RecastRegion.cpp File Reference

#include "CoreMinimal.h"
#include "Stats/Stats.h"
#include "Recast/Recast.h"
#include "Recast/RecastAlloc.h"
#include "Recast/RecastAssert.h"

Classes
struct	rcRegion
struct	rcSweepSpan

Namespaces
namespace	RecastRegionFunc
namespace	UE
namespace	UE::Recast
namespace	UE::Recast::Private

Macros
#define	_USE_MATH_DEFINES

Functions
bool	rcBuildDistanceField (rcContext *ctx, rcCompactHeightfield &chf)
void	UE::Recast::Private::rcMarkBorderRegions (const rcBorderSize borderSize, const int w, const int h, rcCompactHeightfield &chf, unsigned short *srcReg, unsigned short &id)
bool	rcBuildRegionsMonotone (rcContext *ctx, rcCompactHeightfield &chf, const rcBorderSize borderSize, const int minRegionArea, const int mergeRegionArea)
bool	rcBuildRegionsChunky (rcContext *ctx, rcCompactHeightfield &chf, const rcBorderSize borderSize, const int minRegionArea, const int mergeRegionArea, const int regionChunkSize)
bool	rcGatherRegionsNoFilter (rcContext *ctx, rcCompactHeightfield &chf, const rcBorderSize borderSize, unsigned short *spanBuf4)
	helper function from RecastRegion.cpp, requires distance data in compact height field
bool	rcBuildRegions (rcContext *ctx, rcCompactHeightfield &chf, const rcBorderSize borderSize, const int minRegionArea, const int mergeRegionArea)

Macro Definition Documentation

_USE_MATH_DEFINES

#define _USE_MATH_DEFINES

Function Documentation

rcBuildDistanceField()

bool rcBuildDistanceField	(	rcContext *	ctx,
		rcCompactHeightfield &	chf
	)

This is usually the second to the last step in creating a fully built compact heightfield. This step is required before regions are built using rcBuildRegions or rcBuildRegionsMonotone.

After this step, the distance data is available via the rcCompactHeightfield::maxDistance and rcCompactHeightfield::dist fields.

See also

rcCompactHeightfield, rcBuildRegions, rcBuildRegionsMonotone

rcBuildRegions()

bool rcBuildRegions	(	rcContext *	ctx,
		rcCompactHeightfield &	chf,
		const rcBorderSize	borderSize,
		const int	minRegionArea,
		const int	mergeRegionArea
	)

Non-null regions will consist of connected, non-overlapping walkable spans that form a single contour. Contours will form simple polygons.

If multiple regions form an area that is smaller than minRegionArea, then all spans will be re-assigned to the zero (null) region.

Watershed partitioning can result in smaller than necessary regions, especially in diagonal corridors. mergeRegionArea helps reduce unecessarily small regions.

See the rcConfig documentation for more information on the configuration parameters.

The region data will be available via the rcCompactHeightfield::maxRegions and rcCompactSpan::reg fields.

Warning

The distance field must be created using rcBuildDistanceField before attempting to build regions.

See also

rcCompactHeightfield, rcCompactSpan, rcBuildDistanceField, rcBuildRegionsMonotone, rcConfig

rcBuildRegionsChunky()

bool rcBuildRegionsChunky	(	rcContext *	ctx,
		rcCompactHeightfield &	chf,
		const rcBorderSize	borderSize,
		const int	minRegionArea,
		const int	mergeRegionArea,
		const int	chunkSize
	)

Builds region data for the heightfield using simple monotone partitioning.

Parameters

[in,out]	ctx	The build context to use during the operation.
[in,out]	chf	A populated compact heightfield.
[in]	borderSize	The size of the non-navigable border around the heightfield. [Limit: >=0] [Units: vx]
[in]	minRegionArea	The minimum number of cells allowed to form isolated island areas. [Limit: >=0] [Units: vx].
[in]	mergeRegionArea	Any regions with a span count smaller than this value will, if possible, be merged with larger regions. [Limit: >=0] [Units: vx]
[in]	chunkSize	Size of subregion [Units: vx]

Returns

True if the operation completed successfully.

rcBuildRegionsMonotone()

bool rcBuildRegionsMonotone	(	rcContext *	ctx,
		rcCompactHeightfield &	chf,
		const rcBorderSize	borderSize,
		const int	minRegionArea,
		const int	mergeRegionArea
	)

Non-null regions will consist of connected, non-overlapping walkable spans that form a single contour. Contours will form simple polygons.

If multiple regions form an area that is smaller than minRegionArea, then all spans will be re-assigned to the zero (null) region.

Partitioning can result in smaller than necessary regions. mergeRegionArea helps reduce unecessarily small regions.

See the rcConfig documentation for more information on the configuration parameters.

The region data will be available via the rcCompactHeightfield::maxRegions and rcCompactSpan::reg fields.

Warning

The distance field must be created using rcBuildDistanceField before attempting to build regions.

See also

rcCompactHeightfield, rcCompactSpan, rcBuildDistanceField, rcBuildRegionsMonotone, rcConfig

rcGatherRegionsNoFilter()

bool rcGatherRegionsNoFilter	(	rcContext *	ctx,
		rcCompactHeightfield &	chf,
		const rcBorderSize	borderSize,
		unsigned short *	spanBuf4
	)

helper function from RecastRegion.cpp, requires distance data in compact height field

@UE: rcBuildRegions is now split into two functions: gathering regions and merging them it allows reusing existing code for building layer set (flood fill based partitioning)

spanBuf4 is temporary buffer, allocated and freed by caller (size = chf.spanCount * 4)