OpenSWMM Engine — Model editing C API (deletion and type conversion). More...

#include "openswmm_engine.h"

Include dependency graph for openswmm_edit.h:

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Classes
struct	SWMM_ImpactEntry
	One object that references the deletion target. More...

struct	SWMM_ImpactReport
	Aggregate impact report for a deletion operation. More...

struct	SWMM_ConversionResult
	Result of a node or link type conversion. More...

Typedefs
typedef enum SWMM_RefType	SWMM_RefType
	Category of an object that holds a cross-reference to a deleted object.

typedef struct SWMM_ImpactEntry	SWMM_ImpactEntry
	One object that references the deletion target.

typedef struct SWMM_ImpactReport	SWMM_ImpactReport
	Aggregate impact report for a deletion operation.

typedef struct SWMM_ConversionResult	SWMM_ConversionResult
	Result of a node or link type conversion.

Enumerations
enum	SWMM_RefType { SWMM_REF_NODE = 0 , SWMM_REF_LINK = 1 , SWMM_REF_SUBCATCH = 2 , SWMM_REF_GAGE = 3 , SWMM_REF_TABLE = 4 , SWMM_REF_TRANSECT = 5 , SWMM_REF_INLET_USAGE = 6 , SWMM_REF_EXT_INFLOW = 7 , SWMM_REF_DWF_INFLOW = 8 , SWMM_REF_RDII_ASSIGN = 9 , SWMM_REF_TREATMENT = 10 , SWMM_REF_LID_USAGE = 11 , SWMM_REF_SNOWPACK = 12 , SWMM_REF_HYDROGRAPH = 13 , SWMM_REF_POLLUTANT = 14 , SWMM_REF_PATTERN = 15 , SWMM_REF_AQUIFER = 16 , SWMM_REF_LID_CONTROL = 17 , SWMM_REF_STREET = 18 , SWMM_REF_INLET_DESIGN = 19 , SWMM_REF_LANDUSE = 20 , SWMM_REF_CONTROL_RULE = 21 }
	Category of an object that holds a cross-reference to a deleted object. More...

Functions
SWMM_ENGINE_API void	swmm_impact_report_free (SWMM_ImpactReport *report)
	Release heap memory owned by an impact report.

SWMM_ENGINE_API int	swmm_node_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_link_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_subcatch_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_gage_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_table_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_transect_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_pollutant_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_pattern_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_aquifer_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_snowpack_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_lid_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_street_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_inlet_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_landuse_analyze_impact (SWMM_Engine engine, int idx, SWMM_ImpactReport *report_out)
	Analyse which objects reference a given node, without deleting it.

SWMM_ENGINE_API int	swmm_hydrograph_analyze_impact (SWMM_Engine engine, const char uh_name, SWMM_ImpactReport report_out)
	Analyse which objects reference a unit-hydrograph group, without deleting it.

SWMM_ENGINE_API int	swmm_node_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete a node and cascade-delete or nullify all referencing objects.

SWMM_ENGINE_API int	swmm_link_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete a link and cascade-delete or nullify all referencing objects.

SWMM_ENGINE_API int	swmm_subcatch_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete a subcatchment and nullify all referencing objects.

SWMM_ENGINE_API int	swmm_gage_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete a rain gage and nullify subcatchment gage references.

SWMM_ENGINE_API int	swmm_node_delete_many (SWMM_Engine engine, const int indices, int n, SWMM_ImpactReport cascade_out)
	Delete many nodes in one call — equivalent to sequential swmm_node_delete calls in DESCENDING index order, with ONE name-index rebuild for the whole batch.

SWMM_ENGINE_API int	swmm_link_delete_many (SWMM_Engine engine, const int indices, int n, SWMM_ImpactReport cascade_out)
	Delete many nodes in one call — equivalent to sequential swmm_node_delete calls in DESCENDING index order, with ONE name-index rebuild for the whole batch.

SWMM_ENGINE_API int	swmm_subcatch_delete_many (SWMM_Engine engine, const int indices, int n, SWMM_ImpactReport cascade_out)
	Delete many nodes in one call — equivalent to sequential swmm_node_delete calls in DESCENDING index order, with ONE name-index rebuild for the whole batch.

