869,6 +869,21 @@ public:
         }
     }
     
+    virtual const bsp2_dface_t *getPushedRayHitFace(size_t j) {
+        Q_assert(j < _maxrays);
+        
+        const RTCRay &ray = _rays[j];
+        
+        if (ray.geomID == RTC_INVALID_GEOMETRY_ID)
+            return nullptr;
+        
+        const sceneinfo &si = Embree_SceneinfoForGeomID(ray.geomID);
+        const bsp2_dface_t *face = si.triToFace.at(ray.primID);
+        Q_assert(face != nullptr);
+        
+        return face;
+    }
+    
     virtual void getPushedRayDir(size_t j, vec3_t out) {
         Q_assert(j < _maxrays);
         for (int i=0; i<3; i++) {