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test(simulation): gridunit derive + wire encoding benches (T-1178, T-1154, T-1179)

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bmv_gridunit_bench: production build_district_window_layer par_iter path at
330K/2.07M/8.3M cells (throughput holds, ~190-220 ns/cell parallel), block
(128m) and tile (1m/4m) spacing costs, the 83K-cell deepest-step viewport
shape, and the verified zero-savings octave-cutoff finding below District
spacing. wire_encoding_bench: real GJ338Bd derived canvases through
derive_at_metres, five encodings (raw rmp / bit-packed / RLE / PNG-per-field
/ PNG-of-packed) with measured bytes + encode/decode round-trips; corrected
raw density 6.00 B/cell. All #[ignore]d release tests.

Workshop gate measurements (2)(3)(4) for body-map-viewer.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
This commit is contained in:
jpmschweitzer
2026-07-23 19:22:47 +02:00
co-authored by Claude Fable 5
parent 05f9630cb4
commit 53a4c65d62
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server/tests/bmv_gridunit_bench.rs
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//! Body Map Viewer workshop-gate benches (T-1178 / T-1154, brief appendix
//! ②/③; tyre-implications.md §3.2). Two anti-extrapolation measurements the
//! T-1143 planetary-rung post-mortem specifically named as the gap that must
//! close before round 1 of the body-map-viewer workshop can start:
//!
//! - **T-1178 (②):** does the row-chunked `par_iter` throughput measured at
//! 4,096 cells (`zoom_ladder_bench.rs`, 1.785 µs/cell District cutoff)
//! HOLD at real step-canvas sizes (330K, 2.07M, 8.3M cells)? MEASURE, never
//! extrapolate.
//! - **T-1154 (③):** per-cell derive cost at block (128 m) and tile-adjacent
//! (1–4 m) spacing — the ladder's un-costed bottom rungs
//! (`atlas-zoom-ladder-t1143.md` §2: "not estimated").
//!
//! ## Why this is a NEW file, not an extension of `zoom_ladder_bench.rs`
//!
//! `zoom_ladder_bench.rs` measures per-cell rate at the FIXED 4,096-cell
//! shape (`grid_side = 64`, matching the D-226 window wire cap) — that shape
//! is deliberate there (it's the served-window ceiling). This file measures
//! the opposite question: does the SAME per-cell code path hold its rate when
//! swept out to real canvas dimensions the served-window ceiling forbids.
//! Different shape, different question, kept in its own file per the batch
//! instruction (do not touch `server/src/atlas/mod.rs`; extend the bench or
//! add a new file — this adds a new file to avoid entangling two
//! differently-shaped measurement passes in one).
//!
//! ## The `n`-cap problem (why this cannot go through `AtlasLayerRequest`)
//!
//! `build_district_window_layer`'s caller-facing entry (`handle_atlas_request`
//! / `clamp_window_n_v2`) hard-clamps `n` so `side² ≤ WIRE_CAP_CELLS = 4,096`
//! — a REAL client can never request a 330K-cell window over the wire, by
//! design (D-226 T-1124 §2). So "run it through the production path at
//! 330K/8.3M cells" cannot mean "send an `AtlasLayerRequest` for that size" —
//! no such request is legal. It means: call the actual
//! `build_district_window_layer` function — same signature, same row-chunked
//! `into_par_iter()` loop, same `derive_window_cell`/`scatter_row` internals,
//! same `derive_at_metres` calls — with an `n` no wire request could carry,
//! because `build_district_window_layer` itself has NO internal clamp (the
//! clamp lives one layer up, in the request handler). Confirmed by direct
//! read of `layer_proxy.rs:1515-1628` this session. This is exactly what the
//! ticket anticipates: "If the production path caps window n such that you
//! cannot request 330K cells through it directly, bench the underlying
//! chunked loop at those counts and say exactly what you ran."
//!
//! ## Square vs. rectangular canvases
//!
//! `build_district_window_layer` only derives SQUARE `side×side` grids ('n'
//! is a single extent). The real step-canvas shapes the ticket names are
//! 16:9 rectangles (768×432, 1920×1080, 3840×2160) — not square. Two
//! measurements are taken for each cell-count target:
//!
//! 1. **Square, through `build_district_window_layer` itself** (District
//! granularity, `n = side`, real function call, unmodified) — the closest
//! possible approach to "the actual production entry point," at the
//! nearest square cell count to the target (e.g. side=576 → 331,776
//! cells, matching 768×432's 331,776 exactly).
//! 2. **Real 16:9 rectangle, via a row-chunked loop that mirrors
//! `build_district_window_layer`'s internals cell-for-cell** (same
//! `into_par_iter()` row chunking, same `derive_at_metres` call, same
//! per-cell output quantization copied from `derive_window_cell`) but
//! sized to the actual non-square canvas. This is necessarily a
//! hand-written replica for the rectangular case (documented inline,
//! diffed explicitly against the real function in the module doc above),
//! since no production entry point derives a rectangle. Labelled
//! "MEASURED (replica loop)" in the results table to distinguish it from
//! "MEASURED (production fn)".
//!
//! Both converge on the same number at the same cell count (verified by the
//! square case landing within noise of the rectangle case at 331,776 ≈ 576²)
//! — see the results doc for the cross-check.
//!
//! Run: `cargo test --release --test bmv_gridunit_bench -- --ignored --nocapture`
use std::time::Instant;
use settled_reach_server::atlas::district_profile::{
derive_at_metres, BodyParams, ClimateConstants,
};
use settled_reach_server::atlas::drainage;
use settled_reach_server::atlas::features::TerrainAnalysis;
use settled_reach_server::atlas::heightmap::{load_heightmap_png, BodyHeightmap};
use settled_reach_server::atlas::layer_proxy::{build_district_window_layer, WindowGranularity};
use settled_reach_server::atlas::scale;
use settled_reach_server::seed::{SeedChain, SeedDomain};
// ---------------------------------------------------------------------------
// Shared fixtures — same shape as zoom_ladder_bench.rs's own fixtures, reused
// rather than re-invented so the two files' numbers are directly comparable.
// ---------------------------------------------------------------------------
fn bench_hm() -> BodyHeightmap {
let (w, h) = (128u32, 64u32);
let n = (w * h) as usize;
let data = (0..n)
.map(|i| {
let r = (i / w as usize) as f32 / h as f32;
let c = (i % w as usize) as f32 / w as f32;
(r * 0.6 + c * 0.4).min(1.0)
})
.collect();
BodyHeightmap {
body_id: "bench".into(),
width: w,
height: h,
data,
sea_level: 0.3,
}
}
fn bench_ta(hm: &BodyHeightmap) -> TerrainAnalysis {
let dr = drainage::analyze(&hm.data, hm.width, hm.height, hm.sea_level);
TerrainAnalysis::analyze(hm, &dr)
}
fn bench_river_network(
hm: &BodyHeightmap,
) -> settled_reach_server::atlas::body_world_state::RiverNetwork {
drainage::analyze(&hm.data, hm.width, hm.height, hm.sea_level).river_network
}
fn bench_params() -> BodyParams {
BodyParams {
hydrosphere: Some("ocean".into()),
atmosphere: Some("breathable".into()),
planet_class: Some("temperate".into()),
body_radius_km: Some(6371.0),
..Default::default()
}
}
/// The real committed GJ1c heightmap, downsampled to the production working
/// grid (512×256) — used for the "real body" cross-check bench so the
/// headline numbers are not solely a synthetic-gradient artifact.
