diff options
Diffstat (limited to 'src/utility.cpp')
| -rw-r--r-- | src/utility.cpp | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/src/utility.cpp b/src/utility.cpp index 924324b90..d6ca48153 100644 --- a/src/utility.cpp +++ b/src/utility.cpp @@ -102,4 +102,230 @@ void mysrand(unsigned seed) next = seed; } +// Float with distance +struct DFloat +{ + float v; + u32 d; +}; + +float PointAttributeList::getInterpolatedFloat(v3s16 p) +{ + const u32 near_wanted_count = 5; + // Last is nearest, first is farthest + core::list<DFloat> near; + + for(core::list<PointWithAttr>::Iterator + i = m_points.begin(); + i != m_points.end(); i++) + { + PointWithAttr &pwa = *i; + u32 d = pwa.p.getDistanceFrom(p); + + DFloat df; + df.v = pwa.attr.getFloat(); + df.d = d; + + // If near list is empty, add directly and continue + if(near.size() == 0) + { + near.push_back(df); + continue; + } + + // Get distance of farthest in near list + u32 near_d = 100000; + if(near.size() > 0) + { + core::list<DFloat>::Iterator i = near.begin(); + near_d = i->d; + } + + /* + If point is closer than the farthest in the near list or + there are not yet enough points on the list + */ + if(d < near_d || near.size() < near_wanted_count) + { + // Find the right place in the near list and put it there + + // Go from farthest to near in the near list + core::list<DFloat>::Iterator i = near.begin(); + for(; i != near.end(); i++) + { + // Stop when i is at the first nearer node + if(i->d < d) + break; + } + // Add df to before i + if(i == near.end()) + near.push_back(df); + else + near.insert_before(i, df); + + // Keep near list at right size + if(near.size() > near_wanted_count) + { + core::list<DFloat>::Iterator j = near.begin(); + near.erase(j); + } + } + } + + // Return if no values found + if(near.size() == 0) + return 0.0; + + /* +20:58:29 < tejeez> joka pisteelle a += arvo / etäisyys^6; b += 1 / etäisyys^6; ja +lopuks sit otetaan a/b + */ + + float a = 0; + float b = 0; + for(core::list<DFloat>::Iterator i = near.begin(); + i != near.end(); i++) + { + if(i->d == 0) + return i->v; + + //float dd = pow((float)i->d, 6); + float dd = pow((float)i->d, 5); + float v = i->v; + //dstream<<"dd="<<dd<<", v="<<v<<std::endl; + a += v / dd; + b += 1 / dd; + } + + return a / b; +} + +#if 0 +float PointAttributeList::getInterpolatedFloat(v3s16 p) +{ + const u32 near_wanted_count = 2; + const u32 nearest_wanted_count = 2; + // Last is near + core::list<DFloat> near; + + for(core::list<PointWithAttr>::Iterator + i = m_points.begin(); + i != m_points.end(); i++) + { + PointWithAttr &pwa = *i; + u32 d = pwa.p.getDistanceFrom(p); + + DFloat df; + df.v = pwa.attr.getFloat(); + df.d = d; + + // If near list is empty, add directly and continue + if(near.size() == 0) + { + near.push_back(df); + continue; + } + + // Get distance of farthest in near list + u32 near_d = 100000; + if(near.size() > 0) + { + core::list<DFloat>::Iterator i = near.begin(); + near_d = i->d; + } + + /* + If point is closer than the farthest in the near list or + there are not yet enough points on the list + */ + if(d < near_d || near.size() < near_wanted_count) + { + // Find the right place in the near list and put it there + + // Go from farthest to near in the near list + core::list<DFloat>::Iterator i = near.begin(); + for(; i != near.end(); i++) + { + // Stop when i is at the first nearer node + if(i->d < d) + break; + } + // Add df to before i + if(i == near.end()) + near.push_back(df); + else + near.insert_before(i, df); + + // Keep near list at right size + if(near.size() > near_wanted_count) + { + core::list<DFloat>::Iterator j = near.begin(); + near.erase(j); + } + } + } + + // Return if no values found + if(near.size() == 0) + return 0.0; + + /* + Get nearest ones + */ + + u32 nearest_count = nearest_wanted_count; + if(nearest_count > near.size()) + nearest_count = near.size(); + core::list<DFloat> nearest; + { + core::list<DFloat>::Iterator i = near.getLast(); + for(u32 j=0; j<nearest_count; j++) + { + nearest.push_front(*i); + i--; + } + } + + /* + TODO: Try this: +20:58:29 < tejeez> joka pisteelle a += arvo / etäisyys^6; b += 1 / etäisyys^6; ja +lopuks sit otetaan a/b + */ + + /* + Get total distance to nearest points + */ + + float nearest_d_sum = 0; + for(core::list<DFloat>::Iterator i = nearest.begin(); + i != nearest.end(); i++) + { + nearest_d_sum += (float)i->d; + } + + /* + Interpolate a value between the first ones + */ + + dstream<<"nearest.size()="<<nearest.size()<<std::endl; + + float interpolated = 0; + + for(core::list<DFloat>::Iterator i = nearest.begin(); + i != nearest.end(); i++) + { + float weight; + if(nearest_d_sum > 0.001) + weight = (float)i->d / nearest_d_sum; + else + weight = 1. / nearest.size(); + /*dstream<<"i->d="<<i->d<<" nearest_d_sum="<<nearest_d_sum + <<" weight="<<weight<<std::endl;*/ + interpolated += weight * i->v; + } + + return interpolated; +} +#endif + |