diff options
Diffstat (limited to 'src/map.cpp')
| -rw-r--r-- | src/map.cpp | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/src/map.cpp b/src/map.cpp index a1502befa..43a49dc2f 100644 --- a/src/map.cpp +++ b/src/map.cpp @@ -1157,6 +1157,72 @@ void Map::removeNodeTimer(v3s16 p) block->m_node_timers.remove(p_rel); } +bool Map::isOccluded(v3s16 p0, v3s16 p1, float step, float stepfac, + float start_off, float end_off, u32 needed_count) +{ + float d0 = (float)BS * p0.getDistanceFrom(p1); + v3s16 u0 = p1 - p0; + v3f uf = v3f(u0.X, u0.Y, u0.Z) * BS; + uf.normalize(); + v3f p0f = v3f(p0.X, p0.Y, p0.Z) * BS; + u32 count = 0; + for(float s=start_off; s<d0+end_off; s+=step){ + v3f pf = p0f + uf * s; + v3s16 p = floatToInt(pf, BS); + MapNode n = getNodeNoEx(p); + const ContentFeatures &f = m_nodedef->get(n); + if(f.drawtype == NDT_NORMAL){ + // not transparent, see ContentFeature::updateTextures + count++; + if(count >= needed_count) + return true; + } + step *= stepfac; + } + return false; +} + +bool Map::isBlockOccluded(MapBlock *block, v3s16 cam_pos_nodes) { + v3s16 cpn = block->getPos() * MAP_BLOCKSIZE; + cpn += v3s16(MAP_BLOCKSIZE / 2, MAP_BLOCKSIZE / 2, MAP_BLOCKSIZE / 2); + float step = BS * 1; + float stepfac = 1.1; + float startoff = BS * 1; + // The occlusion search of 'isOccluded()' must stop short of the target + // point by distance 'endoff' (end offset) to not enter the target mapblock. + // For the 8 mapblock corners 'endoff' must therefore be the maximum diagonal + // of a mapblock, because we must consider all view angles. + // sqrt(1^2 + 1^2 + 1^2) = 1.732 + float endoff = -BS * MAP_BLOCKSIZE * 1.732050807569; + v3s16 spn = cam_pos_nodes; + s16 bs2 = MAP_BLOCKSIZE / 2 + 1; + // to reduce the likelihood of falsely occluded blocks + // require at least two solid blocks + // this is a HACK, we should think of a more precise algorithm + u32 needed_count = 2; + + return ( + // For the central point of the mapblock 'endoff' can be halved + isOccluded(spn, cpn, + step, stepfac, startoff, endoff / 2.0f, needed_count) && + isOccluded(spn, cpn + v3s16(bs2,bs2,bs2), + step, stepfac, startoff, endoff, needed_count) && + isOccluded(spn, cpn + v3s16(bs2,bs2,-bs2), + step, stepfac, startoff, endoff, needed_count) && + isOccluded(spn, cpn + v3s16(bs2,-bs2,bs2), + step, stepfac, startoff, endoff, needed_count) && + isOccluded(spn, cpn + v3s16(bs2,-bs2,-bs2), + step, stepfac, startoff, endoff, needed_count) && + isOccluded(spn, cpn + v3s16(-bs2,bs2,bs2), + step, stepfac, startoff, endoff, needed_count) && + isOccluded(spn, cpn + v3s16(-bs2,bs2,-bs2), + step, stepfac, startoff, endoff, needed_count) && + isOccluded(spn, cpn + v3s16(-bs2,-bs2,bs2), + step, stepfac, startoff, endoff, needed_count) && + isOccluded(spn, cpn + v3s16(-bs2,-bs2,-bs2), + step, stepfac, startoff, endoff, needed_count)); +} + /* ServerMap */ |