fn gj1c_fixture() -> (BodyHeightmap, TerrainAnalysis) {
let src = std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
.join("../wiki/star-systems/GJ-1/bodies/GJ1c/heightmap.png");
let heightmap = load_heightmap_png(&src, "GJ1c", 0.3).expect("decode committed GJ1c heightmap");
let small = heightmap.downsample(512, 256);
let dr = drainage::analyze(&small.data, small.width, small.height, small.sea_level);
let ta = TerrainAnalysis::analyze(&small, &dr);
(small, ta)
}
/// Report the actual Rayon global-pool thread count in use, not an assumed
/// constant — so the results doc records what really ran, on whatever
/// machine state existed at run time.
fn rayon_threads_report() -> String {
format!(
"available_parallelism={}, rayon::current_num_threads={}",
std::thread::available_parallelism()
.map(|n| n.get())
.unwrap_or(0),
rayon::current_num_threads()
)
}
// ---------------------------------------------------------------------------
// T-1178 (Measurement ②) — square canvases through the REAL production fn.
// ---------------------------------------------------------------------------
/// Square windows through the actual, unmodified `build_district_window_layer`
/// — same function a real `DeriveWindow` work item calls — at `n` values no
/// wire request could legally carry (the `WIRE_CAP_CELLS` clamp lives in the
/// caller, not in this function; see module doc). District granularity
/// (2,048 m spacing) with the matching District cutoff (2,048 m, admits every
/// existing octave band — the "today's shipped cutoff" case) and the same
/// spacing UNCUT (cutoff 0) for comparison.
#[test]
#[ignore]
fn bench_square_window_production_fn_district_spacing() {
let hm = bench_hm();
let ta = bench_ta(&hm);
let rn = bench_river_network(&hm);
let params = bench_params();
let climate = ClimateConstants::default();
let seed = SeedChain::root(99).derive(SeedDomain::Body, 1);
println!("\n=== T-1178 square-window production-fn bench (District spacing) ===");
println!(" {}\n", rayon_threads_report());
// side values chosen to land on/near the ticket's named cell counts:
// 576^2 = 331,776 (~330K, the 5x5-px-per-gridunit fallback)
// 1440^2 = 2,073,600 (~2.07M, the 1920x1080 midpoint)
// 2880^2 = 8,294,400 (~8.3M, the 3840x2160 1x1 ideal)
let side_targets: [u32; 3] = [576, 1440, 2880];
let min_wl_m = scale::DISTRICT_M as u32; // 2,048 m — the shipped District cutoff band
for &side in &side_targets {
let n = side; // District granularity: side == n
let cells = (side as u64) * (side as u64);
// Warm-up call (allocator/page-fault warm-up not counted).
let _ = build_district_window_layer(
seed,
"bench",
&params,
&ta,
&rn,
(0, 0),
n,
&climate,
WindowGranularity::District,
min_wl_m,
);
let t0 = Instant::now();
let layer = build_district_window_layer(
seed,
"bench",
&params,
&ta,
&rn,
(0, 0),
n,
&climate,
WindowGranularity::District,
min_wl_m,
);
let elapsed = t0.elapsed();
std::hint::black_box(layer.elev_q.len());
let ms = elapsed.as_secs_f64() * 1000.0;
let ns_per_cell = elapsed.as_secs_f64() * 1e9 / cells as f64;
println!(
" side={side:>5} n={n:>5} cells={cells:>10} (target ~{}): \
{ms:>9.2} ms warm, {ns_per_cell:>7.1} ns/cell ({:.3} us/cell)",
match cells {
c if c < 500_000 => "330K",
c if c < 4_000_000 => "2.07M",
_ => "8.3M",
},
ns_per_cell / 1000.0
);
}
println!();
}
/// Single-thread comparison at the SAME square shapes — builds a 1-thread
/// Rayon pool via `install()` so the SAME `build_district_window_layer` body
/// runs its `into_par_iter()` on exactly one worker, isolating the
/// parallel-speedup number from a hand-rolled serial loop that might not
/// match the real per-cell overhead exactly.
#[test]
#[ignore]
fn bench_square_window_production_fn_district_spacing_single_thread() {
let hm = bench_hm();
let ta = bench_ta(&hm);
let rn = bench_river_network(&hm);
let params = bench_params();
let climate = ClimateConstants::default();
let seed = SeedChain::root(99).derive(SeedDomain::Body, 1);
println!("\n=== T-1178 square-window production-fn bench, SINGLE THREAD (District spacing) ===\n");
// 8.3M cells single-thread is the ~12s-class case the design doc
// extrapolated (§7); 330K/2.07M included for the full comparison table.
// Skipped: none — this is the case that must NOT be assumed cheap.
let side_targets: [u32; 3] = [576, 1440, 2880];
let min_wl_m = scale::DISTRICT_M as u32;
let pool = rayon::ThreadPoolBuilder::new()
.num_threads(1)
.build()
.expect("build single-thread rayon pool");
for &side in &side_targets {
let n = side;
let cells = (side as u64) * (side as u64);
pool.install(|| {
let _ = build_district_window_layer(
seed,
"bench",
&params,
&ta,
&rn,
(0, 0),
n,
&climate,
WindowGranularity::District,
min_wl_m,
);
});
let t0 = Instant::now();
let layer = pool.install(|| {
build_district_window_layer(
seed,
"bench",
&params,
&ta,
&rn,
(0, 0),
n,
&climate,
WindowGranularity::District,
min_wl_m,
)
});
let elapsed = t0.elapsed();
std::hint::black_box(layer.elev_q.len());
let ms = elapsed.as_secs_f64() * 1000.0;
let ns_per_cell = elapsed.as_secs_f64() * 1e9 / cells as f64;
println!(
" side={side:>5} n={n:>5} cells={cells:>10} (1 thread): \
{ms:>9.2} ms, {ns_per_cell:>7.1} ns/cell ({:.3} us/cell)",
ns_per_cell / 1000.0
);
}
println!();
}
/// Real-body cross-check: the same square sweep, but on the committed GJ1c
/// heightmap/TerrainAnalysis (not the synthetic gradient) and with the real
/// river network live (courses ON, window centred on real river geometry —
/// not an empty network, and not a window that happens to cull every course
/// out) — confirms the synthetic-fixture numbers above are not an artifact of
/// a trivial gradient body or an empty river network's near-zero
/// course-culling cost. Window centring follows `bench_course_cost_on_vs_off`
/// (`zoom_ladder_bench.rs`)'s exact technique: convert a real river cell to
/// world metres via the same `pixel_to_world_m`-equivalent formula, then to
/// the covering `DistrictPos`, so the window is genuinely near GJ1c's rivers
/// rather than at the arbitrary world origin (which measured courses_in_window=0
/// on a first attempt — corrected here). Run at the 330K shape only
/// (real-body I/O + full sweep would duplicate the synthetic-fixture table
/// for no new signal at the larger sizes — the per-cell RATE is what's being
/// cross-checked, not re-measuring 8.3M twice).
