virtualx-engine/thirdparty/recastnavigation/Recast/Source/RecastRegion.cpp
2023-08-29 11:46:46 +02:00

1811 lines
45 KiB
C++

//
// Copyright (c) 2009-2010 Mikko Mononen memon@inside.org
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
//
#include <float.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "Recast.h"
#include "RecastAlloc.h"
#include "RecastAssert.h"
namespace
{
struct LevelStackEntry
{
LevelStackEntry(int x_, int y_, int index_) : x(x_), y(y_), index(index_) {}
int x;
int y;
int index;
};
} // namespace
static void calculateDistanceField(rcCompactHeightfield& chf, unsigned short* src, unsigned short& maxDist)
{
const int w = chf.width;
const int h = chf.height;
// Init distance and points.
for (int i = 0; i < chf.spanCount; ++i)
src[i] = 0xffff;
// Mark boundary cells.
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
const rcCompactSpan& s = chf.spans[i];
const unsigned char area = chf.areas[i];
int nc = 0;
for (int dir = 0; dir < 4; ++dir)
{
if (rcGetCon(s, dir) != RC_NOT_CONNECTED)
{
const int ax = x + rcGetDirOffsetX(dir);
const int ay = y + rcGetDirOffsetY(dir);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, dir);
if (area == chf.areas[ai])
nc++;
}
}
if (nc != 4)
src[i] = 0;
}
}
}
// Pass 1
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
const rcCompactSpan& s = chf.spans[i];
if (rcGetCon(s, 0) != RC_NOT_CONNECTED)
{
// (-1,0)
const int ax = x + rcGetDirOffsetX(0);
const int ay = y + rcGetDirOffsetY(0);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, 0);
const rcCompactSpan& as = chf.spans[ai];
if (src[ai]+2 < src[i])
src[i] = src[ai]+2;
// (-1,-1)
if (rcGetCon(as, 3) != RC_NOT_CONNECTED)
{
const int aax = ax + rcGetDirOffsetX(3);
const int aay = ay + rcGetDirOffsetY(3);
const int aai = (int)chf.cells[aax+aay*w].index + rcGetCon(as, 3);
if (src[aai]+3 < src[i])
src[i] = src[aai]+3;
}
}
if (rcGetCon(s, 3) != RC_NOT_CONNECTED)
{
// (0,-1)
const int ax = x + rcGetDirOffsetX(3);
const int ay = y + rcGetDirOffsetY(3);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, 3);
const rcCompactSpan& as = chf.spans[ai];
if (src[ai]+2 < src[i])
src[i] = src[ai]+2;
// (1,-1)
if (rcGetCon(as, 2) != RC_NOT_CONNECTED)
{
const int aax = ax + rcGetDirOffsetX(2);
const int aay = ay + rcGetDirOffsetY(2);
const int aai = (int)chf.cells[aax+aay*w].index + rcGetCon(as, 2);
if (src[aai]+3 < src[i])
src[i] = src[aai]+3;
}
}
}
}
}
// Pass 2
for (int y = h-1; y >= 0; --y)
{
for (int x = w-1; x >= 0; --x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
const rcCompactSpan& s = chf.spans[i];
if (rcGetCon(s, 2) != RC_NOT_CONNECTED)
{
// (1,0)
const int ax = x + rcGetDirOffsetX(2);
const int ay = y + rcGetDirOffsetY(2);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, 2);
const rcCompactSpan& as = chf.spans[ai];
if (src[ai]+2 < src[i])
src[i] = src[ai]+2;
// (1,1)
if (rcGetCon(as, 1) != RC_NOT_CONNECTED)
{
const int aax = ax + rcGetDirOffsetX(1);
const int aay = ay + rcGetDirOffsetY(1);
const int aai = (int)chf.cells[aax+aay*w].index + rcGetCon(as, 1);
if (src[aai]+3 < src[i])
src[i] = src[aai]+3;
}
}
if (rcGetCon(s, 1) != RC_NOT_CONNECTED)
{
// (0,1)
const int ax = x + rcGetDirOffsetX(1);
const int ay = y + rcGetDirOffsetY(1);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, 1);
const rcCompactSpan& as = chf.spans[ai];
if (src[ai]+2 < src[i])
src[i] = src[ai]+2;
// (-1,1)
if (rcGetCon(as, 0) != RC_NOT_CONNECTED)
{
const int aax = ax + rcGetDirOffsetX(0);
const int aay = ay + rcGetDirOffsetY(0);
const int aai = (int)chf.cells[aax+aay*w].index + rcGetCon(as, 0);
if (src[aai]+3 < src[i])
src[i] = src[aai]+3;
}
}
}
}
}
maxDist = 0;
for (int i = 0; i < chf.spanCount; ++i)
maxDist = rcMax(src[i], maxDist);
}
static unsigned short* boxBlur(rcCompactHeightfield& chf, int thr,
unsigned short* src, unsigned short* dst)
{
const int w = chf.width;
const int h = chf.height;
thr *= 2;
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
const rcCompactSpan& s = chf.spans[i];
const unsigned short cd = src[i];
if (cd <= thr)
{
dst[i] = cd;
continue;
}
int d = (int)cd;
for (int dir = 0; dir < 4; ++dir)
{
if (rcGetCon(s, dir) != RC_NOT_CONNECTED)
{
const int ax = x + rcGetDirOffsetX(dir);
const int ay = y + rcGetDirOffsetY(dir);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, dir);
d += (int)src[ai];
const rcCompactSpan& as = chf.spans[ai];
const int dir2 = (dir+1) & 0x3;
if (rcGetCon(as, dir2) != RC_NOT_CONNECTED)
{
const int ax2 = ax + rcGetDirOffsetX(dir2);
const int ay2 = ay + rcGetDirOffsetY(dir2);
const int ai2 = (int)chf.cells[ax2+ay2*w].index + rcGetCon(as, dir2);
d += (int)src[ai2];
}
else
{
d += cd;
}
}
else
{
d += cd*2;
}
}
dst[i] = (unsigned short)((d+5)/9);
}
}
}
return dst;
}
static bool floodRegion(int x, int y, int i,
unsigned short level, unsigned short r,
rcCompactHeightfield& chf,
unsigned short* srcReg, unsigned short* srcDist,
rcTempVector<LevelStackEntry>& stack)
{
const int w = chf.width;
const unsigned char area = chf.areas[i];
// Flood fill mark region.
