Method autoConnectNodes

Engine/NodeGroup.cpp:648–754

}

bool
NodeCollection::autoConnectNodes(const NodePtr& selected,
                                 const NodePtr& created)
{
    ///We follow this rule:
    //        1) selected is output
    //          a) created is output --> fail
    //          b) created is input --> connect input
    //          c) created is regular --> connect input
    //        2) selected is input
    //          a) created is output --> connect output
    //          b) created is input --> fail
    //          c) created is regular --> connect output
    //        3) selected is regular
    //          a) created is output--> connect output
    //          b) created is input --> connect input
    //          c) created is regular --> connect output

    ///if true if will connect 'created' as input of 'selected',
    ///otherwise as output.
    bool connectAsInput = false;

    ///cannot connect 2 input nodes together: case 2-b)
    if ( (selected->getNInputs() == 0) && (created->getNInputs() == 0) ) {
        return false;
    }
    ///cannot connect 2 output nodes together: case 1-a)
    if ( selected->isOutputNode() && created->isOutputNode() ) {
        return false;
    }

    ///1)
    if ( selected->isOutputNode() ) {
        ///assert we're not in 1-a)
        assert( !created->isOutputNode() );

        ///for either cases 1-b) or 1-c) we just connect the created node as input of the selected node.
        connectAsInput = true;
    }
    ///2) and 3) are similar exceptfor case b)
    else {
        ///case 2 or 3- a): connect the created node as output of the selected node.
        if ( created->isOutputNode() ) {
            connectAsInput = false;
        }
        ///case b)
        else if (created->getNInputs() == 0) {
            assert(selected->getNInputs() != 0);
            ///case 3-b): connect the created node as input of the selected node
            connectAsInput = true;
        }
        ///case c) connect created as output of the selected node
        else {
            connectAsInput = false;
        }
    }

    bool ret = false;