static bool filterSmallRegions(rcContext* ctx, int minRegionArea, int mergeRegionSize,
unsigned short& maxRegionId,
rcCompactHeightfield& chf,
unsigned short* srcReg)
{
const int w = chf.width;
const int h = chf.height;
const int nreg = maxRegionId+1;
rcRegion* regions = (rcRegion*)rcAlloc(sizeof(rcRegion)*nreg, RC_ALLOC_TEMP);
if (!regions)
{
ctx->log(RC_LOG_ERROR, "filterSmallRegions: Out of memory 'regions' (%d).", nreg);
return false;
}
// Construct regions
for (int i = 0; i < nreg; ++i)
new(®ions[i]) 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;
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.resize(0);
trace.resize(0);
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.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)) 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;
}
for (int i = 0; i < nreg; ++i)
regions[i].~rcRegion();
rcFree(regions);
return true;
}
/// @par
///
/// See the #rcConfig documentation for more information on the configuration parameters.
///
/// @see rcAllocHeightfieldLayerSet, rcCompactHeightfield, rcHeightfieldLayerSet, rcConfig
bool rcBuildHeightfieldLayers(rcContext* ctx, rcCompactHeightfield& chf,
const int borderSize, const int walkableHeight,
rcHeightfieldLayerSet& lset)
{
rcAssert(ctx);
ctx->startTimer(RC_TIMER_BUILD_LAYERS);
rcScopedDelete<unsigned short> spanBuf4 = (unsigned short*)rcAlloc(sizeof(unsigned short)*chf.spanCount*4, RC_ALLOC_TEMP);
if (!spanBuf4)
{
ctx->log(RC_LOG_ERROR, "rcBuildHeightfieldLayers: Out of memory 'spanBuf4' (%d).", chf.spanCount*4);
return false;
}
ctx->startTimer(RC_TIMER_BUILD_REGIONS_WATERSHED);
unsigned short* srcReg = spanBuf4;
if (!rcGatherRegionsNoFilter(ctx, chf, borderSize, spanBuf4))
return false;
ctx->stopTimer(RC_TIMER_BUILD_REGIONS_WATERSHED);
ctx->startTimer(RC_TIMER_BUILD_REGIONS_FILTER);
const int w = chf.width;
const int h = chf.height;
const int nreg = chf.maxRegions + 1;
rcLayerRegion* regions = (rcLayerRegion*)rcAlloc(sizeof(rcLayerRegion)*nreg, RC_ALLOC_TEMP);
if (!regions)
{
ctx->log(RC_LOG_ERROR, "rcBuildHeightfieldLayers: Out of memory 'regions' (%d).", nreg);
return false;
}
// Construct regions
memset(regions, 0, sizeof(rcLayerRegion)*nreg);
for (int i = 0; i < nreg; ++i)
{
regions[i].layerId = (unsigned short)i;
regions[i].ymax = 0;
regions[i].ymin = 0xffff;
}
// Find region neighbours and overlapping regions.
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 ri = srcReg[i];
if (ri == 0 || ri >= nreg)
continue;
rcLayerRegion& reg = regions[ri];
reg.ymin = rcMin(reg.ymin, s.y);
reg.ymax = rcMax(reg.ymax, s.y);
reg.hasSpans = true;
// Collect all region layers.
for (int j = (int)c.index; j < ni; ++j)
{
unsigned short nri = srcReg[j];
if (nri == 0 || nri >= nreg)
continue;
if (nri != ri)
{
addUniqueLayerRegion(reg, nri);
}
}
// Have found contour
if (reg.connections.size() > 0)
continue;
// 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 neighbors.
walkContour(x, y, i, ndir, chf, srcReg, reg.connections);
}
}
}
}
// Create 2D layers from regions.
unsigned short layerId = 0;
rcIntArray stack(64);
for (int i = 0; i < nreg; i++)
{
rcLayerRegion& reg = regions[i];
if (reg.visited || !reg.hasSpans)
continue;
reg.layerId = layerId;
reg.visited = true;
reg.base = true;
stack.resize(0);
stack.push(i);
while (stack.size())
{
int ri = stack.pop();
rcLayerRegion& creg = regions[ri];
for (int j = 0; j < creg.connections.size(); j++)
{
const unsigned short nei = (unsigned short)creg.connections[j];
if (nei & RC_BORDER_REG)
continue;
rcLayerRegion& regn = regions[nei];
// Skip already visited.