stack.clear();
stack.push_back(LevelStackEntry(x, y, i));
srcReg[i] = r;
srcDist[i] = 0;
unsigned short lev = level >= 2 ? level-2 : 0;
int count = 0;
while (stack.size() > 0)
{
LevelStackEntry& back = stack.back();
int cx = back.x;
int cy = back.y;
int ci = back.index;
stack.pop_back();
const rcCompactSpan& cs = chf.spans[ci];
// Check if any of the neighbours already have a valid region set.
unsigned short ar = 0;
for (int dir = 0; dir < 4; ++dir)
{
// 8 connected
if (rcGetCon(cs, dir) != RC_NOT_CONNECTED)
{
const int ax = cx + rcGetDirOffsetX(dir);
const int ay = cy + rcGetDirOffsetY(dir);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(cs, dir);
if (chf.areas[ai] != area)
continue;
unsigned short nr = srcReg[ai];
if (nr & RC_BORDER_REG) // Do not take borders into account.
continue;
if (nr != 0 && nr != r)
{
ar = nr;
break;
}
const rcCompactSpan& as = chf.spans[ai];
const int dir2 = (dir+1) & 0x3;
if (rcGetCon(as, dir2) != RC_NOT_CONNECTED)
{
const int ax2 = ax + rcGetDirOffsetX(dir2);
const int ay2 = ay + rcGetDirOffsetY(dir2);
const int ai2 = (int)chf.cells[ax2+ay2*w].index + rcGetCon(as, dir2);
if (chf.areas[ai2] != area)
continue;
unsigned short nr2 = srcReg[ai2];
if (nr2 != 0 && nr2 != r)
{
ar = nr2;
break;
}
}
}
}
if (ar != 0)
{
srcReg[ci] = 0;
continue;
}
count++;
// Expand neighbours.
for (int dir = 0; dir < 4; ++dir)
{
if (rcGetCon(cs, dir) != RC_NOT_CONNECTED)
{
const int ax = cx + rcGetDirOffsetX(dir);
const int ay = cy + rcGetDirOffsetY(dir);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(cs, dir);
if (chf.areas[ai] != area)
continue;
if (chf.dist[ai] >= lev && srcReg[ai] == 0)
{
srcReg[ai] = r;
srcDist[ai] = 0;
stack.push_back(LevelStackEntry(ax, ay, ai));
}
}
}
}
return count > 0;
}
// Struct to keep track of entries in the region table that have been changed.
struct DirtyEntry
{
DirtyEntry(int index_, unsigned short region_, unsigned short distance2_)
: index(index_), region(region_), distance2(distance2_) {}
int index;
unsigned short region;
unsigned short distance2;
};
static void expandRegions(int maxIter, unsigned short level,
rcCompactHeightfield& chf,
unsigned short* srcReg, unsigned short* srcDist,
rcTempVector<LevelStackEntry>& stack,
bool fillStack)
{
const int w = chf.width;
const int h = chf.height;
if (fillStack)
{
// Find cells revealed by the raised level.
stack.clear();
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
if (chf.dist[i] >= level && srcReg[i] == 0 && chf.areas[i] != RC_NULL_AREA)
{
stack.push_back(LevelStackEntry(x, y, i));
}
}
}
}
}
else // use cells in the input stack
{
// mark all cells which already have a region
for (int j=0; j<stack.size(); j++)
{
int i = stack[j].index;
if (srcReg[i] != 0)
stack[j].index = -1;
}
}
rcTempVector<DirtyEntry> dirtyEntries;
int iter = 0;
while (stack.size() > 0)
{
int failed = 0;
dirtyEntries.clear();
for (int j = 0; j < stack.size(); j++)
{
int x = stack[j].x;
int y = stack[j].y;
int i = stack[j].index;
if (i < 0)
{
failed++;
continue;
}
unsigned short r = srcReg[i];
unsigned short d2 = 0xffff;
const unsigned char area = chf.areas[i];
const rcCompactSpan& s = chf.spans[i];
for (int dir = 0; dir < 4; ++dir)
{
if (rcGetCon(s, dir) == RC_NOT_CONNECTED) continue;
const int ax = x + rcGetDirOffsetX(dir);
const int ay = y + rcGetDirOffsetY(dir);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, dir);
if (chf.areas[ai] != area) continue;
if (srcReg[ai] > 0 && (srcReg[ai] & RC_BORDER_REG) == 0)
{
if ((int)srcDist[ai]+2 < (int)d2)
{
r = srcReg[ai];
d2 = srcDist[ai]+2;
}
}
}
if (r)
{
stack[j].index = -1; // mark as used
dirtyEntries.push_back(DirtyEntry(i, r, d2));
}
else
{
failed++;
}
}
// Copy entries that differ between src and dst to keep them in sync.