SWMM_ENGINE_API int	swmm_gage_delete_many (SWMM_Engine engine, const int indices, int n, SWMM_ImpactReport cascade_out)
	Delete many nodes in one call — equivalent to sequential swmm_node_delete calls in DESCENDING index order, with ONE name-index rebuild for the whole batch.

SWMM_ENGINE_API int	swmm_table_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete a time series or curve and nullify all referencing objects.

SWMM_ENGINE_API int	swmm_transect_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete a transect and nullify link xsect_curve references.

SWMM_ENGINE_API int	swmm_pollutant_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete a pollutant and re-pack every per-pollutant matrix.

SWMM_ENGINE_API int	swmm_pattern_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete a time pattern and clear all name-based references.

SWMM_ENGINE_API int	swmm_aquifer_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete an aquifer; referencing subcatchments lose their groundwater (gw_aquifer set to -1) and surviving indices are renumbered.

SWMM_ENGINE_API int	swmm_snowpack_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete a snowpack; referencing subcatchments' snowpack index and raw-name mirror are cleared, surviving indices renumbered.

SWMM_ENGINE_API int	swmm_lid_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete a LID control; LID-usage rows referencing it are cascade-deleted and surviving lid_index values renumbered.

SWMM_ENGINE_API int	swmm_street_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete a street; inlet-usage rows referencing it are cascade-deleted (consistent with link deletion) and street_index values renumbered.

SWMM_ENGINE_API int	swmm_inlet_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete an inlet design; inlet-usage rows referencing it are cascade-deleted and design_index values renumbered.

SWMM_ENGINE_API int	swmm_landuse_delete (SWMM_Engine engine, int idx, SWMM_ImpactReport *cascade_out)
	Delete a land use; buildup/washoff rows and subcatchment coverage columns for it are re-packed.

SWMM_ENGINE_API int	swmm_hydrograph_delete (SWMM_Engine engine, const char uh_name, SWMM_ImpactReport cascade_out)
	Delete a unit-hydrograph group by name.

SWMM_ENGINE_API void	swmm_conversion_result_free (SWMM_ConversionResult *result)
	Release heap memory owned by a conversion result.

SWMM_ENGINE_API int	swmm_node_convert (SWMM_Engine engine, int idx, int new_type, SWMM_ConversionResult *result_out)
	Convert a node to a different type in-place.

SWMM_ENGINE_API int	swmm_link_convert (SWMM_Engine engine, int idx, int new_type, SWMM_ConversionResult *result_out)
	Convert a link to a different type in-place.

SWMM_ENGINE_API int	swmm_conduit_split (SWMM_Engine engine, int link_idx, double t, const char new_node_name, const char new_link_name, int make_virtual, int new_node_idx, int new_link_idx)
	Split a conduit at normalized position t, inserting a new node.

SWMM_ENGINE_API int	swmm_virtual_junction_fuse (SWMM_Engine engine, int node_idx, int *surviving_link_idx)
	Re-fuse the two conduits of a virtual junction into one, deleting the node (inverse of a virtual split).

SWMM_ENGINE_API int	swmm_conduit_split_inlet (SWMM_Engine engine, int link_idx, double t, const char new_node_name, const char new_link_name, const char inlet_id, const char capture_node, int new_node_idx, int new_link_idx)
	Split a STREET conduit at `t` and make the inserted node an inlet junction with the given design and capture node (2026-09-05).

SWMM_ENGINE_API int	swmm_inlet_junction_fuse (SWMM_Engine engine, int node_idx, int *surviving_link_idx)
	Inverse of swmm_conduit_split_inlet: removes the inlet junction's usage row, then re-fuses the conduit pair exactly as swmm_virtual_junction_fuse does.

Detailed Description

OpenSWMM Engine — Model editing C API (deletion and type conversion).

Provides two capabilities for interactive model editing:

1. Object deletion — remove any node, link, subcatchment, rain gage, table/curve, or transect from the model while the engine is in BUILDING or OPENED state. A pre-deletion impact-analysis function is provided so callers can inspect what would be affected before committing.

