server_common/recastnavigation_v1.6.0
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Fix for U-turn path case

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This commit is contained in:
Mikko Mononen 2014-01-21 19:15:03 +02:00
parent cbab6a3825
commit bc964f9994
1 changed files with 65 additions and 1 deletions
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66
RecastDemo/Source/NavMeshTesterTool.cpp
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@ -101,6 +101,66 @@ static int fixupCorridor(dtPolyRef* path, const int npath, const int maxPath,
return req+size;
}
// This function checks if the path has a small U-turn, that is,
// a polygon further in the path is adjacent to the first polygon
// in the path. If that happens, a shortcut is taken.
// This can happen if the target (T) location is at tile boundary,
// and we're (S) approaching it parallel to the tile edge.
// The choice at the vertex can be arbitrary,
// +---+---+
// |:::|:::|
// +-S-+-T-+
// |:::| | <-- the step can end up in here, resulting U-turn path.
// +---+---+
static int fixupShortcuts(dtPolyRef* path, int npath, dtNavMeshQuery* navQuery)
{
if (npath < 3)
return npath;
// Get connected polygons
static const int maxNeis = 16;
dtPolyRef neis[maxNeis];
int nneis = 0;
const dtMeshTile* tile = 0;
const dtPoly* poly = 0;
if (dtStatusFailed(navQuery->getAttachedNavMesh()->getTileAndPolyByRef(path[0], &tile, &poly)))
return npath;
for (unsigned int k = poly->firstLink; k != DT_NULL_LINK; k = tile->links[k].next)
{
const dtLink* link = &tile->links[k];
if (link->ref != 0)
{
if (nneis < maxNeis)
neis[nneis++] = link->ref;
}
}
// If any of the neighbour polygons is within the next few polygons
// in the path, short cut to that polygon directly.
static const int maxLookAhead = 6;
int cut = 0;
for (int i = dtMin(maxLookAhead, npath) - 1; i > 1 && cut == 0; i--) {
for (int j = 0; j < nneis; j++)
{
if (path[i] == neis[j]) {
cut = i;
break;
}
}
}
if (cut > 1)
{
int offset = cut-1;
npath -= offset;
for (int i = 1; i < npath; i++)
path[i] = path[i+offset];
}
return npath;
}
static bool getSteerTarget(dtNavMeshQuery* navQuery, const float* startPos, const float* endPos,
const float minTargetDist,
const dtPolyRef* path, const int pathSize,
@ -503,6 +563,8 @@ void NavMeshTesterTool::handleToggle()
m_navQuery->moveAlongSurface(m_pathIterPolys[0], m_iterPos, moveTgt, &m_filter,
result, visited, &nvisited, 16);
m_pathIterPolyCount = fixupCorridor(m_pathIterPolys, m_pathIterPolyCount, MAX_POLYS, visited, nvisited);
m_pathIterPolyCount = fixupShortcuts(m_pathIterPolys, m_pathIterPolyCount, m_navQuery);
float h = 0;
m_navQuery->getPolyHeight(m_pathIterPolys[0], result, &h);
result[1] = h;
@ -698,8 +760,10 @@ void NavMeshTesterTool::recalc()
int nvisited = 0;
m_navQuery->moveAlongSurface(polys[0], iterPos, moveTgt, &m_filter,
result, visited, &nvisited, 16);
npolys = fixupCorridor(polys, npolys, MAX_POLYS, visited, nvisited);
npolys = fixupShortcuts(polys, npolys, m_navQuery);
float h = 0;
m_navQuery->getPolyHeight(polys[0], result, &h);
result[1] = h;