if (regn.visited)
continue;
// Skip if the neighbor is overlapping root region.
if (reg.layers.contains(nei))
continue;
// Skip if the height range would become too large.
const int ymin = rcMin(reg.ymin, regn.ymin);
const int ymax = rcMin(reg.ymax, regn.ymax);
if ((ymax - ymin) >= 255)
continue;
// visit
stack.push(nei);
regn.visited = true;
regn.layerId = layerId;
// add layers to root
for (int k = 0; k < regn.layers.size(); k++)
addUniqueLayerRegion(reg, regn.layers[k]);
reg.ymin = rcMin(reg.ymin, regn.ymin);
reg.ymax = rcMax(reg.ymax, regn.ymax);
}
}
layerId++;
}
// Merge non-overlapping regions that are close in height.
const unsigned short mergeHeight = (unsigned short)walkableHeight * 4;
for (int i = 0; i < nreg; i++)
{
rcLayerRegion& ri = regions[i];
if (!ri.base) continue;
unsigned short newId = ri.layerId;
for (;;)
{
unsigned short oldId = 0xffff;
for (int j = 0; j < nreg; j++)
{
if (i == j) continue;
rcLayerRegion& rj = regions[j];
if (!rj.base) continue;
// Skip if the regions are not close to each other.
if (!overlapRange(ri.ymin,ri.ymax+mergeHeight, rj.ymin,rj.ymax+mergeHeight))
continue;
// Skip if the height range would become too large.
const int ymin = rcMin(ri.ymin, rj.ymin);
const int ymax = rcMin(ri.ymax, rj.ymax);
if ((ymax - ymin) >= 255)
continue;
// Make sure that there is no overlap when mergin 'ri' and 'rj'.
bool overlap = false;
// Iterate over all regions which have the same layerId as 'rj'
for (int k = 0; k < nreg; ++k)
{
if (regions[k].layerId != rj.layerId)
continue;
// Check if region 'k' is overlapping region 'ri'
// Index to 'regs' is the same as region id.
if (ri.layers.contains(k))
{
overlap = true;
break;
}
}
// Cannot merge of regions overlap.
if (overlap)
continue;
// Can merge i and j.
oldId = rj.layerId;
break;
}
// Could not find anything to merge with, stop.
if (oldId == 0xffff)
break;
// Merge
for (int j = 0; j < nreg; ++j)
{
rcLayerRegion& rj = regions[j];
if (rj.layerId == oldId)
{
rj.base = 0;
// Remap layerIds.
rj.layerId = newId;
// Add overlaid layers from 'rj' to 'ri'.
for (int k = 0; k < rj.layers.size(); ++k)
addUniqueLayerRegion(ri, rj.layers[k]);
// Update height bounds.
ri.ymin = rcMin(ri.ymin, rj.ymin);
ri.ymax = rcMax(ri.ymax, rj.ymax);
}
}
}
}
// Compress layer Ids.
for (int i = 0; i < nreg; ++i)
{
regions[i].remap = regions[i].hasSpans;
if (!regions[i].hasSpans)
{
regions[i].layerId = 0xffff;
}
}
unsigned short maxLayerId = 0;
for (int i = 0; i < nreg; ++i)
{
if (!regions[i].remap)
continue;
unsigned short oldId = regions[i].layerId;
unsigned short newId = maxLayerId;
for (int j = i; j < nreg; ++j)
{
if (regions[j].layerId == oldId)
{
regions[j].layerId = newId;
regions[j].remap = false;
}
}
maxLayerId++;
}
ctx->stopTimer(RC_TIMER_BUILD_REGIONS_FILTER);
if (maxLayerId == 0)
{
ctx->stopTimer(RC_TIMER_BUILD_LAYERS);
return true;
}
// Create layers.