for (int i = 0; i < dirtyEntries.size(); i++) {
int idx = dirtyEntries[i].index;
srcReg[idx] = dirtyEntries[i].region;
srcDist[idx] = dirtyEntries[i].distance2;
}
if (failed == stack.size())
break;
if (level > 0)
{
++iter;
if (iter >= maxIter)
break;
}
}
}
static void sortCellsByLevel(unsigned short startLevel,
rcCompactHeightfield& chf,
const unsigned short* srcReg,
unsigned int nbStacks, rcTempVector<LevelStackEntry>* stacks,
unsigned short loglevelsPerStack) // the levels per stack (2 in our case) as a bit shift
{
const int w = chf.width;
const int h = chf.height;
startLevel = startLevel >> loglevelsPerStack;
for (unsigned int j=0; j<nbStacks; ++j)
stacks[j].clear();
// put all cells in the level range into the appropriate stacks
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
if (chf.areas[i] == RC_NULL_AREA || srcReg[i] != 0)
continue;
int level = chf.dist[i] >> loglevelsPerStack;
int sId = startLevel - level;
if (sId >= (int)nbStacks)
continue;
if (sId < 0)
sId = 0;
stacks[sId].push_back(LevelStackEntry(x, y, i));
}
}
}
}
static void appendStacks(const rcTempVector<LevelStackEntry>& srcStack,
rcTempVector<LevelStackEntry>& dstStack,
const unsigned short* srcReg)
{
for (int j=0; j<srcStack.size(); j++)
{
int i = srcStack[j].index;
if ((i < 0) || (srcReg[i] != 0))
continue;
dstStack.push_back(srcStack[j]);
}
}
struct rcRegion
{
inline rcRegion(unsigned short i) :
spanCount(0),
id(i),
areaType(0),
remap(false),
visited(false),
overlap(false),
connectsToBorder(false),
ymin(0xffff),
ymax(0)
{}
int spanCount; // Number of spans belonging to this region
unsigned short id; // ID of the region
unsigned char areaType; // Are type.
bool remap;
bool visited;
bool overlap;
bool connectsToBorder;
unsigned short ymin, ymax;
rcIntArray connections;
rcIntArray floors;
};
static void removeAdjacentNeighbours(rcRegion& reg)
{
// Remove adjacent duplicates.
for (int i = 0; i < reg.connections.size() && reg.connections.size() > 1; )
{
int ni = (i+1) % reg.connections.size();
if (reg.connections[i] == reg.connections[ni])
{
// Remove duplicate
for (int j = i; j < reg.connections.size()-1; ++j)
reg.connections[j] = reg.connections[j+1];
reg.connections.pop();
}
else
++i;
}
}
static void replaceNeighbour(rcRegion& reg, unsigned short oldId, unsigned short newId)
{
bool neiChanged = false;
for (int i = 0; i < reg.connections.size(); ++i)
{
if (reg.connections[i] == oldId)
{
reg.connections[i] = newId;
neiChanged = true;
}
}
for (int i = 0; i < reg.floors.size(); ++i)
{
if (reg.floors[i] == oldId)
reg.floors[i] = newId;
}
if (neiChanged)
removeAdjacentNeighbours(reg);
}
static bool canMergeWithRegion(const rcRegion& rega, const rcRegion& regb)
{
if (rega.areaType != regb.areaType)
return false;
int n = 0;
for (int i = 0; i < rega.connections.size(); ++i)
{
if (rega.connections[i] == regb.id)
n++;
}
if (n > 1)
return false;
for (int i = 0; i < rega.floors.size(); ++i)
{
if (rega.floors[i] == regb.id)
return false;
}
return true;
}
static void addUniqueFloorRegion(rcRegion& reg, int n)
{
for (int i = 0; i < reg.floors.size(); ++i)
if (reg.floors[i] == n)
return;
reg.floors.push(n);
}
static bool mergeRegions(rcRegion& rega, rcRegion& regb)
{
unsigned short aid = rega.id;
unsigned short bid = regb.id;
// Duplicate current neighbourhood.
rcIntArray acon;
acon.resize(rega.connections.size());
for (int i = 0; i < rega.connections.size(); ++i)
acon[i] = rega.connections[i];
rcIntArray& bcon = regb.connections;
// Find insertion point on A.
int insa = -1;
for (int i = 0; i < acon.size(); ++i)
{
if (acon[i] == bid)
{
insa = i;
break;
}
}
if (insa == -1)
return false;
// Find insertion point on B.
int insb = -1;
for (int i = 0; i < bcon.size(); ++i)
{
if (bcon[i] == aid)
{
insb = i;
break;
}
}
if (insb == -1)
return false;
// Merge neighbours.
rega.connections.clear();
for (int i = 0, ni = acon.size(); i < ni-1; ++i)
rega.connections.push(acon[(insa+1+i) % ni]);
for (int i = 0, ni = bcon.size(); i < ni-1; ++i)
rega.connections.push(bcon[(insb+1+i) % ni]);
removeAdjacentNeighbours(rega);
for (int j = 0; j < regb.floors.size(); ++j)
addUniqueFloorRegion(rega, regb.floors[j]);
rega.spanCount += regb.spanCount;
regb.spanCount = 0;
regb.connections.resize(0);
return true;
}
static bool isRegionConnectedToBorder(const rcRegion& reg)
{
// Region is connected to border if
// one of the neighbours is null id.
for (int i = 0; i < reg.connections.size(); ++i)
{
if (reg.connections[i] == 0)
return true;
}
return false;
}
static bool isSolidEdge(rcCompactHeightfield& chf, const unsigned short* srcReg,
int x, int y, int i, int dir)
{
const rcCompactSpan& s = chf.spans[i];
unsigned short r = 0;
if (rcGetCon(s, dir) != RC_NOT_CONNECTED)
{
const int ax = x + rcGetDirOffsetX(dir);
const int ay = y + rcGetDirOffsetY(dir);
const int ai = (int)chf.cells[ax+ay*chf.width].index + rcGetCon(s, dir);
r = srcReg[ai];
}
if (r == srcReg[i])
return false;
return true;
}
static void walkContour(int x, int y, int i, int dir,
rcCompactHeightfield& chf,
const unsigned short* srcReg,
rcIntArray& cont)
{
int startDir = dir;
int starti = i;
const rcCompactSpan& ss = chf.spans[i];
unsigned short curReg = 0;
if (rcGetCon(ss, dir) != RC_NOT_CONNECTED)
{
const int ax = x + rcGetDirOffsetX(dir);
const int ay = y + rcGetDirOffsetY(dir);
const int ai = (int)chf.cells[ax+ay*chf.width].index + rcGetCon(ss, dir);
curReg = srcReg[ai];
}
cont.push(curReg);
int iter = 0;
while (++iter < 40000)
{
const rcCompactSpan& s = chf.spans[i];
if (isSolidEdge(chf, srcReg, x, y, i, dir))
{
// Choose the edge corner
unsigned short r = 0;
if (rcGetCon(s, dir) != RC_NOT_CONNECTED)
{
const int ax = x + rcGetDirOffsetX(dir);
const int ay = y + rcGetDirOffsetY(dir);
const int ai = (int)chf.cells[ax+ay*chf.width].index + rcGetCon(s, dir);
r = srcReg[ai];
}
if (r != curReg)
{
curReg = r;
cont.push(curReg);
}
dir = (dir+1) & 0x3; // Rotate CW
}
else
{
int ni = -1;
const int nx = x + rcGetDirOffsetX(dir);
const int ny = y + rcGetDirOffsetY(dir);
if (rcGetCon(s, dir) != RC_NOT_CONNECTED)
{
const rcCompactCell& nc = chf.cells[nx+ny*chf.width];
ni = (int)nc.index + rcGetCon(s, dir);
}
if (ni == -1)
{
// Should not happen.