#[test]
#[ignore]
fn bench_square_window_production_fn_gj1c_real_body_crosscheck() {
let (hm, ta) = gj1c_fixture();
let dr = drainage::analyze(&hm.data, hm.width, hm.height, hm.sea_level);
let rn = dr.river_network.clone();
let params = BodyParams {
hydrosphere: Some("ocean".into()),
atmosphere: Some("breathable".into()),
planet_class: Some("temperate".into()),
body_radius_km: Some(6371.0),
..Default::default()
};
let climate = ClimateConstants::default();
let seed = SeedChain::root(0xC0FFEE_u64).derive(SeedDomain::Body, 7);
assert!(
!rn.river_cells.is_empty(),
"GJ1c at production working resolution must have river cells for this bench to be meaningful"
);
// Same centring technique as zoom_ladder_bench.rs's bench_course_cost_on_vs_off.
let river_cell = rn.river_cells[rn.river_cells.len() / 2];
let r_km = params.body_radius_km.unwrap();
let world_pos = (
river_cell.1 as f64 / ta.w as f64 * (std::f64::consts::TAU * r_km * 1000.0),
(river_cell.0 as f64 / (ta.h - 1) as f64 - 0.5) * (std::f64::consts::PI * r_km * 1000.0),
);
let center: (i32, i32) = (
(world_pos.0 / scale::DISTRICT_M as f64).floor() as i32,
(world_pos.1 / scale::DISTRICT_M as f64).floor() as i32,
);
println!("\n=== T-1178 GJ1c real-body cross-check (District spacing, courses ON) ===");
println!(" window centred at district {center:?} (river cell {river_cell:?})");
println!(" {}\n", rayon_threads_report());
let side = 576u32; // ~330K cells
let n = side;
let cells = (side as u64) * (side as u64);
let min_wl_m = scale::DISTRICT_M as u32;
let _ = build_district_window_layer(
seed,
"GJ1c",
&params,
&ta,
&rn,
center,
n,
&climate,
WindowGranularity::District,
min_wl_m,
);
let t0 = Instant::now();
let layer = build_district_window_layer(
seed,
"GJ1c",
&params,
&ta,
&rn,
center,
n,
&climate,
WindowGranularity::District,
min_wl_m,
);
let elapsed = t0.elapsed();
let ms = elapsed.as_secs_f64() * 1000.0;
let ns_per_cell = elapsed.as_secs_f64() * 1e9 / cells as f64;
println!(
" side={side} n={n} cells={cells} courses_in_window={}: \
{ms:.2} ms, {ns_per_cell:.1} ns/cell ({:.3} us/cell)",
layer.courses.len(),
ns_per_cell / 1000.0
);
println!();
}
// ---------------------------------------------------------------------------
// T-1178 (Measurement ②) — real 16:9 rectangular canvases, replica loop.
// ---------------------------------------------------------------------------
/// Row-chunked derive over a REAL (non-square) canvas rectangle, mirroring
/// `build_district_window_layer`'s internal loop shape cell-for-cell (see
/// module doc for the explicit diff against the real function). Returns
/// (elapsed, per_cell_ns).
#[allow(clippy::too_many_arguments)]
fn rect_window_replica(
seed: SeedChain,
body_id: &str,
params: &BodyParams,
ta: &TerrainAnalysis,
climate: &ClimateConstants,
cols: u32,
rows: u32,
step_m: f64,
min_wavelength_m: f64,
) -> (std::time::Duration, f64) {
use rayon::prelude::*;
let cells = (cols as u64) * (rows as u64);
let t0 = Instant::now();
// One Rayon task per row (matches build_district_window_layer's own
// chunking granularity exactly — row-chunked, not per-cell).
let row_results: Vec<u64> = (0..rows)
.into_par_iter()
.map(|row| {
let mut row_acc: u64 = 0;
for col in 0..cols {
let wx = col as f64 * step_m;
let wy = row as f64 * step_m;
let prof = derive_at_metres(
seed,
body_id,
params,
ta,
wx,
wy,
climate,
min_wavelength_m,
&[],
);
// Mirror derive_window_cell's per-cell quantization cost
// (six field casts/clamps) rather than reading one field —
// this is the SAME output shape the real function produces,
// just accumulated into a checksum instead of six Vec<u8>
// scatters (allocation-identical scatter cost is a one-time
// Vec::with_capacity, not a per-cell cost worth replicating
// here; the per-cell COMPUTE is what's being measured).
let morphology = prof.morphology_zone as u8;
let elev_q = prof.elev_q.clamp(0, 100) as u8;
let moisture_q = prof.moisture_q.clamp(0, 100) as u8;
let vegetation = prof.vegetation_class as u8;
let glaciation = prof.glaciation_grade as u8;
row_acc ^= morphology as u64
^ elev_q as u64
^ moisture_q as u64
^ vegetation as u64
^ glaciation as u64;
}
std::hint::black_box(row_acc)
})
.collect();
let checksum: u64 = row_results.into_iter().fold(0, |a, b| a ^ b);
std::hint::black_box(checksum);
let elapsed = t0.elapsed();
let ns_per_cell = elapsed.as_secs_f64() * 1e9 / cells as f64;
(elapsed, ns_per_cell)
}
/// The three named real step-canvas shapes (768x432 / 1920x1080 / 3840x2160),
/// District spacing + District cutoff, through the row-chunked replica loop.
/// This is the DIRECT answer to "does 4,096-cell par_iter throughput hold at
/// real canvas sizes" for the actual non-square shapes the workshop brief
/// names, cross-checked against the square production-fn numbers above.
#[test]
#[ignore]
fn bench_rect_canvas_district_spacing() {
let hm = bench_hm();
let ta = bench_ta(&hm);
let params = bench_params();
let climate = ClimateConstants::default();
let seed = SeedChain::root(99).derive(SeedDomain::Body, 1);
let min_wl_m = scale::DISTRICT_M as f64;
println!("\n=== T-1178 real 16:9 canvas bench, replica row-chunked loop (District spacing) ===");
println!(" {}\n", rayon_threads_report());
let shapes: [(u32, u32, &str); 3] = [
(768, 432, "768x432 (5x5px/gridunit fallback, ~330K)"),
(1920, 1080, "1920x1080 (midpoint, ~2.07M)"),
(3840, 2160, "3840x2160 (1x1 ideal, ~8.3M)"),
];
for (cols, rows, label) in shapes {
let cells = (cols as u64) * (rows as u64);
let (elapsed, ns_per_cell) = rect_window_replica(
seed, "bench", &params, &ta, &climate, cols, rows, min_wl_m, min_wl_m,
);
let ms = elapsed.as_secs_f64() * 1000.0;
println!(
" {label}: cells={cells:>10} {ms:>9.2} ms warm, {ns_per_cell:>7.1} ns/cell \
({:.3} us/cell)",
ns_per_cell / 1000.0
);
}
println!();
}
/// Single-thread version of the same three rectangles (cutoff-matched) —
/// completes the parallel-speedup comparison for the real canvas shapes.
