Method ProbeTree

core/src/core/probe_tree.cpp:46–133

const int ProbeTree::kProbeLookupStackSize = 128;

ProbeTree::ProbeTree(int numProbes,
                     const Probe* probes)
{
    if (numProbes <= 0)
        return;

    mNodes.resize(2 * numProbes - 1);

    Array<int32_t> leafIndices(numProbes);
    Array<Box> leafBounds(numProbes);
    Array<Vector3f> leafBoxCenters(numProbes);
    for (auto i = 0; i < numProbes; ++i)
    {
        leafIndices[i] = i;

        const auto& sphere = probes[i].influence;
        auto delta = sphere.radius * Vector3f(1, 1, 1);

        leafBounds[i] = Box(sphere.center - delta, sphere.center + delta);

        leafBoxCenters[i] = sphere.center;
    }

    Array<CentroidCoordinate, 2> centroids(3, numProbes);

    Stack<ProbeTreeConstructionTask, kProbeLookupStackSize> stack;
    ProbeTreeConstructionTask task{0, 0, numProbes - 1, 1};

    while (true)
    {
        if (task.startIndex == task.endIndex)
        {
            mNodes[task.nodeIndex].box = leafBounds[leafIndices[task.startIndex]];
            mNodes[task.nodeIndex].setProbeIndex(leafIndices[task.startIndex]);

            if (stack.isEmpty())
                break;

            task = stack.pop();
        }
        else
        {
            alignas(float4_t) GrowableBox nodeBounds;
            for (auto i = task.startIndex; i <= task.endIndex; ++i)
            {
                alignas(float4_t) GrowableBox bounds;
                bounds.load(leafBounds[leafIndices[i]]);
                nodeBounds.growToContain(bounds);
            }
            nodeBounds.store(mNodes[task.nodeIndex].box);

            for (auto i = task.startIndex; i <= task.endIndex; ++i)
            {
                centroids[0][i].coordinate = leafBoxCenters[leafIndices[i]].x();
                centroids[1][i].coordinate = leafBoxCenters[leafIndices[i]].y();
                centroids[2][i].coordinate = leafBoxCenters[leafIndices[i]].z();
                centroids[0][i].leafIndex = leafIndices[i];
                centroids[1][i].leafIndex = leafIndices[i];