2. Type conversion — convert a node between JUNCTION/OUTFALL/STORAGE/ DIVIDER, or a link between CONDUIT/PUMP/ORIFICE/WEIR/OUTLET, in-place. Common properties are preserved; type-specific properties are cleared and sensible defaults are applied.

Safety guards

All mutating operations (delete, convert) require the engine to be in SWMM_STATE_BUILDING or SWMM_STATE_OPENED. The impact-analysis functions are read-only and work in any state where data is present (not CREATED, CLOSED, or ERROR).

See also: openswmm_engine.h

Author: Caleb Buahin caleb.nosp@m..bua.nosp@m.hin@g.nosp@m.mail.nosp@m..com

Copyright: Copyright (c) 2026 Caleb Buahin. All rights reserved.

License\n Apache-2.0

Typedef Documentation

◆ SWMM_ConversionResult

typedef struct SWMM_ConversionResult SWMM_ConversionResult

Result of a node or link type conversion.

Lists type-specific fields that were cleared and any topology warnings generated. Caller must pass to swmm_conversion_result_free when done.

◆ SWMM_ImpactEntry

typedef struct SWMM_ImpactEntry SWMM_ImpactEntry

One object that references the deletion target.

field is a static string literal naming the specific cross- reference field (e.g. "node1", "outlet_node", "pump_curve"). The caller must NOT free it.

◆ SWMM_ImpactReport

typedef struct SWMM_ImpactReport SWMM_ImpactReport

Aggregate impact report for a deletion operation.

entries is heap-allocated by the engine. The caller must pass this struct to swmm_impact_report_free when done.

◆ SWMM_RefType

typedef enum SWMM_RefType SWMM_RefType

Category of an object that holds a cross-reference to a deleted object.

Enumeration Type Documentation

◆ SWMM_RefType

enum SWMM_RefType

Category of an object that holds a cross-reference to a deleted object.

Enumerator
SWMM_REF_NODE	A node holds a reference.
SWMM_REF_LINK	A link holds a reference.
SWMM_REF_SUBCATCH	A subcatchment holds a reference.
SWMM_REF_GAGE	A rain gage holds a reference.
SWMM_REF_TABLE	A time series or curve holds a reference.
SWMM_REF_TRANSECT	A transect holds a reference.
SWMM_REF_INLET_USAGE	An inlet usage entry holds a reference.
SWMM_REF_EXT_INFLOW	An external-inflow row holds a reference.
SWMM_REF_DWF_INFLOW	A dry-weather-flow row holds a reference.
SWMM_REF_RDII_ASSIGN	An RDII assignment row holds a reference.
SWMM_REF_TREATMENT	A treatment expression holds a reference.
SWMM_REF_LID_USAGE	A LID usage row holds a reference.
SWMM_REF_SNOWPACK	A snowpack holds a reference.
SWMM_REF_HYDROGRAPH	A unit-hydrograph group holds a reference.
SWMM_REF_POLLUTANT	A pollutant holds a reference.
SWMM_REF_PATTERN	A time pattern holds a reference.
SWMM_REF_AQUIFER	An aquifer holds a reference.
SWMM_REF_LID_CONTROL	A LID control holds a reference.
SWMM_REF_STREET	A street holds a reference.
SWMM_REF_INLET_DESIGN	An inlet design holds a reference.
SWMM_REF_LANDUSE	A land use holds a reference.
SWMM_REF_CONTROL_RULE	A control rule references the object by name.

Function Documentation

◆ swmm_aquifer_analyze_impact()

SWMM_ENGINE_API int swmm_aquifer_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_aquifer_delete()

SWMM_ENGINE_API int swmm_aquifer_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete an aquifer; referencing subcatchments lose their groundwater (gw_aquifer set to -1) and surviving indices are renumbered.

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◆ swmm_conduit_split()

SWMM_ENGINE_API int swmm_conduit_split	(	SWMM_Engine	engine,
		int	link_idx,
		double	t,
		const char *	new_node_name,
		const char *	new_link_name,
		int	make_virtual,
		int *	new_node_idx,
		int *	new_link_idx )

Split a conduit at normalized position t, inserting a new node.

