Function createdMergedPatch

radiantcore/patch/algorithm/General.cpp:249–338

}

scene::INodePtr createdMergedPatch(const PatchNodePtr& patchNode1, const PatchNodePtr& patchNode2)
{
    auto& patch1 = patchNode1->getPatch();
    auto& patch2 = patchNode2->getPatch();

    // Start with the first patch, construct some edges to compare: first row, last row, first col, last col
    // Associate Edge to the Starting Point for copying data to new patch
    std::vector<std::pair<PatchEdge, PatchControlIterator>> patch1Edges =
    {
        { PatchEdge{ SinglePatchRowIterator(patch1, 0), patch1.getWidth(), EdgeType::Row }, RowWisePatchIterator(patch1, patch1.getHeight() - 1, 1) },
        { PatchEdge{ SinglePatchColumnIterator(patch1, 0), patch1.getHeight(), EdgeType::Column }, ColumnWisePatchIterator(patch1, patch1.getWidth() - 1, 1) },
        { PatchEdge{ SinglePatchRowIterator(patch1, patch1.getHeight() - 1), patch1.getWidth(), EdgeType::Row }, RowWisePatchIterator(patch1, 0, patch1.getHeight() - 2) },
        { PatchEdge{ SinglePatchColumnIterator(patch1, patch1.getWidth() - 1), patch1.getHeight(), EdgeType::Column }, ColumnWisePatchIterator(patch1, 0, patch1.getWidth() - 2) }
    };

    // We'll be comparing each of the above edges to all other four edges of the second patch
    // and we're doing it in forward and backwards direction: we're trying to orient patch 2
    // such that the edge vertices are matching up with patch 1
    std::vector<PatchEdge> patch2Edges =
    {
        { RowWisePatchIterator(patch2), patch2.getWidth(), EdgeType::Row },
        { ColumnWisePatchIterator(patch2), patch2.getHeight(), EdgeType::Column },
        { RowWisePatchIterator(patch2, patch2.getHeight() - 1, 0), patch2.getWidth(), EdgeType::Row },
        { ColumnWisePatchIterator(patch2, patch2.getWidth() - 1, 0), patch2.getHeight(), EdgeType::Column },

        { RowWisePatchReverseIterator(patch2), patch2.getWidth(), EdgeType::Row },
        { ColumnWisePatchReverseIterator(patch2), patch2.getHeight(), EdgeType::Column },
        { RowWisePatchReverseIterator(patch2, patch2.getHeight() - 1, 0), patch2.getWidth(), EdgeType::Row },
        { ColumnWisePatchReverseIterator(patch2, patch2.getWidth() - 1, 0), patch2.getHeight(), EdgeType::Column }
    };

    // As soon as we've found a matching edge, we know exactly how the resulting merged patch
    // should look like. We know the dimensions and we know whether we need to expand the
    // patch row-wise or column-wise.
    for (const auto& p1Iter : patch1Edges)
    {
        const auto& patch1Edge = p1Iter.first;
        const auto& patch1FillData = p1Iter.second;

        for (const auto& patch2Edge : patch2Edges)
        {
            if (patch1Edge.edgeLength != patch2Edge.edgeLength)
            {
                continue; // length doesn't match
            }

            if (!firstNItemsAreEqual(patch1Edge.iterator, patch2Edge.iterator, patch1Edge.edgeLength, WELD_EPSILON))
            {
                continue;
            }

            // Calculate the patch dimensions
            std::size_t numNewRows = patch1.getHeight();
            std::size_t numNewColumns = patch1.getWidth();
            std::size_t numNewEdges = patch2.getWidth() * patch2.getHeight() / patch2Edge.edgeLength - 1;

            auto& dimensionToExpand = patch1Edge.edgeType == EdgeType::Row ? numNewRows : numNewColumns;
            dimensionToExpand += numNewEdges;