Sylpheed/crates/sylpheed-formats/examples/t8ad_header_compare.rs

//! Does a `.t32` sprite's own T8aD header carry a per-sprite blend/alpha mode?
//!
//! The declaration entry does not: `ptframe1`/`ptframe2` are kind 0, identical to
//! every other plain sprite on the menu. The remaining place a mode could live is
//! the sprite's own T8aD child. ⚠️ `REFUTED.md` already kills one reading of it —
//! "`T8aD +0x04` bit `0x02` selects an additive blend" — so this is not that
//! claim; it asks whether ANY header word separates the two frames from the
//! sprites the port measures as ordinary.
//!
//!     cargo run -p sylpheed-formats --example t8ad_header_compare
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 ar = PakArchive::open(root.join("dat/GP_TITLE.pak")).expect("GP_TITLE");
    let by = ar.read(&ar.entries()[5]).expect("entry 5");
    let b = ui_layout::parse_build(&by).expect("build");
    let mut names: Vec<&String> = b.sprites.keys().collect();
    names.sort();
    println!("{:<20} {:>8}  first 12 header words", "sprite", "size");
    let mut rows: Vec<(String, Vec<u32>)> = Vec::new();
    for n in names {
        let (off, size) = b.sprites[n];
        let s = &by[off..(off + size).min(by.len())];
        if s.len() < 48 {
            continue;
        }
        let ws: Vec<u32> = (0..12)
            .map(|k| u32::from_be_bytes([s[k * 4], s[k * 4 + 1], s[k * 4 + 2], s[k * 4 + 3]]))
            .collect();
        let mark = if n.starts_with("ptframe") {
            "  <- FRAME"
        } else {
            ""
        };
        println!(
            "{n:<20} {size:>8}  {}{mark}",
            ws.iter()
                .map(|v| format!("{v:08X}"))
                .collect::<Vec<_>>()
                .join(" ")
        );
        rows.push((n.clone(), ws));
    }
    // which words take a value the two frames share and nobody else does?
    let fr: Vec<&(String, Vec<u32>)> = rows
        .iter()
        .filter(|(n, _)| n.starts_with("ptframe"))
        .collect();
    if fr.len() == 2 {
        println!("\nwords where BOTH frames agree and no other sprite has that value:");
        let mut any = false;
        for w in 0..12 {
            let a = fr[0].1[w];
            let bb = fr[1].1[w];
            if a != bb {
                continue;
            }
            if rows
                .iter()
                .any(|(n, v)| !n.starts_with("ptframe") && v[w] == a)
            {
                continue;
            }
            println!("   word {w} (+0x{:02X}) = {a:08X}", w * 4);
            any = true;
        }
        if !any {
            println!("   NONE");
        }
    }
}