ReaperOfVeriod
2ff2abbd32
Chasing where the AD-GIF is, sincef43a1c2established it is not in the packet. Two of the undecoded class-header words are offsets. base + 0x1c and base + 0x34 land inside core_data on 1,864 of 1,864 classes, so both are relative to the class base rather than absolute, and both are non-zero on every class. Both also land **past** that class's own tie packet blocks on every class, so they address per-class data held elsewhere in core_data rather than the tie geometry. That is consistent withf43a1c2: if the packet's own control region is not a tag stream, the per-class draw state is referenced from somewhere else. WHAT IS THERE, AND WHAT IS NOT CLAIMED The bytes are structured, not random -- class 3 shows a fixed-stride table with `80 01 00` recurring, class 2's field is a monotone byte table, class 5's has `38 38 38` and `ff 00 ff ff`. They read like compiled shader programs with small-integer parameters, or lookup tables. **Not identified, and deliberately not named.** None of those three fragments has been run against a control, and all three were picked because they looked like something. That is precisely the finding rule 4 refuses, and having spent this session on four retractions I would rather record an honest "structured, unidentified" than a plausible format that has not earned it. If any of these turns out to be a shader program the next step is a control, not a better-looking hex dump. ALSO SETTLED 0x24 is demonstrably not an offset: only 17 of 1,864 of its values land in range for core_data. Recorded as packed data. 0x28, 0x2c, 0x38 remain high-entropy and unexplained. 281 passing with the disc present (23 + 19 + 61 + 156 + 22), clippy clean.
649 lines
28 KiB
Rust
649 lines
28 KiB
Rust
//! Tie: instanced static props -- the environment sitting on the terrain.
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//!
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//! Spec: `docs/formats/tie.md`.
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//!
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//! A *class* is one prop shape (a crate, a pipe run, a railing); *instances*
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//! place copies of it in the level. The class tables live in the core index and
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//! the geometry sits in `core_data`, addressed by byte offset.
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//!
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//! # What is decoded here, and what is not
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//!
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//! The reference's class header is 0x80 bytes. RAC2 agrees with it only over
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//! the first `0x48`: the per-LOD packet offsets, the three LOD distances and
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//! `o_class` all check out on every class on every level. From `0x48` on, the
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//! RAC1 fields do **not** describe RAC2 data -- `lod_info` reads back as noise,
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//! and `packet_count` and `texture_count` are zero on every class examined.
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//!
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//! So this module decodes the part that is verified and stops there. Guessing
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//! the remainder would repeat the pattern this project keeps running into: a
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//! field order that produces plausible output and is wrong.
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//!
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//! Evidence for what is decoded, over 1,864 classes on all 27 levels:
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//!
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//! * `o_class` at `0x44` equals the core index's class number: **1,864 of 1,864**.
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//! A coincidence is not a plausible explanation for that.
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//! * the LOD distances are ordered `0 < near < mid < far` on most classes, but
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//! **80 of 1,864** break it in an exact pattern: `mid_dist` is exactly
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//! `8192.0` and `far_dist` is exactly `8190.0` in every one. Those classes
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//! have `far < mid`, so `lod_for_depth` can never return 2 (the `far` test is
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//! reached only after the `mid` test). Effectively two LOD tiers, not three.
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//! See `docs/plan/level-assets.md` for the test.
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use crate::buf::{Buf, Error, ErrorKind, Result};
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use crate::level_core::ClassEntry;
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/// Bytes of a tie class header that RAC2 and RAC1 agree on.
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pub const TIE_CLASS_HEADER_MATCHED: usize = 0x48;
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/// Value `TieClassHeader::packets[0]` takes on every one of the 1,864 classes.
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///
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/// It is a constant, not a block offset: the other two `packets` words vary
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/// widely and land at different addresses in `core_data` on every class, while
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/// this one is 256 everywhere. Read as an offset it would name a point just
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/// past the header, which is exactly the kind of field that gets mistaken for
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/// a pointer.
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pub const TIE_PACKETS0: i32 = 256;
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/// A tie class header, decoded as far as the two games agree.
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#[derive(Debug, Clone, Copy, PartialEq)]
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pub struct TieClassHeader {
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/// `0x00`: packet data offsets for LOD 0 (highest detail), 1 and 2.