#[test]
#[ignore]
fn bench_rect_canvas_district_spacing_single_thread() {
let hm = bench_hm();
let ta = bench_ta(&hm);
let params = bench_params();
let climate = ClimateConstants::default();
let seed = SeedChain::root(99).derive(SeedDomain::Body, 1);
let min_wl_m = scale::DISTRICT_M as f64;
println!("\n=== T-1178 real 16:9 canvas bench, SINGLE THREAD (District spacing) ===\n");
let pool = rayon::ThreadPoolBuilder::new()
.num_threads(1)
.build()
.expect("build single-thread rayon pool");
let shapes: [(u32, u32, &str); 3] = [
(768, 432, "768x432 (~330K)"),
(1920, 1080, "1920x1080 (~2.07M)"),
(3840, 2160, "3840x2160 (~8.3M)"),
];
for (cols, rows, label) in shapes {
let cells = (cols as u64) * (rows as u64);
let (elapsed, ns_per_cell) = pool.install(|| {
rect_window_replica(
seed, "bench", &params, &ta, &climate, cols, rows, min_wl_m, min_wl_m,
)
});
let ms = elapsed.as_secs_f64() * 1000.0;
println!(
" {label}: cells={cells:>10} {ms:>9.2} ms, {ns_per_cell:>7.1} ns/cell \
({:.3} us/cell)",
ns_per_cell / 1000.0
);
}
println!();
}
// ---------------------------------------------------------------------------
// T-1154 (Measurement ③) — block (128 m) and tile-adjacent spacing.
// ---------------------------------------------------------------------------
/// Per-cell derive cost at Block (128 m) and Tile-adjacent (1 m, 4 m)
/// spacing, with the matching octave cutoff active — the ladder rungs
/// `atlas-zoom-ladder-t1143.md` §2 marks "not estimated". Uses the SAME
/// 64x64 = 4,096-cell sweep shape as `zoom_ladder_bench.rs`'s District/
/// Quarter sweeps so the per-cell rate is directly comparable across every
/// rung on one table.
///
/// `MIN_WL_BANDS_M` (the request-facing quantized cutoff set,
/// `layer_proxy.rs:451`) bottoms out at 1,024 m (Quarter's own band) — there
/// is NO existing wire-facing band for Block or Tile. This bench calls
/// `derive_at_metres` directly with a cutoff value no real window request can
/// carry today (same "call the underlying function, not the wire path"
/// discipline as the T-1178 benches above), matching each spacing to its OWN
/// Nyquist floor (cutoff = spacing) the same way the existing District/
/// Quarter sweeps do.
#[test]
#[ignore]
fn bench_block_and_tile_spacing_4096_cells() {
let hm = bench_hm();
let ta = bench_ta(&hm);
let params = bench_params();
let climate = ClimateConstants::default();
let seed = SeedChain::root(99).derive(SeedDomain::Body, 1);
let grid_side = 64u32; // 4,096 cells — matches zoom_ladder_bench.rs's shape
println!("\n=== T-1154 block/tile-spacing derive_at_metres benchmark (4,096-cell sweep) ===");
println!(
"grid: {grid_side}x{grid_side} = {} cells/sweep\n",
grid_side * grid_side
);
let block_m = scale::BLOCK_M as f64; // 128 m
let tile_4m = 4.0_f64; // coarsest "tile-adjacent" spacing named in the ticket
let tile_1m = 1.0_f64; // the literal voxel/tile spacing (D-243)
for (label, step_m, cutoff_m) in [
("block (128m), cutoff=128m", block_m, block_m),
("tile-adjacent (4m), cutoff=4m", tile_4m, tile_4m),
("tile (1m), cutoff=1m", tile_1m, tile_1m),
] {
let n_cells = (grid_side * grid_side) as u64;
let t0 = Instant::now();
for row in 0..grid_side {
for col in 0..grid_side {
let wx = col as f64 * step_m;
let wy = row as f64 * step_m;
let prof = derive_at_metres(
seed, "bench", &params, &ta, wx, wy, &climate, cutoff_m, &[],
);
std::hint::black_box(prof.elev_q);
}
}
let elapsed = t0.elapsed();
let per_cell_ns = elapsed.as_secs_f64() * 1e9 / n_cells as f64;
println!(
" {label:<32}: {:>8.2} ms total, {:>7.1} ns/cell ({:.3} us/cell)",
elapsed.as_secs_f64() * 1000.0,
per_cell_ns,
per_cell_ns / 1000.0
);
}
println!();
}
/// The realistic deep-step canvas: at the ~10 px-per-1m-tile bottom-out on a
/// 2,160-px SMALLER axis (a 1920x1080 viewport, portrait-safe on the smaller
/// dimension per the brief's "viewport's smaller axis" convention), the
/// world extent covered is `1080 px / 10 px-per-tile = 108 tiles = 108 m` on
/// the smaller axis, `1920 / 10 = 192 m` on the larger — a 192m x 108m
/// window at 1 m spacing. Re-stated against the ticket's own worked example
/// (2160 px smaller axis, ~216m x ~384m) for the 3840x2160 canvas instead:
/// `2160/10 = 216 m` (smaller axis), `3840/10 = 384 m` (larger axis) — EXACT
/// geometry used below, matching the ticket's stated numbers precisely.
///
/// At 1 m spacing that is a 216x384 CELL grid (1 world-metre per gridunit,
/// 10 screen px per gridunit) = 82,944 cells — the ticket's "~83K cells"
/// figure, confirmed exactly (216 * 384 = 82,944).
#[test]
#[ignore]
fn bench_deep_step_realistic_canvas_83k_cells() {
let hm = bench_hm();
let ta = bench_ta(&hm);
let params = bench_params();
let climate = ClimateConstants::default();
let seed = SeedChain::root(99).derive(SeedDomain::Body, 1);
// Geometry: 3840x2160 canvas, 10 px per 1m tile, smaller axis 2160.
// world extent: 216 m (smaller/rows) x 384 m (larger/cols), 1 m spacing.
let rows = 216u32; // world metres on the smaller (2160px/10) axis
let cols = 384u32; // world metres on the larger (3840px/10) axis
let cells = (rows as u64) * (cols as u64);
assert_eq!(cells, 82_944, "geometry must match the ticket's stated ~83K cells exactly");
let step_m = 1.0_f64;
let cutoff_m = 1.0_f64; // Nyquist-matched to 1 m spacing
println!("\n=== T-1154 deep-step realistic-canvas bench (216m x 384m @ 1m spacing) ===");
println!(
" geometry: 3840x2160 canvas @ 10px/tile, smaller axis 2160 -> 216m, larger axis 3840 -> 384m"
);
println!(" cells = 216 * 384 = {cells}");
println!(" {}\n", rayon_threads_report());
// Parallel, through the SAME row-chunked replica loop T-1178 uses (this
// is the production par_iter SHAPE, not the exact function, for the same
// reason as the T-1178 rectangular benches: no square-only production fn
// covers a non-square metre-spacing window).
let (elapsed_par, ns_per_cell_par) = rect_window_replica(
seed, "bench", &params, &ta, &climate, cols, rows, step_m, cutoff_m,
);
println!(
" PARALLEL (row-chunked): {:.2} ms, {:.1} ns/cell ({:.3} us/cell)",
elapsed_par.as_secs_f64() * 1000.0,
ns_per_cell_par,
ns_per_cell_par / 1000.0
);
// Single-thread comparison.
let pool = rayon::ThreadPoolBuilder::new()
.num_threads(1)
.build()
.expect("build single-thread rayon pool");
let (elapsed_seq, ns_per_cell_seq) = pool.install(|| {
rect_window_replica(
seed, "bench", &params, &ta, &climate, cols, rows, step_m, cutoff_m,
)
});
println!(
" SINGLE-THREAD: {:.2} ms, {:.1} ns/cell ({:.3} us/cell)",
elapsed_seq.as_secs_f64() * 1000.0,
ns_per_cell_seq,
ns_per_cell_seq / 1000.0
);
println!(
" speedup: {:.2}x\n",
elapsed_seq.as_secs_f64() / elapsed_par.as_secs_f64()
);
}
/// Cutoff sweep AT Block-spacing sample positions, varying the cutoff itself
/// from uncut (0, every octave band in `OCTAVE_WAVELENGTHS_M` [4,096..32,768]
/// AND `VOXEL_OCTAVE_WAVELENGTHS_M` [128..1,024] survives) up through
/// District-coarse (2,048m, truncates nothing extra vs. uncut — every
/// `OCTAVE_WAVELENGTHS_M` entry is still ≥2,048) to Region-coarse (204,800m,
/// truncates EVERY octave in both bands, `enveloped_fbm`'s "every octave cut"
/// empty-sum guard fires).
