public function testCloneDoubleInvertedIsOriginal()
{
$edgeInverted = $this->edge->createEdgeCloneInverted();
$this->assertInstanceOf(get_class($this->edge), $edgeInverted);
$edge = $edgeInverted->createEdgeCloneInverted();
$this->assertEdgeEquals($this->edge, $edge);
}
/**
* Will merge all edges that are parallel to to given edge
*
* @param Edge $newEdge
*/
private function mergeParallelEdges(Edge $newEdge)
{
$parallelEdges = $newEdge->getEdgesParallel();
if ($parallelEdges) {
$mergedCapacity = 0;
foreach ($parallelEdges as $parallelEdge) {
$mergedCapacity += $parallelEdge->getCapacity();
}
$newEdge->setCapacity($newEdge->getCapacity() + $mergedCapacity);
foreach ($parallelEdges as $parallelEdge) {
$parallelEdge->destroy();
}
}
}
/**
* get set of all Edges parallel to this edge (excluding self)
*
* @param Edge $edge
* @return Edges
* @throws LogicException
*/
public function getEdgesParallelEdge(Edge $edge)
{
if ($edge instanceof DirectedEdge) {
// get all edges between this edge's endpoints
$edges = $edge->getVertexStart()->getEdgesTo($edge->getVertexEnd())->getVector();
} else {
// edge points into both directions (undirected/bidirectional edge)
// also get all edges in other direction
$ends = $edge->getVertices();
$edges = $ends->getVertexFirst()->getEdges()->getEdgesIntersection($ends->getVertexLast()->getEdges())->getVector();
}
$pos = array_search($edge, $edges, true);
if ($pos === false) {
// @codeCoverageIgnoreStart
throw new LogicException('Internal error: Current edge not found');
// @codeCoverageIgnoreEnd
}
// exclude current edge from parallel edges
unset($edges[$pos]);
return new Edges(array_values($edges));
}
/**
* get label for given $edge
*
* @param Edge $edge
* @return string label (may be empty if there's nothing to be described)
*/
protected function getEdgeLabel(Edge $edge)
{
$label = '';
$flow = $edge->getFlow();
$capacity = $edge->getCapacity();
// flow is set
if ($flow !== NULL) {
// NULL capacity = infinite capacity
$label = $flow . '/' . ($capacity === NULL ? '∞' : $capacity);
// capacity set, but not flow (assume zero flow)
} elseif ($capacity !== NULL) {
$label = '0/' . $capacity;
}
$weight = $edge->getWeight();
// weight is set
if ($weight !== NULL) {
if ($label === '') {
$label = $weight;
} else {
$label .= '/' . $weight;
}
}
return $label;
}
/**
* @expectedException InvalidArgumentException
*/
public function testFlowMustBePositive()
{
$this->edge->setFlow(-10);
}
/**
* Extracts inverted edge from this graph
*
* @param Edge $edge
* @return Edge
* @throws UnderflowException if no edge was found
* @throws OverflowException if multiple edges match
*/
public function getEdgeCloneInverted(Edge $edge)
{
// Extract endpoints from edge
$vertices = $edge->getVertices()->getVector();
return $this->getEdgeCloneInternal($edge, $vertices[1], $vertices[0]);
}
protected function getLayoutEdge(Edge $edge)
{
$layout = $edge->getLayout();
// use flow/capacity/weight as edge label
$label = NULL;
$flow = $edge->getFlow();
$capacity = $edge->getCapacity();
// flow is set
if ($flow !== NULL) {
// NULL capacity = infinite capacity
$label = $flow . '/' . ($capacity === NULL ? '∞' : $capacity);
// capacity set, but not flow (assume zero flow)
} elseif ($capacity !== NULL) {
$label = '0/' . $capacity;
}
$weight = $edge->getWeight();
// weight is set
if ($weight !== NULL) {
if ($label === NULL) {
$label = $weight;
} else {
$label .= '/' . $weight;
}
}
if ($label !== NULL) {
if (isset($layout['label'])) {
$layout['label'] .= ' ' . $label;
} else {
$layout['label'] = $label;
}
}
return $layout;
}