Function pushmove

source/core/gamefuncs.cpp:1171–1225

//==========================================================================

int pushmove(DVector3& pos, sectortype** pSect, double walldist, double ceildist, double floordist, unsigned cliptype)
{
	auto wallflags = EWallFlags::FromInt(cliptype & 65535);
	int maxhitwalls = 0;
	bool pushed = true;

	for(int direction = 1; pushed; direction = -direction)
	{
		pushed = false;

		if (*pSect == nullptr)
			return -1;

		BFSSectorSearch search(*pSect);

		while (auto sec = search.GetNext())
		{
			// this must go both forward and backward so we cannot use iterators. Pity
			for (unsigned i = 0; i < sec->walls.Size(); i++)
			{
				auto wal = direction > 0 ? &sec->walls[i] : &sec->walls[sec->walls.Size() - 1 - i];

				if (IsCloseToWall(pos.XY(), wal, walldist - 0.25) == EClose::InFront)
				{
					bool blocked = false;
					if (!wal->twoSided() || wal->cstat & wallflags) blocked = true;
					else
					{
						auto pvect = NearestPointOnWall(pos.X, pos.Y, wal);
						blocked = checkOpening(pvect, pos.Z, sec, wal->nextSector(), ceildist, floordist);
					}

					if (blocked)
					{
						auto dv = wal->delta().Rotated90CCW().Unit() * 0.5;
						for (int t = 0; t < 16; t++)
						{
							pos += dv;
							if (IsCloseToWall(pos.XY(), wal, (walldist - 0.25)) == EClose::Outside) break;
						}
						pushed = true;

						updatesector(pos, pSect);
						if (++maxhitwalls >= 32) return -1;
						if (*pSect == nullptr) return -1;
					}
					else
						search.Add(wal->nextSector());
				}
			}
		}
		if (!pushed) return 0;
	}
	return -1;
}

//==========================================================================
//