///
/// **Why "cutoff=128m (Block's own Nyquist floor)" shows ZERO delta vs.
/// uncut** (confirmed by direct read of `enveloped_fbm`,
/// `detail_scatter.rs:198-251`: `if wl < min_wavelength_m { skip }` — a
/// cutoff only skips octaves STRICTLY FINER than itself. At Block's own
/// floor (128m), every entry in BOTH octave arrays is `>= 128m`
/// (`VOXEL_OCTAVE_WAVELENGTHS_M`'s finest is exactly 128m, `>=` not `<`), so
/// nothing is skipped — Block sits at the bottom of the invented-detail
/// octave stack, with nothing finer left to truncate. This is a genuine,
/// verified finding (not a bench bug): **the cutoff mechanism has no
/// truncation work left to do at Block spacing or finer** — every rung from
/// Block down to Tile pays the SAME full per-cell octave-sum cost, because
/// the const octave arrays bottom out at 128m and neither
/// `MOSAIC_OCTAVE_WAVELENGTHS_M` (64/32/16/8m) nor any Tile-specific band is
/// wired into `derive_at_metres`'s call graph (see the module doc's
/// voxel_mosaic finding). The cutoff only pays off at COARSER rungs
/// (District, Quarter, Region) where it truncates the fine end of the octave
/// stack that those rungs' sample density can't resolve anyway.
#[test]
#[ignore]
fn bench_block_cutoff_confirms_savings() {
let hm = bench_hm();
let ta = bench_ta(&hm);
let params = bench_params();
let climate = ClimateConstants::default();
let seed = SeedChain::root(99).derive(SeedDomain::Body, 1);
let grid_side = 64u32;
let block_m = scale::BLOCK_M as f64;
let district_m = scale::DISTRICT_M as f64;
let region_m = scale::REGION_M as f64;
println!("\n=== T-1154 Block-spacing-position cutoff sweep (varying cutoff value) ===\n");
for (label, cutoff_m) in [
("uncut (cutoff=0)", 0.0),
("cutoff=128m (Block's own floor, expect NO delta vs uncut)", block_m),
("cutoff=2048m (District-coarse, truncates the VOXEL band, real savings)", district_m),
("cutoff=204800m (Region-coarse, expect EVERY octave truncated)", region_m),
] {
let n_cells = (grid_side * grid_side) as u64;
let t0 = Instant::now();
for row in 0..grid_side {
for col in 0..grid_side {
// Sample POSITIONS stay at Block spacing throughout — only the
// cutoff VALUE varies — so this isolates the cutoff's cost
// effect from a spacing change.
let wx = col as f64 * block_m;
let wy = row as f64 * block_m;
let prof = derive_at_metres(
seed, "bench", &params, &ta, wx, wy, &climate, cutoff_m, &[],
);
std::hint::black_box(prof.elev_q);
}
}
let elapsed = t0.elapsed();
let per_cell_ns = elapsed.as_secs_f64() * 1e9 / n_cells as f64;
println!(
" {label:<58}: {:>8.2} ms total, {:>7.1} ns/cell ({:.3} us/cell)",
elapsed.as_secs_f64() * 1000.0,
per_cell_ns,
per_cell_ns / 1000.0
);
}
println!();
}
server/tests/wire_encoding_bench.rs
+651
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@@ -0,0 +1,651 @@
//! T-1179 — wire-size table for step-canvas encodings (body-map-viewer
//! workshop, measurement ④).
//!
//! Produces a REAL step-canvas-shaped [`DistrictWindowLayer`]-field dataset
//! (elev_q, morphology, temp_dc, moisture_q, vegetation, glaciation — the
//! exact six arrays that struct ships today, D-226 T-1124 amendment §4) at
//! ~330K/2.07M/8.3M gridunits, via the SAME derivation call
//! `build_district_window_layer`'s row-chunked `par_iter` uses
//! (`derive_at_metres`, district spacing, no octave cutoff, no river-course
//! packing — courses are a separate variable-length field orthogonal to this
//! raster wire-size question). Real derived data (not synthetic noise or
//! constant fills) so RLE/PNG compression ratios reflect genuine spatial
//! coherence — see the workshop brief's measurement ④ scope note.
//!
//! Candidate encodings measured on the SAME canvas:
//! (a) raw dense `u8`/`i16` arrays through `rmp_serde` (today's wire format)
//! (b) bit-packed (sub-byte field widths, see `pack_bits` doc)
//! (c) per-field run-length encoding
//! (d) PNG-encoded raster per field (the `png` crate — already a main
//! dependency, `server/Cargo.toml`; no new dependency added)
//! (e) PNG applied to the bit-packed planes (cheap combination of b+d)
//!
//! Run: `cargo test --release --test wire_encoding_bench -- --ignored --nocapture`
//! (debug numbers are not representative — this repo's benches are always run
//! `--release`, matching `zoom_ladder_bench.rs`'s convention).
//!
//! Body/seed: GJ338Bd, `--seed yolo` (`seed_to_u64("yolo")`) — the same
//! body+seed pair `aliveness_probe`'s doc example and the believability
//! harness default to (`server/src/atlas/believability.rs`).
use std::io::Cursor;
use std::time::Instant;
use settled_reach_server::atlas::believability::seed_to_u64;
use settled_reach_server::atlas::district_profile::{
derive_at_metres, BodyParams, ClimateConstants,
};
use settled_reach_server::atlas::drainage;
use settled_reach_server::atlas::features::TerrainAnalysis;
use settled_reach_server::atlas::heightmap::load_heightmap_png;
use settled_reach_server::atlas::layer_proxy::REGION_TEMP_NONE_DC;
use settled_reach_server::atlas::scale;
use settled_reach_server::seed::SeedChain;
use serde::{Deserialize, Serialize};
/// The six wire arrays `DistrictWindowLayer` ships today (layer_proxy.rs),
/// derived at full canvas size rather than the 4,096-cell window cap.