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///
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/// [`TIE_PACKETS0`] is constant across all 1,864 classes and is reported
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/// separately. `packets[1]` and `packets[2]` are the LOD block offsets,
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/// **signed**, relative to the class header: **zero means that class has no
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/// block at that LOD**, which is 1,551 of the 3,728 slots; the other 2,177
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/// point at a [`TieBlock`].
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///
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/// They are strictly increasing on only 461 of 1,864 classes, so neither one
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/// bounds the other -- the `0xf6` terminator does that instead.
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pub packets: [i32; 3],
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/// `0x0c`: the record table's length of each LOD, as three `u8` counts
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/// followed by one unidentified byte.
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///
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/// The word was read as R&C1's 64-light-slot *normals offset* and skipped,
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/// which was the right thing to do with the wrong information: the byte at
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/// `+0x0c` is not an offset at all. It is the **record count of the LOD 0
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/// block**, `+0x0d` of LOD 1, `+0x0e` of LOD 2, verified on **1,864 of
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/// 1,864** classes on all 27 levels. R&C1 carries the same quadruple at
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/// `+0x20`; R&C2 has it here.
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///
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/// `+0x0f` is not the shader (ad-gif) total, which disagrees on 1,827 of
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/// the classes measured; it is left unnamed rather than guessed at.
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pub packet_counts: [u8; 3],
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/// `0x0f`: unidentified. Not the shader total.
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pub unknown_0f: u8,
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/// `0x10`, `0x14`, `0x18`: LOD switch distances in world units.
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pub near_dist: f32,
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pub mid_dist: f32,
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pub far_dist: f32,
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/// `0x44`: the class's own number.
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///
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/// Matches the core index's `o_class` for the class, which is what makes
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/// the header base trustworthy.
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pub o_class: i32,
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}
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impl TieClassHeader {
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/// Parse the agreed-on prefix. Needs `TIE_CLASS_HEADER_MATCHED` bytes.
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pub fn parse(bytes: &[u8]) -> Result<TieClassHeader> {
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let mut b = Buf::new(bytes);
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let mut packets = [0i32; 3];
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for slot in packets.iter_mut() {
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*slot = b.i32("tie packet offset")?;
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}
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// 0x0c: the three LOD record counts and one unidentified byte.
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let packet_counts = [
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b.u8("tie LOD0 record count")?,
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b.u8("tie LOD1 record count")?,
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b.u8("tie LOD2 record count")?,
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];
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let unknown_0f = b.u8("tie class word 0x0f")?;
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let near_dist = b.f32("tie near distance")?;
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let mid_dist = b.f32("tie mid distance")?;
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let far_dist = b.f32("tie far distance")?;
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// 0x1c..0x44. Profiled over all 1,864 classes by
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// `tie_class_header_tail_words`; three words are now characterised and
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// the rest are deliberately skipped rather than guessed at.
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// 0x20, 0x30 reserved -- zero on 1,864 of 1,864
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// 0x3c six values: 0 (1,384 classes), 16 (435), 48 (21),
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// 32 (18), 2 (3), 4 (3). NOT the ad-gif count: mean
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// bfc_distance is flat across every bucket.
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// 0x40 a float -- 0.00208 to 10.84, no negatives. The bounding
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// sphere radius or the class scale; not distinguished.
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// 0x1c and 0x34 are base-relative offsets: base + offset lands inside
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// core_data on 1,864 of 1,864 classes, and always *past* the class's own
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// tie packet blocks, so they address per-class data stored elsewhere.
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// The bytes there are structured -- repeating small-integer records,
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// occasional `ff 00 ff ff` -- but are not VIF or GIF DMA tags and are
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// not identified. See tie_class_tail_offsets_point_past_the_tie_packets.
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// 0x24, 0x28, 0x2c, 0x38 are high-entropy and unidentified; 0x24 is
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// demonstrably not an offset (17 of 1,864 land in range).