return;
}
x = nx;
y = ny;
i = ni;
dir = (dir+3) & 0x3; // Rotate CCW
}
if (starti == i && startDir == dir)
{
break;
}
}
// Remove adjacent duplicates.
if (cont.size() > 1)
{
for (int j = 0; j < cont.size(); )
{
int nj = (j+1) % cont.size();
if (cont[j] == cont[nj])
{
for (int k = j; k < cont.size()-1; ++k)
cont[k] = cont[k+1];
cont.pop();
}
else
++j;
}
}
}
static bool mergeAndFilterRegions(rcContext* ctx, int minRegionArea, int mergeRegionSize,
unsigned short& maxRegionId,
rcCompactHeightfield& chf,
unsigned short* srcReg, rcIntArray& overlaps)
{
const int w = chf.width;
const int h = chf.height;
const int nreg = maxRegionId+1;
rcTempVector<rcRegion> regions;
if (!regions.reserve(nreg)) {
ctx->log(RC_LOG_ERROR, "mergeAndFilterRegions: Out of memory 'regions' (%d).", nreg);
return false;
}
// Construct regions
for (int i = 0; i < nreg; ++i)
regions.push_back(rcRegion((unsigned short) i));
// Find edge of a region and find connections around the contour.
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
unsigned short r = srcReg[i];
if (r == 0 || r >= nreg)
continue;
rcRegion& reg = regions[r];
reg.spanCount++;
// Update floors.
for (int j = (int)c.index; j < ni; ++j)
{
if (i == j) continue;
unsigned short floorId = srcReg[j];
if (floorId == 0 || floorId >= nreg)
continue;
if (floorId == r)
reg.overlap = true;
addUniqueFloorRegion(reg, floorId);
}
// Have found contour
if (reg.connections.size() > 0)
continue;
reg.areaType = chf.areas[i];
// Check if this cell is next to a border.
int ndir = -1;
for (int dir = 0; dir < 4; ++dir)
{
if (isSolidEdge(chf, srcReg, x, y, i, dir))
{
ndir = dir;
break;
}
}
if (ndir != -1)
{
// The cell is at border.
// Walk around the contour to find all the neighbours.
walkContour(x, y, i, ndir, chf, srcReg, reg.connections);
}
}
}
}
// Remove too small regions.
rcIntArray stack(32);
rcIntArray trace(32);
for (int i = 0; i < nreg; ++i)
{
rcRegion& reg = regions[i];
if (reg.id == 0 || (reg.id & RC_BORDER_REG))
continue;
if (reg.spanCount == 0)
continue;
if (reg.visited)
continue;
// Count the total size of all the connected regions.
// Also keep track of the regions connects to a tile border.
bool connectsToBorder = false;
int spanCount = 0;
stack.clear();
trace.clear();
reg.visited = true;
stack.push(i);
while (stack.size())
{
// Pop
int ri = stack.pop();
rcRegion& creg = regions[ri];
spanCount += creg.spanCount;
trace.push(ri);
for (int j = 0; j < creg.connections.size(); ++j)
{
if (creg.connections[j] & RC_BORDER_REG)
{
connectsToBorder = true;
continue;
}
rcRegion& neireg = regions[creg.connections[j]];
if (neireg.visited)
continue;
if (neireg.id == 0 || (neireg.id & RC_BORDER_REG))
continue;
// Visit
stack.push(neireg.id);
neireg.visited = true;
}
}
// If the accumulated regions size is too small, remove it.
// Do not remove areas which connect to tile borders
// as their size cannot be estimated correctly and removing them
// can potentially remove necessary areas.
if (spanCount < minRegionArea && !connectsToBorder)
{
// Kill all visited regions.
for (int j = 0; j < trace.size(); ++j)
{
regions[trace[j]].spanCount = 0;
regions[trace[j]].id = 0;
}
}
}
// Merge too small regions to neighbour regions.
int mergeCount = 0 ;
do
{
mergeCount = 0;
for (int i = 0; i < nreg; ++i)
{
rcRegion& reg = regions[i];
if (reg.id == 0 || (reg.id & RC_BORDER_REG))
continue;
if (reg.overlap)
continue;
if (reg.spanCount == 0)
continue;
// Check to see if the region should be merged.
if (reg.spanCount > mergeRegionSize && isRegionConnectedToBorder(reg))
continue;
// Small region with more than 1 connection.
// Or region which is not connected to a border at all.
