/// @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);
rcScopedTimer timer(ctx, RC_TIMER_BUILD_LAYERS);
const int w = chf.width;
const int h = chf.height;
rcScopedDelete<unsigned char> srcReg((unsigned char*)rcAlloc(sizeof(unsigned char)*chf.spanCount, RC_ALLOC_TEMP));
if (!srcReg)
{
ctx->log(RC_LOG_ERROR, "rcBuildHeightfieldLayers: Out of memory 'srcReg' (%d).", chf.spanCount);
return false;
}
memset(srcReg,0xff,sizeof(unsigned char)*chf.spanCount);
const int nsweeps = chf.width;
rcScopedDelete<rcLayerSweepSpan> sweeps((rcLayerSweepSpan*)rcAlloc(sizeof(rcLayerSweepSpan)*nsweeps, RC_ALLOC_TEMP));
if (!sweeps)
{
ctx->log(RC_LOG_ERROR, "rcBuildHeightfieldLayers: Out of memory 'sweeps' (%d).", nsweeps);
return false;
}
// Partition walkable area into monotone regions.
int prevCount[256];
unsigned char regId = 0;
for (int y = borderSize; y < h-borderSize; ++y)
{
memset(prevCount,0,sizeof(int)*regId);
unsigned char sweepId = 0;
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;
unsigned char sid = 0xff;
// -x
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 (chf.areas[ai] != RC_NULL_AREA && srcReg[ai] != 0xff)
sid = srcReg[ai];
}
if (sid == 0xff)
{
sid = sweepId++;
sweeps[sid].nei = 0xff;
sweeps[sid].ns = 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);
const unsigned char nr = srcReg[ai];
if (nr != 0xff)
{
// Set neighbour when first valid neighbour is encoutered.
if (sweeps[sid].ns == 0)
sweeps[sid].nei = nr;
if (sweeps[sid].nei == nr)
{
// Update existing neighbour
sweeps[sid].ns++;
prevCount[nr]++;
}
else
{
// This is hit if there is nore than one neighbour.
// Invalidate the neighbour.
sweeps[sid].nei = 0xff;
}
}
}
srcReg[i] = sid;
}
}
// Create unique ID.
for (int i = 0; i < sweepId; ++i)
{
// If the neighbour is set and there is only one continuous connection to it,
// the sweep will be merged with the previous one, else new region is created.
if (sweeps[i].nei != 0xff && prevCount[sweeps[i].nei] == (int)sweeps[i].ns)
{
sweeps[i].id = sweeps[i].nei;
}
else
{
if (regId == 255)
{
ctx->log(RC_LOG_ERROR, "rcBuildHeightfieldLayers: Region ID overflow.");
return false;
}
sweeps[i].id = regId++;
}
}
// Remap local sweep ids to region 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] != 0xff)
srcReg[i] = sweeps[srcReg[i]].id;
}
}
}
// Allocate and init layer regions.
const int nregs = (int)regId;
rcScopedDelete<rcLayerRegion> regs((rcLayerRegion*)rcAlloc(sizeof(rcLayerRegion)*nregs, RC_ALLOC_TEMP));
if (!regs)
{
ctx->log(RC_LOG_ERROR, "rcBuildHeightfieldLayers: Out of memory 'regs' (%d).", nregs);
return false;
}
memset(regs, 0, sizeof(rcLayerRegion)*nregs);
for (int i = 0; i < nregs; ++i)
{
regs[i].layerId = 0xff;
regs[i].ymin = 0xffff;
regs[i].ymax = 0;
}
// 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];
unsigned char lregs[RC_MAX_LAYERS];
int nlregs = 0;
for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
{
const rcCompactSpan& s = chf.spans[i];
const unsigned char ri = srcReg[i];
if (ri == 0xff) continue;
regs[ri].ymin = rcMin(regs[ri].ymin, s.y);
regs[ri].ymax = rcMax(regs[ri].ymax, s.y);
// Collect all region layers.
if (nlregs < RC_MAX_LAYERS)
lregs[nlregs++] = 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 char rai = srcReg[ai];
if (rai != 0xff && rai != ri)
{
// Don't check return value -- if we cannot add the neighbor
// it will just cause a few more regions to be created, which
// is fine.
addUnique(regs[ri].neis, regs[ri].nneis, RC_MAX_NEIS, rai);
}
}
}
}
// Update overlapping regions.
for (int i = 0; i < nlregs-1; ++i)
{
for (int j = i+1; j < nlregs; ++j)
{
if (lregs[i] != lregs[j])
{
rcLayerRegion& ri = regs[lregs[i]];
rcLayerRegion& rj = regs[lregs[j]];
if (!addUnique(ri.layers, ri.nlayers, RC_MAX_LAYERS, lregs[j]) ||
!addUnique(rj.layers, rj.nlayers, RC_MAX_LAYERS, lregs[i]))
{
ctx->log(RC_LOG_ERROR, "rcBuildHeightfieldLayers: layer overflow (too many overlapping walkable platforms). Try increasing RC_MAX_LAYERS.");
return false;
}
}
}
}
}
}
// Create 2D layers from regions.