The split point lies at fraction t of the conduit's vertex-aware polyline length (0 < t < 1). The original conduit keeps its name and upstream end and is shortened to t·L; a new conduit named new_link_name carries the remaining length, copying cross-section, roughness and barrels, and taking over the downstream offset. The break-point invert is interpolated along the conduit gradient and interior vertices are partitioned. With make_virtual != 0 the new node becomes a virtual junction (validation runs; on a rule failure the split still stands as a regular junction and the rule code is returned).

Parameters

	engine	Engine handle.
	link_idx	Zero-based conduit index.
	t	Normalized split position along the polyline (0..1 exclusive).
	new_node_name	Unique name for the inserted node.
	new_link_name	Unique name for the new downstream conduit.
	make_virtual	1 to flag the new node as a virtual junction.
[out]	new_node_idx	Receives the new node index (may be NULL).
[out]	new_link_idx	Receives the new conduit index (may be NULL).

Returns: SWMM_OK on success; SWMM_ERR_LIFECYCLE, SWMM_ERR_BADHANDLE, SWMM_ERR_BADINDEX, SWMM_ERR_BADPARAM (bad t / duplicate or empty name / non-conduit); or an ERR_VJ_* rule code (609/611/613/617) when make_virtual validation fails after a successful split.

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◆ swmm_conduit_split_inlet()

SWMM_ENGINE_API int swmm_conduit_split_inlet	(	SWMM_Engine	engine,
		int	link_idx,
		double	t,
		const char *	new_node_name,
		const char *	new_link_name,
		const char *	inlet_id,
		const char *	capture_node,
		int *	new_node_idx,
		int *	new_link_idx )

Split a STREET conduit at t and make the inserted node an inlet junction with the given design and capture node (2026-09-05).

Equivalent to swmm_conduit_split(make_virtual=1) followed by swmm_node_set_inlet(1) and swmm_inlet_usage_set(host=node), but atomic: on any failure after the split the split is undone (fused back) and the error returned. The usage row is created with num_inlets=1, 0 % clogged, no flow limit, no local depression, AUTOMATIC placement; adjust with swmm_inlet_usage_set.

Parameters

inlet_id	Existing inlet design name.
capture_node	Existing node name (not virtual, not the new node).

Returns: SWMM_OK; generic codes; ERR_VJ_ / ERR_IJ_ rule codes; 625 for an unknown design; 627 for a bad capture node.

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◆ swmm_conversion_result_free()

SWMM_ENGINE_API void swmm_conversion_result_free ( SWMM_ConversionResult * result )

Release heap memory owned by a conversion result.

Does not free the struct itself. Safe to call on a zero-initialised struct.

◆ swmm_gage_analyze_impact()

SWMM_ENGINE_API int swmm_gage_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_gage_delete()

SWMM_ENGINE_API int swmm_gage_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete a rain gage and nullify subcatchment gage references.

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◆ swmm_gage_delete_many()

SWMM_ENGINE_API int swmm_gage_delete_many	(	SWMM_Engine	engine,
		const int *	indices,
		int	n,
		SWMM_ImpactReport *	cascade_out )

Delete many nodes in one call — equivalent to sequential swmm_node_delete calls in DESCENDING index order, with ONE name-index rebuild for the whole batch.

The per-object path rebuilds the entire name→index hash after EVERY delete, which dominates bulk deletions on large models (K deletes = K full rehashes over every remaining name). The batch runs the identical per-object cascade logic — semantics, cascade behaviour and final state match the sequential descending equivalent exactly — but rehashes once.

indices are pre-batch indices; duplicates are tolerated (deduplicated internally). Every index is validated BEFORE any mutation: an out-of-range entry fails the whole call with SWMM_ERR_BADINDEX and no changes. Cascade entries in cascade_out carry the indices the sequential-descending equivalent would report.