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b.skip(0x44 - 0x1c, "tie class fields not decoded yet")?;
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let o_class = b.i32("tie class number")?;
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Ok(TieClassHeader {
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packets,
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packet_counts,
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unknown_0f,
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near_dist,
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mid_dist,
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far_dist,
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o_class,
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})
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}
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/// The LOD this class draws at a view depth, or `None` past its far
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/// distance.
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pub fn lod_for_depth(&self, depth: f32) -> Option<usize> {
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if depth < self.near_dist {
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Some(0)
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} else if depth < self.mid_dist {
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Some(1)
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} else if depth < self.far_dist {
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Some(2)
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} else {
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None
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}
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}
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}
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/// Size of a tie LOD block's own header.
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pub const TIE_BLOCK_HEADER_SIZE: usize = 0x10;
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/// The four most common values of [`TieBlockHeader::packed_texture`].
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///
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/// Low byte 1-4, high byte 5/10/15/20, so the word is two small fields rather
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/// than a magnitude. These are the *only* values the slot takes: 0x501 on 1,069
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/// blocks, 0xa02 on 720, 0xf03 on 350, 0x1404 on 38.
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pub const TIE_PACKED_TEXTURE_VALUES: [u16; 4] = [0x0501, 0x0a02, 0x0f03, 0x1404];
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/// A tie LOD block's fixed 16-byte header.
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///
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/// Every figure here is measured over the **922** blocks where "the next
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/// `packets` offset ends this block" holds, across all 27 levels. The other
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/// 1,403 classes are unmeasured, not measured-and-different.
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#[derive(Debug, Clone, Copy, PartialEq, Eq)]
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pub struct TieBlockHeader {
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/// `+0x00`: the byte offset from the start of the block to the vertex
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/// data -- that is, the length of the record table that follows this
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/// header. A multiple of 16 on all 2,177 blocks (42 distinct values, never
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/// zero), because the table holds 16-byte records: one block with this
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/// word at 0x10 has one record, one at 0x50 has five.
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///
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/// This was read as an element *count* for a while, and the reading failed
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/// in a way worth recording: the block's payload length divided by it is a
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/// whole number on 0 of 922 blocks, at any record size and any header up
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/// to 512 bytes. A count of what is in the payload was never going to fit,
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/// because the word is not about the payload -- it is where the payload
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/// starts.
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///
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/// Confirmed against the running game: each record's leading word is
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/// relocated at load to `table_address + word`, and the table's length is
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/// this word, on every block checked in RAM (16 of 16 on level 1).
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pub data_offset: u16,
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/// `+0x02`: zero on all 2,177 blocks.
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pub reserved_02: u16,
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/// `+0x04`: one of exactly [`TIE_PACKED_TEXTURE_VALUES`] on all 2,177 blocks.
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pub packed_texture: u16,
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/// `+0x06`: 16 distinct values, never zero.
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pub field_06: u16,
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/// `+0x08`: 180 distinct values, never zero.
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pub field_08: u16,
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/// `+0x0a`: 61 distinct values, never zero.
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pub field_0a: u16,
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/// `+0x0c`: 125 distinct values, never zero, clustered at 0x043f to 0x0443
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/// (~1,087 to 1,091). **Not** the payload length: the difference against the
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/// true length scatters from -12 to -172.
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pub field_0c: u16,
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/// `+0x0e`: 11 distinct values, zero on 2,162 of 2,177 -- the only field
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/// here that is not universal.
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pub reserved_0e: u16,
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}
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impl TieBlockHeader {
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/// Parse the block header, bounds-checked against `block`.
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pub fn parse(block: &[u8]) -> Result<Self> {
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let mut b = Buf::new(block);
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Ok(Self {
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data_offset: b.u16("tie block data offset")?,
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reserved_02: b.u16("tie block reserved")?,
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packed_texture: b.u16("tie block packed texture")?,
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field_06: b.u16("tie block field_06")?,
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field_08: b.u16("tie block field_08")?,
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field_0a: b.u16("tie block field_0a")?,
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field_0c: b.u16("tie block field_0c")?,
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reserved_0e: b.u16("tie block reserved_0e")?,
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})
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}
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/// True when every invariant measured across all 27 levels holds.
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///
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/// Only the two that are universal: the data offset is a non-zero multiple
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/// of 16 and `reserved_02` is zero, both on all 2,177 blocks.
