void rcMergeSpans( rcContext* ctx, rcHeightfield& solid )
{
rcAssert( ctx );
ctx->startTimer( RC_TIMER_TEMPORARY );
const int w = solid.width;
const int h = solid.height;
for( int y = 0; y < h; ++y ) {
for( int x = 0; x < w; ++x ) {
for( rcSpan* s = solid.spans[x + y*w]; s != NULL && s->next != NULL; s = s->next ) {
if( !rcIsSimilarTypeArea( s->area, s->next->area ) && rcAbs( static_cast<int>( s->next->smin ) - static_cast<int>( s->smax ) ) <= 2 ) {
// merge
rcSpan* next = s->next;
s->smax = next->smax;
const bool walkable = rcIsWalkableArea( s->area ) || rcIsWalkableArea( next->area );
s->area = next->area;
s->area &= walkable ? ~RC_UNWALKABLE_AREA : ~RC_WALKABLE_AREA;
s->area |= walkable ? RC_WALKABLE_AREA : RC_UNWALKABLE_AREA;
s->next = next->next;
freeSpan( solid, next );
}
}
}
}
ctx->stopTimer( RC_TIMER_TEMPORARY );
}
static bool addSpan(rcHeightfield& hf, const int x, const int y,
const unsigned short smin, const unsigned short smax,
const unsigned char area, const int flagMergeThr)
{
int idx = x + y*hf.width;
rcSpan* s = allocSpan(hf);
if (!s)
return false;
s->smin = smin;
s->smax = smax;
s->area = area;
s->next = 0;
// Empty cell, add the first span.
if (!hf.spans[idx])
{
hf.spans[idx] = s;
return true;
}
rcSpan* prev = 0;
rcSpan* cur = hf.spans[idx];
// Insert and merge spans.
while (cur)
{
if (cur->smin > s->smax)
{
// Current span is further than the new span, break.
break;
}
else if (cur->smax < s->smin)
{
// Current span is before the new span advance.
prev = cur;
cur = cur->next;
}
else
{
// Merge spans.
if (cur->smin < s->smin)
s->smin = cur->smin;
if (cur->smax > s->smax)
s->smax = cur->smax;
// Merge flags.
if (rcAbs((int)s->smax - (int)cur->smax) <= flagMergeThr)
s->area = rcMax(s->area, cur->area);
// Remove current span.
rcSpan* next = cur->next;
freeSpan(hf, cur);
if (prev)
prev->next = next;
else
hf.spans[idx] = next;
cur = next;
}
}
// Insert new span.
if (prev)
{
s->next = prev->next;
prev->next = s;
}
else
{
s->next = hf.spans[idx];
hf.spans[idx] = s;
}
return true;
}