Parameters

engine	Engine handle.
indices	Array of `n` zero-based node indices (pre-batch).
n	Number of entries in `indices`; 0 is a no-op.
cascade_out	If non-NULL, receives the aggregate cascade report. Caller must free with swmm_impact_report_free.

Returns: SWMM_OK, SWMM_ERR_LIFECYCLE if not BUILDING/OPENED, SWMM_ERR_BADHANDLE, SWMM_ERR_BADPARAM if indices is NULL with n > 0, or SWMM_ERR_BADINDEX.

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◆ swmm_hydrograph_analyze_impact()

SWMM_ENGINE_API int swmm_hydrograph_analyze_impact	(	SWMM_Engine	engine,
		const char *	uh_name,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a unit-hydrograph group, without deleting it.

Groups are keyed by name (they have no stable index — a group is the set of [HYDROGRAPHS] parameter lines sharing one name).

Parameters

engine	Engine handle.
uh_name	Unit-hydrograph group name.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADPARAM if the name is NULL/empty or names no existing group.

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◆ swmm_hydrograph_delete()

SWMM_ENGINE_API int swmm_hydrograph_delete	(	SWMM_Engine	engine,
		const char *	uh_name,
		SWMM_ImpactReport *	cascade_out )

Delete a unit-hydrograph group by name.

Cascade-deletes RDII assignments using the group, then removes the group's parameter lines, gage assignment, and RDII-decay rows. swmm_hydrograph_remove_group is the report-less equivalent.

Returns: SWMM_OK, SWMM_ERR_LIFECYCLE, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADPARAM if the name is NULL/empty or unknown.

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◆ swmm_impact_report_free()

SWMM_ENGINE_API void swmm_impact_report_free ( SWMM_ImpactReport * report )

Release heap memory owned by an impact report.

Does not free the struct itself (typically stack-allocated by the caller). Safe to call on a zero-initialised struct.

◆ swmm_inlet_analyze_impact()

SWMM_ENGINE_API int swmm_inlet_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_inlet_delete()

SWMM_ENGINE_API int swmm_inlet_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete an inlet design; inlet-usage rows referencing it are cascade-deleted and design_index values renumbered.

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◆ swmm_inlet_junction_fuse()

SWMM_ENGINE_API int swmm_inlet_junction_fuse	(	SWMM_Engine	engine,
		int	node_idx,
		int *	surviving_link_idx )

Inverse of swmm_conduit_split_inlet: removes the inlet junction's usage row, then re-fuses the conduit pair exactly as swmm_virtual_junction_fuse does.

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◆ swmm_landuse_analyze_impact()

SWMM_ENGINE_API int swmm_landuse_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_landuse_delete()

SWMM_ENGINE_API int swmm_landuse_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete a land use; buildup/washoff rows and subcatchment coverage columns for it are re-packed.

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◆ swmm_lid_analyze_impact()

SWMM_ENGINE_API int swmm_lid_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_lid_delete()

SWMM_ENGINE_API int swmm_lid_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete a LID control; LID-usage rows referencing it are cascade-deleted and surviving lid_index values renumbered.

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◆ swmm_link_analyze_impact()

SWMM_ENGINE_API int swmm_link_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_link_convert()

SWMM_ENGINE_API int swmm_link_convert	(	SWMM_Engine	engine,
		int	idx,
		int	new_type,
		SWMM_ConversionResult *	result_out )

Convert a link to a different type in-place.

Common properties (node1, node2, offset1, offset2, q0, q_limit, setting, comments) are preserved. Type-specific fields are cleared and new-type defaults applied.

Parameters

engine	Engine handle.
idx	Zero-based link index.
new_type	Target SWMM_LinkType value.
result_out	If non-NULL, receives the conversion result.

Returns: SWMM_OK on success, SWMM_ERR_BADPARAM if new_type equals current type, SWMM_ERR_LIFECYCLE, SWMM_ERR_BADHANDLE, SWMM_ERR_BADINDEX.

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◆ swmm_link_delete()

SWMM_ENGINE_API int swmm_link_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete a link and cascade-delete or nullify all referencing objects.

Divider node divider_link fields that reference this link are nullified. Inlet usage entries whose link_index equals idx are deleted.