rcAssert(lset.layers == 0);
const int lw = w - borderSize*2;
const int lh = h - borderSize*2;
// Build contracted bbox for layers.
float bmin[3], bmax[3];
rcVcopy(bmin, chf.bmin);
rcVcopy(bmax, chf.bmax);
bmin[0] += borderSize*chf.cs;
bmin[2] += borderSize*chf.cs;
bmax[0] -= borderSize*chf.cs;
bmax[2] -= borderSize*chf.cs;
lset.nlayers = (int)maxLayerId;
lset.layers = (rcHeightfieldLayer*)rcAlloc(sizeof(rcHeightfieldLayer)*lset.nlayers, RC_ALLOC_PERM);
if (!lset.layers)
{
ctx->log(RC_LOG_ERROR, "rcBuildHeightfieldLayers: Out of memory 'layers' (%d).", lset.nlayers);
return false;
}
memset(lset.layers, 0, sizeof(rcHeightfieldLayer)*lset.nlayers);
// Store layers.
for (int i = 0; i < lset.nlayers; ++i)
{
unsigned short curId = (unsigned short)i;
// Allocate memory for the current layer.
rcHeightfieldLayer* layer = &lset.layers[i];
memset(layer, 0, sizeof(rcHeightfieldLayer));
const int gridSize = sizeof(unsigned char)*lw*lh;
layer->heights = (unsigned char*)rcAlloc(gridSize, RC_ALLOC_PERM);
if (!layer->heights)
{
ctx->log(RC_LOG_ERROR, "rcBuildHeightfieldLayers: Out of memory 'heights' (%d).", gridSize);
return false;
}
memset(layer->heights, 0xff, gridSize);
layer->areas = (unsigned char*)rcAlloc(gridSize, RC_ALLOC_PERM);
if (!layer->areas)
{
ctx->log(RC_LOG_ERROR, "rcBuildHeightfieldLayers: Out of memory 'areas' (%d).", gridSize);
return false;
}
memset(layer->areas, 0, gridSize);
layer->cons = (unsigned char*)rcAlloc(gridSize, RC_ALLOC_PERM);
if (!layer->cons)
{
ctx->log(RC_LOG_ERROR, "rcBuildHeightfieldLayers: Out of memory 'cons' (%d).", gridSize);
return false;
}
memset(layer->cons, 0, gridSize);
// Find layer height bounds.
int hmin = 0, hmax = 0;
for (int j = 0; j < nreg; ++j)
{
if (regions[j].base && regions[j].layerId == curId)
{
hmin = (int)regions[j].ymin;
hmax = (int)regions[j].ymax;
}
}
layer->width = lw;
layer->height = lh;
layer->cs = chf.cs;
layer->ch = chf.ch;
// Adjust the bbox to fit the heighfield.
rcVcopy(layer->bmin, bmin);
rcVcopy(layer->bmax, bmax);
layer->bmin[1] = bmin[1] + hmin*chf.ch;
layer->bmax[1] = bmin[1] + hmax*chf.ch;
layer->hmin = hmin;
layer->hmax = hmax;
// Update usable data region.
layer->minx = layer->width;
layer->maxx = 0;
layer->miny = layer->height;
layer->maxy = 0;
// Copy height and area from compact heighfield.
for (int y = 0; y < lh; ++y)
{
for (int x = 0; x < lw; ++x)
{
const int cx = borderSize+x;
const int cy = borderSize+y;
const rcCompactCell& c = chf.cells[cx+cy*w];
for (int j = (int)c.index, nj = (int)(c.index+c.count); j < nj; ++j)
{
const rcCompactSpan& s = chf.spans[j];
// Skip unassigned regions.
if (srcReg[j] == 0 || srcReg[j] >= nreg)
continue;
// Skip of does not belong to current layer.
unsigned short lid = regions[srcReg[j]].layerId;
if (lid != curId)
continue;
// Update data bounds.
layer->minx = rcMin(layer->minx, x);
layer->maxx = rcMax(layer->maxx, x);
layer->miny = rcMin(layer->miny, y);
layer->maxy = rcMax(layer->maxy, y);
// Store height and area type.