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pub fn invariants_hold(&self) -> bool {
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self.data_offset % 16 == 0 && self.data_offset != 0 && self.reserved_02 == 0
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}
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/// The number of 16-byte records in this block's table.
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pub fn record_count(&self) -> usize {
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self.data_offset as usize / TIE_RECORD_SIZE
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}
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/// The block's records, as byte slices of [`TIE_RECORD_SIZE`].
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///
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/// Bounds-checked against `block`, which is the block starting at its
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/// header. **The header is the first record**: the table runs from the
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/// block start to `data_offset`, so a block with `data_offset == 0x50`
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/// holds five records, the first of which is the header itself and whose
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/// pointer names where the payload begins. A header whose table runs past
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/// the block yields nothing rather than a short slice.
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pub fn records<'b>(&self, block: &'b [u8]) -> impl Iterator<Item = &'b [u8]> + 'b {
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block
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.get(..self.record_count() * TIE_RECORD_SIZE)
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.unwrap_or(&[])
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.chunks_exact(TIE_RECORD_SIZE)
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}
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}
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/// One 16-byte tie block record.
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///
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/// A block is a table of these, followed by the vertex payload at
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/// [`TieBlockHeader::data_offset`]. The shape is R&C1's `TiePacketHeader`
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/// offset for offset, and R&C1's invariants hold -- see [`TieRecord`].
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#[derive(Debug, Clone, Copy, PartialEq, Eq)]
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pub struct TieRecord {
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/// The record's leading word: a pointer **relative to the start of the
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/// record table**, relocating at load to `table_address + pointer`.
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///
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/// Confirmed on every block checked in PCSX2's RAM: the word becomes
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/// `table + word` with the other twelve bytes untouched.
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pub pointer: u32,
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/// `+0x04`: AD-GIF (material) blocks this packet references; 1..4 on disc.
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pub shader_count: u8,
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/// `+0x05`: equals `5 * shader_count` on every record measured.
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///
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/// **This is not the length of the control region**, despite what the field
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/// is usually described as. It runs 5..20 quadwords and the control region is
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/// `vert_ofs`, 3..8, so for two or more shaders the value exceeds the region
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/// on *every* record -- 9,315 of 15,219 pooled, which is a number describing
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/// nothing; partitioned by `shader_count` it is 100% for 2, 3 and 4 and 32%
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/// for 1, which is exactly the share whose `vert_ofs` is below 5.
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///
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/// So the AD-GIF is **not stored in the tie packet**. What this value means
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/// is not established; the `5 * shader_count` relation is solid and the
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/// "quadwords of ad-gif data" reading of it is not. See
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/// `tie_bfc_distance_is_not_the_control_region_length`.
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pub bfc_distance: u8,
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/// `+0x06`: 4..18 on disc.
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pub control_count: u8,
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/// `+0x07`: 1..5 on disc, never above `control_count`.
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pub control_size: u8,
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/// `+0x08`: **quadwords of control data before the vertices**, 3..8 on disc
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/// (`3`: 5 records, `4`: 3,364, `5`: 4,571, `6`: 3,469, `7`: 1,632,
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/// `8`: 1 of 15,219). Peak at 5.
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///
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/// **Not a vertex offset.** The name is the one thing about this record that
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/// is wrong: the value is the *length* of the leading region, not where the
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/// vertices start within some larger array. The vertex data begins at this
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/// many quadwords into the packet. Renamed in intent, not in the field name,
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/// because the on-disc order is fixed and `vert_ofs` is what every existing
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/// test and doc says.
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pub vert_ofs: u8,
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/// `+0x09`: quadwords of vertex data; 4..60 on disc.
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pub vert_size: u8,
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/// `+0x0a`: equals `vert_size` on every record measured.
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pub color_ofs: u8,
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/// `+0x0b`: zero on every record measured.
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pub color_count: u8,
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/// `+0x0c`: quadword offset of the scissor data — and **exactly
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/// `vert_ofs + vert_size`, on 15,219 of 15,219 records across all 27
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/// levels**, including every record whose `strip_count` is non-zero.