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◆ swmm_link_delete_many()

SWMM_ENGINE_API int swmm_link_delete_many	(	SWMM_Engine	engine,
		const int *	indices,
		int	n,
		SWMM_ImpactReport *	cascade_out )

Delete many nodes in one call — equivalent to sequential swmm_node_delete calls in DESCENDING index order, with ONE name-index rebuild for the whole batch.

The per-object path rebuilds the entire name→index hash after EVERY delete, which dominates bulk deletions on large models (K deletes = K full rehashes over every remaining name). The batch runs the identical per-object cascade logic — semantics, cascade behaviour and final state match the sequential descending equivalent exactly — but rehashes once.

indices are pre-batch indices; duplicates are tolerated (deduplicated internally). Every index is validated BEFORE any mutation: an out-of-range entry fails the whole call with SWMM_ERR_BADINDEX and no changes. Cascade entries in cascade_out carry the indices the sequential-descending equivalent would report.

Parameters

engine	Engine handle.
indices	Array of `n` zero-based node indices (pre-batch).
n	Number of entries in `indices`; 0 is a no-op.
cascade_out	If non-NULL, receives the aggregate cascade report. Caller must free with swmm_impact_report_free.

Returns: SWMM_OK, SWMM_ERR_LIFECYCLE if not BUILDING/OPENED, SWMM_ERR_BADHANDLE, SWMM_ERR_BADPARAM if indices is NULL with n > 0, or SWMM_ERR_BADINDEX.

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◆ swmm_node_analyze_impact()

SWMM_ENGINE_API int swmm_node_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_node_convert()

SWMM_ENGINE_API int swmm_node_convert	(	SWMM_Engine	engine,
		int	idx,
		int	new_type,
		SWMM_ConversionResult *	result_out )

Convert a node to a different type in-place.

Common properties (invert_elev, full_depth, init_depth, sur_depth, ponded_area, coordinates) are preserved. Type-specific fields for the old type are cleared and type-specific defaults for the new type are applied. Topology warnings are generated but conversion still proceeds.

Parameters

engine	Engine handle.
idx	Zero-based node index.
new_type	Target SWMM_NodeType value.
result_out	If non-NULL, receives the conversion result. Caller must free with swmm_conversion_result_free.

Returns: SWMM_OK on success, SWMM_ERR_LIFECYCLE if not BUILDING/OPENED, SWMM_ERR_BADPARAM if new_type is invalid or equals current type, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_node_delete()

SWMM_ENGINE_API int swmm_node_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete a node and cascade-delete or nullify all referencing objects.

Links that reference the node as node1 or node2 are deleted. Subcatchment outlet_node and inlet_usage node_index references are nullified (set to -1). All remaining integer cross-references whose value is greater than idx are decremented by 1.

Parameters

engine	Engine handle.
idx	Zero-based node index.
cascade_out	If non-NULL, receives the cascade report describing what was deleted or nullified. Caller must free with swmm_impact_report_free.

Returns: SWMM_OK on success, SWMM_ERR_LIFECYCLE if not BUILDING/OPENED, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_node_delete_many()

SWMM_ENGINE_API int swmm_node_delete_many	(	SWMM_Engine	engine,
		const int *	indices,
		int	n,
		SWMM_ImpactReport *	cascade_out )

Delete many nodes in one call — equivalent to sequential swmm_node_delete calls in DESCENDING index order, with ONE name-index rebuild for the whole batch.

The per-object path rebuilds the entire name→index hash after EVERY delete, which dominates bulk deletions on large models (K deletes = K full rehashes over every remaining name). The batch runs the identical per-object cascade logic — semantics, cascade behaviour and final state match the sequential descending equivalent exactly — but rehashes once.

indices are pre-batch indices; duplicates are tolerated (deduplicated internally). Every index is validated BEFORE any mutation: an out-of-range entry fails the whole call with SWMM_ERR_BADINDEX and no changes. Cascade entries in cascade_out carry the indices the sequential-descending equivalent would report.

