Function splitn_edge_no_alloc

pub fn splitn_edge_no_alloc<T: CoordsFloat>(
    cmap: &mut CMap2<T>,
    edge_id: EdgeIdType,
    new_darts: &[DartIdType],
    midpoint_vertices: &[T],
) -> Result<(), SplitEdgeError>

Split an edge into n segments.

This implementation is 2D specific.

This method is a variant of splitn_edge where inline dart allocations are removed. The aim of this variant is to enhance performance by enabling the user to pre-allocate a number of darts.

The method follows the same logic as the regular splitn_edge, the only difference being that the new darts won’t be added to the map on the fly. Instead, the method uses darts passed as argument (new_darts) to build the new segments. Consequently, there is no guarantee that IDs will be consistent between this and the regular method.

Arguments

• cmap: &mut CMap2<T> – Reference to the modified map.
• edge_id: EdgeIdentifier – Edge to split in two.
• new_darts: &[DartIdentifier] – Dart IDs used to build the new segments.
• midpoint_vertices: &[T] – Relative positions of new vertices, starting from the vertex of the dart sharing edge_id as its identifier.

Dart IDs Requirements & Usage

Because of the dimension, we can easily compute the number of dart needed to perform this operation. These are the requirements for the darts:

• identifiers are passed as a slice:
  • slice length should verify new_darts.len() == 2 * midpoint_vertices.len()
• the first half of the slice will always be used if the operation is successful.
• the second half of the slice will only be used if the original edge is made of two darts; if that is not the case, the second half IDs can all be NULL_DART_IDs.
• all of these darts should be free

Return / Errors

This method will return:

• Ok(()) if the operation is successful & the edge was split
• Err(SplitEdgeError) if the operation fails & the edge is left unchanged. Causes of failure are described in SplitEdgeError’s documentation and in requirements mentionned above.