Function swap_extension

native/shared/src/models.rs:1846–1856

Replace the extension on a URI (keeps directories / query strings untouched). Used to fall back from `foo.png` → `foo.dds` when a glTF references a PNG URI that isn't on disk but the DDS sibling is.

(uri: &str, new_ext: &str)

/// untouched). Used to fall back from `foo.png` → `foo.dds` when a
/// glTF references a PNG URI that isn't on disk but the DDS sibling is.
fn swap_extension(uri: &str, new_ext: &str) -> String {
    let q = uri.find('?').unwrap_or(uri.len());
    let (path, query) = uri.split_at(q);
    let new_path = match path.rfind('.') {
        Some(dot) if dot > path.rfind('/').unwrap_or(0) => {
            format!("{}.{}", &path[..dot], new_ext)
        }
        _ => format!("{}.{}", path, new_ext),
    };
    format!("{}{}", new_path, query)
}

/// Decode a texture byte slice into RGBA8 pixels + dimensions. Tries
/// DDS first when the URI extension suggests it (for asset packs like