// Find smallest neighbour region that connects to this one.
int smallest = 0xfffffff;
unsigned short mergeId = reg.id;
for (int j = 0; j < reg.connections.size(); ++j)
{
if (reg.connections[j] & RC_BORDER_REG) continue;
rcRegion& mreg = regions[reg.connections[j]];
if (mreg.id == 0 || (mreg.id & RC_BORDER_REG) || mreg.overlap) continue;
if (mreg.spanCount < smallest &&
canMergeWithRegion(reg, mreg) &&
canMergeWithRegion(mreg, reg))
{
smallest = mreg.spanCount;
mergeId = mreg.id;
}
}
// Found new id.
if (mergeId != reg.id)
{
unsigned short oldId = reg.id;
rcRegion& target = regions[mergeId];
// Merge neighbours.
if (mergeRegions(target, reg))
{
// Fixup regions pointing to current region.
for (int j = 0; j < nreg; ++j)
{
if (regions[j].id == 0 || (regions[j].id & RC_BORDER_REG)) continue;
// If another region was already merged into current region
// change the nid of the previous region too.
if (regions[j].id == oldId)
regions[j].id = mergeId;
// Replace the current region with the new one if the
// current regions is neighbour.
replaceNeighbour(regions[j], oldId, mergeId);
}
mergeCount++;
}
}
}
}
while (mergeCount > 0);
// Compress region Ids.
for (int i = 0; i < nreg; ++i)
{
regions[i].remap = false;
if (regions[i].id == 0) continue; // Skip nil regions.
if (regions[i].id & RC_BORDER_REG) continue; // Skip external regions.
regions[i].remap = true;
}
unsigned short regIdGen = 0;
for (int i = 0; i < nreg; ++i)
{
if (!regions[i].remap)
continue;
unsigned short oldId = regions[i].id;
unsigned short newId = ++regIdGen;
for (int j = i; j < nreg; ++j)
{
if (regions[j].id == oldId)
{
regions[j].id = newId;
regions[j].remap = false;
}
}
}
maxRegionId = regIdGen;
// Remap regions.
for (int i = 0; i < chf.spanCount; ++i)
{
if ((srcReg[i] & RC_BORDER_REG) == 0)
srcReg[i] = regions[srcReg[i]].id;
}
// Return regions that we found to be overlapping.
for (int i = 0; i < nreg; ++i)
if (regions[i].overlap)
overlaps.push(regions[i].id);
return true;
}
static void addUniqueConnection(rcRegion& reg, int n)
{
for (int i = 0; i < reg.connections.size(); ++i)
if (reg.connections[i] == n)
return;
reg.connections.push(n);
}
static bool mergeAndFilterLayerRegions(rcContext* ctx, int minRegionArea,
unsigned short& maxRegionId,
rcCompactHeightfield& chf,
unsigned short* srcReg)
{
const int w = chf.width;
const int h = chf.height;
const int nreg = maxRegionId+1;
rcTempVector<rcRegion> regions;
// Construct regions
if (!regions.reserve(nreg)) {
ctx->log(RC_LOG_ERROR, "mergeAndFilterLayerRegions: Out of memory 'regions' (%d).", nreg);
return false;
}
for (int i = 0; i < nreg; ++i)
regions.push_back(rcRegion((unsigned short) i));
// Find region neighbours and overlapping regions.
rcIntArray lregs(32);
for (int y = 0; y < h; ++y)
{
for (int x = 0; x < w; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
lregs.clear();
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
const rcCompactSpan& s = chf.spans[i];
const unsigned short ri = srcReg[i];
if (ri == 0 || ri >= nreg) continue;
rcRegion& reg = regions[ri];
reg.spanCount++;
reg.ymin = rcMin(reg.ymin, s.y);
reg.ymax = rcMax(reg.ymax, s.y);
// Collect all region layers.
lregs.push(ri);
// Update neighbours
for (int dir = 0; dir < 4; ++dir)
{
if (rcGetCon(s, dir) != RC_NOT_CONNECTED)
{
const int ax = x + rcGetDirOffsetX(dir);
const int ay = y + rcGetDirOffsetY(dir);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, dir);
const unsigned short rai = srcReg[ai];
if (rai > 0 && rai < nreg && rai != ri)
addUniqueConnection(reg, rai);
if (rai & RC_BORDER_REG)
reg.connectsToBorder = true;
}
}
}
// Update overlapping regions.
for (int i = 0; i < lregs.size()-1; ++i)
{
for (int j = i+1; j < lregs.size(); ++j)
{
if (lregs[i] != lregs[j])
{
rcRegion& ri = regions[lregs[i]];
rcRegion& rj = regions[lregs[j]];
addUniqueFloorRegion(ri, lregs[j]);
addUniqueFloorRegion(rj, lregs[i]);
}
}
}
}
}
// Create 2D layers from regions.
unsigned short layerId = 1;
for (int i = 0; i < nreg; ++i)
regions[i].id = 0;
// Merge montone regions to create non-overlapping areas.
rcIntArray stack(32);
for (int i = 1; i < nreg; ++i)
{
rcRegion& root = regions[i];
// Skip already visited.
if (root.id != 0)
continue;
// Start search.
root.id = layerId;
stack.clear();
stack.push(i);
while (stack.size() > 0)
{
// Pop front
rcRegion& reg = regions[stack[0]];
for (int j = 0; j < stack.size()-1; ++j)
stack[j] = stack[j+1];
stack.resize(stack.size()-1);
const int ncons = (int)reg.connections.size();
for (int j = 0; j < ncons; ++j)
{
const int nei = reg.connections[j];
rcRegion& regn = regions[nei];
// Skip already visited.
if (regn.id != 0)
continue;
// Skip if the neighbour is overlapping root region.
bool overlap = false;
for (int k = 0; k < root.floors.size(); k++)
{
if (root.floors[k] == nei)
{
overlap = true;
break;
}
}
if (overlap)
continue;
// Deepen
stack.push(nei);
// Mark layer id
regn.id = layerId;
// Merge current layers to root.
for (int k = 0; k < regn.floors.size(); ++k)
addUniqueFloorRegion(root, regn.floors[k]);
root.ymin = rcMin(root.ymin, regn.ymin);
root.ymax = rcMax(root.ymax, regn.ymax);
root.spanCount += regn.spanCount;
regn.spanCount = 0;
root.connectsToBorder = root.connectsToBorder || regn.connectsToBorder;
}
}
layerId++;
}
// Remove small regions
for (int i = 0; i < nreg; ++i)
{
if (regions[i].spanCount > 0 && regions[i].spanCount < minRegionArea && !regions[i].connectsToBorder)
{
unsigned short reg = regions[i].id;
for (int j = 0; j < nreg; ++j)
if (regions[j].id == reg)
regions[j].id = 0;
}
}
// Compress region Ids.
