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Sylpheed/crates/sylpheed-formats/examples/blend_prediction_splash.rs
MechaCat02 62376dd4a1 style: rustfmt sweep — 107 files the lint gate never saw
This branch predates CI on `main`. `cargo fmt --all` only; no behaviour.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-12 16:34:40 +02:00

62 lines
2.5 KiB
Rust

//! A PREDICTION, written before the capture that tests it.
//!
//! `blend_vs_t8ad_bit` finds that `T8aD +0x04` bit `0x02` separates additive from
//! alpha-over on all 35 elements whose blend has been measured off the GPU, and
//! that no other bit of the 48-byte header does. That is a fit to three screens.
//!
//! The developer splash (`GP_TITLE` entries 10 and 13) has **never been captured**
//! and is one of the five screens the port ships. This prints what the bit says
//! its elements should be, so the capture can falsify it rather than confirm it.
//!
//! Takes an archive and a build list, so the prediction can be written for any
//! screen -- including one in a DIFFERENT pak, which is the sharper test: the
//! splash predicts alpha-over for both its elements and so can only fail, never
//! discriminate, while a screen with a predicted MIX can do both.
//!
//! cargo run -p sylpheed-formats --example blend_prediction_splash
//! cargo run -p sylpheed-formats --example blend_prediction_splash -- GP_OPTIONS 0 1 2
use std::path::PathBuf;
use sylpheed_formats::{pak::PakArchive, ui_layout};
fn main() {
let root = PathBuf::from(std::env::var("SYLPHEED_DISC").expect("SYLPHEED_DISC"));
let args: Vec<String> = std::env::args().skip(1).collect();
let pak = args
.iter()
.find(|a| a.parse::<usize>().is_err())
.cloned()
.unwrap_or_else(|| "GP_TITLE".to_string());
let ar = PakArchive::open(root.join(format!("dat/{pak}.pak"))).expect("pak");
let builds: Vec<usize> = args.iter().filter_map(|a| a.parse().ok()).collect();
let builds = if builds.is_empty() {
(0..ar.entries().len()).collect()
} else {
builds
};
for e in builds {
let Ok(by) = ar.read(&ar.entries()[e]) else {
continue;
};
let Some(b) = ui_layout::parse_build(&by) else {
continue;
};
println!("=== {pak} entry {e} ===");
let mut names: Vec<&String> = b.sprites.keys().collect();
names.sort();
for n in names {
let (off, size) = b.sprites[n];
let s = &by[off..(off + size).min(by.len())];
if s.len() < 8 || &s[0..4] != b"T8aD" {
continue;
}
let w = u32::from_be_bytes([s[4], s[5], s[6], s[7]]);
println!(
"{n:<26} +0x04 = {w:08X} bit 0x02 {} PREDICT {}",
if w & 2 != 0 { "SET " } else { "clear" },
if w & 2 != 0 { "ADDITIVE" } else { "alpha-over" }
);
}
println!();
}
}