const int idx = x+y*lw;
layer->heights[idx] = (unsigned char)(s.y - hmin);
layer->areas[idx] = chf.areas[j];
// Check connection.
unsigned char portal = 0;
unsigned char con = 0;
for (int dir = 0; dir < 4; ++dir)
{
if (rcGetCon(s, 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(s, dir);
unsigned short alid = (srcReg[ai] < nreg) ? regions[srcReg[ai]].layerId : 0xffff;
// Portal mask
if (chf.areas[ai] != RC_NULL_AREA && lid != alid)
{
portal |= (unsigned char)(1<<dir);
// Update height so that it matches on both sides of the portal.
const rcCompactSpan& as = chf.spans[ai];
if (as.y > hmin)
layer->heights[idx] = rcMax(layer->heights[idx], (unsigned char)(as.y - hmin));
}
// Valid connection mask
if (chf.areas[ai] != RC_NULL_AREA && lid == alid)
{
const int nx = ax - borderSize;
const int ny = ay - borderSize;
if (nx >= 0 && ny >= 0 && nx < lw && ny < lh)
con |= (unsigned char)(1<<dir);
}
}
}
layer->cons[idx] = (portal << 4) | con;
}
}
}
if (layer->minx > layer->maxx)
layer->minx = layer->maxx = 0;
if (layer->miny > layer->maxy)
layer->miny = layer->maxy = 0;
}
ctx->stopTimer(RC_TIMER_BUILD_LAYERS);
return true;
}
static bool filterSmallRegions(int minRegionSize, int mergeRegionSize,
unsigned short& maxRegionId,
rcCompactHeightfield& chf,
unsigned short* src)
{
const int w = chf.width;
const int h = chf.height;
int nreg = maxRegionId+1;
rcRegion* regions = new rcRegion[nreg];
if (!regions)
{
if (rcGetLog())
rcGetLog()->log(RC_LOG_ERROR, "filterSmallRegions: Out of memory 'regions' (%d).", nreg);
return false;
}
for (int i = 0; i < nreg; ++i)
regions[i].id = (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 = src[i*2];
if (r == 0 || r >= nreg)
continue;
rcRegion& reg = regions[r];
reg.count++;
// Update floors.
for (int j = (int)c.index; j < ni; ++j)
{
if (i == j) continue;
unsigned short floorId = src[j*2];
if (floorId == 0 || floorId >= nreg)
continue;
addUniqueFloorRegion(reg, floorId);
}
// Have found contour
if (reg.connections.size() > 0)
continue;
// Check if this cell is next to a border.
int ndir = -1;
for (int dir = 0; dir < 4; ++dir)
{
if (isSolidEdge(chf, src, 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, src, reg.connections);
}
}
}
}
// Remove too small unconnected regions.
for (int i = 0; i < nreg; ++i)
{
rcRegion& reg = regions[i];
if (reg.id == 0 || (reg.id & RC_BORDER_REG))
continue;
if (reg.count == 0)
continue;
if (reg.connections.size() == 1 && reg.connections[0] == 0)
{
if (reg.count < minRegionSize)
{
// Non-connected small region, remove.
reg.count = 0;
reg.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.count == 0)
continue;
// Check to see if the region should be merged.
if (reg.count > 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)) continue;
if (mreg.count < smallest &&
canMergeWithRegion(reg, mreg.id) &&
canMergeWithRegion(mreg, reg.id))
{
smallest = mreg.count;
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 ((src[i*2] & RC_BORDER_REG) == 0)
src[i*2] = regions[src[i*2]].id;
}
delete [] regions;
return true;
}
/// @par
///
/// The raw contours will match the region outlines exactly. The @p maxError and @p maxEdgeLen
/// parameters control how closely the simplified contours will match the raw contours.
///
/// Simplified contours are generated such that the vertices for portals between areas match up.
/// (They are considered mandatory vertices.)
///
/// Setting @p maxEdgeLength to zero will disabled the edge length feature.
///
/// See the #rcConfig documentation for more information on the configuration parameters.
