Files
voxelforge/core/src/Region.cpp
T

191 lines
6.2 KiB
C++

#include "vf/Region.h"
namespace vf {
namespace {
constexpr uint32_t regionMagic = 0x31525856; // "VXR1"
constexpr uint32_t regionVersion = 1;
constexpr uint32_t regionsMagic = 0x53525856; // "VXRS"
void putU32(std::vector<uint8_t>& out, uint32_t value) {
out.push_back(static_cast<uint8_t>(value & 0xff));
out.push_back(static_cast<uint8_t>((value >> 8) & 0xff));
out.push_back(static_cast<uint8_t>((value >> 16) & 0xff));
out.push_back(static_cast<uint8_t>((value >> 24) & 0xff));
}
void putI32(std::vector<uint8_t>& out, int32_t value) { putU32(out, static_cast<uint32_t>(value)); }
void putU16(std::vector<uint8_t>& out, uint16_t value) {
out.push_back(static_cast<uint8_t>(value & 0xff));
out.push_back(static_cast<uint8_t>((value >> 8) & 0xff));
}
struct Reader {
const uint8_t* data;
std::size_t size;
std::size_t pos = 0;
bool u32(uint32_t& out) {
if (pos + 4 > size) return false;
out = static_cast<uint32_t>(data[pos]) | (static_cast<uint32_t>(data[pos + 1]) << 8) |
(static_cast<uint32_t>(data[pos + 2]) << 16) |
(static_cast<uint32_t>(data[pos + 3]) << 24);
pos += 4;
return true;
}
bool i32(int32_t& out) {
uint32_t v;
if (!u32(v)) return false;
out = static_cast<int32_t>(v);
return true;
}
bool u16(uint16_t& out) {
if (pos + 2 > size) return false;
out = static_cast<uint16_t>(data[pos]) | (static_cast<uint16_t>(data[pos + 1]) << 8);
pos += 2;
return true;
}
bool u8(uint8_t& out) {
if (pos + 1 > size) return false;
out = data[pos++];
return true;
}
};
void encodeChunk(std::vector<uint8_t>& out, const Chunk& chunk) {
const auto& blocks = chunk.raw();
std::size_t i = 0;
while (i < blocks.size()) {
Block value = blocks[i];
uint16_t run = 1;
while (i + run < blocks.size() && blocks[i + run] == value && run < 0xffff) ++run;
out.push_back(static_cast<uint8_t>(value));
putU16(out, run);
i += run;
}
}
bool decodeChunk(Reader& reader, Chunk& chunk) {
auto& blocks = chunk.raw();
std::size_t written = 0;
while (written < blocks.size()) {
uint8_t value;
uint16_t run;
if (!reader.u8(value) || !reader.u16(run)) return false;
if (run == 0 || written + run > blocks.size()) return false;
for (uint16_t r = 0; r < run; ++r) blocks[written++] = static_cast<Block>(value);
}
return true;
}
} // namespace
RegionCoord regionForChunk(const Vec3i& chunkCoord) {
return {floorDiv(chunkCoord.x, regionSize), floorDiv(chunkCoord.z, regionSize)};
}
void Region::putChunk(const Vec3i& chunkCoord, const Chunk& chunk) {
chunks[chunkCoord] = chunk;
}
bool Region::getChunk(const Vec3i& chunkCoord, Chunk& out) const {
auto it = chunks.find(chunkCoord);
if (it == chunks.end()) return false;
out = it->second;
return true;
}
std::vector<uint8_t> Region::serialize() const {
std::vector<uint8_t> out;
putU32(out, regionMagic);
putU32(out, regionVersion);
putI32(out, coord.x);
putI32(out, coord.z);
putU32(out, static_cast<uint32_t>(chunks.size()));
for (const auto& entry : chunks) {
putI32(out, entry.first.x);
putI32(out, entry.first.y);
putI32(out, entry.first.z);
std::vector<uint8_t> payload;
encodeChunk(payload, entry.second);
putU32(out, static_cast<uint32_t>(payload.size()));
out.insert(out.end(), payload.begin(), payload.end());
}
return out;
}
bool Region::deserialize(const uint8_t* data, std::size_t size, Region& out) {
Reader reader{data, size};
uint32_t magic = 0, version = 0, count = 0;
int32_t rx = 0, rz = 0;
if (!reader.u32(magic) || magic != regionMagic) return false;
if (!reader.u32(version) || version != regionVersion) return false;
if (!reader.i32(rx) || !reader.i32(rz)) return false;
if (!reader.u32(count)) return false;
out.coord = {rx, rz};
out.chunks.clear();
for (uint32_t c = 0; c < count; ++c) {
int32_t cx, cy, cz;
uint32_t length;
if (!reader.i32(cx) || !reader.i32(cy) || !reader.i32(cz)) return false;
if (!reader.u32(length)) return false;
if (reader.pos + length > size) return false;
Reader chunkReader{data + reader.pos, length};
Chunk chunk;
if (!decodeChunk(chunkReader, chunk)) return false;
out.chunks[{cx, cy, cz}] = chunk;
reader.pos += length;
}
return true;
}
std::unordered_map<RegionCoord, Region, RegionCoordHash> splitWorldIntoRegions(const World& world) {
std::unordered_map<RegionCoord, Region, RegionCoordHash> regions;
for (const auto& entry : world.allChunks()) {
if (entry.second->empty()) continue;
RegionCoord rc = regionForChunk(entry.first);
auto it = regions.find(rc);
if (it == regions.end()) it = regions.emplace(rc, Region{rc}).first;
it->second.putChunk(entry.first, *entry.second);
}
return regions;
}
std::vector<uint8_t> serializeRegions(const World& world) {
auto regions = splitWorldIntoRegions(world);
std::vector<uint8_t> out;
putU32(out, regionsMagic);
putU32(out, static_cast<uint32_t>(regions.size()));
for (const auto& entry : regions) {
std::vector<uint8_t> payload = entry.second.serialize();
putU32(out, static_cast<uint32_t>(payload.size()));
out.insert(out.end(), payload.begin(), payload.end());
}
return out;
}
bool deserializeRegions(const uint8_t* data, std::size_t size, World& out) {
Reader reader{data, size};
uint32_t magic = 0, count = 0;
if (!reader.u32(magic) || magic != regionsMagic) return false;
if (!reader.u32(count)) return false;
for (uint32_t r = 0; r < count; ++r) {
uint32_t length;
if (!reader.u32(length)) return false;
if (reader.pos + length > size) return false;
Region region;
if (!Region::deserialize(data + reader.pos, length, region)) return false;
reader.pos += length;
for (const auto& entry : region.allChunks())
out.ensureChunk(entry.first) = entry.second;
}
return true;
}
} // namespace vf