Property | Value |
---|---|
Type: | advanced |
Identifier: | org.eclipse.elk.layered.directionCongruency |
Meta Data Provider: | options.LayeredMetaDataProvider |
Value Type: | org.eclipse.elk.alg.layered.options.DirectionCongruency (Enum) |
Possible Values: | READING_DIRECTION ROTATION |
Default Value: | DirectionCongruency.READING_DIRECTION (as defined in org.eclipse.elk.layered ) |
Applies To: | parents |
Specifies how drawings of the same graph with different layout directions compare to each other: either a natural reading direction is preserved or the drawings are rotated versions of each other.
Internally, we map any desired layout direction to the variant of creating a left-to-right drawing. This is done by transforming the input graph’s coordinates in various ways. Depending on the way this transformation is performed, one can either preserve a reading direction or rotation.
When preserving reading direction, the vertical reading direction of a left-to-right or right-to-left layout (and thus the node, edge, and edge label order) corresponds to the horizontal reading direction of a top-to-bottom or bottom-to-top layout. When preserving rotation, the four possible drawings are simply rotated versions of the left-to-right variant. This might be of interest if one wants to preserve a clockwise orientation of feedback loops.
The following drawings illustrate the different behaviors.