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///
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/// It carries no information the other two fields do not. It is the end of
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/// the vertex region, stored twice. The universality is itself the useful
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/// part: it is the check that showed the packet really does partition as
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/// control / vertices / scissor, since a derived quantity only lands on the
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/// same value everywhere if those three regions are laid out the way the
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/// length formula already assumed.
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pub scissor_ofs: u8,
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/// `+0x0d`: 1..5 on disc.
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pub scissor_size: u8,
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/// `+0x0e`: zero on every record measured.
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pub strip_count: u8,
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/// `+0x0f`: zero on every record measured.
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pub strip_vertex_count: u8,
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}
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impl TieRecord {
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/// Parse one 16-byte record.
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pub fn parse(bytes: &[u8]) -> Result<TieRecord> {
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let mut b = Buf::new(bytes);
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Ok(TieRecord {
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pointer: b.u32("tie packet data offset")?,
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shader_count: b.u8("tie packet shader count")?,
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bfc_distance: b.u8("tie packet bfc distance")?,
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control_count: b.u8("tie packet control count")?,
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control_size: b.u8("tie packet control size")?,
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vert_ofs: b.u8("tie packet vertex offset")?,
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vert_size: b.u8("tie packet vertex size")?,
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color_ofs: b.u8("tie packet colour offset")?,
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color_count: b.u8("tie packet colour count")?,
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scissor_ofs: b.u8("tie packet scissor offset")?,
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scissor_size: b.u8("tie packet scissor size")?,
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strip_count: b.u8("tie packet strip count")?,
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strip_vertex_count: b.u8("tie packet strip vertex count")?,
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})
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}
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/// The twelve bytes after the pointer, verbatim.
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///
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/// The comparison against the running game checks these are copied
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/// unchanged, so they are worth having as one value rather than a
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/// field-by-field walk.
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pub fn trailing_bytes(&self) -> [u8; 12] {
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[
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self.shader_count,
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self.bfc_distance,
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self.control_count,
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self.control_size,
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self.vert_ofs,
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self.vert_size,
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self.color_ofs,
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self.color_count,
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self.scissor_ofs,
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self.scissor_size,
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self.strip_count,
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self.strip_vertex_count,
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]
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}
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/// True when every invariant that holds on **every** record measured holds.
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///
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/// `bfc_distance == 5 * shader_count` is R&C1's documented rule for this
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/// field and it holds on all 15,219 records of all 2,177 blocks on all 27
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/// levels; that is what identifies the record as this struct rather than a
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/// resemblance. The three orderings are also universal.
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///
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/// Relations that hold on most records but not all are deliberately *not*
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/// here -- a check that fails on a real record is worse than no check --
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/// and the disc test counts them instead. `color_ofs == vert_size` is the
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/// largest of those: 12,640 of 15,219.
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pub fn invariants_hold(&self) -> bool {
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self.bfc_distance == 5 * self.shader_count
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&& self.vert_ofs <= self.vert_size
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&& self.scissor_size <= self.scissor_ofs
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&& self.control_size <= self.control_count
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// Universal on 15,219 of 15,219 records, so unlike the first four --
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// which are the large-partition rule plus three smaller ones -- this
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// one can be a hard check. See `scissor_ofs`.
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&& u16::from(self.scissor_ofs) == u16::from(self.vert_ofs) + u16::from(self.vert_size)
|
|
}
|
|
|
|
/// Quadwords of packet data: `vert_ofs + vert_size + scissor_size`.
|
|
///
|
|
/// Holds on **12,927 of 12,927** record pairs whose `strip_count` is zero,
|
|
/// and on **0 of 115** whose it is not -- the partition is exact, so the
|
|
/// formula is safe to use when `strip_count == 0` and knows nothing
|
|
/// otherwise. R&C1's `strip_count` is the strip count, and strips are
|
|
/// variable-length data, so a non-zero count most likely adds a record
|
|
/// count's worth of per-strip bytes this cannot see.
|
|
pub fn packet_quadwords(&self) -> usize {
|
|
self.vert_ofs as usize + self.vert_size as usize + self.scissor_size as usize
|
|
}
|
|
|
|
/// Whether [`Self::packet_quadwords`] is known to describe this record.
