features(libtlg-rs): Add tlg5 grayscale decode support

Cargo.lock

@@ -164,7 +164,7 @@ checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 
 [[package]]
 name = "libtlg-rs"
-version = "0.1.2"
+version = "0.1.3"
 dependencies = [
  "lazy_static",
  "overf",
@@ -253,7 +253,7 @@ dependencies = [
 
 [[package]]
 name = "tlg"
-version = "0.1.2"
+version = "0.1.3"
 dependencies = [
  "clap",
  "libtlg-rs",

libtlg-rs/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "libtlg-rs"
-version = "0.1.2"
+version = "0.1.3"
 description = "Rust version of libtlg"
 edition = "2024"
 license = "MIT"

libtlg-rs/src/load_tlg.rs

@@ -12,6 +12,7 @@ fn load_tlg5<T: Read + Seek>(src: &mut T) -> Result<Tlg> {
     let color = match colors {
         3 => TlgColorType::Bgr24,
         4 => TlgColorType::Bgra32,
+        1 => TlgColorType::Grayscale8,
         _ => return Err(TlgError::UnsupportedColorType(colors)),
     };
     let blockcount = ((height - 1) / blockheight) + 1;
@@ -62,7 +63,10 @@ fn load_tlg5<T: Read + Seek>(src: &mut T) -> Result<Tlg> {
                         outbufp[2] = &outbufp[2][width as usize..];
                         outbufp[3] = &outbufp[3][width as usize..];
                     }
-                    _ => {}
+                    TlgColorType::Grayscale8 => {
+                        tlg5_compose_colors1(current, &prev, &outbufp, width);
+                        outbufp[0] = &outbufp[0][width as usize..];
+                    }
                 },
                 None => match color {
                     TlgColorType::Bgra32 => {
@@ -125,7 +129,19 @@ fn load_tlg5<T: Read + Seek>(src: &mut T) -> Result<Tlg> {
                         outbufp[1] = &outbufp[1][width as usize..];
                         outbufp[2] = &outbufp[2][width as usize..];
                     }
-                    _ => {}
+                    TlgColorType::Grayscale8 => {
+                        let mut current_pos = 0usize;
+                        let mut pb = 0u8;
+                        for x in 0..width as usize {
+                            let b = outbufp[0][x];
+                            wrapping! {
+                                pb += b;
+                            }
+                            current[current_pos] = pb;
+                            current_pos += 1;
+                        }
+                        outbufp[0] = &outbufp[0][width as usize..];
+                    }
                 },
             }
             prevline = Some(current.to_vec());

libtlg-rs/src/tvpgl.rs

@@ -54,6 +54,19 @@ fn tlg6_init_golomb_table() -> [[i8; TLG6_GOLOMB_N_COUNT]; TLG6_GLOBMB_TABLE_SIZ
     table
 }
 
+pub fn tlg5_compose_colors1(outp: &mut [u8], upper: &[u8], buf: &[&[u8]], width: u32) {
+    let mut outpos = 0usize;
+    let mut upper_pos = 0usize;
+    let mut pb = 0u8;
+    for x in 0..width as usize {
+        let b = buf[0][x];
+        wrapping! { pb += b };
+        outp[outpos] = wrapping! { pb + upper[upper_pos]};
+        outpos += 1;
+        upper_pos += 1;
+    }
+}
+
 pub fn tlg5_compose_colors3(outp: &mut [u8], upper: &[u8], buf: &[&[u8]], width: u32) {
     let mut outpos = 0usize;
     let mut upper_pos = 0usize;

tlg/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "tlg"
-version = "0.1.2"
+version = "0.1.3"
 description = "Tools to process TLG image file."
 edition = "2024"
 license = "MIT"