Parameters

engine	Engine handle.
indices	Array of `n` zero-based node indices (pre-batch).
n	Number of entries in `indices`; 0 is a no-op.
cascade_out	If non-NULL, receives the aggregate cascade report. Caller must free with swmm_impact_report_free.

Returns: SWMM_OK, SWMM_ERR_LIFECYCLE if not BUILDING/OPENED, SWMM_ERR_BADHANDLE, SWMM_ERR_BADPARAM if indices is NULL with n > 0, or SWMM_ERR_BADINDEX.

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◆ swmm_pattern_analyze_impact()

SWMM_ENGINE_API int swmm_pattern_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_pattern_delete()

SWMM_ENGINE_API int swmm_pattern_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete a time pattern and clear all name-based references.

Clears matching DWF pat1..4, ext-inflow baseline patterns, aquifer ET patterns, and the global evaporation-recovery pattern. Unlike swmm_pattern_remove this reports what was cleared and rejects out-of-range indices.

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◆ swmm_pollutant_analyze_impact()

SWMM_ENGINE_API int swmm_pollutant_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_pollutant_delete()

SWMM_ENGINE_API int swmm_pollutant_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete a pollutant and re-pack every per-pollutant matrix.

Cascades: ext-inflow/DWF rows whose constituent names the pollutant. Re-packs: buildup/washoff (per-pollutant columns), treatment expressions, per-object concentration state (including [LOADINGS] initial buildup). Nullifies: co-pollutant references, LID removal pairs. Remaining co_pollut indices are renumbered.

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◆ swmm_snowpack_analyze_impact()

SWMM_ENGINE_API int swmm_snowpack_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_snowpack_delete()

SWMM_ENGINE_API int swmm_snowpack_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete a snowpack; referencing subcatchments' snowpack index and raw-name mirror are cleared, surviving indices renumbered.

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◆ swmm_street_analyze_impact()

SWMM_ENGINE_API int swmm_street_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_street_delete()

SWMM_ENGINE_API int swmm_street_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete a street; inlet-usage rows referencing it are cascade-deleted (consistent with link deletion) and street_index values renumbered.

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◆ swmm_subcatch_analyze_impact()

SWMM_ENGINE_API int swmm_subcatch_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_subcatch_delete()

SWMM_ENGINE_API int swmm_subcatch_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete a subcatchment and nullify all referencing objects.

Other subcatchments' outlet_subcatch fields and outfall nodes' outfall_route_to fields that reference this subcatchment are nullified.

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◆ swmm_subcatch_delete_many()

SWMM_ENGINE_API int swmm_subcatch_delete_many	(	SWMM_Engine	engine,
		const int *	indices,
		int	n,
		SWMM_ImpactReport *	cascade_out )

Delete many nodes in one call — equivalent to sequential swmm_node_delete calls in DESCENDING index order, with ONE name-index rebuild for the whole batch.

The per-object path rebuilds the entire name→index hash after EVERY delete, which dominates bulk deletions on large models (K deletes = K full rehashes over every remaining name). The batch runs the identical per-object cascade logic — semantics, cascade behaviour and final state match the sequential descending equivalent exactly — but rehashes once.

indices are pre-batch indices; duplicates are tolerated (deduplicated internally). Every index is validated BEFORE any mutation: an out-of-range entry fails the whole call with SWMM_ERR_BADINDEX and no changes. Cascade entries in cascade_out carry the indices the sequential-descending equivalent would report.

Parameters

engine	Engine handle.
indices	Array of `n` zero-based node indices (pre-batch).
n	Number of entries in `indices`; 0 is a no-op.
cascade_out	If non-NULL, receives the aggregate cascade report. Caller must free with swmm_impact_report_free.

Returns: SWMM_OK, SWMM_ERR_LIFECYCLE if not BUILDING/OPENED, SWMM_ERR_BADHANDLE, SWMM_ERR_BADPARAM if indices is NULL with n > 0, or SWMM_ERR_BADINDEX.

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◆ swmm_table_analyze_impact()

SWMM_ENGINE_API int swmm_table_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_table_delete()

SWMM_ENGINE_API int swmm_table_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete a time series or curve and nullify all referencing objects.