|
|
///
|
|
/// `strip_count == 0` on every record the formula has been verified on;
|
|
/// the 115 records where it is not decode to a fourth term of 0..19
|
|
/// quadwords that is not `strip_count` and is not established.
|
|
pub fn packet_quadwords_are_known(&self) -> bool {
|
|
self.strip_count == 0
|
|
}
|
|
}
|
|
|
|
/// Byte that terminates a tie LOD block's payload.
|
|
pub const TIE_BLOCK_TERMINATOR: u8 = 0xf6;
|
|
|
|
/// Bytes in one tie block record.
|
|
pub const TIE_RECORD_SIZE: usize = 0x10;
|
|
|
|
/// A tie LOD block: its header, its payload, and the zero padding that follows
|
|
/// the terminator.
|
|
///
|
|
/// **The blocks are self-delimiting.** Each ends with [`TIE_BLOCK_TERMINATOR`]
|
|
/// followed by zeros, on **2,177 of 2,177** blocks across all 27 levels. That is
|
|
/// what makes them parseable without trusting `packets[1]` to bound the block,
|
|
/// which it only does on 461 of 1,864 classes.
|
|
///
|
|
/// The terminator is not a coincidence of byte frequency: `0xf6` occurs at 0.83x
|
|
/// the uniform rate in payloads, i.e. slightly *less* often than chance, while
|
|
/// the last non-zero byte is `0xf6` on 909 of 922 blocks in the first subset
|
|
/// tested against **17 of 922** for the same blocks cut at a random point.
|
|
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
|
|
pub struct TieBlock<'a> {
|
|
/// The 16-byte header.
|
|
pub header: TieBlockHeader,
|
|
/// Bytes from `0x10` up to and including the terminator.
|
|
///
|
|
/// **This is short.** The `0xf6` the walk stops at lies inside the last
|
|
/// packet's data, an even 2 to 16 bytes before that packet's computed end,
|
|
/// so the block's real extent runs past it. `tie_block_payload_divides_
|
|
/// into_contiguous_packets` measures this; finding a terminator packet
|
|
/// data cannot imitate is its own task.
|
|
pub payload: &'a [u8],
|
|
/// Zero bytes between the terminator and the next block.
|
|
pub padding: &'a [u8],
|
|
}
|
|
|
|
/// Walk `region` from `offset` to the first `0xf6` that is followed by a zero,
|
|
/// and return the block there.
|
|
///
|
|
/// Returns `None` if no terminator is found before the end of the region.
|
|
pub fn parse_tie_block(region: &[u8], offset: usize) -> Option<TieBlock<'_>> {
|
|
if offset.checked_add(TIE_BLOCK_HEADER_SIZE)? > region.len() {
|
|
return None;
|
|
}
|
|
let header = TieBlockHeader::parse(®ion[offset..]).ok()?;
|
|
let start = offset + TIE_BLOCK_HEADER_SIZE;
|
|
let mut i = start;
|
|
while i + 1 < region.len() {
|
|
if region[i] == TIE_BLOCK_TERMINATOR && region[i + 1] == 0 {
|
|
let after = i + 1;
|
|
let mut e = after;
|
|
while e < region.len() && region[e] == 0 {
|
|
e += 1;
|
|
}
|
|
return Some(TieBlock {
|
|
header,
|
|
payload: ®ion[start..after],
|
|
padding: ®ion[after..e],
|
|
});
|
|
}
|
|
i += 1;
|
|
}
|
|
None
|
|
}
|
|
|
|
/// A tie class resolved through both of its indirections.
|
|
///
|
|
/// The chain is two steps and both are easy to get wrong, so it is worth
|
|
/// stating plainly:
|
|
///
|
|
/// 1. The class **table** lives in the level's `core_index.bin`, not in
|
|
/// `core_data.bin`. On level 0 the tables chain as moby at `192`,
|
|
/// 238 x 32 bytes later tie at `7808`, 74 x 32 later shrub at `10176`,
|
|
/// which closes. Reading the same table out of `core_data.bin` yields
|
|
/// plausible-looking garbage rather than an error.
|
|
/// 2. [`ClassEntry::offset_in_asset_wad`] addresses `core_data.bin`, despite the
|
|
/// field's name and despite `core_data.wad` existing alongside it.
