cz/Cargo.toml

@@ -9,11 +9,17 @@ Prototype Ltd.
 license = "MIT"
 authors.workspace = true
 
+[features]
+png = ["dep:image"]
+
 [dependencies]
-byteorder-lite = "0.1"
+byteorder-lite = "0.1.0"
-thiserror = "2.0"
+thiserror = "1.0"
 imagequant = "4.3"
 rgb = "0.8"
 
+# Only active on PNG feature
+image = { version = "0.25", optional = true }
+
 [lints]
 workspace = true

cz/src/dynamic.rs

@@ -192,6 +192,35 @@ impl DynamicCz {
         Ok(())
     }
 
+    /// Save the CZ# image as a lossless PNG file.
+    ///
+    /// Internally, the [`DynamicCz`] struct operates on 32-bit RGBA values,
+    /// which is the highest encountered in CZ# files, therefore saving them
+    /// as a PNG of the same or better quality is lossless.
+    #[cfg(feature = "png")]
+    pub fn save_as_png<P: ?Sized + AsRef<std::path::Path>>(
+        &self,
+        path: &P,
+    ) -> Result<(), image::error::EncodingError> {
+        let size = (self.header_common.width() as u32 * self.header_common.height() as u32) * 4;
+
+        let mut buf = vec![0; size as usize];
+        buf[..self.bitmap.len()].copy_from_slice(&self.bitmap);
+
+        let image = image::RgbaImage::from_raw(
+            self.header_common.width() as u32,
+            self.header_common.height() as u32,
+            buf.clone(),
+        )
+        .unwrap();
+
+        image
+            .save_with_format(path, image::ImageFormat::Png)
+            .unwrap();
+
+        Ok(())
+    }
+
     /// Create a CZ# image from RGBA bytes. The bytes *must* be RGBA, as that
     /// is the only format that is used internally.
     pub fn from_raw(version: CzVersion, width: u16, height: u16, bitmap: Vec<u8>) -> Self {

pak_explorer/Cargo.toml

@@ -11,10 +11,9 @@ publish = false
 
 [dependencies]
 colog = "1.3.0"
-cz = { path = "../cz/" }
+cz = { path = "../cz/", features = ["png"] }
 eframe = { version = "0.28.1", default-features = false, features = ["wayland", "x11", "accesskit", "default_fonts", "wgpu"] }
 egui_extras = "0.28.1"
-image = { version = "0.25.5", default-features = false, features = ["png"] }
 log = "0.4.22"
 luca_pak = { path = "../luca_pak/" }
 rfd = "0.14.1"

pak_explorer/src/main.rs

@@ -162,14 +162,7 @@ impl eframe::App for PakExplorer {
                                     entry.as_bytes(),
                                 ))
                                 .unwrap();
-                                image::save_buffer_with_format(
+                                cz.save_as_png(&path).unwrap();
-                                    path,
-                                    cz.as_raw(),
-                                    cz.header().width() as u32,
-                                    cz.header().height() as u32,
-                                    image::ColorType::Rgba8,
-                                    image::ImageFormat::Png
-                                ).unwrap();
                             }
                         }
 

utils/Cargo.toml

@@ -13,7 +13,7 @@ name = "czutil"
 name = "pakutil"
 
 [dependencies]
-cz = { path = "../cz/" }
+cz = { path = "../cz/", features = ["png"] }
 luca_pak = { path = "../luca_pak/" }
 
 image = { version = "0.25", default-features = false, features = ["png"] }

utils/src/bin/czutil.rs

@@ -1,5 +1,4 @@
-use clap::{error::ErrorKind, Error, Parser, Subcommand};
+use clap::{error::ErrorKind, Command, Error, Parser, Subcommand};
-use image::ColorType;
 use std::{
     fs,
     path::{Path, PathBuf},
@@ -147,37 +146,16 @@ fn main() {
                         }
                     };
 
-                    image::save_buffer_with_format(
+                    cz.save_as_png(&final_path).unwrap();
-                        final_path,
-                        cz.as_raw(),
-                        cz.header().width() as u32,
-                        cz.header().height() as u32,
-                        ColorType::Rgba8,
-                        image::ImageFormat::Png
-                    ).unwrap();
                 }
             } else {
                 let cz = cz::open(input).unwrap();
 
                 if let Some(output) = output {
-                    image::save_buffer_with_format(
+                    cz.save_as_png(output).unwrap();
-                        output,
-                        cz.as_raw(),
-                        cz.header().width() as u32,
-                        cz.header().height() as u32,
-                        ColorType::Rgba8,
-                        image::ImageFormat::Png
-                    ).unwrap();
                 } else {
                     let file_stem = PathBuf::from(input.file_name().unwrap());
-                    image::save_buffer_with_format(
+                    cz.save_as_png(&file_stem.with_extension("png")).unwrap();
-                        file_stem.with_extension("png"),
-                        cz.as_raw(),
-                        cz.header().width() as u32,
-                        cz.header().height() as u32,
-                        ColorType::Rgba8,
-                        image::ImageFormat::Png
-                    ).unwrap();
                 }
             }
         }