///
/// @see rcAllocContourSet, rcCompactHeightfield, rcContourSet, rcConfig
bool rcBuildContours(rcContext* ctx, rcCompactHeightfield& chf,
const float maxError, const int maxEdgeLen,
rcContourSet& cset, const int buildFlags)
{
rcAssert(ctx);
const int w = chf.width;
const int h = chf.height;
const int borderSize = chf.borderSize;
ctx->startTimer(RC_TIMER_BUILD_CONTOURS);
rcVcopy(cset.bmin, chf.bmin);
rcVcopy(cset.bmax, chf.bmax);
if (borderSize > 0)
{
// If the heightfield was build with bordersize, remove the offset.
const float pad = borderSize*chf.cs;
cset.bmin[0] += pad;
cset.bmin[2] += pad;
cset.bmax[0] -= pad;
cset.bmax[2] -= pad;
}
cset.cellSizeXZ = chf.cs;
cset.cellSizeY = chf.ch;
cset.width = chf.width - chf.borderSize*2;
cset.height = chf.height - chf.borderSize*2;
cset.borderSize = chf.borderSize;
int maxContours = rcMax((int)chf.maxRegions, 8);
cset.conts = (rcContour*)rcAlloc(sizeof(rcContour)*maxContours, RC_ALLOC_PERM);
if (!cset.conts)
return false;
cset.nconts = 0;
rcScopedDelete<unsigned char> flags = (unsigned char*)rcAlloc(sizeof(unsigned char)*chf.spanCount, RC_ALLOC_TEMP);
if (!flags)
{
ctx->log(RC_LOG_ERROR, "rcBuildContours: Out of memory 'flags' (%d).", chf.spanCount);
return false;
}
ctx->startTimer(RC_TIMER_BUILD_CONTOURS_TRACE);
// Mark boundaries.
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 char res = 0;
const rcCompactSpan& s = chf.spans[i];
if (!chf.spans[i].regionID || (chf.spans[i].regionID & RC_BORDER_REG))
{
flags[i] = 0;
continue;
}
for (int dir = 0; dir < 4; ++dir)
{
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*w].index + rcGetCon(s, dir);
r = chf.spans[ai].regionID;
}
if (r == chf.spans[i].regionID)
res |= (1 << dir);
}
flags[i] = res ^ 0xf; // Inverse, mark non connected edges.
}
}
}
ctx->stopTimer(RC_TIMER_BUILD_CONTOURS_TRACE);
rcIntArray verts(256);
rcIntArray simplified(64);
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 (flags[i] == 0 || flags[i] == 0xf)
{
flags[i] = 0;
continue;
}
const unsigned short reg = chf.spans[i].regionID;
if (!reg || (reg & RC_BORDER_REG))
continue;
const navAreaMask areaMask = chf.areaMasks[ i ];
verts.resize(0);
simplified.resize(0);
ctx->startTimer(RC_TIMER_BUILD_CONTOURS_TRACE);
walkContour(x, y, i, chf, flags, verts);
ctx->stopTimer(RC_TIMER_BUILD_CONTOURS_TRACE);
ctx->startTimer(RC_TIMER_BUILD_CONTOURS_SIMPLIFY);
simplifyContour(verts, simplified, maxError, maxEdgeLen, buildFlags);
removeDegenerateSegments(simplified);
ctx->stopTimer(RC_TIMER_BUILD_CONTOURS_SIMPLIFY);
// Store region->contour remap info.
// Create contour.
if (simplified.size()/4 >= 3)
{
if (cset.nconts >= maxContours)
{
// Allocate more contours.
// This happens when a region has holes.
const int oldMax = maxContours;
maxContours *= 2;
rcContour* newConts = (rcContour*)rcAlloc(sizeof(rcContour)*maxContours, RC_ALLOC_PERM);
for (int j = 0; j < cset.nconts; ++j)
{
newConts[j] = cset.conts[j];
// Reset source pointers to prevent data deletion.
