Method BuildTree

GTE/Graphics/BoundTree.h:143–197

    private:
        void BuildTree(size_t maxTrisPerLeaf, bool storeInteriorTris,
            std::vector<Vector3<float>> const& centroids, size_t i0,
            size_t i1, std::vector<int32_t>& inSplit,
            std::vector<int32_t>& outSplit)
        {
            LogAssert(
                i0 <= i1,
                "Invalid index ordering.");

            Vector3<float> origin{}, direction{};
            CreateModelBound(i0, i1, inSplit, origin, direction);

            if (i1 - i0 < maxTrisPerLeaf)
            {
                // At a leaf node.
                size_t numTriangles = i1 - i0 + 1;
                mTriangles.resize(numTriangles);
                for (size_t t0 = 0, t1 = i0; t0 < numTriangles; ++t0, ++t1)
                {
                    mTriangles[t0] = inSplit[t1];
                }

                mLChild.reset();
                mRChild.reset();
            }
            else
            {
                // At an interior node.
                if (storeInteriorTris)
                {
                    size_t numTriangles = i1 - i0 + 1;
                    mTriangles.resize(numTriangles);
                    for (size_t t0 = 0, t1 = i0; t0 < numTriangles; ++t0, ++t1)
                    {
                        mTriangles[t0] = inSplit[t1];
                    }
                }
                else
                {
                    mTriangles.clear();
                }

                size_t j0{}, j1{};
                SplitTriangles(centroids, i0, i1, inSplit, j0, j1, outSplit,
                    origin, direction);

                mLChild = std::make_shared<BoundTree<Mesh, Bound>>(mMesh, 0, false);
                mLChild->BuildTree(maxTrisPerLeaf, storeInteriorTris,
                    centroids, i0, j0, outSplit, inSplit);

                mRChild = std::make_shared<BoundTree<Mesh, Bound>>(mMesh, 0, false);
                mRChild->BuildTree(maxTrisPerLeaf, storeInteriorTris,
                    centroids, j1, i1, outSplit, inSplit);
            }
        }

        // Compute the model bound for the subset of triangles.  Return a
        // line used for splitting the projections of the triangle centroids.