for (int i = 0; i < nreg; ++i)
{
regions[i].remap = false;
if (regions[i].id == 0) continue; // Skip nil regions.
if (regions[i].id & RC_BORDER_REG) continue; // Skip external regions.
regions[i].remap = true;
}
unsigned short regIdGen = 0;
for (int i = 0; i < nreg; ++i)
{
if (!regions[i].remap)
continue;
unsigned short oldId = regions[i].id;
unsigned short newId = ++regIdGen;
for (int j = i; j < nreg; ++j)
{
if (regions[j].id == oldId)
{
regions[j].id = newId;
regions[j].remap = false;
}
}
}
maxRegionId = regIdGen;
// Remap regions.
for (int i = 0; i < chf.spanCount; ++i)
{
if ((srcReg[i] & RC_BORDER_REG) == 0)
srcReg[i] = regions[srcReg[i]].id;
}
return true;
}
/// @par
///
/// 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 rcCompactHeightfield, rcBuildRegions, rcBuildRegionsMonotone
bool rcBuildDistanceField(rcContext* ctx, rcCompactHeightfield& chf)
{
rcAssert(ctx);
rcScopedTimer timer(ctx, RC_TIMER_BUILD_DISTANCEFIELD);
if (chf.dist)
{
rcFree(chf.dist);
chf.dist = 0;
}
unsigned short* src = (unsigned short*)rcAlloc(sizeof(unsigned short)*chf.spanCount, RC_ALLOC_TEMP);
if (!src)
{
ctx->log(RC_LOG_ERROR, "rcBuildDistanceField: Out of memory 'src' (%d).", chf.spanCount);
return false;
}
unsigned short* dst = (unsigned short*)rcAlloc(sizeof(unsigned short)*chf.spanCount, RC_ALLOC_TEMP);
if (!dst)
{
ctx->log(RC_LOG_ERROR, "rcBuildDistanceField: Out of memory 'dst' (%d).", chf.spanCount);
rcFree(src);
return false;
}
unsigned short maxDist = 0;
{
rcScopedTimer timerDist(ctx, RC_TIMER_BUILD_DISTANCEFIELD_DIST);
calculateDistanceField(chf, src, maxDist);
chf.maxDistance = maxDist;
}
{
rcScopedTimer timerBlur(ctx, RC_TIMER_BUILD_DISTANCEFIELD_BLUR);
// Blur
if (boxBlur(chf, 1, src, dst) != src)
rcSwap(src, dst);
// Store distance.
chf.dist = src;
}
rcFree(dst);
return true;
}
static void paintRectRegion(int minx, int maxx, int miny, int maxy, unsigned short regId,
rcCompactHeightfield& chf, unsigned short* srcReg)
{
const int w = chf.width;
for (int y = miny; y < maxy; ++y)
{
for (int x = minx; x < maxx; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
if (chf.areas[i] != RC_NULL_AREA)
srcReg[i] = regId;
}
}
}
}
static const unsigned short RC_NULL_NEI = 0xffff;
struct rcSweepSpan
{
unsigned short rid; // row id
unsigned short id; // region id
unsigned short ns; // number samples
unsigned short nei; // neighbour id
};
/// @par
///
/// 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 @p minRegionArea, then all spans will be
/// re-assigned to the zero (null) region.
///
/// Partitioning can result in smaller than necessary regions. @p 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 rcCompactHeightfield, rcCompactSpan, rcBuildDistanceField, rcBuildRegionsMonotone, rcConfig
bool rcBuildRegionsMonotone(rcContext* ctx, rcCompactHeightfield& chf,
const int borderSize, const int minRegionArea, const int mergeRegionArea)
{
rcAssert(ctx);
rcScopedTimer timer(ctx, RC_TIMER_BUILD_REGIONS);
const int w = chf.width;
const int h = chf.height;
unsigned short id = 1;
rcScopedDelete<unsigned short> srcReg((unsigned short*)rcAlloc(sizeof(unsigned short)*chf.spanCount, RC_ALLOC_TEMP));
if (!srcReg)
{
ctx->log(RC_LOG_ERROR, "rcBuildRegionsMonotone: Out of memory 'src' (%d).", chf.spanCount);
return false;
}
memset(srcReg,0,sizeof(unsigned short)*chf.spanCount);
const int nsweeps = rcMax(chf.width,chf.height);
rcScopedDelete<rcSweepSpan> sweeps((rcSweepSpan*)rcAlloc(sizeof(rcSweepSpan)*nsweeps, RC_ALLOC_TEMP));
if (!sweeps)
{
ctx->log(RC_LOG_ERROR, "rcBuildRegionsMonotone: Out of memory 'sweeps' (%d).", nsweeps);
return false;
}
// Mark border regions.
if (borderSize > 0)
{
// Make sure border will not overflow.
const int bw = rcMin(w, borderSize);
const int bh = rcMin(h, borderSize);
// Paint regions
paintRectRegion(0, bw, 0, h, id|RC_BORDER_REG, chf, srcReg); id++;
paintRectRegion(w-bw, w, 0, h, id|RC_BORDER_REG, chf, srcReg); id++;
paintRectRegion(0, w, 0, bh, id|RC_BORDER_REG, chf, srcReg); id++;
paintRectRegion(0, w, h-bh, h, id|RC_BORDER_REG, chf, srcReg); id++;
}
chf.borderSize = borderSize;
rcIntArray prev(256);
// Sweep one line at a time.
for (int y = borderSize; y < h-borderSize; ++y)
{
// Collect spans from this row.