unsigned char layerId = 0;
static const int MAX_STACK = 64;
unsigned char stack[MAX_STACK];
int nstack = 0;
for (int i = 0; i < nregs; ++i)
{
rcLayerRegion& root = regs[i];
// Skip already visited.
if (root.layerId != 0xff)
continue;
// Start search.
root.layerId = layerId;
root.base = 1;
nstack = 0;
stack[nstack++] = (unsigned char)i;
while (nstack)
{
// Pop front
rcLayerRegion& reg = regs[stack[0]];
nstack--;
for (int j = 0; j < nstack; ++j)
stack[j] = stack[j+1];
const int nneis = (int)reg.nneis;
for (int j = 0; j < nneis; ++j)
{
const unsigned char nei = reg.neis[j];
rcLayerRegion& regn = regs[nei];
// Skip already visited.
if (regn.layerId != 0xff)
continue;
// Skip if the neighbour is overlapping root region.
if (contains(root.layers, root.nlayers, nei))
continue;
// Skip if the height range would become too large.
const int ymin = rcMin(root.ymin, regn.ymin);
const int ymax = rcMax(root.ymax, regn.ymax);
if ((ymax - ymin) >= 255)
continue;
if (nstack < MAX_STACK)
{
// Deepen
stack[nstack++] = (unsigned char)nei;
// Mark layer id
regn.layerId = layerId;
// Merge current layers to root.
for (int k = 0; k < regn.nlayers; ++k)
{
if (!addUnique(root.layers, root.nlayers, RC_MAX_LAYERS, regn.layers[k]))
{
ctx->log(RC_LOG_ERROR, "rcBuildHeightfieldLayers: layer overflow (too many overlapping walkable platforms). Try increasing RC_MAX_LAYERS.");
return false;
}
}
root.ymin = rcMin(root.ymin, regn.ymin);
root.ymax = rcMax(root.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 < nregs; ++i)
{
rcLayerRegion& ri = regs[i];
if (!ri.base) continue;
unsigned char newId = ri.layerId;
for (;;)
{
unsigned char oldId = 0xff;
for (int j = 0; j < nregs; ++j)
{
if (i == j) continue;
rcLayerRegion& rj = regs[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 = rcMax(ri.ymax, rj.ymax);
if ((ymax - ymin) >= 255)
continue;
// Make sure that there is no overlap when merging 'ri' and 'rj'.
bool overlap = false;
// Iterate over all regions which have the same layerId as 'rj'
for (int k = 0; k < nregs; ++k)
{
if (regs[k].layerId != rj.layerId)
continue;
// Check if region 'k' is overlapping region 'ri'
// Index to 'regs' is the same as region id.
if (contains(ri.layers,ri.nlayers, (unsigned char)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 == 0xff)
break;
// Merge
for (int j = 0; j < nregs; ++j)
{
rcLayerRegion& rj = regs[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.nlayers; ++k)
{
if (!addUnique(ri.layers, ri.nlayers, RC_MAX_LAYERS, rj.layers[k]))
{
ctx->log(RC_LOG_ERROR, "rcBuildHeightfieldLayers: layer overflow (too many overlapping walkable platforms). Try increasing RC_MAX_LAYERS.");
return false;
}
}
// Update height bounds.
ri.ymin = rcMin(ri.ymin, rj.ymin);
ri.ymax = rcMax(ri.ymax, rj.ymax);
}
}
}
}
// Compact layerIds
unsigned char remap[256];
memset(remap, 0, 256);
// Find number of unique layers.
layerId = 0;
for (int i = 0; i < nregs; ++i)
remap[regs[i].layerId] = 1;
for (int i = 0; i < 256; ++i)
{
if (remap[i])
remap[i] = layerId++;
else
remap[i] = 0xff;
}
// Remap ids.
for (int i = 0; i < nregs; ++i)
regs[i].layerId = remap[regs[i].layerId];
// No layers, return empty.
if (layerId == 0)
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)layerId;
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 char curId = (unsigned char)i;
rcHeightfieldLayer* layer = &lset.layers[i];
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 < nregs; ++j)
{
if (regs[j].base && regs[j].layerId == curId)
{
hmin = (int)regs[j].ymin;
hmax = (int)regs[j].ymax;
}
}
layer->width = lw;
layer->height = lh;
layer->cs = chf.cs;
layer->ch = chf.ch;
// Adjust the bbox to fit the heightfield.
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 heightfield.
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] == 0xff)
continue;
// Skip of does nto belong to current layer.
unsigned char lid = regs[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 char alid = srcReg[ai] != 0xff ? regs[srcReg[ai]].layerId : 0xff;
// 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;
}
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, "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 monotone regions to layers and remove small regions.
rcIntArray overlaps;
chf.maxRegions = id;
if (!mergeAndFilterLayerRegions(ctx, minRegionArea, chf.maxRegions, chf, srcReg, overlaps))
return false;
}
// Store the result out.
for (int i = 0; i < chf.spanCount; ++i)
chf.spans[i].reg = srcReg[i];
return true;
}