|
|
///
|
|
/// With both handled, all **1,864** tie classes on the disc resolve to a header
|
|
/// whose `o_class` matches the class entry's own.
|
|
#[derive(Debug, Clone, Copy, PartialEq)]
|
|
pub struct ResolvedTieClass {
|
|
/// The index entry this came from.
|
|
pub entry: ClassEntry,
|
|
/// Its index within the level's tie table.
|
|
pub index: usize,
|
|
/// The class header, at `offset_in_asset_wad` in `core_data`.
|
|
pub header: TieClassHeader,
|
|
}
|
|
|
|
/// Resolve one tie class. `class_index` counts from zero.
|
|
///
|
|
/// `core_index` is the level's `core_index.bin`; `core_data` is the
|
|
/// decompressed `core_data.bin`. Both are bounds-checked.
|
|
pub fn resolve_tie_class(
|
|
core_index: &[u8],
|
|
core_data: &[u8],
|
|
classes: crate::level_core::ArrayRange,
|
|
class_index: usize,
|
|
) -> Result<ResolvedTieClass> {
|
|
const ENTRY: usize = 32;
|
|
let start = classes.offset as usize + class_index * ENTRY;
|
|
if classes.offset < 0 || start.checked_add(ENTRY).is_none() || start + ENTRY > core_index.len()
|
|
{
|
|
return Err(Error {
|
|
offset: start,
|
|
context: "tie class table entry",
|
|
kind: ErrorKind::OutOfBounds {
|
|
needed: ENTRY,
|
|
available: core_index.len().saturating_sub(start),
|
|
},
|
|
});
|
|
}
|
|
if class_index >= classes.count as usize {
|
|
return Err(Error {
|
|
offset: start,
|
|
context: "tie class index",
|
|
kind: ErrorKind::Invalid("class index past the table count"),
|
|
});
|
|
}
|
|
let entry = ClassEntry::parse(&core_index[start..start + ENTRY])?;
|
|
let base = entry.offset_in_asset_wad as usize;
|
|
if base < TIE_CLASS_HEADER_MATCHED || base + TIE_CLASS_HEADER_MATCHED > core_data.len() {
|
|
return Err(Error {
|
|
offset: base,
|
|
context: "tie class header",
|
|
kind: ErrorKind::OutOfBounds {
|
|
needed: TIE_CLASS_HEADER_MATCHED,
|
|
available: core_data.len().saturating_sub(base),
|
|
},
|
|
});
|
|
}
|
|
let header = TieClassHeader::parse(&core_data[base..base + TIE_CLASS_HEADER_MATCHED])?;
|
|
Ok(ResolvedTieClass {
|
|
entry,
|
|
index: class_index,
|
|
header,
|
|
})
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use super::*;
|
|
|
|
/// A header as measured on level 0's first tie class.
|
|
fn header() -> Vec<u8> {
|
|
let mut v = vec![0u8; TIE_CLASS_HEADER_MATCHED];
|
|
for (i, x) in [256i32, 20_592, 26_048].iter().enumerate() {
|
|
v[i * 4..i * 4 + 4].copy_from_slice(&x.to_le_bytes());
|
|
}
|
|
for (i, x) in [12.0f32, 25.0, 40.0].iter().enumerate() {
|
|
let o = 0x10 + i * 4;
|
|
v[o..o + 4].copy_from_slice(&x.to_le_bytes());
|
|
}
|
|
v[0x44..0x48].copy_from_slice(&2592i32.to_le_bytes());
|
|
v
|
|
}
|
|
|
|
#[test]
|
|
fn parses_the_measured_prefix() {
|
|
let h = TieClassHeader::parse(&header()).unwrap();
|
|
assert_eq!(h.packets, [256, 20_592, 26_048]);
|
|
assert_eq!(h.near_dist, 12.0);
|
|
assert_eq!(h.mid_dist, 25.0);
|
|
assert_eq!(h.far_dist, 40.0);
|
|
assert_eq!(h.o_class, 2592);
|
|
}
|
|
|
|
#[test]
|
|
fn a_short_header_is_an_error_not_a_panic() {
|
|
assert!(TieClassHeader::parse(&[0u8; 0x20]).is_err());
|
|
assert!(TieClassHeader::parse(&[]).is_err());
|
|
}
|
|
|
|
#[test]
|
|
fn lod_bands_follow_the_three_distances() {
|
|
let h = TieClassHeader::parse(&header()).unwrap();
|
|
assert_eq!(h.lod_for_depth(5.0), Some(0));
|
|
assert_eq!(h.lod_for_depth(20.0), Some(1));
|
|
assert_eq!(h.lod_for_depth(30.0), Some(2));
|
|
assert_eq!(h.lod_for_depth(50.0), None);
|
|
}
|
|
|
|
/// A block whose data offset names a four-record table, the first of
|
|
/// which is the header itself.
