push it

.gitignore

@@ -1,2 +1,3 @@
 /target
-*.bin
+*.bin
+*.sav

Cargo.lock

@@ -14,11 +14,21 @@ version = "1.0.75"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a4668cab20f66d8d020e1fbc0ebe47217433c1b6c8f2040faf858554e394ace6"
 
+[[package]]
+name = "deflate"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c86f7e25f518f4b81808a2cf1c50996a61f5c2eb394b2393bd87f2a4780a432f"
+dependencies = [
+ "adler32",
+]
+
 [[package]]
 name = "fot-save-edit"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "deflate",
  "inflate",
 ]
 

Cargo.toml

@@ -7,4 +7,5 @@ edition = "2021"
 
 [dependencies]
 anyhow = "1.0.75"
+deflate = "1.0.0"
 inflate = "0.4.5"

src/main.rs

@@ -12,7 +12,9 @@ fn main() {
     };*/
     
     let save = Save::load(Path::new(save_path)).expect("load save");
-    for w in save.worlds {
+    for w in save.worlds.iter() {
         println!("World {:x} size {}", w.offset, w.size);
     }
+
+    save.save(Path::new("out.sav")).expect("failed to save");
 }

src/save.rs

@@ -1,9 +1,13 @@
-use std::fs;
+use std::io::Write;
 use std::str;
+use std::fs;
+use std::fs::File;
+use std::fs::OpenOptions;
 use std::path::Path;
 use anyhow::anyhow;
 use anyhow::Result;
 use inflate::inflate_bytes_zlib;
+use deflate::deflate_bytes_zlib;
 
 #[derive(Debug)]
 pub struct World {
@@ -24,6 +28,10 @@ impl World {
         Ok(Self { offset, size, data })
     }
 
+    fn encode(&self) -> Vec<u8> {
+        deflate_bytes_zlib(&self.data)
+    }
+
     pub fn dump(&self, path: &Path) -> Result<()> {
         Ok(fs::write(path, &self.data)?)
     }
@@ -69,4 +77,22 @@ impl Save {
 
         Ok(Self { raw, worlds })
     }
+
+    pub fn save(&self, path: &Path) -> Result<()> {
+        let mut file = OpenOptions::new()
+            .create(true).write(true).open(path)?;
+
+        // write unknown block
+        let unk_size = match self.worlds.first() {
+            Some(w) => w.offset - 1,
+            None => return Err(anyhow!("no offsets found"))
+        };
+        file.write(&self.raw[..unk_size])?;
+
+        for world in self.worlds.iter() {
+            file.write(&world.encode())?;
+        }
+
+        Ok(())
+    }
 }