cset.conts[j].verts = 0;
cset.conts[j].rverts = 0;
}
rcFree(cset.conts);
cset.conts = newConts;
ctx->log(RC_LOG_WARNING, "rcBuildContours: Expanding max contours from %d to %d.", oldMax, maxContours);
}
rcContour* cont = &cset.conts[cset.nconts++];
cont->nverts = simplified.size()/4;
cont->verts = (int*)rcAlloc(sizeof(int)*cont->nverts*4, RC_ALLOC_PERM);
if (!cont->verts)
{
ctx->log(RC_LOG_ERROR, "rcBuildContours: Out of memory 'verts' (%d).", cont->nverts);
return false;
}
memcpy(cont->verts, &simplified[0], sizeof(int)*cont->nverts*4);
if (borderSize > 0)
{
// If the heightfield was build with bordersize, remove the offset.
for (int j = 0; j < cont->nverts; ++j)
{
int* v = &cont->verts[j*4];
v[0] -= borderSize;
v[2] -= borderSize;
}
}
cont->nrverts = verts.size()/4;
cont->rverts = (int*)rcAlloc(sizeof(int)*cont->nrverts*4, RC_ALLOC_PERM);
if (!cont->rverts)
{
ctx->log(RC_LOG_ERROR, "rcBuildContours: Out of memory 'rverts' (%d).", cont->nrverts);
return false;
}
memcpy(cont->rverts, &verts[0], sizeof(int)*cont->nrverts*4);
if (borderSize > 0)
{
// If the heightfield was build with bordersize, remove the offset.
for (int j = 0; j < cont->nrverts; ++j)
{
int* v = &cont->rverts[j*4];
v[0] -= borderSize;
v[2] -= borderSize;
}
}
cont->reg = reg;
cont->areaMask = areaMask;
}
}
}
}
// Merge holes if needed.
if (cset.nconts > 0)
{
// Calculate winding of all polygons.
rcScopedDelete<char> winding = (char*)rcAlloc(sizeof(char)*cset.nconts, RC_ALLOC_TEMP);
if (!winding)
{
ctx->log(RC_LOG_ERROR, "rcBuildContours: Out of memory 'hole' (%d).", cset.nconts);
return false;
}
int nholes = 0;
for (int i = 0; i < cset.nconts; ++i)
{
rcContour& cont = cset.conts[i];
// If the contour is wound backwards, it is a hole.
winding[i] = calcAreaOfPolygon2D(cont.verts, cont.nverts) < 0 ? -1 : 1;
if (winding[i] < 0)
nholes++;
}
if (nholes > 0)
{
// Collect outline contour and holes contours per region.
// We assume that there is one outline and multiple holes.
const int nregions = chf.maxRegions+1;
rcScopedDelete<rcContourRegion> regions = (rcContourRegion*)rcAlloc(sizeof(rcContourRegion)*nregions, RC_ALLOC_TEMP);
if (!regions)
{
ctx->log(RC_LOG_ERROR, "rcBuildContours: Out of memory 'regions' (%d).", nregions);
return false;
}
memset(regions, 0, sizeof(rcContourRegion)*nregions);
rcScopedDelete<rcContourHole> holes = (rcContourHole*)rcAlloc(sizeof(rcContourHole)*cset.nconts, RC_ALLOC_TEMP);
if (!holes)
{
ctx->log(RC_LOG_ERROR, "rcBuildContours: Out of memory 'holes' (%d).", cset.nconts);
return false;
}
memset(holes, 0, sizeof(rcContourHole)*cset.nconts);
for (int i = 0; i < cset.nconts; ++i)
{
rcContour& cont = cset.conts[i];
// Positively would contours are outlines, negative holes.
if (winding[i] > 0)
{
if (regions[cont.reg].outline)
ctx->log(RC_LOG_ERROR, "rcBuildContours: Multiple outlines for region %d.", cont.reg);
regions[cont.reg].outline = &cont;
}
else
{
regions[cont.reg].nholes++;
}
}
int index = 0;
for (int i = 0; i < nregions; i++)
{
if (regions[i].nholes > 0)
{
regions[i].holes = &holes[index];
index += regions[i].nholes;
regions[i].nholes = 0;
}
}
for (int i = 0; i < cset.nconts; ++i)
{
rcContour& cont = cset.conts[i];
rcContourRegion& reg = regions[cont.reg];
if (winding[i] < 0)
reg.holes[reg.nholes++].contour = &cont;
}
// Finally merge each regions holes into the outline.
for (int i = 0; i < nregions; i++)
{
rcContourRegion& reg = regions[i];
if (!reg.nholes) continue;
if (reg.outline)
{
mergeRegionHoles(ctx, reg);
}
else
{
// The region does not have an outline.