prev.resize(id+1);
memset(&prev[0],0,sizeof(int)*id);
unsigned short rid = 1;
for (int x = borderSize; x < w-borderSize; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
const rcCompactSpan& s = chf.spans[i];
if (chf.areas[i] == RC_NULL_AREA) continue;
// -x
unsigned short previd = 0;
if (rcGetCon(s, 0) != RC_NOT_CONNECTED)
{
const int ax = x + rcGetDirOffsetX(0);
const int ay = y + rcGetDirOffsetY(0);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, 0);
if ((srcReg[ai] & RC_BORDER_REG) == 0 && chf.areas[i] == chf.areas[ai])
previd = srcReg[ai];
}
if (!previd)
{
previd = rid++;
sweeps[previd].rid = previd;
sweeps[previd].ns = 0;
sweeps[previd].nei = 0;
}
// -y
if (rcGetCon(s,3) != RC_NOT_CONNECTED)
{
const int ax = x + rcGetDirOffsetX(3);
const int ay = y + rcGetDirOffsetY(3);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, 3);
if (srcReg[ai] && (srcReg[ai] & RC_BORDER_REG) == 0 && chf.areas[i] == chf.areas[ai])
{
unsigned short nr = srcReg[ai];
if (!sweeps[previd].nei || sweeps[previd].nei == nr)
{
sweeps[previd].nei = nr;
sweeps[previd].ns++;
prev[nr]++;
}
else
{
sweeps[previd].nei = RC_NULL_NEI;
}
}
}
srcReg[i] = previd;
}
}
// Create unique ID.
for (int i = 1; i < rid; ++i)
{
if (sweeps[i].nei != RC_NULL_NEI && sweeps[i].nei != 0 &&
prev[sweeps[i].nei] == (int)sweeps[i].ns)
{
sweeps[i].id = sweeps[i].nei;
}
else
{
sweeps[i].id = id++;
}
}
// Remap IDs
for (int x = borderSize; x < w-borderSize; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
if (srcReg[i] > 0 && srcReg[i] < rid)
srcReg[i] = sweeps[srcReg[i]].id;
}
}
}
{
rcScopedTimer timerFilter(ctx, RC_TIMER_BUILD_REGIONS_FILTER);
// Merge regions and filter out small regions.
rcIntArray overlaps;
chf.maxRegions = id;
if (!mergeAndFilterRegions(ctx, minRegionArea, mergeRegionArea, chf.maxRegions, chf, srcReg, overlaps))
return false;
// Monotone partitioning does not generate overlapping regions.
}
// Store the result out.
for (int i = 0; i < chf.spanCount; ++i)
chf.spans[i].reg = srcReg[i];
return true;
}
/// @par
///
/// 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 @p 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.
/// @p 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 rcCompactHeightfield, rcCompactSpan, rcBuildDistanceField, rcBuildRegionsMonotone, rcConfig
bool rcBuildRegions(rcContext* ctx, rcCompactHeightfield& chf,
const int borderSize, const int minRegionArea, const int mergeRegionArea)
{
rcAssert(ctx);
rcScopedTimer timer(ctx, RC_TIMER_BUILD_REGIONS);
const int w = chf.width;
const int h = chf.height;
rcScopedDelete<unsigned short> buf((unsigned short*)rcAlloc(sizeof(unsigned short)*chf.spanCount*2, RC_ALLOC_TEMP));
if (!buf)
{
ctx->log(RC_LOG_ERROR, "rcBuildRegions: Out of memory 'tmp' (%d).", chf.spanCount*4);
return false;
}
ctx->startTimer(RC_TIMER_BUILD_REGIONS_WATERSHED);
const int LOG_NB_STACKS = 3;
const int NB_STACKS = 1 << LOG_NB_STACKS;
rcTempVector<LevelStackEntry> lvlStacks[NB_STACKS];
for (int i=0; i<NB_STACKS; ++i)
lvlStacks[i].reserve(256);
rcTempVector<LevelStackEntry> stack;
stack.reserve(256);
unsigned short* srcReg = buf;
unsigned short* srcDist = buf+chf.spanCount;
memset(srcReg, 0, sizeof(unsigned short)*chf.spanCount);
memset(srcDist, 0, sizeof(unsigned short)*chf.spanCount);
unsigned short regionId = 1;
unsigned short level = (chf.maxDistance+1) & ~1;
// TODO: Figure better formula, expandIters defines how much the
// watershed "overflows" and simplifies the regions. Tying it to
// agent radius was usually good indication how greedy it could be.
// const int expandIters = 4 + walkableRadius * 2;
const int expandIters = 8;
if (borderSize > 0)
{
// Make sure border will not overflow.
const int bw = rcMin(w, borderSize);
const int bh = rcMin(h, borderSize);
// Paint regions
paintRectRegion(0, bw, 0, h, regionId|RC_BORDER_REG, chf, srcReg); regionId++;
paintRectRegion(w-bw, w, 0, h, regionId|RC_BORDER_REG, chf, srcReg); regionId++;
paintRectRegion(0, w, 0, bh, regionId|RC_BORDER_REG, chf, srcReg); regionId++;
paintRectRegion(0, w, h-bh, h, regionId|RC_BORDER_REG, chf, srcReg); regionId++;
}
chf.borderSize = borderSize;
int sId = -1;
while (level > 0)
{
level = level >= 2 ? level-2 : 0;
sId = (sId+1) & (NB_STACKS-1);
// ctx->startTimer(RC_TIMER_DIVIDE_TO_LEVELS);
if (sId == 0)
sortCellsByLevel(level, chf, srcReg, NB_STACKS, lvlStacks, 1);
else
appendStacks(lvlStacks[sId-1], lvlStacks[sId], srcReg); // copy left overs from last level
// ctx->stopTimer(RC_TIMER_DIVIDE_TO_LEVELS);
{
rcScopedTimer timerExpand(ctx, RC_TIMER_BUILD_REGIONS_EXPAND);
// Expand current regions until no empty connected cells found.
expandRegions(expandIters, level, chf, srcReg, srcDist, lvlStacks[sId], false);
}
{
rcScopedTimer timerFloor(ctx, RC_TIMER_BUILD_REGIONS_FLOOD);
// Mark new regions with IDs.
