Merge pull request #1149 from AbigailBuccaneer/tighter-visibility-checking

Improve object visibility culling with tighter bounding spheres

src/graphics/engine/engine.cpp

@@ -765,7 +765,7 @@ void CEngine::AddBaseObjTriangles(int baseObjRank, const std::vector<VertexTex2>
         p1.bboxMax.z = Math::Max(vertices[i].coord.z, p1.bboxMax.z);
     }
 
-    p1.radius = Math::Max(p1.bboxMin.Length(), p1.bboxMax.Length());
+    p1.boundingSphere = Math::BoundingSphereForBox(p1.bboxMin, p1.bboxMax);
 
     p1.totalTriangles += vertices.size() / 3;
 }
@@ -801,7 +801,7 @@ void CEngine::AddBaseObjQuick(int baseObjRank, const EngineBaseObjDataTier& buff
             p1.bboxMax.z = Math::Max(p3.vertices[i].coord.z, p1.bboxMax.z);
         }
 
-        p1.radius = Math::Max(p1.bboxMin.Length(), p1.bboxMax.Length());
+        p1.boundingSphere = Math::BoundingSphereForBox(p1.bboxMin, p1.bboxMax);
     }
 
     if (p3.type == ENG_TRIANGLE_TYPE_TRIANGLES)
@@ -856,7 +856,7 @@ void CEngine::DebugObject(int objRank)
     vecStr = p1.bboxMax.ToString();
     l->Debug("  bboxMax: %s\n", vecStr.c_str());
     l->Debug("  totalTriangles: %d\n", p1.totalTriangles);
-    l->Debug("  radius: %f\n", p1.radius);
+    l->Debug("  radius: %f\n", p1.boundingSphere.radius);
 
     for (int l2 = 0; l2 < static_cast<int>( p1.next.size() ); l2++)
     {
@@ -1659,7 +1659,6 @@ void CEngine::UpdateGeometry()
 
         p1.bboxMin.LoadZero();
         p1.bboxMax.LoadZero();
-        p1.radius = 0;
 
         for (int l2 = 0; l2 < static_cast<int>( p1.next.size() ); l2++)
         {
@@ -1678,10 +1677,10 @@ void CEngine::UpdateGeometry()
                         p1.bboxMax.y = Math::Max(p3.vertices[i].coord.y, p1.bboxMax.y);
                         p1.bboxMax.z = Math::Max(p3.vertices[i].coord.z, p1.bboxMax.z);
                 }
+            }
+        }
 
-                p1.radius = Math::Max(p1.bboxMin.Length(), p1.bboxMax.Length());
+        p1.boundingSphere = Math::BoundingSphereForBox(p1.bboxMin, p1.bboxMax);
-            }
-        }
     }
 
     m_updateGeometry = false;
@@ -1925,9 +1924,8 @@ bool CEngine::IsVisible(int objRank)
 
     assert(baseObjRank >= 0 && baseObjRank < static_cast<int>(m_baseObjects.size()));
 
-    float radius = m_baseObjects[baseObjRank].radius;
+    const auto& sphere = m_baseObjects[baseObjRank].boundingSphere;
-    Math::Vector center(0.0f, 0.0f, 0.0f);
+    if (m_device->ComputeSphereVisibility(sphere.pos, sphere.radius) == Gfx::FRUSTUM_PLANE_ALL)
-    if (m_device->ComputeSphereVisibility(center, radius) == Gfx::FRUSTUM_PLANE_ALL)
     {
         m_objects[objRank].visible = true;
         return true;

src/graphics/engine/engine.h

@@ -246,8 +246,8 @@ struct EngineBaseObject
     Math::Vector           bboxMin;
     //! bounding box max (origin 0,0,0 always included)
     Math::Vector           bboxMax;
-    //! Radius of the sphere at the origin
+    //! A bounding sphere that contains all the vertices in this EngineBaseObject
-    float                  radius = 0.0f;
+    Math::Sphere           boundingSphere;
     //! Next tier (Tex)
     std::vector<EngineBaseObjTexTier> next;
 

src/math/sphere.h

@@ -44,4 +44,11 @@ inline float DistanceBetweenSpheres(const Sphere& sphere1, const Sphere& sphere2
     return Math::Distance(sphere1.pos, sphere2.pos) - sphere1.radius - sphere2.radius;
 }
 
+inline Sphere BoundingSphereForBox(Vector mins, Vector maxs)
+{
+    auto centroid = (maxs + mins) / 2.0f;
+    auto halfExtent = (maxs - centroid);
+    return Sphere{centroid, halfExtent.Length()};
+}
+
 } // namespace Math