// This can happen if the contour becaomes selfoverlapping because of
// too aggressive simplification settings.
ctx->log(RC_LOG_ERROR, "rcBuildContours: Bad outline for region %d, contour simplification is likely too aggressive.", i);
}
}
}
}
ctx->stopTimer(RC_TIMER_BUILD_CONTOURS);
return true;
}
static dtStatus filterSmallRegions(dtTileCacheAlloc* alloc, dtTileCacheLayer& layer, int minRegionArea, int mergeRegionSize,
unsigned short& maxRegionId, unsigned short* srcReg)
{
const int w = (int)layer.header->width;
const int h = (int)layer.header->height;
const int nreg = maxRegionId+1;
dtFixedArray<dtLayerRegion> regions(alloc, nreg);
if (!regions)
{
return DT_FAILURE | DT_OUT_OF_MEMORY;
}
// Construct regions
regions.set(0);
for (int i = 0; i < nreg; ++i)
regions[i] = dtLayerRegion((unsigned short)i);
// Find edge of a region and find connections around the contour.
for (int y = 0; y < h; ++y)
{
const bool borderY = (y == 0) || (y == (h - 1));
for (int x = 0; x < w; ++x)
{
const int i = x+y*w;
unsigned short r = srcReg[i];
if (r == DT_TILECACHE_NULL_AREA || r >= nreg)
continue;
dtLayerRegion& reg = regions[r];
reg.cellCount++;
reg.border |= borderY || (x == 0) || (x == (w - 1));
// Have found contour
if (reg.connections.size() > 0)
continue;
reg.areaType = layer.areas[i];
// Check if this cell is next to a border.
int ndir = -1;
for (int dir = 0; dir < 4; ++dir)
{
if (isSolidEdge(layer, 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, layer, srcReg, reg.connections);
}
}
}
// Remove too small regions.
dtIntArray stack(32);
dtIntArray trace(32);
for (int i = 0; i < nreg; ++i)
{
dtLayerRegion& reg = regions[i];
if (reg.id == 0)
continue;
if (reg.cellCount == 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 cellCount = 0;
stack.resize(0);
trace.resize(0);
reg.visited = true;
stack.push(i);
while (stack.size())
{
// Pop
int ri = stack.pop();
dtLayerRegion& creg = regions[ri];
connectsToBorder |= creg.border;
cellCount += creg.cellCount;
trace.push(ri);
for (int j = 0; j < creg.connections.size(); ++j)
{
dtLayerRegion& neireg = regions[creg.connections[j]];
if (neireg.visited)
continue;
if (neireg.id == 0)
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 (cellCount < minRegionArea && !connectsToBorder)
{
// Kill all visited regions.
for (int j = 0; j < trace.size(); ++j)
{
regions[trace[j]].cellCount = 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)
{
dtLayerRegion& reg = regions[i];
if (reg.id == 0)
continue;
if (reg.cellCount == 0)
continue;
// Check to see if the region should be merged.
if (reg.cellCount > mergeRegionSize && reg.border)
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)
{
dtLayerRegion& mreg = regions[reg.connections[j]];
if (mreg.id == 0) continue;
if (mreg.cellCount < smallest &&
canMergeWithRegion(reg, mreg) &&
canMergeWithRegion(mreg, reg))
{
smallest = mreg.cellCount;
mergeId = mreg.id;
}
}
// Found new id.
if (mergeId != reg.id)
{
unsigned short oldId = reg.id;
dtLayerRegion& 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) 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 == DT_TILECACHE_NULL_AREA) continue; // Skip nil 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 = w*h-1; i >= 0; i--)
{
srcReg[i] = regions[srcReg[i]].id;
}
for (int i = 0; i < nreg; ++i)
regions[i].~dtLayerRegion();
return DT_SUCCESS;
}