#[derive(Serialize, Deserialize)]
struct WireCanvas {
cols: u32,
rows: u32,
morphology: Vec<u8>,
elev_q: Vec<u8>,
temp_dc: Vec<i16>,
moisture_q: Vec<u8>,
vegetation: Vec<u8>,
glaciation: Vec<u8>,
}
fn load_gj338bd() -> (BodyParams, TerrainAnalysis, SeedChain) {
let src = std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"))
.join("../wiki/star-systems/GJ-338B/bodies/GJ338Bd/heightmap.png");
let heightmap =
load_heightmap_png(&src, "GJ338Bd", 0.3).expect("decode committed GJ338Bd heightmap");
let small = heightmap.downsample(512, 256); // GRID_W x GRID_H, production working grid
let dr = drainage::analyze(&small.data, small.width, small.height, small.sea_level);
let ta = TerrainAnalysis::analyze(&small, &dr);
let params = BodyParams {
hydrosphere: Some("ocean".into()),
atmosphere: Some("breathable".into()),
planet_class: Some("temperate".into()),
body_radius_km: Some(6371.0),
..Default::default()
};
let seed = SeedChain::for_body(seed_to_u64("yolo"), "GJ338Bd");
(params, ta, seed)
}
/// Derive a `cols x rows` canvas at district spacing (2,048 m/cell), origin
/// at world (0,0), via the SAME `derive_at_metres` call + row-chunked
/// `par_iter` shape `build_district_window_layer` uses internally
/// (`layer_proxy.rs::derive_window_cell`/the row-scatter loop) — just at
/// canvas sizes above the 4,096-cell `WIRE_CAP_CELLS` window ceiling, since
/// that ceiling is a SERVED-window cap, not a derivation-cost cap (the
/// workshop question is what a whole step canvas costs, pre-windowing).
fn derive_canvas(
seed: SeedChain,
params: &BodyParams,
ta: &TerrainAnalysis,
cols: u32,
rows: u32,
) -> (WireCanvas, std::time::Duration) {
use rayon::prelude::*;
let climate = ClimateConstants::default();
let step_m = scale::DISTRICT_M as f64;
let cells = (cols as usize) * (rows as usize);
let t0 = Instant::now();
let row_results: Vec<Vec<(u8, u8, i16, u8, u8, u8)>> = (0..rows)
.into_par_iter()
.map(|row| {
(0..cols)
.map(|col| {
let wx = col as f64 * step_m;
let wy = row as f64 * step_m;
let prof = derive_at_metres(
seed, "GJ338Bd", params, ta, wx, wy, &climate, 0.0, &[],
);
let temp_dc = match prof.temperature_c {
Some(t) => ((t * 10.0).round() as i32)
.clamp(i16::MIN as i32 + 1, i16::MAX as i32)
as i16,
None => REGION_TEMP_NONE_DC,
};
(
prof.morphology_zone as u8,
prof.elev_q.clamp(0, 100) as u8,
temp_dc,
prof.moisture_q.clamp(0, 100) as u8,
prof.vegetation_class as u8,
prof.glaciation_grade as u8,
)
})
.collect()
})
.collect();
let elapsed = t0.elapsed();
let mut morphology = Vec::with_capacity(cells);
let mut elev_q = Vec::with_capacity(cells);
let mut temp_dc = Vec::with_capacity(cells);
let mut moisture_q = Vec::with_capacity(cells);
let mut vegetation = Vec::with_capacity(cells);
let mut glaciation = Vec::with_capacity(cells);
for row in row_results {
for (m, e, t, mo, v, g) in row {
morphology.push(m);
elev_q.push(e);
temp_dc.push(t);
moisture_q.push(mo);
vegetation.push(v);
glaciation.push(g);
}
}
(
WireCanvas {
cols,
rows,
morphology,
elev_q,
temp_dc,
moisture_q,
vegetation,
glaciation,
},
elapsed,
)
}
// ---------------------------------------------------------------------------
// Encoding (a): raw dense arrays via rmp_serde — today's wire format.
// ---------------------------------------------------------------------------
fn encode_rmp(canvas: &WireCanvas) -> (Vec<u8>, std::time::Duration, std::time::Duration) {
let t0 = Instant::now();
let bytes = rmp_serde::to_vec(canvas).expect("rmp_serde encode");
let enc_time = t0.elapsed();
let t1 = Instant::now();
let decoded: WireCanvas = rmp_serde::from_slice(&bytes).expect("rmp_serde decode");
let dec_time = t1.elapsed();
std::hint::black_box(decoded.morphology.len());
(bytes, enc_time, dec_time)
}
// ---------------------------------------------------------------------------
// Encoding (b): bit-packed planes.
//
// Field widths (minimal, from the real discriminant ranges):
// morphology: 0-16 (17 zones, D-239 §6) -> 5 bits
// elev_q: 0-100 -> 7 bits
// moisture_q: 0-100 -> 7 bits
// vegetation: 0-6 (7 classes incl. Marine) -> 3 bits
// glaciation: 0-4 (5 grades) -> 3 bits
// temp_dc: i16 incl. REGION_TEMP_NONE_DC sentinel -> left at 16 bits
// (full dynamic range is genuinely used across class bands +
// the sentinel; no safe narrower width without a second
// encoding scheme for the sentinel case, out of scope here)
// ---------------------------------------------------------------------------
/// Pack `values` (each `< 2^width`) into a bitstream, LSB-first within each
/// byte, fields concatenated in stream order — the simplest fixed-width
/// packing (no entropy coding). Returns the packed byte buffer.
fn pack_bits(values: &[u8], width: u32) -> Vec<u8> {
let mut out = Vec::with_capacity((values.len() * width as usize).div_ceil(8));
let mut acc: u32 = 0;
let mut acc_bits: u32 = 0;
for &v in values {
acc |= (v as u32) << acc_bits;
acc_bits += width;
while acc_bits >= 8 {
out.push((acc & 0xFF) as u8);
acc >>= 8;
acc_bits -= 8;
}
}
if acc_bits > 0 {
out.push((acc & 0xFF) as u8);
}
out
}
fn unpack_bits(packed: &[u8], width: u32, count: usize) -> Vec<u8> {
let mut out = Vec::with_capacity(count);
let mut acc: u32 = 0;
let mut acc_bits: u32 = 0;
let mask = (1u32 << width) - 1;
let mut byte_iter = packed.iter();
while out.len() < count {
while acc_bits < width {
let Some(&b) = byte_iter.next() else { break };
acc |= (b as u32) << acc_bits;
acc_bits += 8;
}
out.push((acc & mask) as u8);
acc >>= width;
acc_bits -= width;
}
out
}
#[derive(Serialize, Deserialize)]
struct BitPacked {
cols: u32,
rows: u32,
morphology_bits: Vec<u8>, // 5 bits/cell
elev_q_bits: Vec<u8>, // 7 bits/cell
temp_dc: Vec<i16>, // unpacked, full 16 bits (see doc above)
moisture_q_bits: Vec<u8>, // 7 bits/cell
vegetation_bits: Vec<u8>, // 3 bits/cell
glaciation_bits: Vec<u8>, // 3 bits/cell
}
fn encode_bitpacked(canvas: &WireCanvas) -> (Vec<u8>, std::time::Duration, std::time::Duration) {
let n = canvas.morphology.len();
let t0 = Instant::now();
let packed = BitPacked {
cols: canvas.cols,
rows: canvas.rows,
morphology_bits: pack_bits(&canvas.morphology, 5),
elev_q_bits: pack_bits(&canvas.elev_q, 7),
temp_dc: canvas.temp_dc.clone(),
moisture_q_bits: pack_bits(&canvas.moisture_q, 7),
vegetation_bits: pack_bits(&canvas.vegetation, 3),
glaciation_bits: pack_bits(&canvas.glaciation, 3),
};
let bytes = rmp_serde::to_vec(&packed).expect("rmp_serde encode bitpacked");
let enc_time = t0.elapsed();
let t1 = Instant::now();
let decoded: BitPacked = rmp_serde::from_slice(&bytes).expect("rmp_serde decode bitpacked");
let morphology = unpack_bits(&decoded.morphology_bits, 5, n);
let elev_q = unpack_bits(&decoded.elev_q_bits, 7, n);
let moisture_q = unpack_bits(&decoded.moisture_q_bits, 7, n);
let vegetation = unpack_bits(&decoded.vegetation_bits, 3, n);
let glaciation = unpack_bits(&decoded.glaciation_bits, 3, n);
let dec_time = t1.elapsed();
std::hint::black_box((morphology.len(), elev_q.len(), moisture_q.len(), vegetation.len(), glaciation.len()));
(bytes, enc_time, dec_time)
}
// ---------------------------------------------------------------------------
// Encoding (c): per-field run-length encoding.
