NavMeshPtr makeEmptyNavMesh(const Settings& settings)
{
// Max tiles and max polys affect how the tile IDs are caculated.
// There are 22 bits available for identifying a tile and a polygon.
const int polysAndTilesBits = 22;
const auto polysBits = getMinValuableBitsNumber(settings.mMaxPolys);
if (polysBits >= polysAndTilesBits)
throw InvalidArgument("Too many polygons per tile");
const auto tilesBits = polysAndTilesBits - polysBits;
dtNavMeshParams params;
std::fill_n(params.orig, 3, 0.0f);
params.tileWidth = settings.mTileSize * settings.mCellSize;
params.tileHeight = settings.mTileSize * settings.mCellSize;
params.maxTiles = 1 << tilesBits;
params.maxPolys = 1 << polysBits;
NavMeshPtr navMesh(dtAllocNavMesh(), &dtFreeNavMesh);
const auto status = navMesh->init(¶ms);
if (!dtStatusSucceed(status))
throw NavigatorException("Failed to init navmesh");
return navMesh;
}
NavMeshLoader::LoadResult NavMeshLoader::LoadZoneMeshData(const std::shared_ptr<char>& data, DWORD length)
{
ReadCursor cursor{ data.get(), length };
//------------------------------------------------------------------------
// Read the header
NavMeshSetHeader header;
if (!FillStructure(cursor, header)) {
DebugSpewAlways("Failed to read header from mesh file!");
return CORRUPT;
}
if (header.magic != NAVMESHSET_MAGIC) {
DebugSpewAlways("Header Magic value mismatch!");
return CORRUPT;
}
if (header.version != NAVMESHSET_VERSION) {
DebugSpewAlways("Header version mismatch!");
return VERSION_MISMATCH;
}
std::unique_ptr<dtNavMesh> navMesh(new dtNavMesh);
if (!navMesh->init(&header.params)) {
DebugSpewAlways("Header params are bad!");
return CORRUPT;
}
//------------------------------------------------------------------------
// Read the tiles
int passtile = 0, failtile = 0;
for (int i = 0; i < header.numTiles; ++i)
{
NavMeshTileHeader tileHeader;
if (!FillStructure(cursor, tileHeader)) {
DebugSpewAlways("Failed to read tile header for tile %d!", i);
return CORRUPT;
}
if (!tileHeader.tileRef || !tileHeader.dataSize) {
continue;
}
// validate the size. For sure it should not exceed the remainder of the
// file size.
if (tileHeader.dataSize < 0 || tileHeader.dataSize > cursor.length) {
DebugSpewAlways("tileHeader's dataSize has invalid size %d for tile %d",
tileHeader.dataSize, i);
return CORRUPT;
}
unsigned char* tileData = (unsigned char*)dtAlloc(tileHeader.dataSize, DT_ALLOC_PERM);
memcpy(tileData, cursor.data, tileHeader.dataSize);
cursor.length -= tileHeader.dataSize;
cursor.data += tileHeader.dataSize;
if (navMesh->addTile(tileData, tileHeader.dataSize, DT_TILE_FREE_DATA, tileHeader.tileRef, 0))
passtile++;
else
{
DebugSpewAlways("Failed to load tile %d", i);
failtile++;
}
}
// these values shouldn't be set until we have a successful load
m_loadedTiles = passtile;
m_mesh = std::move(navMesh);
OnNavMeshChanged(m_mesh.get());
return SUCCESS;
}
