feat: multithread building vbo

src/Engine/Operator/AttributeHandle.h

@@ -75,7 +75,7 @@ public:
     {
         // TODO:protect against invalid positions
         // TODO: cast types
-        return data_[pos];
+        return (*data_)[pos];
     }
 
     void setValue(size_t pos, const T& value)

src/Engine/Operator/Geometry.cpp

@@ -170,13 +170,16 @@ enzo::geo::HeMesh geo::Geometry::computeHalfEdgeMesh()
     return heMesh;
 }
 
-unsigned int geo::Geometry::getPrimStartVertex(ga::Offset primOffset)
+ga::Offset geo::Geometry::getPrimStartVertex(ga::Offset primOffset) const
+{
+
+    return primStarts_[primOffset];
+}
+
+// TODO: handle this automatically
+void geo::Geometry::computePrimStartVertices()
 {
     const ga::Offset handleSize = vertexCountHandlePrim_.getSize();
-    // TODO: add smarter system to recompute primStarts_, also move to separate function 
-    // if size changed, recompute
-    if(handleSize!=primStarts_.size())
-    {
     bt::intT primStart = 0;
     for(size_t i=0; i<handleSize; ++i)
     {
@@ -185,8 +188,6 @@ unsigned int geo::Geometry::getPrimStartVertex(ga::Offset primOffset)
     }
 }
 
-    return primStarts_[primOffset];
-}
 
 
 

src/Engine/Operator/Geometry.h

@@ -31,14 +31,15 @@ public:
     std::vector<bt::Vector3> derivePointNormals();
     HeMesh computeHalfEdgeMesh();
     // returns the first vertex of the primitive
-    unsigned int getPrimStartVertex(ga::Offset primOffset);
     void addFace(std::initializer_list<ga::Offset> pointOffsets);
 
+    ga::Offset getPrimStartVertex(ga::Offset primOffset) const;
     bt::Vector3 getPosFromVert(ga::Offset vertexOffset) const;
     bt::Vector3 getPointPos(ga::Offset pointOffset) const;
     unsigned int getPrimVertCount(ga::Offset primOffset) const;
     ga::Offset getNumPrims() const;
     ga::Offset getNumVerts() const;
+    void computePrimStartVertices();
 private:
     using attribVector = std::vector<std::shared_ptr<ga::Attribute>>;
     attribVector& getAttributeStore(ga::AttributeOwner& owner);

src/Gui/Viewport/GLMesh.cpp

@@ -5,6 +5,8 @@
 #include "Engine/Operator/Geometry.h"
 #include "Engine/Types.h"
 #include <CGAL/Polygon_mesh_processing/compute_normal.h>
+#include <oneapi/tbb/blocked_range.h>
+#include <oneapi/tbb/parallel_for.h>
 #include "icecream.hpp"
 
 
@@ -61,16 +63,16 @@ void GLMesh::setPosBuffer(enzo::geo::Geometry& geometry)
     const size_t numPrims = geometry.getNumPrims();
 
     vertices.resize(geometry.getNumVerts());
+    geometry.computePrimStartVertices();
 
-
-    for (int primOffset=0; primOffset<numPrims; ++primOffset)
+    tbb::parallel_for(tbb::blocked_range<size_t>(0, numPrims), [&](tbb::blocked_range<size_t> range)
     {
-        const unsigned int primStartVert = geometry.getPrimStartVertex(primOffset);
-        auto faceIndex = primOffset;
+        for (int primOffset=range.begin(); primOffset<range.end(); ++primOffset)
+        {
+            const enzo::ga::Offset primStartVert = geometry.getPrimStartVertex(primOffset);
+            const unsigned int faceVertCnt = geometry.getPrimVertCount(primOffset);
 
-        int faceVertCnt = geometry.getPrimVertCount(primOffset);
-
-        enzo::bt::Vector3 n;
+            enzo::bt::Vector3 Normal;
 
             // compute normal
             if(faceVertCnt>=3)
@@ -89,7 +91,7 @@ void GLMesh::setPosBuffer(enzo::geo::Geometry& geometry)
                 tang1.normalize();
                 tang2.normalize();
 
-            n = tang1.cross(tang2);
+                Normal = tang1.cross(tang2);
             }
 
             for(int i=0; i< faceVertCnt; ++i)
@@ -101,13 +103,14 @@ void GLMesh::setPosBuffer(enzo::geo::Geometry& geometry)
                     { p.x(),
                       p.y(),
                       p.z()},
-                { n.x(),
-                  n.y(),
-                  n.z()}
+                    { Normal.x(),
+                      Normal.y(),
+                      Normal.z()}
                 };
             }
 
         }
+    });
 
     glBufferData(GL_ARRAY_BUFFER, vertices.size()*sizeof(Vertex), vertices.data(), GL_STATIC_DRAW);
     unbind();