// ---------------------------------------------------------------------------
/// (run_length, value) pairs, run_length capped at u16::MAX (wraps to a new
/// run — no run ever exceeds 65,535 cells, larger than any canvas row here).
fn rle_encode_u8(values: &[u8]) -> Vec<(u16, u8)> {
let mut out = Vec::new();
let mut iter = values.iter();
let Some(&first) = iter.next() else {
return out;
};
let mut cur = first;
let mut run: u16 = 1;
for &v in iter {
if v == cur && run < u16::MAX {
run += 1;
} else {
out.push((run, cur));
cur = v;
run = 1;
}
}
out.push((run, cur));
out
}
fn rle_encode_i16(values: &[i16]) -> Vec<(u16, i16)> {
let mut out = Vec::new();
let mut iter = values.iter();
let Some(&first) = iter.next() else {
return out;
};
let mut cur = first;
let mut run: u16 = 1;
for &v in iter {
if v == cur && run < u16::MAX {
run += 1;
} else {
out.push((run, cur));
cur = v;
run = 1;
}
}
out.push((run, cur));
out
}
#[derive(Serialize, Deserialize)]
struct RleCanvas {
cols: u32,
rows: u32,
morphology: Vec<(u16, u8)>,
elev_q: Vec<(u16, u8)>,
temp_dc: Vec<(u16, i16)>,
moisture_q: Vec<(u16, u8)>,
vegetation: Vec<(u16, u8)>,
glaciation: Vec<(u16, u8)>,
}
struct RlePerFieldRuns {
morphology: usize,
elev_q: usize,
temp_dc: usize,
moisture_q: usize,
vegetation: usize,
glaciation: usize,
}
fn encode_rle(
canvas: &WireCanvas,
) -> (
Vec<u8>,
std::time::Duration,
std::time::Duration,
RlePerFieldRuns,
) {
let t0 = Instant::now();
let morphology = rle_encode_u8(&canvas.morphology);
let elev_q = rle_encode_u8(&canvas.elev_q);
let temp_dc = rle_encode_i16(&canvas.temp_dc);
let moisture_q = rle_encode_u8(&canvas.moisture_q);
let vegetation = rle_encode_u8(&canvas.vegetation);
let glaciation = rle_encode_u8(&canvas.glaciation);
let runs = RlePerFieldRuns {
morphology: morphology.len(),
elev_q: elev_q.len(),
temp_dc: temp_dc.len(),
moisture_q: moisture_q.len(),
vegetation: vegetation.len(),
glaciation: glaciation.len(),
};
let rle = RleCanvas {
cols: canvas.cols,
rows: canvas.rows,
morphology,
elev_q,
temp_dc,
moisture_q,
vegetation,
glaciation,
};
let bytes = rmp_serde::to_vec(&rle).expect("rmp_serde encode rle");
let enc_time = t0.elapsed();
let t1 = Instant::now();
let decoded: RleCanvas = rmp_serde::from_slice(&bytes).expect("rmp_serde decode rle");
// Expand back to dense arrays (real decode cost — a consumer needs the
// dense form to render).
let mut morphology_dense = Vec::with_capacity(canvas.morphology.len());
for (run, v) in &decoded.morphology {
morphology_dense.extend(std::iter::repeat_n(*v, *run as usize));
}
let dec_time = t1.elapsed();
std::hint::black_box(morphology_dense.len());
(bytes, enc_time, dec_time, runs)
}
// ---------------------------------------------------------------------------
// Encoding (d): PNG-encoded raster per field.
// ---------------------------------------------------------------------------
fn png_encode_u8_plane(cols: u32, rows: u32, data: &[u8]) -> Vec<u8> {
let mut out = Vec::new();
{
let mut enc = png::Encoder::new(&mut out, cols, rows);
enc.set_color(png::ColorType::Grayscale);
enc.set_depth(png::BitDepth::Eight);
let mut writer = enc.write_header().expect("png header");
writer.write_image_data(data).expect("png data");
}
out
}
fn png_decode_u8_plane(bytes: &[u8]) -> Vec<u8> {
let mut decoder = png::Decoder::new(Cursor::new(bytes)).read_info().expect("png read_info");
let mut buf = vec![0u8; decoder.output_buffer_size()];
let frame = decoder.next_frame(&mut buf).expect("png next_frame");
buf[..frame.buffer_size()].to_vec()
}
/// PNG the five u8 planes; temp_dc (i16, includes negative + sentinel values,
/// not representable as an 8-bit grayscale plane without a lossy remap) ships
/// via rmp_serde alongside, same as the bit-packed encoding's treatment.
fn encode_png(canvas: &WireCanvas) -> (Vec<u8>, std::time::Duration, std::time::Duration) {
let t0 = Instant::now();
let morphology_png = png_encode_u8_plane(canvas.cols, canvas.rows, &canvas.morphology);
let elev_q_png = png_encode_u8_plane(canvas.cols, canvas.rows, &canvas.elev_q);
let moisture_q_png = png_encode_u8_plane(canvas.cols, canvas.rows, &canvas.moisture_q);
let vegetation_png = png_encode_u8_plane(canvas.cols, canvas.rows, &canvas.vegetation);
let glaciation_png = png_encode_u8_plane(canvas.cols, canvas.rows, &canvas.glaciation);
let temp_dc_bytes = rmp_serde::to_vec(&canvas.temp_dc).expect("rmp_serde encode temp_dc");
let total = morphology_png.len()
+ elev_q_png.len()
+ moisture_q_png.len()
+ vegetation_png.len()
+ glaciation_png.len()
+ temp_dc_bytes.len();
let enc_time = t0.elapsed();
let t1 = Instant::now();
let morphology_d = png_decode_u8_plane(&morphology_png);
let elev_q_d = png_decode_u8_plane(&elev_q_png);
let moisture_q_d = png_decode_u8_plane(&moisture_q_png);
let vegetation_d = png_decode_u8_plane(&vegetation_png);
let glaciation_d = png_decode_u8_plane(&glaciation_png);
let temp_dc_d: Vec<i16> = rmp_serde::from_slice(&temp_dc_bytes).expect("rmp_serde decode temp_dc");
let dec_time = t1.elapsed();
std::hint::black_box((
morphology_d.len(),
elev_q_d.len(),
moisture_q_d.len(),
vegetation_d.len(),
glaciation_d.len(),
temp_dc_d.len(),
));
// Return a synthetic combined buffer sized to `total` (not a real single
// envelope — the workshop's wire contract question is exactly whether
// these become five separate frames in a tagged envelope) so callers can
// report a single byte count. Filled with zero bytes; only `.len()` is
// used by the reporting harness below.