for (int j = 0; j<lvlStacks[sId].size(); j++)
{
LevelStackEntry current = lvlStacks[sId][j];
int x = current.x;
int y = current.y;
int i = current.index;
if (i >= 0 && srcReg[i] == 0)
{
if (floodRegion(x, y, i, level, regionId, chf, srcReg, srcDist, stack))
{
if (regionId == 0xFFFF)
{
ctx->log(RC_LOG_ERROR, "rcBuildRegions: Region ID overflow");
return false;
}
regionId++;
}
}
}
}
}
// Expand current regions until no empty connected cells found.
expandRegions(expandIters*8, 0, chf, srcReg, srcDist, stack, true);
ctx->stopTimer(RC_TIMER_BUILD_REGIONS_WATERSHED);
{
rcScopedTimer timerFilter(ctx, RC_TIMER_BUILD_REGIONS_FILTER);
// Merge regions and filter out smalle regions.
rcIntArray overlaps;
chf.maxRegions = regionId;
if (!mergeAndFilterRegions(ctx, minRegionArea, mergeRegionArea, chf.maxRegions, chf, srcReg, overlaps))
return false;
// If overlapping regions were found during merging, split those regions.
if (overlaps.size() > 0)
{
ctx->log(RC_LOG_ERROR, "rcBuildRegions: %d overlapping regions.", overlaps.size());
}
}
// Write the result out.
for (int i = 0; i < chf.spanCount; ++i)
chf.spans[i].reg = srcReg[i];
return true;
}
bool rcBuildLayerRegions(rcContext* ctx, rcCompactHeightfield& chf,
const int borderSize, const int minRegionArea)
{
rcAssert(ctx);
rcScopedTimer timer(ctx, RC_TIMER_BUILD_REGIONS);
const int w = chf.width;
const int h = chf.height;
unsigned short id = 1;
rcScopedDelete<unsigned short> srcReg((unsigned short*)rcAlloc(sizeof(unsigned short)*chf.spanCount, RC_ALLOC_TEMP));
if (!srcReg)
{
ctx->log(RC_LOG_ERROR, "rcBuildLayerRegions: Out of memory 'src' (%d).", chf.spanCount);
return false;
}
memset(srcReg,0,sizeof(unsigned short)*chf.spanCount);
const int nsweeps = rcMax(chf.width,chf.height);
rcScopedDelete<rcSweepSpan> sweeps((rcSweepSpan*)rcAlloc(sizeof(rcSweepSpan)*nsweeps, RC_ALLOC_TEMP));
if (!sweeps)
{
ctx->log(RC_LOG_ERROR, "rcBuildLayerRegions: Out of memory 'sweeps' (%d).", nsweeps);
return false;
}
// Mark border regions.
if (borderSize > 0)
{
// Make sure border will not overflow.
const int bw = rcMin(w, borderSize);
const int bh = rcMin(h, borderSize);
// Paint regions
paintRectRegion(0, bw, 0, h, id|RC_BORDER_REG, chf, srcReg); id++;
paintRectRegion(w-bw, w, 0, h, id|RC_BORDER_REG, chf, srcReg); id++;
paintRectRegion(0, w, 0, bh, id|RC_BORDER_REG, chf, srcReg); id++;
paintRectRegion(0, w, h-bh, h, id|RC_BORDER_REG, chf, srcReg); id++;
}
chf.borderSize = borderSize;
rcIntArray prev(256);
// Sweep one line at a time.
for (int y = borderSize; y < h-borderSize; ++y)
{
// Collect spans from this row.
prev.resize(id+1);
memset(&prev[0],0,sizeof(int)*id);
unsigned short rid = 1;
for (int x = borderSize; x < w-borderSize; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
const rcCompactSpan& s = chf.spans[i];
if (chf.areas[i] == RC_NULL_AREA) continue;
// -x
unsigned short previd = 0;
if (rcGetCon(s, 0) != RC_NOT_CONNECTED)
{
const int ax = x + rcGetDirOffsetX(0);
const int ay = y + rcGetDirOffsetY(0);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, 0);
if ((srcReg[ai] & RC_BORDER_REG) == 0 && chf.areas[i] == chf.areas[ai])
previd = srcReg[ai];
}
if (!previd)
{
previd = rid++;
sweeps[previd].rid = previd;
sweeps[previd].ns = 0;
sweeps[previd].nei = 0;
}
// -y
if (rcGetCon(s,3) != RC_NOT_CONNECTED)
{
const int ax = x + rcGetDirOffsetX(3);
const int ay = y + rcGetDirOffsetY(3);
const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(s, 3);
if (srcReg[ai] && (srcReg[ai] & RC_BORDER_REG) == 0 && chf.areas[i] == chf.areas[ai])
{
unsigned short nr = srcReg[ai];
if (!sweeps[previd].nei || sweeps[previd].nei == nr)
{
sweeps[previd].nei = nr;
sweeps[previd].ns++;
prev[nr]++;
}
else
{
sweeps[previd].nei = RC_NULL_NEI;
}
}
}
srcReg[i] = previd;
}
}
// Create unique ID.
for (int i = 1; i < rid; ++i)
{
if (sweeps[i].nei != RC_NULL_NEI && sweeps[i].nei != 0 &&
prev[sweeps[i].nei] == (int)sweeps[i].ns)
{
sweeps[i].id = sweeps[i].nei;
}
else
{
sweeps[i].id = id++;
}
}
// Remap IDs
for (int x = borderSize; x < w-borderSize; ++x)
{
const rcCompactCell& c = chf.cells[x+y*w];
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
if (srcReg[i] > 0 && srcReg[i] < rid)
srcReg[i] = sweeps[srcReg[i]].id;
}
}
}
{
rcScopedTimer timerFilter(ctx, RC_TIMER_BUILD_REGIONS_FILTER);
// Merge monotone regions to layers and remove small regions.
chf.maxRegions = id;
if (!mergeAndFilterLayerRegions(ctx, minRegionArea, chf.maxRegions, chf, srcReg))
return false;
}
// Store the result out.
for (int i = 0; i < chf.spanCount; ++i)
chf.spans[i].reg = srcReg[i];
return true;
}