Maths and network NBT

mod_api::strict_math provides the established platform-independent StrictMath operations: log, log10, cbrt, hypot, atan, asin, acos and atan2. They are pure functions with identical bits on native and wasm. It does not expose sin, cos, tan, exp, pow, or the AArch64 FMA variants.

mod_api::java_math exposes every engine jmath free function for native mods, including round and round_f32. These are the paths used for vanilla Math call sites; rounding can differ by machine, and universal HotSpot bit equality is not promised. Calling them on wasm fails to compile and points to strict_math.

Tag::to_network_bytes() writes the engine's nameless network root, preserving NaN bits and modified UTF-8 (including unpaired UTF-16 surrogates). Reading follows the engine codec: negative floating zero normalizes to positive zero, and mixed-list compound wrappers are unwrapped. Tag::from_network_bytes(&bytes, None) returns (tag, consumed_bytes); bytes following the root remain unread. Tag::End encodes as [0] and represents vanilla's null marker. Errors have the exported mod_api::NbtError type.

The default read quota is mod_api::NETWORK_NBT_QUOTA (2,097,152 bytes), matching vanilla 26.3 ByteBufCodecs.TAG and NbtAccounter.defaultQuota. It counts heap charges, not wire bytes: primitive tag overhead, array contents, UTF-16 strings and compound keys, list references, and distinct compound entries. Pass Some(larger_quota) for trusted data. Both methods allow 512 container levels; the writer refuses strings over 65,535 modified UTF-8 bytes. Vanilla applies heap quotas on reads, so writing does not impose a heap quota.

The implementation follows vanilla 26.3 NbtIo.readAnyTag/writeAnyTag, FriendlyByteBuf.readNbt/writeNbt, NbtAccounter, and each TagType.load. It shares the engine reader and writer. These explicit codec calls cost time proportional to the encoded data and add no tick-time work or Host calls.