RecastRasterization.cpp File Reference

#include <math.h>
#include "Recast.h"
#include "RecastAlloc.h"
#include "RecastAssert.h"

Enumerations
enum	rcAxis { RC_AXIS_X = 0 , RC_AXIS_Y = 1 , RC_AXIS_Z = 2 }

Functions
static bool	overlapBounds (const float *aMin, const float *aMax, const float *bMin, const float *bMax)
	Check whether two bounding boxes overlap. More...
static rcSpan *	allocSpan (rcHeightfield &heightfield)
	Allocates a new span in the heightfield. More...
static void	freeSpan (rcHeightfield &heightfield, rcSpan *span)
	Releases the memory used by the span back to the heightfield, so it can be re-used for new spans. More...
static bool	addSpan (rcHeightfield &heightfield, const int x, const int z, const unsigned short min, const unsigned short max, const unsigned char areaID, const int flagMergeThreshold)
	Adds a span to the heightfield. More...
bool	rcAddSpan (rcContext *context, rcHeightfield &heightfield, const int x, const int z, const unsigned short spanMin, const unsigned short spanMax, const unsigned char areaID, const int flagMergeThreshold)
	Adds a span to the specified heightfield. More...
static void	dividePoly (const float *inVerts, int inVertsCount, float *outVerts1, int *outVerts1Count, float *outVerts2, int *outVerts2Count, float axisOffset, rcAxis axis)
	Divides a convex polygon of max 12 vertices into two convex polygons across a separating axis. More...
static bool	rasterizeTri (const float *v0, const float *v1, const float *v2, const unsigned char areaID, rcHeightfield &heightfield, const float *heightfieldBBMin, const float *heightfieldBBMax, const float cellSize, const float inverseCellSize, const float inverseCellHeight, const int flagMergeThreshold)
	Rasterize a single triangle to the heightfield. More...
bool	rcRasterizeTriangle (rcContext *context, const float *v0, const float *v1, const float *v2, const unsigned char areaID, rcHeightfield &heightfield, const int flagMergeThreshold)
	Rasterizes a single triangle into the specified heightfield. More...
bool	rcRasterizeTriangles (rcContext *context, const float *verts, const int, const int *tris, const unsigned char *triAreaIDs, const int numTris, rcHeightfield &heightfield, const int flagMergeThreshold)
	Rasterizes an indexed triangle mesh into the specified heightfield. More...
bool	rcRasterizeTriangles (rcContext *context, const float *verts, const int, const unsigned short *tris, const unsigned char *triAreaIDs, const int numTris, rcHeightfield &heightfield, const int flagMergeThreshold)
	Rasterizes an indexed triangle mesh into the specified heightfield. More...
bool	rcRasterizeTriangles (rcContext *context, const float *verts, const unsigned char *triAreaIDs, const int numTris, rcHeightfield &heightfield, const int flagMergeThreshold)
	Rasterizes a triangle list into the specified heightfield. More...

Enumeration Type Documentation

rcAxis

enum rcAxis

Enumerator
RC_AXIS_X
RC_AXIS_Y
RC_AXIS_Z

Function Documentation

addSpan()

static bool addSpan ( rcHeightfield &  heightfield, const int  x, const int  z, const unsigned short  min, const unsigned short  max, const unsigned char  areaID, const int  flagMergeThreshold  )

static

Adds a span to the heightfield.

If the new span overlaps existing spans, it will merge the new span with the existing ones.

Parameters

[in]	heightfield	Heightfield to add spans to
[in]	x	The new span's column cell x index
[in]	z	The new span's column cell z index
[in]	min	The new span's minimum cell index
[in]	max	The new span's maximum cell index
[in]	areaID	The new span's area type ID
[in]	flagMergeThreshold	How close two spans maximum extents need to be to merge area type IDs

allocSpan()

static rcSpan* allocSpan ( rcHeightfield &  heightfield )

static

Allocates a new span in the heightfield.

Use a memory pool and free list to minimize actual allocations.

Parameters

[in]

heightfield

The heightfield

Returns

A pointer to the allocated or re-used span memory.

dividePoly()

static void dividePoly ( const float *  inVerts, int  inVertsCount, float *  outVerts1, int *  outVerts1Count, float *  outVerts2, int *  outVerts2Count, float  axisOffset, rcAxis  axis  )

static

Divides a convex polygon of max 12 vertices into two convex polygons across a separating axis.

Parameters

[in]	inVerts	The input polygon vertices
[in]	inVertsCount	The number of input polygon vertices
[out]	outVerts1	Resulting polygon 1's vertices
[out]	outVerts1Count	The number of resulting polygon 1 vertices
[out]	outVerts2	Resulting polygon 2's vertices
[out]	outVerts2Count	The number of resulting polygon 2 vertices
[in]	axisOffset	THe offset along the specified axis
[in]	axis	The separating axis

freeSpan()

static void freeSpan ( rcHeightfield &  heightfield, rcSpan *  span  )

static

Releases the memory used by the span back to the heightfield, so it can be re-used for new spans.

Parameters

[in]	heightfield	The heightfield.
[in]	span	A pointer to the span to free

overlapBounds()

static bool overlapBounds ( const float *  aMin, const float *  aMax, const float *  bMin, const float *  bMax  )

static

Check whether two bounding boxes overlap.

Parameters

[in]	aMin	Min axis extents of bounding box A
[in]	aMax	Max axis extents of bounding box A
[in]	bMin	Min axis extents of bounding box B
[in]	bMax	Max axis extents of bounding box B

Returns

true if the two bounding boxes overlap. False otherwise.

rasterizeTri()

static bool rasterizeTri ( const float *  v0, const float *  v1, const float *  v2, const unsigned char  areaID, rcHeightfield &  heightfield, const float *  heightfieldBBMin, const float *  heightfieldBBMax, const float  cellSize, const float  inverseCellSize, const float  inverseCellHeight, const int  flagMergeThreshold  )

static

Rasterize a single triangle to the heightfield.

This code is extremely hot, so much care should be given to maintaining maximum perf here.

Parameters

[in]	v0	Triangle vertex 0
[in]	v1	Triangle vertex 1
[in]	v2	Triangle vertex 2
[in]	areaID	The area ID to assign to the rasterized spans
[in]	heightfield	Heightfield to rasterize into
[in]	heightfieldBBMin	The min extents of the heightfield bounding box
[in]	heightfieldBBMax	The max extents of the heightfield bounding box
[in]	cellSize	The x and z axis size of a voxel in the heightfield
[in]	inverseCellSize	1 / cellSize
[in]	inverseCellHeight	1 / cellHeight
[in]	flagMergeThreshold	The threshold in which area flags will be merged

Returns

true if the operation completes successfully. false if there was an error adding spans to the heightfield.