|
|
fn block() -> Vec<u8> {
|
|
let mut v = Vec::new();
|
|
// data_offset 0x40 -- four records -- reserved 0, packed, then the
|
|
// remaining fields.
|
|
v.extend_from_slice(&0x40u16.to_le_bytes());
|
|
v.extend_from_slice(&0u16.to_le_bytes());
|
|
v.extend_from_slice(&0x0501u16.to_le_bytes());
|
|
v.extend_from_slice(&0x1234u16.to_le_bytes());
|
|
v.extend_from_slice(&0x5678u16.to_le_bytes());
|
|
v.extend_from_slice(&0x9abcu16.to_le_bytes());
|
|
v.extend_from_slice(&0x0442u16.to_le_bytes());
|
|
v.extend_from_slice(&0u16.to_le_bytes());
|
|
assert_eq!(v.len(), TIE_BLOCK_HEADER_SIZE);
|
|
// Three packet headers, each a data pointer and R&C1's byte fields.
|
|
for k in 0..3u32 {
|
|
v.extend_from_slice(&(0x40 + k * 0x20).to_le_bytes());
|
|
v.extend_from_slice(&[
|
|
1, 5, // shader_count, bfc_distance = 5 * shader_count
|
|
7, 2, // control_count, control_size
|
|
4, 0x20, // vert_ofs, vert_size
|
|
0x20, 0, // color_ofs (= vert_size), color_count
|
|
0x24, 0x20, // scissor_ofs (= vert_ofs + vert_size), scissor_size
|
|
0, 0, // strip_count, strip_vertex_count
|
|
]);
|
|
}
|
|
v.extend_from_slice(&[0xa5u8; 8]);
|
|
v
|
|
}
|
|
|
|
#[test]
|
|
fn the_data_offset_bounds_the_record_table() {
|
|
let b = block();
|
|
let h = TieBlockHeader::parse(&b).unwrap();
|
|
assert!(h.invariants_hold());
|
|
assert_eq!(h.record_count(), 4);
|
|
let records: Vec<_> = h.records(&b).collect();
|
|
assert_eq!(records.len(), 4);
|
|
// The first record is the header itself, pointing at the payload.
|
|
let first = TieRecord::parse(records[0]).unwrap();
|
|
assert_eq!(first.pointer, 0x40);
|
|
// The fields follow R&C1's packet-header byte layout.
|
|
let second = TieRecord::parse(records[1]).unwrap();
|
|
assert_eq!(second.shader_count, 1);
|
|
assert_eq!(second.bfc_distance, 5);
|
|
// scissor_ofs is vert_ofs + vert_size: 4 + 0x20 = 0x24.
|
|
assert_eq!(second.scissor_ofs, 0x24);
|
|
assert!(second.invariants_hold());
|
|
}
|
|
|
|
#[test]
|
|
fn a_table_running_past_the_block_yields_nothing() {
|
|
let mut b = block();
|
|
// Claim a table far longer than the block.
|
|
b[0..2].copy_from_slice(&0x400u16.to_le_bytes());
|
|
let h = TieBlockHeader::parse(&b).unwrap();
|
|
assert_eq!(h.record_count(), 0x40);
|
|
assert_eq!(h.records(&b).count(), 0, "must not slice past the block");
|
|
// A 0x400 offset is still a multiple of 16, so the invariant holds even
|
|
// though the table cannot exist.
|
|
assert!(h.invariants_hold());
|
|
}
|
|
}
|