(vec![0u8; total], enc_time, dec_time)
}
/// PNG applied to the bit-packed byte planes (b+d combined) — cheap to try
/// since both encodings already exist above.
fn encode_png_of_bitpacked(
canvas: &WireCanvas,
) -> (Vec<u8>, std::time::Duration, std::time::Duration) {
let t0 = Instant::now();
let morphology_bits = pack_bits(&canvas.morphology, 5);
let elev_q_bits = pack_bits(&canvas.elev_q, 7);
let moisture_q_bits = pack_bits(&canvas.moisture_q, 7);
let vegetation_bits = pack_bits(&canvas.vegetation, 3);
let glaciation_bits = pack_bits(&canvas.glaciation, 3);
// PNG needs a rectangular raster; the packed byte streams aren't
// canvas-shaped, so wrap each as a 1-row grayscale "image" of its own
// byte length — this measures DEFLATE-over-packed-bytes cost/ratio
// honestly (PNG's filter step is a no-op on a 1-row image, so this
// isolates the DEFLATE contribution cleanly).
let png_plane = |bits: &[u8]| -> Vec<u8> {
let mut out = Vec::new();
let mut enc = png::Encoder::new(&mut out, bits.len() as u32, 1);
enc.set_color(png::ColorType::Grayscale);
enc.set_depth(png::BitDepth::Eight);
let mut writer = enc.write_header().expect("png header");
writer.write_image_data(bits).expect("png data");
drop(writer);
out
};
let morphology_png = png_plane(&morphology_bits);
let elev_q_png = png_plane(&elev_q_bits);
let moisture_q_png = png_plane(&moisture_q_bits);
let vegetation_png = png_plane(&vegetation_bits);
let glaciation_png = png_plane(&glaciation_bits);
let temp_dc_bytes = rmp_serde::to_vec(&canvas.temp_dc).expect("rmp_serde encode temp_dc");
let total = morphology_png.len()
+ elev_q_png.len()
+ moisture_q_png.len()
+ vegetation_png.len()
+ glaciation_png.len()
+ temp_dc_bytes.len();
let enc_time = t0.elapsed();
let t1 = Instant::now();
let n = canvas.morphology.len();
let morphology_d = unpack_bits(&png_decode_u8_plane(&morphology_png), 5, n);
let elev_q_d = unpack_bits(&png_decode_u8_plane(&elev_q_png), 7, n);
let moisture_q_d = unpack_bits(&png_decode_u8_plane(&moisture_q_png), 7, n);
let vegetation_d = unpack_bits(&png_decode_u8_plane(&vegetation_png), 3, n);
let glaciation_d = unpack_bits(&png_decode_u8_plane(&glaciation_png), 3, n);
let temp_dc_d: Vec<i16> = rmp_serde::from_slice(&temp_dc_bytes).expect("rmp_serde decode temp_dc");
let dec_time = t1.elapsed();
std::hint::black_box((
morphology_d.len(),
elev_q_d.len(),
moisture_q_d.len(),
vegetation_d.len(),
glaciation_d.len(),
temp_dc_d.len(),
));
(vec![0u8; total], enc_time, dec_time)
}
// ---------------------------------------------------------------------------
// Reporting
// ---------------------------------------------------------------------------
fn report_row(label: &str, bytes: usize, raw_bytes: usize, enc_ms: f64, dec_ms: f64) {
let ratio = bytes as f64 / raw_bytes as f64;
let wire_cap_multiple = bytes as f64 / 30_000.0; // ~30 KB context row
println!(
" {label:<28} {bytes:>10} bytes {ratio:>6.3}x raw {wire_cap_multiple:>8.1}x (30KB cap) enc {enc_ms:>7.2} ms dec {dec_ms:>7.2} ms"
);
}
#[test]
#[ignore]
fn wire_size_table_330k() {
let (params, ta, seed) = load_gj338bd();
run_canvas_report(&params, &ta, seed, 768, 432, "330K (768x432)");
}
#[test]
#[ignore]
fn wire_size_table_2_07m() {
let (params, ta, seed) = load_gj338bd();
run_canvas_report(&params, &ta, seed, 1920, 1080, "2.07M (1920x1080)");
}
#[test]
#[ignore]
fn wire_size_table_8_3m() {
let (params, ta, seed) = load_gj338bd();
run_canvas_report(&params, &ta, seed, 3840, 2160, "8.3M (3840x2160)");
}
fn run_canvas_report(
params: &BodyParams,
ta: &TerrainAnalysis,
seed: SeedChain,
cols: u32,
rows: u32,
label: &str,
) {
println!("\n=== T-1179 wire-size table: {label} = {} gridunits ===", cols as u64 * rows as u64);
let (canvas, derive_time) = derive_canvas(seed, params, ta, cols, rows);
println!(
" derive: {:.2} ms ({} cells, {} Rayon threads available)\n",
derive_time.as_secs_f64() * 1000.0,
canvas.morphology.len(),
std::thread::available_parallelism().map(|n| n.get()).unwrap_or(0)
);
let (rmp_bytes, rmp_enc, rmp_dec) = encode_rmp(&canvas);
let raw_bytes = rmp_bytes.len();
report_row(
"(a) raw dense rmp_serde",
raw_bytes,
raw_bytes,
rmp_enc.as_secs_f64() * 1000.0,
rmp_dec.as_secs_f64() * 1000.0,
);
let (bp_bytes, bp_enc, bp_dec) = encode_bitpacked(&canvas);
report_row(
"(b) bit-packed",
bp_bytes.len(),
raw_bytes,
bp_enc.as_secs_f64() * 1000.0,
bp_dec.as_secs_f64() * 1000.0,
);
let (rle_bytes, rle_enc, rle_dec, runs) = encode_rle(&canvas);
report_row(
"(c) per-field RLE",
rle_bytes.len(),
raw_bytes,
rle_enc.as_secs_f64() * 1000.0,
rle_dec.as_secs_f64() * 1000.0,
);
let (png_bytes, png_enc, png_dec) = encode_png(&canvas);
report_row(
"(d) PNG per field",
png_bytes.len(),
raw_bytes,
png_enc.as_secs_f64() * 1000.0,
png_dec.as_secs_f64() * 1000.0,
);
let (pngbp_bytes, pngbp_enc, pngbp_dec) = encode_png_of_bitpacked(&canvas);
report_row(
"(e) PNG-of-bit-packed",
pngbp_bytes.len(),
raw_bytes,
pngbp_enc.as_secs_f64() * 1000.0,
pngbp_dec.as_secs_f64() * 1000.0,
);
let n = canvas.morphology.len();
println!("\n per-field RLE run counts (lower = more compressible; n={n} cells):");
println!(
" morphology: {:>8} runs ({:.1}% of dense)",
runs.morphology,
100.0 * runs.morphology as f64 / n as f64
);
println!(
" elev_q: {:>8} runs ({:.1}% of dense)",
runs.elev_q,
100.0 * runs.elev_q as f64 / n as f64
);
println!(
" temp_dc: {:>8} runs ({:.1}% of dense)",
runs.temp_dc,
100.0 * runs.temp_dc as f64 / n as f64
);
println!(
" moisture_q: {:>8} runs ({:.1}% of dense)",
runs.moisture_q,
100.0 * runs.moisture_q as f64 / n as f64
);
println!(
" vegetation: {:>8} runs ({:.1}% of dense)",
runs.vegetation,
100.0 * runs.vegetation as f64 / n as f64
);
println!(
" glaciation: {:>8} runs ({:.1}% of dense)",
runs.glaciation,
100.0 * runs.glaciation as f64 / n as f64
);
println!();
}