Affected references: gage ts_index, node storage_curve / outfall_param (TIDAL/TIMESERIES) / divider_curve, link pump_curve / xsect_curve.

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◆ swmm_transect_analyze_impact()

SWMM_ENGINE_API int swmm_transect_analyze_impact	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	report_out )

Analyse which objects reference a given node, without deleting it.

Parameters

engine	Engine handle.
idx	Zero-based node index.
report_out	Receives the impact report (may be NULL if not needed).

Returns: SWMM_OK, SWMM_ERR_BADHANDLE, or SWMM_ERR_BADINDEX.

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◆ swmm_transect_delete()

SWMM_ENGINE_API int swmm_transect_delete	(	SWMM_Engine	engine,
		int	idx,
		SWMM_ImpactReport *	cascade_out )

Delete a transect and nullify link xsect_curve references.

Links with IRREGULAR cross-section shape whose xsect_curve equals idx have their xsect_curve set to -1 and shape reset to CIRCULAR.

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◆ swmm_virtual_junction_fuse()

SWMM_ENGINE_API int swmm_virtual_junction_fuse	(	SWMM_Engine	engine,
		int	node_idx,
		int *	surviving_link_idx )

Re-fuse the two conduits of a virtual junction into one, deleting the node (inverse of a virtual split).

The upstream conduit's name survives; lengths sum; the node coordinate becomes an interior vertex of the merged conduit so map alignment is preserved; the downstream conduit's identifiers are retired. Requires a through orientation (one conduit flowing in, one flowing out).

Parameters

	engine	Engine handle.
	node_idx	Zero-based node index of the virtual junction.
[out]	surviving_link_idx	Receives the surviving conduit's index AFTER deletions renumber (may be NULL).

Returns: SWMM_OK on success; SWMM_ERR_LIFECYCLE, SWMM_ERR_BADHANDLE, SWMM_ERR_BADINDEX, SWMM_ERR_BADPARAM (not a virtual junction); or 609 (ERR_VJ_LINK_COUNT) when the node is not a two-conduit through pair.

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Classes

Typedefs

Enumerations

Functions

Detailed Description

Safety guards

Typedef Documentation

◆ SWMM_ConversionResult

◆ SWMM_ImpactEntry

◆ SWMM_ImpactReport

◆ SWMM_RefType

Enumeration Type Documentation

◆ SWMM_RefType

Function Documentation

◆ swmm_aquifer_analyze_impact()

◆ swmm_aquifer_delete()

◆ swmm_conduit_split()

◆ swmm_conduit_split_inlet()

◆ swmm_conversion_result_free()

◆ swmm_gage_analyze_impact()

◆ swmm_gage_delete()

◆ swmm_gage_delete_many()

◆ swmm_hydrograph_analyze_impact()

◆ swmm_hydrograph_delete()

◆ swmm_impact_report_free()

◆ swmm_inlet_analyze_impact()

◆ swmm_inlet_delete()

◆ swmm_inlet_junction_fuse()

◆ swmm_landuse_analyze_impact()

◆ swmm_landuse_delete()

◆ swmm_lid_analyze_impact()

◆ swmm_lid_delete()

◆ swmm_link_analyze_impact()

◆ swmm_link_convert()

◆ swmm_link_delete()

◆ swmm_link_delete_many()

◆ swmm_node_analyze_impact()

◆ swmm_node_convert()

◆ swmm_node_delete()

◆ swmm_node_delete_many()

◆ swmm_pattern_analyze_impact()

◆ swmm_pattern_delete()

◆ swmm_pollutant_analyze_impact()

◆ swmm_pollutant_delete()

◆ swmm_snowpack_analyze_impact()

◆ swmm_snowpack_delete()

◆ swmm_street_analyze_impact()

◆ swmm_street_delete()

◆ swmm_subcatch_analyze_impact()

◆ swmm_subcatch_delete()

◆ swmm_subcatch_delete_many()

◆ swmm_table_analyze_impact()

◆ swmm_table_delete()

◆ swmm_transect_analyze_impact()

◆ swmm_transect_delete()

◆ swmm_virtual_junction_fuse()